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Sample records for transport polypeptide 1d1

  1. Interaction of environmental contaminants with zebrafish organic anion transporting polypeptide, Oatp1d1 (Slco1d1)

    Energy Technology Data Exchange (ETDEWEB)

    Popovic, Marta; Zaja, Roko [Laboratory for Molecular Ecotoxicology, Division for Marine and Environmental Research, Rudjer Boskovic Institute, Bijenicka 54, 10 000 Zagreb (Croatia); Fent, Karl [University of Applied Sciences Northwestern Switzerland, School of Life Sciences, Gründenstrasse 40, CH-4132 Muttenz (Switzerland); Swiss Federal Institute of Technology (ETH Zürich), Department of Environmental System Sciences, Institute of Biogeochemistry and Pollution Dynamics, CH-8092 Zürich (Switzerland); Smital, Tvrtko, E-mail: smital@irb.hr [Laboratory for Molecular Ecotoxicology, Division for Marine and Environmental Research, Rudjer Boskovic Institute, Bijenicka 54, 10 000 Zagreb (Croatia)

    2014-10-01

    Polyspecific transporters from the organic anion transporting polypeptide (OATP/Oatp) superfamily mediate the uptake of a wide range of compounds. In zebrafish, Oatp1d1 transports conjugated steroid hormones and cortisol. It is predominantly expressed in the liver, brain and testes. In this study we have characterized the transport of xenobiotics by the zebrafish Oatp1d1 transporter. We developed a novel assay for assessing Oatp1d1 interactors using the fluorescent probe Lucifer yellow and transient transfection in HEK293 cells. Our data showed that numerous environmental contaminants interact with zebrafish Oatp1d1. Oatp1d1 mediated the transport of diclofenac with very high affinity, followed by high affinity towards perfluorooctanesulfonic acid (PFOS), nonylphenol, gemfibrozil and 17α-ethinylestradiol; moderate affinity towards carbaryl, diazinon and caffeine; and low affinity towards metolachlor. Importantly, many environmental chemicals acted as strong inhibitors of Oatp1d1. A strong inhibition of Oatp1d1 transport activity was found by perfluorooctanoic acid (PFOA), chlorpyrifos-methyl, estrone (E1) and 17β-estradiol (E2), followed by moderate to low inhibition by diethyl phthalate, bisphenol A, 7-acetyl-1,1,3,4,4,6-hexamethyl-1,2,3,4 tetrahydronapthalene and clofibrate. In this study we identified Oatp1d1 as a first Solute Carrier (SLC) transporter involved in the transport of a wide range of xenobiotics in fish. Considering that Oatps in zebrafish have not been characterized before, our work on zebrafish Oatp1d1 offers important new insights on the understanding of uptake processes of environmental contaminants, and contributes to the better characterization of zebrafish as a model species. - Highlights: • We optimized a novel assay for determination of Oatp1d1 interactors • Oatp1d1 is the first SLC characterized fish xenobiotic transporter • PFOS, nonylphenol, diclofenac, EE2, caffeine are high affinity Oatp1d1substrates • PFOA, chlorpyrifos

  2. Interaction of environmental contaminants with zebrafish organic anion transporting polypeptide, Oatp1d1 (Slco1d1)

    International Nuclear Information System (INIS)

    Popovic, Marta; Zaja, Roko; Fent, Karl; Smital, Tvrtko

    2014-01-01

    Polyspecific transporters from the organic anion transporting polypeptide (OATP/Oatp) superfamily mediate the uptake of a wide range of compounds. In zebrafish, Oatp1d1 transports conjugated steroid hormones and cortisol. It is predominantly expressed in the liver, brain and testes. In this study we have characterized the transport of xenobiotics by the zebrafish Oatp1d1 transporter. We developed a novel assay for assessing Oatp1d1 interactors using the fluorescent probe Lucifer yellow and transient transfection in HEK293 cells. Our data showed that numerous environmental contaminants interact with zebrafish Oatp1d1. Oatp1d1 mediated the transport of diclofenac with very high affinity, followed by high affinity towards perfluorooctanesulfonic acid (PFOS), nonylphenol, gemfibrozil and 17α-ethinylestradiol; moderate affinity towards carbaryl, diazinon and caffeine; and low affinity towards metolachlor. Importantly, many environmental chemicals acted as strong inhibitors of Oatp1d1. A strong inhibition of Oatp1d1 transport activity was found by perfluorooctanoic acid (PFOA), chlorpyrifos-methyl, estrone (E1) and 17β-estradiol (E2), followed by moderate to low inhibition by diethyl phthalate, bisphenol A, 7-acetyl-1,1,3,4,4,6-hexamethyl-1,2,3,4 tetrahydronapthalene and clofibrate. In this study we identified Oatp1d1 as a first Solute Carrier (SLC) transporter involved in the transport of a wide range of xenobiotics in fish. Considering that Oatps in zebrafish have not been characterized before, our work on zebrafish Oatp1d1 offers important new insights on the understanding of uptake processes of environmental contaminants, and contributes to the better characterization of zebrafish as a model species. - Highlights: • We optimized a novel assay for determination of Oatp1d1 interactors • Oatp1d1 is the first SLC characterized fish xenobiotic transporter • PFOS, nonylphenol, diclofenac, EE2, caffeine are high affinity Oatp1d1substrates • PFOA, chlorpyrifos

  3. Comparative effects of nodularin and microcystin-LR in zebrafish: 1. Uptake by organic anion transporting polypeptide Oatp1d1 (Slco1d1).

    Science.gov (United States)

    Faltermann, Susanne; Prétôt, René; Pernthaler, Jakob; Fent, Karl

    2016-02-01

    Microcystin-LR (MC-LR) and nodularin are hepatotoxins produced by several cyanobacterial species. Their toxicity is based on active cellular uptake and subsequent inhibition of protein phosphatases PP1/2A, leading to hyperphosphorylation and cell death. To date, uptake of MC-LR and nodularin in fish is poorly understood. Here, we investigated the role of the organic anion transporting polypeptide Oatp1d1 in zebrafish (drOatp1d1, Slco1d1) in cellular uptake in zebrafish. We stably transfected CHO and HEK293 cell lines expressing drOatp1d1. In both transfectants, uptake of MC-LR and nodularin was demonstrated by competitive inhibition of uptake with fluorescent substrate lucifer yellow. Direct uptake of MC-LR was demonstrated by immunostaining, and indirectly by the high cytotoxicity in stable transfectants. By means of a synthesized fluorescent labeled MC-LR derivative, direct uptake was further confirmed in HEK293 cells expressing drOatp1d1. Additionally, uptake and toxicity was investigated in the permanent zebrafish liver cell line ZFL. These cells had only a low relative abundance of drOatp1d1, drOatp2b1 and drOatp1f transcripts, which correlated with the lack of MC-LR induced cytotoxicity and transcriptional changes of genes indicative of endoplasmic reticulum stress, a known effect of this toxin. Our study demonstrates that drOatp1d1 functions as an uptake transporter for both MC-LR and nodularin in zebrafish. Copyright © 2015 Elsevier B.V. All rights reserved.

  4. A family of microbial lysine transporter polypeptides

    DEFF Research Database (Denmark)

    2017-01-01

    The present invention provides a genetically modified microbial cell for production of lysine, comprising a transgene encoding a polypeptide capable of exporting lysine from the cell. The genetically modified microbial cell for production of lysine may be further characterized by genetic modifica......The present invention provides a genetically modified microbial cell for production of lysine, comprising a transgene encoding a polypeptide capable of exporting lysine from the cell. The genetically modified microbial cell for production of lysine may be further characterized by genetic...... a novel family of lysine transporter polypeptides; and the use of said polypeptide to enhance production of extracellular lysine in a microbial cell....

  5. Effect-directed analysis reveals inhibition of zebrafish uptake transporter Oatp1d1 by caulerpenyne, a major secondary metabolite from the invasive marine alga Caulerpa taxifolia.

    Science.gov (United States)

    Marić, P; Ahel, M; Senta, I; Terzić, S; Mikac, I; Žuljević, A; Smital, T

    2017-05-01

    Caulerpa taxifolia is a marine alga of tropical and subtropical distribution and a well-known invasive species in several temperate regions. Its invasiveness mainly stems from the production of secondary metabolites, some of which are toxic or repellent substances. In this study we investigated the possible inhibitory effects of C. taxifolia secondary metabolites on the activity of two zebrafish (Danio rerio) uptake transporters that transport organic anions (Oatp1d1) and cations (Oct1). Both transporters were transiently transfected and overexpressed in human embryonic kidney HEK293T cells. Transport activity assays using lucifer yellow (LY) and 4-(4-(dimethylamino)styryl)-N-methylpyridinium iodide (ASP+) as model substrates were applied for the determination of Oatp1d1 and Oct1 interactors. A two-step Effect-Directed Analysis (EDA) procedure was applied for the separation and identification of compounds. We identified caulerpenyne (CYN) as the major metabolite in C. taxifolia and reveal its potent inhibitory effect towards zebrafish Oatp1d1 as well as weak effect on zebrafish Oct1 transport. The observed effect was confirmed by testing CYN purified from C. taxifolia, resulting in an IC 50 of 17.97 μM, and a weak CYN interaction was also determined for the zebrafish Oct1 transporter. Finally, using Michaelis-Menten kinetics experiments, we identified CYN as a non-competitive inhibitor of the zebrafish Oatp1d1. In conclusion, this study describes a novel mechanism of biological activity in C. taxifolia, shows that CYN was a potent non-competitive inhibitor of zebrafish Oatp1d1, and demonstrates that EDA can be reliably used for characterization of environmentally relevant complex biological samples. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Organic anion transporting polypeptide 1B transporters modulate hydroxyurea pharmacokinetics

    Science.gov (United States)

    Lancaster, Cynthia S.; Finkelstein, David; Ware, Russell E.; Sparreboom, Alex

    2013-01-01

    Hydroxyurea is currently the only FDA-approved drug that ameliorates the pathophysiology of sickle cell anemia. Unfortunately, substantial interpatient variability in the pharmacokinetics (PK) of hydroxyurea may result in variation of the drug's efficacy. However, little is known about mechanisms that modulate hydroxyurea PK. Recent in vitro studies identifying hydroxyurea as a substrate for organic anion transporting polypeptide (OATP1B) transporters prompted the current investigation assessing the role of OATP1B transporters in modulating hydroxyurea PK. Using wild-type and Oatp1b knockout (Oatp1b−/−) mice, hydroxyurea PK was analyzed in vivo by measuring [14C]hydroxyurea distribution in plasma, kidney, liver, urine, or the exhaled 14CO2 metabolite. Plasma levels were significantly reduced by 20% in Oatp1b−/− mice compared with wild-type (area under the curve of 38.64 or 48.45 μg·h−1·ml−1, respectively) after oral administration, whereas no difference was observed between groups following intravenous administration. Accumulation in the kidney was significantly decreased by twofold in Oatp1b−/− mice (356.9 vs. 748.1 pmol/g), which correlated with a significant decrease in urinary excretion. Hydroxyurea accumulation in the liver was also decreased (136.6 vs. 107.3 pmol/g in wild-type or Oatp1b−/− mice, respectively) correlating with a decrease in exhaled 14CO2. These findings illustrate that deficiency of Oatp1b transporters alters the absorption, distribution, and elimination of hydroxyurea thus providing the first in vivo evidence that cell membrane transporters may play a significant role in modulating hydroxyurea PK. Future studies to investigate other transporters and their role in hydroxyurea disposition are warranted for understanding the sources of variation in hydroxyurea's PK. PMID:23986199

  7. The Rab-GTPase-activating protein TBC1D1 regulates skeletal muscle glucose metabolism

    DEFF Research Database (Denmark)

    Szekeres, Ferenc; Chadt, Alexandra; Tom, Robby Z

    2012-01-01

    production was increased in TBC1D1-deficient mice. In isolated extensor digitorum longus (EDL) but not soleus muscle, glucose transport in response to insulin, AICAR, or contraction was impaired by TBC1D1 deficiency. The reduction in glucose transport in EDL muscle from TBC1D1-deficient Nob1.10(SJL) mice may...

  8. Polyspecific organic anion transporting polypeptides mediate hepatic uptake of amphipathic type II organic cations

    NARCIS (Netherlands)

    van Montfoort, J.E; Hagenbuch, B; Fattinger, K.E; Muller, M; Groothuis, Geny; Meijer, D.K F; Meier, P.J

    1999-01-01

    Hepatic uptake of albumin-bound amphipathic organic cations has been suggested to be mediated by multispecific bile salt and organic anion transport systems. Therefore, we investigated whether the recently cloned rat organic anion transporting polypeptides 1 and 2 as well as the human organic anion

  9. Organic anion transporting polypeptide 2 transports valproic acid in rat brain microvascular endothelial cells.

    Science.gov (United States)

    Guo, Yi; Jiang, Li

    2016-07-01

    Abnormal drug transporter expression or function in the brain may lead to decreased concentrations of antiepileptic drugs (AEDs) in the central nervous system in patients with drug-resistant epilepsy. We previously showed the influx transporter organic anion transport polypeptide 2 (Oatp2) was expressed in rat brain microvascular endothelial cells (BMECs). Seizures decrease expression of Oatp2, but it remains unclear whether Oatp2 transports AEDs. In this study, we utilized rat BMECs as an in vitro model of the blood-brain barrier (BBB) to study Oatp2-mediated transport of valproic acid (VPA), the most common clinically used AEDs. In vivo injection of pregnenolone-16-carbonitrile was used to induce high expression of Oatp2 in isolated BMECs. Small interfering RNA treatment was used to silence Oatp2, and uptake of VPA was assessed. Increased expression of Oatp2 in BMECs increased the uptake of VPA, while inhibition of Oatp2 reduced VPA uptake. This study indicates Oatp2 transports VPA across the BBB, and suggests altered Oatp2 expression may contribute to resistance to VPA in patients with drug-resistant epilepsy.

  10. Organic anion transporter 3- and organic anion transporting polypeptides 1B1- and 1B3-mediated transport of catalposide

    Directory of Open Access Journals (Sweden)

    Jeong HU

    2015-01-01

    Full Text Available Hyeon-Uk Jeong,1 Mihwa Kwon,2 Yongnam Lee,3 Ji Seok Yoo,3 Dae Hee Shin,3 Im-Sook Song,2 Hye Suk Lee1 1College of Pharmacy, The Catholic University of Korea, Bucheon 420-743, Korea; 2College of Pharmacy and Research Institute of Pharmaceutical Sciences, Kyungpook National University, Daegu 702-701, Korea; 3Central R&D Institute, Yungjin Pharm Co., Ltd., Suwon 443-270, Korea Abstract: We investigated the in vitro transport characteristics of catalposide in HEK293 cells overexpressing organic anion transporter 1 (OAT1, OAT3, organic anion transporting polypeptide 1B1 (OATP1B1, OATP1B3, organic cation transporter 1 (OCT1, OCT2, P-glycoprotein (P-gp, and breast cancer resistance protein (BCRP. The transport mechanism of catalposide was investigated in HEK293 and LLC-PK1 cells overexpressing the relevant transporters. The uptake of catalposide was 319-, 13.6-, and 9.3-fold greater in HEK293 cells overexpressing OAT3, OATP1B1, and OATP1B3 transporters, respectively, than in HEK293 control cells. The increased uptake of catalposide via the OAT3, OATP1B1, and OATP1B3 transporters was decreased to basal levels in the presence of representative inhibitors such as probenecid, furosemide, and cimetidine (for OAT3 and cyclosporin A, gemfibrozil, and rifampin (for OATP1B1 and OATP1B3. The concentration-dependent OAT3-mediated uptake of catalposide revealed the following kinetic parameters: Michaelis constant (Km =41.5 µM, maximum uptake rate (Vmax =46.2 pmol/minute, and intrinsic clearance (CLint =1.11 µL/minute. OATP1B1- and OATP1B3-mediated catalposide uptake also showed concentration dependency, with low CLint values of 0.035 and 0.034 µL/minute, respectively. However, the OCT1, OCT2, OAT1, P-gp, and BCRP transporters were apparently not involved in the uptake of catalposide into cells. In addition, catalposide inhibited the transport activities of OAT3, OATP1B1, and OATP1B3 with half-maximal inhibitory concentration values of 83, 200, and 235 µ

  11. Genetics or environment in drug transport: the case of organic anion transporting polypeptides and adverse drug reactions.

    Science.gov (United States)

    Clarke, John D; Cherrington, Nathan J

    2012-03-01

    Organic anion transporting polypeptide (OATP) uptake transporters are important for the disposition of many drugs and perturbed OATP activity can contribute to adverse drug reactions (ADRs). It is well documented that both genetic and environmental factors can alter OATP expression and activity. Genetic factors include single nucleotide polymorphisms (SNPs) that change OATP activity and epigenetic regulation that modify OATP expression levels. SNPs in OATPs contribute to ADRs. Environmental factors include the pharmacological context of drug-drug interactions and the physiological context of liver diseases. Liver diseases such as non-alcoholic fatty liver disease, cholestasis and hepatocellular carcinoma change the expression of multiple OATP isoforms. The role of liver diseases in the occurrence of ADRs is unknown. This article covers the roles OATPs play in ADRs when considered in the context of genetic or environmental factors. The reader will gain a greater appreciation for the current evidence regarding the salience and importance of each factor in OATP-mediated ADRs. A SNP in a single OATP transporter can cause changes in drug pharmacokinetics and contribute to ADRs but, because of overlap in substrate specificities, there is potential for compensatory transport by other OATP isoforms. By contrast, the expression of multiple OATP isoforms is decreased in liver diseases, reducing compensatory transport and thereby increasing the probability of ADRs. To date, most research has focused on the genetic factors in OATP-mediated ADRs while the impact of environmental factors has largely been ignored.

  12. Uptake of perfluorooctanoic acid by Caco-2 cells: Involvement of organic anion transporting polypeptides.

    Science.gov (United States)

    Kimura, Osamu; Fujii, Yukiko; Haraguchi, Koichi; Kato, Yoshihisa; Ohta, Chiho; Koga, Nobuyuki; Endo, Tetsuya

    2017-08-05

    The mechanism underlying the intestinal absorption of perfluorooctanoic acid (PFOA) was investigated using Caco-2 cells. The uptake of PFOA from the apical membrane of Caco-2 cells was fast, and pH, temperature, and concentration dependent, but Na + independent. Coincubation with sulfobromophthalein (BSP), glibenclamide, estron-3-sulfate, cyclosporine A or rifamycin SV, which are typical substrates or inhibitors of organic anion transporting polypeptides (OATPs), significantly decreased the uptake of PFOA. However, coincubation with probenecid or p-aminohippuric acid, typical substrates of organic anion transporters, did not decrease the uptake of PFOA. Furthermore, coincubation with l-lactic acid or benzoic acid, substrates of monocarboxylic acid transporters, did not decrease PFOA uptake. The relationship between the initial uptake of PFOA and its concentration was saturable, suggesting the involvement of a carrier-mediated process. The calculated K m and uptake clearance (V max /K m ) values for PFOA were 8.3μM and 55.0μL/mg protein/min, respectively. This clearance value was about 3-fold greater than that of the non-saturable uptake clearance (K d : 18.1μL/mg protein/min). Lineweaver-Burk plots revealed that BSP competitively inhibits the uptake of PFOA, with a K i value of 23.1μM. These results suggest that the uptake of PFOA from the apical membranes of Caco-2 cells could be, at least in part, mediated by OATPs along with BSP. Copyright © 2017 Elsevier B.V. All rights reserved.

  13. 75 FR 27411 - Airworthiness Directives; Turbomeca Arriel 1B, 1D, 1D1, and 1S1 Turboshaft Engines

    Science.gov (United States)

    2010-05-17

    ..., Version 148), 1D1, and 1D. since-new (TSN) or in-service-since-last- E, dated October 29, time-since...,200 hours TSN Within 150 hours TSLRPC A292 72 0810, Version or TSO or 3,500 CSN or C, dated July 24...

  14. 75 FR 11072 - Airworthiness Directives; Turbomeca Arriel 1B, 1D, 1D1, and 1S1 Turboshaft Engines

    Science.gov (United States)

    2010-03-10

    ..., Version 148), 1D1, and 1D. since-new (TSN) or in-service-since-last- E, dated October 29, time-since...,200 hours TSN Within 150 hours TSLRPC A292 72 0810, Version or TSO or 3,500 CSN or C, dated July 24...

  15. Elastomeric polypeptides.

    Science.gov (United States)

    van Eldijk, Mark B; McGann, Christopher L; Kiick, Kristi L; van Hest, Jan C M

    2012-01-01

    Elastomeric polypeptides are very interesting biopolymers and are characterized by rubber-like elasticity, large extensibility before rupture, reversible deformation without loss of energy, and high resilience upon stretching. Their useful properties have motivated their use in a wide variety of materials and biological applications. This chapter focuses on elastin and resilin - two elastomeric biopolymers - and the recombinant polypeptides derived from them (elastin-like polypeptides and resilin-like polypeptides). This chapter also discusses the applications of these recombinant polypeptides in the fields of purification, drug delivery, and tissue engineering.

  16. Energy transport mechanism in the form of proton soliton in a one-dimensional hydrogen-bonded polypeptide chain.

    Science.gov (United States)

    Kavitha, L; Priya, R; Ayyappan, N; Gopi, D; Jayanthi, S

    2016-01-01

    The dynamics of protons in a one-dimensional hydrogen-bonded (HB) polypeptide chain (PC) is investigated theoretically. A new Hamiltonian is formulated with the inclusion of higher-order molecular interactions between peptide groups (PGs). The wave function of the excitation state of a single particle is replaced by a new wave function of a two-quanta quasi-coherent state. The dynamics is governed by a higher-order nonlinear Schrödinger equation and the energy transport is performed by the proton soliton. A nonlinear multiple-scale perturbation analysis has been performed and the evolution of soliton parameters such as velocity and amplitude is explored numerically. The proton soliton is thermally stable and very robust against these perturbations. The energy transport by the proton soliton is more appropriate to understand the mechanism of energy transfer in biological processes such as muscle contraction, DNA replication, and neuro-electric pulse transfer on biomembranes.

  17. The RabGAP TBC1D1 plays a central role in exercise-regulated glucose metabolism in skeletal muscle

    DEFF Research Database (Denmark)

    Stöckli, Jacqueline; Meoli, Christopher C; Hoffman, Nolan J

    2015-01-01

    in this process: AS160 for insulin stimulation and its homolog, TBC1D1, are suggested to regulate exercise-mediated glucose uptake into muscle. TBC1D1 has also been implicated in obesity in humans and mice. We investigated the role of TBC1D1 in glucose metabolism by generating TBC1D1(-/-) mice and analyzing body......Insulin and exercise stimulate glucose uptake into skeletal muscle via different pathways. Both stimuli converge on the translocation of the glucose transporter GLUT4 from intracellular vesicles to the cell surface. Two Rab guanosine triphosphatases-activating proteins (GAPs) have been implicated...... weight, insulin action, and exercise. TBC1D1(-/-) mice showed normal glucose and insulin tolerance, with no difference in body weight compared with wild-type littermates. GLUT4 protein levels were reduced by ∼40% in white TBC1D1(-/-) muscle, and TBC1D1(-/-) mice showed impaired exercise endurance...

  18. Interactions between crude drug extracts used in Japanese traditional Kampo medicines and organic anion-transporting polypeptide 2B1.

    Science.gov (United States)

    Iijima, Rie; Watanabe, Tomoki; Ishiuchi, Kan'ichiro; Matsumoto, Takashi; Watanabe, Junko; Makino, Toshiaki

    2018-03-25

    The use of herbal medicines has become popular worldwide, and the information on drug interactions between herbal medicines and chemical drugs is needed. We screened the inhibitory effects of crude drugs used in Kampo medicines used in Japan on organic anion-transporting polypeptide (OATP) 2B1 to predict potential interactions between Kampo medicines and chemical drugs used together. We chose 98 kinds of crude drugs frequently used as ingredients of Kampo formulations in Japan and prepared their boiling water extracts. We then screened their inhibitory effects on OATP2B1 by measuring the uptake of estrone 3-sulphate (E3S) by HEK293 cells stably expressing OATP2B1. At the concentration of 100µg/ml, the extracts prepared from 12 kinds of crude drugs, Scuteralliae Radix, Arecae Semen, Aurantii Fructus Immaturus, Perillae Herba, Panacis Japonici Rhizoma, Moutan Cortex, Polygalae Radix, Rhei Rhizoma, Cannabis Fructus, Chrysanthemi Flos, Eriobotryae Folium, and Querci Cortex, suppressed the function of OATP2B1 by less than 20%. The extract of bofutsushosan, a representative Kampo formulation, inhibited OATP2B1 function with sufficient levels to suppress absorption of OATP2B1 substrates in clinics. We further evaluated the inhibitory effects of several ingredients containing Rhei Rhizoma, Perillae Herba, and Moutan Cortex on OATP2B1. Because of crude drugs used in Kampo medicines might suppress absorption of OATP2B1 substrates, these results may contribute to the safe and effective use of Kampo medicine in clinics. A list of abbreviations: EC, (-)-epicatechin; ECG, epicatechin gallate; EGC, epigallocatechin; EGCG, Epigallocatechin gallate; FBS, fetal bovine serum; grapefruit juice; HEK293, Human embryonic kidney; IC 50, The half inhibitory concentration; OATP, organic anion-transporting polypeptide; β-PGG, penta-O-galloyl-β-D-glucose; t.i.d, 3 times a day. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. Analogies between solitonic bio-energy transport along polypeptide chains and nonautonomous optical solitons in structurated nonuniform fibers

    Science.gov (United States)

    Morales-Lara, L.; Peña-Moreno, R.; Mena-Contla, A.; Serkin, V. N.; Belyaeva, T. L.

    2015-01-01

    The interpenetration of the main ideas and methods being used in different fields of science and technology has become one of the decisive factors in the progress of science as a whole. Mathematical analogies between different physical systems can be extremely fruitful in understanding the novel physical concepts. Accordingly to the new theory of bio-energy transport along protein molecules in living systems and modified Davydov molecular soliton theory, we propose a nonautonomous model that can be considered as a candidate of the bio-energy transport mechanism in protein molecules. Based on the generalized nonlinear Schrödinger equation model with varying-intime harmonic oscillator potential, we show that conditions of its exact integrability in one-dimensional case indicate conclusively the way for solitonlike pulse generation in polypeptide molecular systems. The most important properties of this soliton transport of bio-energy are related with periodically changed energy-release conditions and the influences of structure nonuniformity in protein molecules. By analogy with the corresponding optical phenomena in inhomogeneous optical fibers with varying properties along the length, we study the main features of modified Davydov soliton on the basis of the unified nonautonomous nonlinear Schrodinger model in the parameters region of the exact integrability of the model under consideration.

  20. Influence of non-steroidal anti-inflammatory drugs on organic anion transporting polypeptide (OATP) 1B1- and OATP1B3-mediated drug transport.

    Science.gov (United States)

    Kindla, Juergen; Müller, Fabian; Mieth, Maren; Fromm, Martin F; König, Jörg

    2011-06-01

    The transporter-mediated uptake of drugs from blood into hepatocytes is a prerequisite for intrahepatic drug action or intracellular drug metabolism before excretion. Therefore, uptake transporters, e.g., members of the organic anion transporting polypeptide (OATP) family are important determinants of drug pharmacokinetics. Highly and almost exclusively expressed in hepatocytes are the OATP family members OATP1B1 (SLCO1B1) and OATP1B3 (SLCO1B3). Drug substrates of OATP1B1 and OATP1B3 include antibiotics and HMG-CoA reductase inhibitors (statins). It has been demonstrated that administration of two or more drugs that are substrates for these hepatic uptake transporters may lead to transporter-mediated drug-drug interactions, resulting in altered transport kinetics for drug substrates. In this study we investigated whether non-steroidal anti-inflammatory drugs (NSAIDs) and paracetamol interact with OATP1B1 and OATP1B3 using the standard substrate BSP and the drug substrate pravastatin. Using human embryonic kidney cells stably expressing OATP1B1 or OATP1B3, we demonstrated that bromosulfophthalein uptake was inhibited by diclofenac, ibuprofen. and lumiracoxib. Of interest, pravastatin uptake was stimulated by these NSAIDs, and for ibuprofen we determined activation constants (EC₅₀ values) of 64.0 and 93.1 μM for OATP1B1- and OATP1B3-mediated uptake, respectively. Furthermore, we investigated whether NSAIDs were also substrates for OATP1B1 and OATP1B3 and demonstrated that only diclofenac was significantly transported by OATP1B3, whereas all other NSAIDs investigated were not substrates for these uptake transporters. These results demonstrated that drugs may interact with transport proteins by allosteric mechanisms without being substrates and, therefore, not only uptake inhibition but also allosteric-induced modulation of transport function may be an important mechanism in transporter-mediated drug-drug interactions.

  1. The role of organic anion transporting polypeptides in drug absorption, distribution, excretion and drug-drug interactions.

    Science.gov (United States)

    Kovacsics, Daniella; Patik, Izabel; Özvegy-Laczka, Csilla

    2017-04-01

    The in vivo fate and effectiveness of a drug depends highly on its absorption, distribution, metabolism, excretion and toxicity (ADME-Tox). Organic anion transporting polypeptides (OATPs) are membrane proteins involved in the cellular uptake of various organic compounds, including clinically used drugs. Since OATPs are significant players in drug absorption and distribution, modulation of OATP function via pharmacotherapy with OATP substrates/inhibitors, or modulation of their expression, affects drug pharmacokinetics. Given their cancer-specific expression, OATPs may also be considered anticancer drug targets. Areas covered: We describe the human OATP family, discussing clinically relevant consequences of altered OATP function. We offer a critical analysis of published data on the role of OATPs in ADME and in drug-drug interactions, especially focusing on OATP1A2, 1B1, 1B3 and 2B1. Expert opinion: Four members of the OATP family, 1A2, 1B1, 1B3 and 2B1, have been characterized in detail. As biochemical and pharmacological knowledge on the other OATPs is lacking, it seems timely to direct research efforts towards developing the experimental framework needed to investigate the transport mechanism and substrate specificity of the poorly described OATPs. In addition, elucidating the role of OATPs in tumor development and therapy response are critical avenues for further research.

  2. Multi-functional roles for the polypeptide transport associated domains of Toc75 in chloroplast protein import

    Science.gov (United States)

    Paila, Yamuna D; Richardson, Lynn GL; Inoue, Hitoshi; Parks, Elizabeth S; McMahon, James; Inoue, Kentaro; Schnell, Danny J

    2016-01-01

    Toc75 plays a central role in chloroplast biogenesis in plants as the membrane channel of the protein import translocon at the outer envelope of chloroplasts (TOC). Toc75 is a member of the Omp85 family of bacterial and organellar membrane insertases, characterized by N-terminal POTRA (polypeptide-transport associated) domains and C-terminal membrane-integrated β-barrels. We demonstrate that the Toc75 POTRA domains are essential for protein import and contribute to interactions with TOC receptors, thereby coupling preprotein recognition at the chloroplast surface with membrane translocation. The POTRA domains also interact with preproteins and mediate the recruitment of molecular chaperones in the intermembrane space to facilitate membrane transport. Our studies are consistent with the multi-functional roles of POTRA domains observed in other Omp85 family members and demonstrate that the domains of Toc75 have evolved unique properties specific to the acquisition of protein import during endosymbiotic evolution of the TOC system in plastids. DOI: http://dx.doi.org/10.7554/eLife.12631.001 PMID:26999824

  3. Organic anion transporting polypeptide 2B1 and breast cancer resistance protein interact in the transepithelial transport of steroid sulfates in human placenta.

    Science.gov (United States)

    Grube, Markus; Reuther, Sebastian; Meyer Zu Schwabedissen, Henriette; Köck, Kathleen; Draber, Katrin; Ritter, Christoph A; Fusch, Christoph; Jedlitschky, Gabriele; Kroemer, Heyo K

    2007-01-01

    The human placenta has both protective and nurturing functions for the fetal organism. Uptake and elimination of xenobiotics and endogenous substances are facilitated by various transport proteins from the solute carrier (SLC) and ABC families, respectively. A functional interaction of uptake and elimination, which is a prerequisite for vectorial transport across cellular barriers, has not been described for placenta. In this study, we examined expression of organic anion transporter (OAT) 4 (SLC22A11), organic anion transporting polypeptide (OATP) 2B1 (SLCO2B1, OATP-B), and breast cancer resistance protein (BCRP) (ABCG2) in human placenta (n = 71) because all three proteins are involved in transmembranal transfer of estrone 3 sulfate (E3S; metabolic product) and dehydroepiandrosterone sulfate (DHEAS; precursor molecule). On the mRNA level, we found a significant correlation of OATP2B1 and BCRP (R(2) = 0.534; p 0.05). Localization studies confirmed basal expression of OATP2B1 and apical expression of BCRP. To study functional interactions between OATP2B1 and BCRP, we developed a Madin-Darby canine kidney cell model expressing both transport proteins simultaneously (OATP2B1 and BCRP in the basal and apical membrane, respectively). Using this cell model in a transwell system resulted in a significantly increased basal to apical transport of both E3S and DHEAS, when both transporters were expressed with no change of transfer in the apical to basal direction. Taken together, these data show the potential for a functional interaction of OATP2B1 and BCRP in transepithelial transport of steroid sulfates in human placenta.

  4. Epigenetic regulation of organic anion transporting polypeptide 1B3 in cancer cell lines.

    Science.gov (United States)

    Imai, Satoki; Kikuchi, Ryota; Tsuruya, Yuri; Naoi, Sotaro; Nishida, Sho; Kusuhara, Hiroyuki; Sugiyama, Yuichi

    2013-11-01

    The expression of a multispecific organic anion transporter, OATP1B3/SLCO1B3, is associated with clinical prognosis and survival of cancer cells. The aims of present study were to investigate the involvement of epigenetic regulation in mRNA expression of a cancer-type variant of OATP1B3 (Ct-OATP1B3) in cancer cell lines. The membrane localization and transport functions of Ct-OATP1B3 were investigated in HEK293 cells transiently expressing Ct-OATP1B3. DNA methylation profiles around the transcriptional start site of Ct-OATP1B3 in cancer cell lines were determined. The effects of a DNA methyltransferase inhibitor and siRNA knockdown of methyl-DNA binding proteins (MBDs) on the expression of Ct-OATP1B3 mRNA were investigated. 5'-RACE identified the TSS of Ct-OATP1B3 in PK-8 cells. Ct-OATP1B3 was localized on the plasma membrane, and showed the transport activities of E217βG, fluvastatin, rifampicin, and Gd-EOB-DTPA. The CpG dinucleotides were hypomethylated in Ct-OATP1B3-positive cell lines (DLD-1, TFK-1, PK-8, and PK-45P) but were hypermethylated in Ct-OATP1B3-negative cell lines (HepG2 and Caco-2). Treatment with a DNA methyltransferase inhibitor and siRNA knockdown of MBD2 significantly increased the expression of Ct-OATP1B3 mRNA in HepG2 and Caco-2. Ct-OATP1B3 is capable of transporting its substrates into cancer cells. Its mRNA expression is regulated by DNA methylation-dependent gene silencing involving MBD2.

  5. DNA methylation profiles of organic anion transporting polypeptide 1B3 in cancer cell lines.

    Science.gov (United States)

    Ichihara, Sayaka; Kikuchi, Ryota; Kusuhara, Hiroyuki; Imai, Satoki; Maeda, Kazuya; Sugiyama, Yuichi

    2010-03-01

    Multispecific organic anion transporter, OATP1B3/SLCO1B3, is expressed in several cancer cell lines as well as tumor tissues, and its expression sensitizes the cells to some anti-cancer agents. The present study was aimed to characterize the DNA methylation profiles around the transcriptional start site (TSS) of OATP1B3 and correlate them with the mRNA expression in cancer and immortalized cell lines. The mRNA expression and DNA methylation profiles of OATP1B3 were determined by RT-PCR and bisulfite sequencing, respectively. The expression of OATP1B3 mRNA was detected in DLD-1, TFK-1, PK-8, and PK-45P cells, but below the limit of detection in HepG2, Caco-2, and HEK293 cells. Bisulfite sequencing demonstrated that CpG dinucleotides around the TSS are differentially methylated among cell lines and partly associated with the mRNA expression profile of OATP1B3. Furthermore, treatment with 5-aza-2'-deoxycytidine, an inhibitor of DNA methyltransferase, significantly increased the mRNA expression of OATP1B3 in HepG2 and Caco-2 cells by 18- and 14-fold, respectively, but not in DLD-1 and TFK-1 cells. DNA methylation-dependent gene silencing is at least partly involved in the regulation of OATP1B3 expression in cancer/immortalized cell lines.

  6. Expression of organic anion transporting polypeptide 1c1 and monocarboxylate transporter 8 in the rat placental barrier and the compensatory response to thyroid dysfunction.

    Directory of Open Access Journals (Sweden)

    Yi-na Sun

    Full Text Available Thyroid hormones (THs must pass from mother to fetus for normal fetal development and require the expression of placental TH transporters. We investigate the compensatory effect of placental organic anion transporting polypeptide 1c1 (Oatp1c1 and monocarboxylate transporter 8 (Mct8 on maternal thyroid dysfunction. We describe the expressions of these two transporters in placental barriers and trophoblastic cell populations in euthyroidism and thyroid dysfunction resulting from differential iodine nutrition at gestation day (GD 16 and 20, that is, before and after the onset of fetal thyroid function. Immunohistochemistry revealed that in the blood-placenta barrier, these two TH transporters were strongly expressed in the villous interstitial substance and were weakly expressed in trophoblast cells. Levels of Oatp1c1 protein obviously increased in the placental fetal portion during maternal thyroid deficiency at GD16. Under maternal thyroid deficiency after the production of endogenous fetal TH, quantitative PCR analysis revealed down-regulation of Oatp1c1 occurred along with up-regulation of Mct8 in trophoblast cell populations isolated by laser capture microdissection (LCM; this was consistent with the protein levels in the fetal portion of the placenta. In addition, decreased D3 mRNA at GD16 and increased D2 mRNA on two gestational days were observed in trophoblast cells with thyroid dysfunction. However, levels of Oatp1c1 mRNA at GD16 and D3 mRNA at GD20 were too low to be detectable in trophoblast cells. In conclusion, placental Oatp1c1 plays an essential compensatory role when the transplacental passage of maternal THs is insufficient at the stage before the fetal TH production. In addition, the coordinated effects of Oatp1c1, Mct8, D2 and D3 in the placental barrier may regulate both transplacental TH passage and the development of trophoblast cells during thyroid dysfunction throughout the pregnancy.

  7. Age- and sex-related differences of organic anion-transporting polypeptide gene expression in livers of rats

    International Nuclear Information System (INIS)

    Hou, Wei-Yu; Xu, Shang-Fu; Zhu, Qiong-Ni; Lu, Yuan-Fu; Cheng, Xing-Guo; Liu, Jie

    2014-01-01

    Organic anion-transporting polypeptides (Oatps) play important roles in transporting endogenous substances and xenobiotics into the liver and are implicated in drug-drug interactions. Many factors could influence their expression and result in alterations in drug disposition, efficacy and toxicity. This study was aimed to examine the development-, aging-, and sex-dependent Oatps expression in livers of rats. The livers from SD rats during development (− 2, 1, 7, 14, 21, 28, 35, and 60 d) and aging (60, 180, 540 and/or 800 d) were collected and total RNAs were extracted, purified, and subjected to real-time PCR analysis. Total proteins were extracted for western-blot analysis. Results showed that Oatp1a1, Oatp1a4, Oatp1a5 and Oatp1b2 were all hardly detectable in fetal rat livers, low at birth, rapidly increased after weaning (21 d), and reached the peak at 60 d. The Oatps remained stable during the age between 60–180 d, and decreased at elderly (540 and/or 800 d). After birth, Oatp1a1, Oatp1a4, and Oatp1b2 were all highly expressed in liver, in contrast, Oatp1a5 expression was low. Oatp expressions are male-predominant in rat livers. In the livers of aged rats, the Oatp expression decreased and shared a consistent ontogeny pattern at the mRNA and protein level. In conclusion, this study showed that in rat liver, Oatp1a1, Oatp1a4, Oatp1a5 and Oatp1b2 gene expressions are influenced by age and gender, which could provide a basis of individual variation in drug transport, metabolism and toxicity in children, elderly and women. - Highlights: • Oatp1a1, Oatp1a4, Oatp1a5 and Oatp1b2 expression in livers of rats. • Ontogenic changes of Oatps at − 2, 1, 7, 14, 21, 28, 35, and 60 days. • Age-related changes of Oatps at 60, 180, 540, and 800 days. • Sex-difference of Oatps at the both mRNA and protein levels

  8. Age- and sex-related differences of organic anion-transporting polypeptide gene expression in livers of rats

    Energy Technology Data Exchange (ETDEWEB)

    Hou, Wei-Yu; Xu, Shang-Fu; Zhu, Qiong-Ni; Lu, Yuan-Fu [Key Lab for Pharmacology of Ministry of Education, Zunyi Medical College, Zunyi 563003 (China); Cheng, Xing-Guo [Department of Pharmaceutical Sciences, St. John’s University, New York, NY 11439 (United States); Liu, Jie, E-mail: Jieliu@zmc.edu.cn [Key Lab for Pharmacology of Ministry of Education, Zunyi Medical College, Zunyi 563003 (China)

    2014-10-15

    Organic anion-transporting polypeptides (Oatps) play important roles in transporting endogenous substances and xenobiotics into the liver and are implicated in drug-drug interactions. Many factors could influence their expression and result in alterations in drug disposition, efficacy and toxicity. This study was aimed to examine the development-, aging-, and sex-dependent Oatps expression in livers of rats. The livers from SD rats during development (− 2, 1, 7, 14, 21, 28, 35, and 60 d) and aging (60, 180, 540 and/or 800 d) were collected and total RNAs were extracted, purified, and subjected to real-time PCR analysis. Total proteins were extracted for western-blot analysis. Results showed that Oatp1a1, Oatp1a4, Oatp1a5 and Oatp1b2 were all hardly detectable in fetal rat livers, low at birth, rapidly increased after weaning (21 d), and reached the peak at 60 d. The Oatps remained stable during the age between 60–180 d, and decreased at elderly (540 and/or 800 d). After birth, Oatp1a1, Oatp1a4, and Oatp1b2 were all highly expressed in liver, in contrast, Oatp1a5 expression was low. Oatp expressions are male-predominant in rat livers. In the livers of aged rats, the Oatp expression decreased and shared a consistent ontogeny pattern at the mRNA and protein level. In conclusion, this study showed that in rat liver, Oatp1a1, Oatp1a4, Oatp1a5 and Oatp1b2 gene expressions are influenced by age and gender, which could provide a basis of individual variation in drug transport, metabolism and toxicity in children, elderly and women. - Highlights: • Oatp1a1, Oatp1a4, Oatp1a5 and Oatp1b2 expression in livers of rats. • Ontogenic changes of Oatps at − 2, 1, 7, 14, 21, 28, 35, and 60 days. • Age-related changes of Oatps at 60, 180, 540, and 800 days. • Sex-difference of Oatps at the both mRNA and protein levels.

  9. Involvement of organic anion transporting polypeptide 1a5 (Oatp1a5) in intestinal absorption of endothelin receptor antagonist in rats

    DEFF Research Database (Denmark)

    Tani, Takeshe; Gram, Luise Kvisgaard; Arakawa, Hiroshi

    2008-01-01

    PURPOSE: To assess the contribution of organic anion transporting polypeptide 1a5 (Oatp1a5/Oatp3) in the intestinal absorption of an orally active endothelin receptor antagonist, (+)-(5S,6R,7R)-2-butyl-7-[2-((2S)-2-carboxypropyl)-4-methoxyphenyl]-5-(3,4-methylene-dioxyphenyl)cyclopenteno[1,2-b...... and taurocholic acid. CONCLUSIONS: These results consistently suggested that Oatp1a5 is contributing to the intestinal absorption of compound-A at least in part, and the transporter-mediated absorption seems to be maximized at the acidic microenvironment of epithelial cells in the small intestine in rats....

  10. Novel insights into xenobiotic transport by organic anion transporting polypeptides (OATPs) and OATP-expression profiling in ovarian carcinoma and other solid tumors

    International Nuclear Information System (INIS)

    Svoboda, M.

    2010-01-01

    Eleven members of the organic anion transporting polypeptides (OATP) family have been identified in humans. They are responsible for the Na+ independent cellular uptake of a broad range of substances. The aim of this thesis was to investigate the possible role of OATPs present in various cancer entities including breast, bone, liver and ovary. In the first study, carrier-mediated uptake of paclitaxel was studied in X. laevis oocytes expressing all known human OATPs and in ovarian cancer cell lines. OATP1B1 could be identified as an uptake transporter for paclitaxel showing a Km value of 0.6 μM indicating high affinity to this taxane. Subsequently, the expression status of OATPs and several ABC transporters was assessed in malignant specimens from 191 ovarian cancer patients. OATP3A1 was significantly correlated with the FIGO stage of tumors. Moreover, OATP6A1, ABCB2 and ABCC3 were identified as highly significant predictor for the disease free survival of ovarian cancer patients. In additional studies we showed distinct OATP expression patterns in cancer tissues compared to normal tissue or benign tumors. In general, higher OATP levels were detected in normal tissues compared to malignant ones in breast cancer as well as bone cancer. In liver cancer, we observed upregulation of OATP2A1 and 5A1 in primary and secondary hepatic tumors but OATP4A1 was only upregulated in secondary hepatic tumors. The distinct expression pattern for individual OATPs in tumor cells suggest their specific functions which may involve transport of molecules important for cellular signaling as well as of drugs used in therapy. (author) [de

  11. Hepatic uptake of conjugated bile acids is mediated by both sodium taurocholate cotransporting polypeptide and organic anion transporting polypeptides and modulated by intestinal sensing of plasma bile acid levels in mice.

    Science.gov (United States)

    Slijepcevic, Davor; Roscam Abbing, Reinout L P; Katafuchi, Takeshi; Blank, Antje; Donkers, Joanne M; van Hoppe, Stéphanie; de Waart, Dirk R; Tolenaars, Dagmar; van der Meer, Jonathan H M; Wildenberg, Manon; Beuers, Ulrich; Oude Elferink, Ronald P J; Schinkel, Alfred H; van de Graaf, Stan F J

    2017-11-01

    The Na + -taurocholate cotransporting polypeptide (NTCP/SLC10A1) is believed to be pivotal for hepatic uptake of conjugated bile acids. However, plasma bile acid levels are normal in a subset of NTCP knockout mice and in mice treated with myrcludex B, a specific NTCP inhibitor. Here, we elucidated which transport proteins mediate the hepatic uptake of conjugated bile acids and demonstrated intestinal sensing of elevated bile acid levels in plasma in mice. Mice or healthy volunteers were treated with myrcludex B. Hepatic bile acid uptake kinetics were determined in wild-type (WT), organic anion transporting polypeptide (OATP) knockout mice (lacking Slco1a/1b isoforms), and human OATP1B1-transgenic mice. Effects of fibroblast growth factor 19 (FGF19) on hepatic transporter mRNA levels were assessed in rat hepatoma cells and in mice by peptide injection or adeno-associated virus-mediated overexpression. NTCP inhibition using myrcludex B had only moderate effects on bile acid kinetics in WT mice, but completely inhibited active transport of conjugated bile acid species in OATP knockout mice. Cholesterol 7α-hydroxylase Cyp7a1 expression was strongly down-regulated upon prolonged inhibition of hepatic uptake of conjugated bile acids. Fgf15 (mouse counterpart of FGF19) expression was induced in hypercholanemic OATP and NTCP knockout mice, as well as in myrcludex B-treated cholestatic mice, whereas plasma FGF19 was not induced in humans treated with myrcludex B. Fgf15/FGF19 expression was induced in polarized human enterocyte-models and mouse organoids by basolateral incubation with a high concentration (1 mM) of conjugated bile acids. NTCP and OATPs contribute to hepatic uptake of conjugated bile acids in mice, whereas the predominant uptake in humans is NTCP mediated. Enterocytes sense highly elevated levels of (conjugated) bile acids in the systemic circulation to induce FGF15/19, which modulates hepatic bile acid synthesis and uptake. (Hepatology 2017;66:1631-1643).

  12. Comparative pharmacophore modeling of organic anion transporting polypeptides: a meta-analysis of rat Oatp1a1 and human OATP1B1.

    Science.gov (United States)

    Chang, Cheng; Pang, K Sandy; Swaan, Peter W; Ekins, Sean

    2005-08-01

    The organic anion transporting polypeptides OATPs are key membrane transporters for which crystal structures are not currently available. They transport a diverse array of xenobiotics and are expressed at the interface of hepatocytes, renal tubular cells, enterocytes, and the choroid plexus. To aid the understanding of the key molecular features for substrate-transporter interactions, pharmacophore models were produced for the two OATPs that have been most extensively studied, namely rat Oatp1a1 and human OATP1B1. Literature data from Chinese hamster ovary, HeLa, human embryonic kidney 293 cells, and Xenopus laevis oocytes were used to construct pharmacophores for each individual transporter which were later merged to show similarities across cell lines for the same transporter. Additionally, meta-pharmacophores were generated from the combined datasets of each cell system used with the same transporter. The pharmacophores for each transporter consisted of hydrogen bond acceptor and hydrophobic features. There was good agreement between the merged and meta-pharmacophores containing two hydrogen bond acceptors and two or three hydrophobic features for Oatp1a1 and OATP1B1. External test sets were used to validate the individual pharmacophores. The meta-pharmacophores were also used to make predictions for molecules not included in the models and provided new molecular insight into the key features for these OATP transporters. This approach can be extended to other transporters for which limited data are available.

  13. Experimental Conditions: SE24_S1_M1_D1 [Metabolonote[Archive

    Lifescience Database Archive (English)

    Full Text Available rometry with 13C‑Labeling for Chemical Assignment of Sulfur-Containing Metabolites ...SE24_S1_M1_D1 SE24 Combination of Liquid Chromatography-Fourier Transform Ion Cyclotron Resonance-Mass Spect

  14. Insulin stimulation regulates AS160 and TBC1D1 phosphorylation sites in human skeletal muscle

    DEFF Research Database (Denmark)

    Middelbeek, R J W; Chambers, M A; Tantiwong, P

    2013-01-01

    Individuals with obesity and type 2 diabetes (T2D) are typically insulin resistant, exhibiting impaired skeletal muscle glucose uptake. Animal and cell culture experiments have shown that site-specific phosphorylation of the Rab-GTPase-activating proteins AS160 and TBC1D1 is critical for GLUT4 tr...... translocation facilitating glucose uptake, but their regulation in human skeletal muscle is not well understood....

  15. Comparison of the Predictability of Human Hepatic Clearance for Organic Anion Transporting Polypeptide Substrate Drugs Between Different In Vitro-In Vivo Extrapolation Approaches.

    Science.gov (United States)

    Izumi, Saki; Nozaki, Yoshitane; Komori, Takafumi; Takenaka, Osamu; Maeda, Kazuya; Kusuhara, Hiroyuki; Sugiyama, Yuichi

    2017-09-01

    Prediction of human pharmacokinetic profiles of drug candidates is an essential step toward first-in-human studies. However, it remains difficult to quantitatively predict hepatic clearance, particularly when hepatic uptake is mediated by transporter(s). Using 15 organic anion transporting polypeptide (OATP) substrate drugs, we tested 3 in vitro-in vivo extrapolation (IVIVE) approaches to predict overall hepatic intrinsic clearance in vivo (CL int,all,vivo ). IVIVE approaches involved metabolic intrinsic clearance in human liver microsomes (CL int,met ) with or without hepatocyte-to-buffer maximum unbound concentration ratio (K p,uu,max ) correction and uptake intrinsic clearance at 37°C (PS inf,37°C ) in human hepatocyte suspensions. K p,uu,max and PS inf,37°C values were determined in 2 hepatocyte batches, and all tested compounds showed temperature-dependent uptake, consistent with the fact of transporter-mediated uptake. CL int,met substantially underestimated CL int,all,vivo . By multiplying CL int,met by K p,uu,max values, the prediction performance was much improved; however, in vitro-in vivo correlation was poor. Among the IVIVE approaches, PS inf,37°C showed the most robust correlation with CL int,all,vivo , and one of the hepatocyte batches could predict CL int,all,vivo with a minimal empirical scaling factor. These results suggested IVIVE with hepatic uptake clearance determined in hepatocyte suspensions as one of the most practical approaches for predicting CL int,all,vivo of OATP substrate drugs. Copyright © 2017 American Pharmacists Association®. Published by Elsevier Inc. All rights reserved.

  16. Thyroxine (T4 Transfer from Blood to Cerebrospinal Fluid in Sheep Isolated Perfused Choroid Plexus: Role of Multidrug Resistance-Associated Proteins and Organic Anion Transporting Polypeptides

    Directory of Open Access Journals (Sweden)

    Kazem Zibara

    2017-05-01

    Full Text Available Thyroxine (T4 enters the brain either directly across the blood–brain barrier (BBB or indirectly via the choroid plexus (CP, which forms the blood–cerebrospinal fluid barrier (B-CSF-B. In this study, using isolated perfused CP of the sheep by single-circulation paired tracer and steady-state techniques, T4 transport mechanisms from blood into lateral ventricle CP has been characterized as the first step in the transfer across the B-CSF-B. After removal of sheep brain, the CPs were perfused with 125I-T4 and 14C-mannitol. Unlabeled T4 was applied during single tracer technique to assess the mode of maximum uptake (Umax and the net uptake (Unet on the blood side of the CP. On the other hand, in order to characterize T4 protein transporters, steady-state extraction of 125I-T4 was measured in presence of different inhibitors such as probenecid, verapamil, BCH, or indomethacin. Increasing the concentration of unlabeled-T4 resulted in a significant reduction in Umax%, which was reflected by a complete inhibition of T4 uptake into CP. In fact, the obtained Unet% decreased as the concentration of unlabeled-T4 increased. The addition of probenecid caused a significant inhibition of T4 transport, in comparison to control, reflecting the presence of a carrier mediated process at the basolateral side of the CP and the involvement of multidrug resistance-associated proteins (MRPs: MRP1 and MRP4 and organic anion transporting polypeptides (Oatp1, Oatp2, and Oatp14. Moreover, verapamil, the P-glycoprotein (P-gp substrate, resulted in ~34% decrease in the net extraction of T4, indicating that MDR1 contributes to T4 entry into CSF. Finally, inhibition in the net extraction of T4 caused by BCH or indomethacin suggests, respectively, a role for amino acid “L” system and MRP1/Oatp1 in mediating T4 transfer. The presence of a carrier-mediated transport mechanism for cellular uptake on the basolateral membrane of the CP, mainly P-gp and Oatp2, would account

  17. Tryptophan Residue Located at the Middle of Putative Transmembrane Domain 11 Is Critical for the Function of Organic Anion Transporting Polypeptide 2B1.

    Science.gov (United States)

    Bian, Jialin; Jin, Meng; Yue, Mei; Wang, Meiyu; Zhang, Hongjian; Gui, Chunshan

    2016-10-03

    Organic anion transporting polypeptide 2B1 (OATP2B1), which is highly expressed in enterocytes and hepatocytes could be a key determinant for the intestinal absorption and hepatic uptake of its substrates, most of which are amphipathic organic anions. Tryptophan residues may possess a multitude of functions for a transport protein through aromatic interactions, such as maintaining the proper protein structure, guiding the depth of membrane insertion, or interacting directly with substrates. There are totally six tryptophan residues in OATP2B1. However, little is known about their role in the function and expression of OATP2B1. Our results show that, while W272, W276, and W277 located at the border of extracellular loop 3 and transmembrane domain 6 exhibit a moderate effect on the surface expression of OATP2B1, W611 located at the middle of transmembrane domain 11 plays a critical role in the function of OATP2B1. The tryptophan-to-alanine mutation of W611 changes the kinetic characteristics of OATP2B1-mediated estrone-3-sulfate (E3S) transport radically, from a monophasic saturation curve (with K m and V max values being of 7.1 ± 1.1 μM and 182 ± 7 pmol/normalized mg/min, respectively) to a linear curve. Replacing alanine with a phenylalanine will rescue most of OATP2B1's function, suggesting that the aromatic side chain of residue 611 is very important. However, hydrogen-bond forming and positively charged groups at this position are not favorable. The important role of W611 is not substrate-dependent. Molecular modeling indicates that the side chain of W611 faces toward the substrate translocation pathway and might interact with substrates directly. Taken together, our findings reveal that W611 is critical for the function of OATP2B1.

  18. Casein Kinase 2 Is a Novel Regulator of the Human Organic Anion Transporting Polypeptide 1A2 (OATP1A2) Trafficking.

    Science.gov (United States)

    Chan, Ting; Cheung, Florence Shin Gee; Zheng, Jian; Lu, Xiaoxi; Zhu, Ling; Grewal, Thomas; Murray, Michael; Zhou, Fanfan

    2016-01-04

    Human organic anion transporting polypeptides (OATPs) mediate the influx of many important drugs into cells. Casein kinase 2 (CK2) is a critical protein kinase that phosphorylates >300 protein substrates and is dysregulated in a number of disease states. Among the CK2 substrates are several transporters, although whether this includes human OATPs has not been evaluated. The current study was undertaken to evaluate the regulation of human OATP1A2 by CK2. HEK-239T cells in which OATP1A2 was overexpressed were treated with CK2 specific inhibitors or transfected with CK2 specific siRNA, and the activity, expression, and subcellular trafficking of OATP1A2 was evaluated. CK2 inhibition decreased the uptake of the prototypic OATP1A2 substrate estrone-3-sulfate (E3S). Kinetic studies revealed that this was due to a decrease in the maximum velocity (Vmax) of E3S uptake, while the Michaelis constant was unchanged. The cell surface expression, but not the total cellular expression of OATP1A2, was impaired by CK2 inhibition and knockdown of the catalytic α-subunits of CK2. CK2 inhibition decreased the internalization of OATP1A2 via a clathrin-dependent pathway, decreased OATP1A2 recycling, and likely impaired OATP1A2 targeting to the cell surface. Consistent with these findings, CK2 inhibition also disrupted the colocalization of OATP1A2 and Rab GTPase (Rab)4-, Rab8-, and Rab9-positive endosomal and secretory vesicles. Taken together, CK2 has emerged as a novel regulator of the subcellular trafficking and stability of OATP1A2. Because OATP1A2 transports many molecules of physiological and pharmacological importance, the present data may inform drug selection in patients with diseases in which CK2 and OATP1A2 are dysregulated.

  19. Characterization of simvastatin acid uptake by organic anion transporting polypeptide 3A1 (OATP3A1) and influence of drug-drug interaction.

    Science.gov (United States)

    Atilano-Roque, Amandla; Joy, Melanie S

    2017-12-01

    Human organic anion transporting polypeptide 3A1 (OATP3A1) is predominately expressed in the heart. The ability of OATP3A1 to transport statins into cardiomyocytes is unknown, although other OATPs are known to mediate the uptake of statin drugs in liver. The pleiotropic effects and uptake of simvastatin acid were analyzed in primary human cardiomyocytes and HEK293 cells transfected with the OATP3A1 gene. Treatment with simvastatin acid reduced indoxyl sulfate-mediated reactive oxygen species and modulated OATP3A1 expression in cardiomyocytes and HEK293 cells transfected with the OATP3A1 gene. We observed a pH-dependent effect on OATP3A1 uptake, with more efficient simvastatin acid uptake at pH5.5 in HEK293 cells transfected with the OATP3A1 gene. The Michaelis-Menten constant (K m ) for simvastatin acid uptake by OATP3A1 was 0.017±0.002μM and the V max was 0.995±0.027fmol/min/10 5 cells. Uptake of simvastatin acid was significantly increased by known (benzylpenicillin and estrone-3-sulfate) and potential (indoxyl sulfate and cyclosporine) substrates of OATP3A1. In conclusion, the presence of OATP3A1 in cardiomyocytes suggests that this transporter may modulate the exposure of cardiac tissue to simvastatin acid due to its enrichment in cardiomyocytes. Increases in uptake of simvastatin acid by OATP3A1 when combined with OATP substrates suggest the potential for drug-drug interactions that could influence clinical outcomes. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. Na+-taurocholate cotransporting polypeptide (NTCP/SLC10A1) ortholog in the marine skateLeucoraja erinaceais not a physiological bile salt transporter.

    Science.gov (United States)

    Yu, Dongke; Zhang, Han; Lionarons, Daniel A; Boyer, James L; Cai, Shi-Ying

    2017-04-01

    The Na + -dependent taurocholate cotransporting polypeptide (NTCP/SLC10A1) is a hepatocyte-specific solute carrier, which plays an important role in maintaining bile salt homeostasis in mammals. The absence of a hepatic Na + -dependent bile salt transport system in marine skate and rainbow trout raises a question regarding the function of the Slc10a1 gene in these species. Here, we have characterized the Slc10a1 gene in the marine skate, Leucoraja erinacea The transcript of skate Slc10a1 (skSlc10a1) encodes 319 amino acids and shares 46% identity to human NTCP (hNTCP) with similar topology to mammalian NTCP. SkSlc10a1 mRNA was mostly confined to the brain and testes with minimal expression in the liver. An FXR-bile salt reporter assay indicated that skSlc10a1 transported taurocholic acid (TCA) and scymnol sulfate, but not as effectively as hNTCP. An [ 3 H]TCA uptake assay revealed that skSlc10a1 functioned as a Na + -dependent transporter, but with low affinity for TCA ( K m = 92.4 µM) and scymnol sulfate ( K i = 31 µM), compared with hNTCP (TCA, K m = 5.4 µM; Scymnol sulfate, K i = 3.5 µM). In contrast, the bile salt concentration in skate plasma was 2 µM, similar to levels seen in mammals. Interestingly, skSlc10a1 demonstrated transport activity for the neurosteroids dehydroepiandrosterone sulfate and estrone-3-sulfate at physiological concentration, similar to hNTCP. Together, our findings indicate that skSlc10a1 is not a physiological bile salt transporter, providing a molecular explanation for the absence of a hepatic Na + -dependent bile salt uptake system in skate. We speculate that Slc10a1 is a neurosteroid transporter in skate that gained its substrate specificity for bile salts later in vertebrate evolution. Copyright © 2017 the American Physiological Society.

  1. In silico analysis and experimental validation of azelastine hydrochloride (N4) targeting sodium taurocholate co-transporting polypeptide (NTCP) in HBV therapy.

    Science.gov (United States)

    Fu, L-L; Liu, J; Chen, Y; Wang, F-T; Wen, X; Liu, H-Q; Wang, M-Y; Ouyang, L; Huang, J; Bao, J-K; Wei, Y-Q

    2014-08-01

    The aim of this study was to explore sodium taurocholate co-transporting polypeptide (NTCP) exerting its function with hepatitis B virus (HBV) and its targeted candidate compounds, in HBV therapy. Identification of NTCP as a novel HBV target for screening candidate small molecules, was used by phylogenetic analysis, network construction, molecular modelling, molecular docking and molecular dynamics (MD) simulation. In vitro virological examination, q-PCR, western blotting and cytotoxicity studies were used for validating efficacy of the candidate compound. We used the phylogenetic analysis of NTCP and constructed its protein-protein network. Also, we screened compounds from Drugbank and ZINC, among which five were validated for their authentication in HepG 2.2.15 cells. Then, we selected compound N4 (azelastine hydrochloride) as the most potent of them. This showed good inhibitory activity against HBsAg (IC50 = 7.5 μm) and HBeAg (IC50 = 3.7 μm), as well as high SI value (SI = 4.68). Further MD simulation results supported good interaction between compound N4 and NTCP. In silico analysis and experimental validation together demonstrated that compound N4 can target NTCP in HepG2.2.15 cells, which may shed light on exploring it as a potential anti-HBV drug. © 2014 John Wiley & Sons Ltd.

  2. Investigation of associations between NR1D1, RORA and RORB genes and bipolar disorder.

    Directory of Open Access Journals (Sweden)

    Yin-Chieh Lai

    Full Text Available Several genes that are involved in the regulation of circadian rhythms are implicated in the susceptibility to bipolar disorder (BD. The current study aimed to investigate the relationships between genetic variants in NR1D1 RORA, and RORB genes and BD in the Han Chinese population. We conducted a case-control genetic association study with two samples of BD patients and healthy controls. Sample I consisted of 280 BD patients and 200 controls. Sample II consisted of 448 BD patients and 1770 healthy controls. 27 single nucleotide polymorphisms in the NR1D1, RORA, and RORB genes were genotyped using GoldenGate VeraCode assays in sample I, and 492 markers in the three genes were genotyped using Affymetrix Genome-Wide CHB Array in sample II. Single marker and gene-based association analyses were performed using PLINK. A combined p-value for the joining effects of all markers within a gene was calculated using the rank truncated product method. Multifactor dimensionality reduction (MDR method was also applied to test gene-gene interactions in sample I. All markers were in Hardy-Weinberg equilibrium (P>0.001. In sample I, the associations with BD were observed for rs4774388 in RORA (OR = 1.53, empirical p-value, P = 0.024, and rs1327836 in RORB (OR = 1.75, P = 0.003. In Sample II, there were 45 SNPs showed associations with BD, and the most significant marker in RORA was rs11639084 (OR = 0.69, P = 0.002, and in RORB was rs17611535 (OR = 3.15, P = 0.027. A combined p-value of 1.6×10-6, 0.7, and 1.0 was obtained for RORA, RORB and NR1D1, respectively, indicting a strong association for RORA with the risk of developing BD. A four way interaction was found among markers in NR1D1, RORA, and RORB with the testing accuracy 53.25% and a cross-validation consistency of 8 out of 10. In sample II, 45 markers had empirical p-values less than 0.05. The most significant markers in RORA and RORB genes were rs11639084 (OR = 0.69, P = 0.002, and rs17611535 (OR = 3

  3. The eighth and ninth transmembrane domains in organic anion transporting polypeptide 1B1 affect the transport kinetics of estrone-3-sulfate and estradiol-17beta-D-glucuronide.

    Science.gov (United States)

    Miyagawa, Mayuko; Maeda, Kazuya; Aoyama, Akinori; Sugiyama, Yuichi

    2009-05-01

    Organic anion transporting polypeptide (OATP) 1B1 and OATP1B3 are responsible for the hepatic uptake of organic anions. They share similar sequences and structures with 12 putative transmembrane domains (TMs). Their substrate specificities are very broad and overlap each other, whereas each transporter specifically recognizes certain substrates. Because the homology of the amino acid sequence in the latter part of OATP1B1 and OATP1B3 is relatively low, to determine which TMs in the latter part of OATP1B1 are important for its substrate recognition, we constructed several cell lines expressing chimeric transporters in which some TMs of OATP1B1 were substituted with those of OATP1B3, and we investigated the transport kinetics of estrone-3-sulfate (E-sul; a substrate preferentially accepted by OATP1B1) and estradiol-17beta-D-glucuronide (EG; a substrate accepted by both transporters). As the number of substituted TMs at the N terminus with those of OATP1B3 increased, the K(m) value of E-sul greatly increased and its uptake clearance decreased. The substitution of TM7 or TM9 of OATP1B1 with that of OATP1B3 (named 1B1-TM7 or 1B1-TM9) did not change the transport kinetics of EG, whereas the K(m) value of E-sul in 1B1-TM9 increased 7.4-fold. Conversely, the substitution of TM8 resulted in an 18-fold increase in the K(m) value of E-sul and abolished the transporter-mediated uptake of EG. These results suggest that TM8 in OATP1B1 is critical for the substrate recognition of both E-sul and EG and that TM9 is important for the recognition of E-sul, whereas it is interchangeable with that of OATP1B3 for EG transport.

  4. Gastric inhibitory polypeptide analogues

    DEFF Research Database (Denmark)

    Holst, Jens Juul

    2002-01-01

    Gastric inhibitory polypeptide (GIP, also called glucose-dependent insulinotropic polypeptide) and glucagon-like peptide-1 (GLP-1) are peptide hormones from the gut that enhance nutrient-stimulated insulin secretion (the 'incretin' effect). Judging from experiments in mice with targeted deletions...

  5. Lack of Contribution of Multidrug Resistance-associated Protein and Organic Anion-transporting Polypeptide to Pharmacokinetics of Regorafenib, a Novel Multi-Kinase Inhibitor, in Rats.

    Science.gov (United States)

    Hotta, Kazuo; Ueyama, Jun; Tatsumi, Yasuaki; Tsukiyama, Ikuto; Sugiura, Yuka; Saito, Hiroko; Matsuura, Katsuhiko; Hasegawa, Takaaki

    2015-09-01

    We investigated whether hepatic multidrug resistance-associated protein 2 (ABCC2) is involved in the hepatobiliary excretion of regorafenib, a novel multi-kinase inhibitor, using Sprague-Dawley (SD) rats and Eisai hyperbilirubinemic rats (EHBR) lacking the efflux transporter ABCC2. The involvement of organic anion-transporting polypeptide 1 (OATP1; OATP in humans) and OATP2 in the hepatic uptake of regorafenib and their protein levels in the liver were also investigated in the two rat groups. When regorafenib (5 mg/kg) was administered intravenously, the plasma concentrations of regorafenib were higher in EHBR than those in SD rats. However, the slope of the plasma concentration-time curves was the same for the two groups. Although the apparent biliary clearance of regorafenib in EHBR was lower than that of SD rats, no significant difference in the biliary excretion rate was observed between them, suggesting that regorafenib is not a substrate for ABCC2 and is not excreted into bile by ABCC2. It was also found that the contribution of biliary excretion to the systemic elimination of regorafenib is small. The protein-binding profiles of regorafenib were found to be linear in both rat groups. The binding potency, which was very high in both rat groups (>99.5%), was significantly higher in EHBR than that in SD rats. No significant differences in the plasma concentrations of unbound regorafenib were observed between the two rat groups, suggesting that the differences observed in the pharmacokinetic behaviors of regorafenib between the two rat groups were due to differences in protein-binding. When the protein levels of hepatic OATP1 and OATP2 were measured by immunoblot analysis, the expression of both transporters in EHBR was less than 40% of that in SD rats. The present results suggest that regorafenib is not a substrate for OATP1 and OATP2. These findings suggest the possibility that ABCC2-mediated hepatobiliary excretion and OATP1/OATP2-mediated hepatic uptake do

  6. Identification of amino acids essential for estrone-3-sulfate transport within transmembrane domain 2 of organic anion transporting polypeptide 1B1.

    Directory of Open Access Journals (Sweden)

    Nan Li

    Full Text Available As an important structure in membrane proteins, transmembrane domains have been found to be crucial for properly targeting the protein to cell membrane as well as carrying out transport functions in transporters. Computer analysis of OATP sequences revealed transmembrane domain 2 (TM2 is among those transmembrane domains that have high amino acid identities within different family members. In the present study, we identify four amino acids (Asp70, Phe73, Glu74, and Gly76 that are essential for the transport function of OATP1B1, an OATP member that is specifically expressed in the human liver. A substitution of these four amino acids with alanine resulted in significantly reduced transport activity. Further mutagenesis showed the charged property of Asp70 and Glu74 is critical for proper function of the transporter protein. Comparison of the kinetic parameters indicated that Asp70 is likely to interact with the substrate while Glu74 may be involved in stabilizing the binding site through formation of a salt-bridge. The aromatic ring structure of Phe73 seems to play an important role because substitution of Phe73 with tyrosine, another amino acid with a similar structure, led to partially restored transport function. On the other hand, replacement of Gly76 with either alanine or valine could not recover the function of the transporter. Considering the nature of a transmembrane helix, we proposed that Gly76 may be important for maintaining the proper structure of the protein. Interestingly, when subjected to transport function analysis of higher concentration of esteone-3-sulfate (50 µM that corresponds to the low affinity binding site of OATP1B1, mutants of Phe73, Glu74, and Gly76 all showed a transport function that is comparable to that of the wild-type, suggesting these amino acids may have less impact on the low affinity component of esteone-3-sulfate within OATP1B1, while Asp 70 seems to be involved in the interaction of both sites.

  7. Rubella virion polypeptides

    International Nuclear Information System (INIS)

    Ho-Terry, L.; Cohen, A.

    1982-01-01

    Four polypeptides with molecular weights of 55K, 47K, 45K, and 33K have been resolved by polyacrylamide gel electrophoresis of immune precipitated rubella virus. The 47K and 45K components have similar peptide maps but different isoelectric points so that the same polypeptide may exist in more than one charged form. The 55K and 45K components have similar isoelectric points but different peptide maps showing that similarity of isoelectric point is not evidence of identity. (Author)

  8. Optimized 1d-1v Vlasov-Poisson simulations using Fourier- Hermite spectral discretizations

    Science.gov (United States)

    Schumer, Joseph Wade

    1997-08-01

    A 1d-1v spatially-periodic, Maxwellian-like, charged particle phase-space distribution f(x, v, t) is represented by one of two different Fourier-Hermite basis sets (asymmetric or symmetric Hermite normalization) and evolved with a similarly transformed and filtered Vlasov- Poisson set of equations. The set of coefficients fαmn(t) are advanced through time with an O(/Delta t2)-accurate splitting method,1 using a O(/Delta t4) Runge-Kutta time advancement scheme on the v∂xf and E∂vf terms separately, between which the self-consistent electric field is calculated. This method improves upon that of previous works by the combined use of two optimization techniques: exact Gaussian filtering2 and variable velocity-scaled3 Hermite basis functions.4 The filter width, vo, reduces the error introduced by the finite computational system, yet does not alter the low-order velocity modes; therefore, the self-consistent fields are not affected by the filtering. In addition, a variable velocity scale length U is introduced into the Hermite basis functions to provide improved spectral accuracy, yielding orders of magnitude reduction in the L2-norm error.5 The asymmetric Hermite algorithm conserves particles and momentum exactly, and total energy in the limit of continuous time. However, this method does not conserve the Casimir [/int/int] f2dxdu, and is, in fact, numerically unstable. The symmetric Hermite algorithm can either conserve particles and energy or momentum (in the limit of continuous time), depending on the parity of the highest-order Hermite function. Its conservation properties improve greatly with the use of velocity filtering. Also, the symmetric Hermite method conserves [/int/int] f2dxdu and, therefore, remains numerically stable. Relative errors with respect to linear Landau damping and linear bump-on-tail instability are shown to be less than 1% (orders of magnitude lower than those found in comparable Fourier-Fourier and PIC schemes). Varying the Hermite

  9. Prebiotic polynucleotides and polypeptides

    Science.gov (United States)

    Orgel, L. E.

    1975-01-01

    Work on the nonenzymatic replication of polynucleotides is discussed emphasizing sequence dependence and showing that alternating polynucleotides should replicate more easily than any others. Experimental work is described showing that polypeptides in which hydrophobic and hydrophilic residues alternate, adopt a beta structure in aqueous solution. The possible relevance of these observations for the evolution of the genetic code is given.

  10. Inhibition of Human Steroid 5-Reductase (AKR1D1) by Finasteride and Structure of the Enzyme-Inhibitor Complex

    Energy Technology Data Exchange (ETDEWEB)

    Drury, J.; Di Costanzo, L; Penning, T; Christianson, D

    2009-01-01

    The {Delta}{sup 4}-3-ketosteroid functionality is present in nearly all steroid hormones apart from estrogens. The first step in functionalization of the A-ring is mediated in humans by steroid 5{alpha}- or 5{beta}-reductase. Finasteride is a mechanism-based inactivator of 5{alpha}-reductase type 2 with subnanomolar affinity and is widely used as a therapeutic for the treatment of benign prostatic hyperplasia. It is also used for androgen deprivation in hormone-dependent prostate carcinoma, and it has been examined as a chemopreventive agent in prostate cancer. The effect of finasteride on steroid 5{beta}-reductase (AKR1D1) has not been previously reported. We show that finasteride competitively inhibits AKR1D1 with low micromolar affinity but does not act as a mechanism-based inactivator. The structure of the AKR1D1 {center_dot} NADP{sup +} {center_dot} finasteride complex determined at 1.7 {angstrom} resolution shows that it is not possible for NADPH to reduce the {Delta}{sup 1-2}-ene of finasteride because the cofactor and steroid are not proximal to each other. The C3-ketone of finasteride accepts hydrogen bonds from the catalytic residues Tyr-58 and Glu-120 in the active site of AKR1D1, providing an explanation for the competitive inhibition observed. This is the first reported structure of finasteride bound to an enzyme involved in steroid hormone metabolism.

  11. Phosphorylation-Dependent PIH1D1 Interactions Define Substrate Specificity of the R2TP Cochaperone Complex

    Directory of Open Access Journals (Sweden)

    Zuzana Hořejší

    2014-04-01

    Full Text Available The R2TP cochaperone complex plays a critical role in the assembly of multisubunit machines, including small nucleolar ribonucleoproteins (snoRNPs, RNA polymerase II, and the mTORC1 and SMG1 kinase complexes, but the molecular basis of substrate recognition remains unclear. Here, we describe a phosphopeptide binding domain (PIH-N in the PIH1D1 subunit of the R2TP complex that preferentially binds to highly acidic phosphorylated proteins. A cocrystal structure of a PIH-N domain/TEL2 phosphopeptide complex reveals a highly specific phosphopeptide recognition mechanism in which Lys57 and 64 in PIH1D1, along with a conserved DpSDD phosphopeptide motif within TEL2, are essential and sufficient for binding. Proteomic analysis of PIH1D1 interactors identified R2TP complex substrates that are recruited by the PIH-N domain in a sequence-specific and phosphorylation-dependent manner suggestive of a common mechanism of substrate recognition. We propose that protein complexes assembled by the R2TP complex are defined by phosphorylation of a specific motif and recognition by the PIH1D1 subunit.

  12. Mosaic HIV envelope immunogenic polypeptides

    Energy Technology Data Exchange (ETDEWEB)

    Korber, Bette T. M.; Gnanakaran, S.; Perkins, Simon; Sodroski, Joseph; Haynes, Barton

    2018-01-02

    Disclosed herein are mosaic HIV envelope (Env) polypeptides that can elicit an immune response to HIV (such as cytotoxic T cell (CTL), helper T cell, and/or humoral responses). Also disclosed are sets of the disclosed mosaic Env polypeptides, which include two or more (for example, three) of the polypeptides. Also disclosed herein are methods for treating or inhibiting HIV in a subject including administering one or more of the disclosed immunogenic polypeptides or compositions to a subject infected with HIV or at risk of HIV infection. In some embodiments, the methods include inducing an immune response to HIV in a subject comprising administering to the subject at least one (such as two, three, or more) of the immunogenic polypeptides or at least one (such as two, three, or more) nucleic acids encoding at least one of the immunogenic polypeptides disclosed herein.

  13. Radiolysis of polypeptide

    International Nuclear Information System (INIS)

    Ogura, Isao; Nakamura, Katsuichi; Tanaka, Hiroshi; Takahashi, Katsuhiro; Ozaki, Makoto

    1981-01-01

    Almost the same results were obtained from the additional dipeptide, Gly-DL-Ala and DL-Ala-DL-Phe, by the γ-irradiation as previous report. Tri and tetrapeptide consisted of the same amino acid signified good stability than the others. Every polypeptide composed from sulfur contained amino acid exhaled the smell of hydrogen sulfide by the irradiation. It seemed that the stability by the difference of position of amino group in amino acid increased in order α, β, γ ... amino acid and that by the existence of hydroxyl group became smaller. (author)

  14. Development of Elastomeric Polypeptide BIomaterials

    National Research Council Canada - National Science Library

    Urry, Dan

    1998-01-01

    To design elastic polypeptide biomaterials in order to achieve diverse forms of free energy transduction by these water-miscible hydrophobic folding and assembling macromolecules, thereby to elucidate...

  15. Genetic disruption of AMPK signaling abolishes both contraction- and insulin-stimulated TBC1D1 phosphorylation and 14-3-3 binding in mouse skeletal muscle

    DEFF Research Database (Denmark)

    Pehmøller, Christian; Treebak, Jonas Thue; Birk, Jesper Bratz

    2009-01-01

    TBC1D1 is a Rab-GTPase-activating protein (GAP) known to be phosphorylated in response to insulin, growth factors, pharmacological agonists that activate 5'-AMP-activated protein kinase (AMPK), and muscle contraction. Silencing TBC1D1 in L6 muscle cells by siRNA increases insulin-stimulated GLUT4...... contraction increases 14-3-3 binding to TBC1D1 as well as phosphorylation of Ser(237) and Thr(596) in an AMPK-dependent manner. AMPK activation by AICAR induced similar Ser(237) and Thr(596) phosphorylation of, and 14-3-3 binding to, TBC1D1 as muscle contraction. Insulin did not increase Ser(237...... translocation, and overexpression of TBC1D1 in 3T3-L1 adipocytes with low endogenous TBC1D1 expression inhibits insulin-stimulated GLUT4 translocation, suggesting a role of TBC1D1 in regulating GLUT4 translocation. Aiming to unravel the regulation of TBC1D1 during contraction and the potential role of AMPK...

  16. Exercise-induced TBC1D1 Ser237 phosphorylation and 14-3-3 protein binding capacity in human skeletal muscle

    DEFF Research Database (Denmark)

    Frøsig, Christian; Pehmøller, Christian; Birk, Jesper Bratz

    2010-01-01

    increasing 60 - 250% (Pprotein kinase (AMPK) induced both Ser237 phosphorylation and 14-3-3 binding properties on human TBC1D1 when evaluated in vitro. To further characterize the role of AMPK as an upstream kinase regulating TBC1D1, extensor digitorum longus......TBC1D1 is a Rab-GTPase activating protein involved in regulation of GLUT4 translocation in skeletal muscle. We here evaluated exercise-induced regulation of TBC1D1 Ser237 phosphorylation and 14-3-3 protein binding capacity in human skeletal muscle. In separate experiments healthy men performed all......-out cycle exercise lasting either 30 sec, 2 min or 20 min. After all exercise protocols, TBC1D1 Ser237 phosphorylation increased (~70 - 230%, Pprotein showed a similar pattern of regulation...

  17. Organic Anion-Transporting Polypeptide (OATP)-Mediated Drug-Drug Interaction Study between Rosuvastatin and Cyclosporine A in Chimeric Mice with Humanized Liver.

    Science.gov (United States)

    Uchida, Masashi; Tajima, Yoriko; Kakuni, Masakazu; Kageyama, Yutaka; Okada, Taro; Sakurada, Eri; Tateno, Chise; Hayashi, Ryoji

    2018-01-01

    The influence of transporters on the pharmacokinetics of drugs is being increasingly recognized, and DDIs via transporters may be a risk factor for adverse events. Cyclosporine A, a strong OATP inhibitor, has been reported to increase the systemic exposure of rosuvastatin, an OATP substrate, by 7.1-fold in clinical studies. PXB mice are chimeric mice with humanized livers that are highly repopulated with human hepatocytes and have been widely used for drug discovery in drug metabolism and pharmacokinetics studies. In the present study, we examined in vivo and in vitro DDIs between rosuvastatin and cyclosporine A in PXB mice and fresh human hepatocytes (PXB cells) obtained from PXB mice. We initially investigated the active transport of rosuvastatin into PXB cells, and found concentration-dependent uptake with a Michaelis-Menten constant value of 4.0 μ mol/l and a V max value of 4.63 pmol/min per 10 6 cells. Cyclosporine A inhibited the uptake of rosuvastatin with an IC 50 value of 0.21 μ mol/l. We then examined in vivo DDIs, and the exposure of orally administered rosuvastatin increased by 3.3-fold and 11-fold in PXB mice pretreated with 10 and 50 mg/kg cyclosporine A, whereas it increased by 2.5-fold and 6.2-fold when rosuvastatin was administered intravenously, in studies that were conducted for considering gastrointestinal DDIs. The liver-to-blood concentration ratio of rosuvastatin was dose-dependently decreased by pretreatment with cyclosporine A in PXB mice and SCID mice. Observed DDIs in vivo were considered to be reasonable based on the estimated concentrations of cyclosporine A at the inlet to the liver and in the liver tissues of both mice. In conclusion, our results indicate that PXB mice might be a useful tool for predicting human OATP-mediated DDIs in drug discovery, and its limitation due to the differences of gastrointestinal condition from human should also be considered. Copyright © 2017 by The American Society for Pharmacology and Experimental

  18. Galanin and vasoactive intestinal polypeptide

    DEFF Research Database (Denmark)

    Harling, H; Messell, T; Poulsen, Steen Seier

    1991-01-01

    By immunohistochemistry and double staining technique, almost complete coexistence of galanin-like immunoreactivity (GAL-LI) and vasoactive intestinal polypeptide-like immunoreactivity (VIP-LI) was demonstrated in submucosal ganglionic cells and mucosal nerve fibers of the porcine ileum. The rele......By immunohistochemistry and double staining technique, almost complete coexistence of galanin-like immunoreactivity (GAL-LI) and vasoactive intestinal polypeptide-like immunoreactivity (VIP-LI) was demonstrated in submucosal ganglionic cells and mucosal nerve fibers of the porcine ileum...

  19. Glucose-dependent insulinotropic polypeptide

    DEFF Research Database (Denmark)

    Christensen, Mikkel Bring

    2016-01-01

    The hormones glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) are secreted by enteroendocrine cells in the intestinal mucosa in response to nutrient ingestion. They are called incretin hormones because of their ability to enhance insulin secretion. However...

  20. Glucose-dependent insulinotropic polypeptide

    DEFF Research Database (Denmark)

    Christensen, Mikkel; Vedtofte, Louise; Holst, Jens Juul

    2011-01-01

    OBJECTIVE To evaluate the glucose dependency of glucose-dependent insulinotropic polypeptide (GIP) effects on insulin and glucagon release in 10 healthy male subjects ([means ± SEM] aged 23 ± 1 years, BMI 23 ± 1 kg/m2, and HbA1c 5.5 ± 0.1%). RESEARCH DESIGN AND METHODS Saline or physiological doses...

  1. Glucose-dependent Insulinotropic Polypeptide

    DEFF Research Database (Denmark)

    Christensen, Mikkel B; Calanna, Salvatore; Holst, Jens Juul

    2014-01-01

    CONTEXT: Patients with type 2 diabetes mellitus (T2DM) have clinically relevant disturbances in the effects of the hormone glucose-dependent insulinotropic polypeptide (GIP). OBJECTIVE: We aimed to evaluate the importance of the prevailing plasma glucose levels for the effect of GIP on responses...

  2. Ochratoxin A transport by the human breast cancer resistance protein (BCRP), multidrug resistance protein 2 (MRP2), and organic anion-transporting polypeptides 1A2, 1B1 and 2B1.

    Science.gov (United States)

    Qi, Xiaozhe; Wagenaar, Els; Xu, Wentao; Huang, Kunlun; Schinkel, Alfred H

    2017-08-15

    Ochratoxin A (OTA) is a fungal secondary metabolite that can contaminate various foods. OTA has several toxic effects like nephrotoxicity, hepatotoxicity, and neurotoxicity in different animal species, but its mechanisms of toxicity are still unclear. How OTA accumulates in kidney, liver, and brain is as yet unknown, but transmembrane transport proteins are likely involved. We studied transport of OTA in vitro, using polarized MDCKII cells transduced with cDNAs of the efflux transporters mouse (m)Bcrp, human (h)BCRP, mMrp2, or hMRP2, and HEK293 cells overexpressing cDNAs of the human uptake transporters OATP1A2, OATP1B1, OATP1B3, or OATP2B1 at pH7.4 and 6.4. MDCKII-mBcrp cells were more resistant to OTA toxicity than MDCKII parental and hBCRP-transduced cells. Transepithelial transport experiments showed some apically directed transport by MDCKII-mBcrp cells at pH7.4, whereas both mBcrp and hBCRP clearly transported OTA at pH6.4. There was modest transport of OTA by mMrp2 and hMRP2 only at pH6.4. OATP1A2 and OATP2B1 mediated uptake of OTA both at pH7.4 and 6.4, but OATP1B1 only at pH7.4. There was no detectable transport of OTA by OATP1B3. Our data indicate that human BCRP and MRP2 can mediate elimination of OTA from cells, thus reducing OTA toxicity. On the other hand, human OATP1A2, OATP1B1, and OATP2B1 can mediate cellular uptake of OTA, which could aggravate OTA toxicity. Copyright © 2017 Elsevier Inc. All rights reserved.

  3. Methods for using polypeptides having cellobiohydrolase activity

    Science.gov (United States)

    Morant, Marc D; Harris, Paul

    2016-08-23

    The present invention relates to isolated polypeptides having cellobiohydrolase activity and isolated polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides.

  4. Phycobilisome structure of porphyridium cruentum: polypeptide composition

    Energy Technology Data Exchange (ETDEWEB)

    Redlinger, T.; Gantt, E.

    1981-01-01

    Purified phycobilisomes of porphyridium cruentum were solubilized in sodium dodecyl sulfate and resolved by sodium dodecyl sulfate-acrylamide gel electrophoresis into nine colored and nine colorless polypeptides. The colored polypeptides accounted for about 84% of the total stainable protein, and the colorless polypeptides accounted for the remaining 16%. Five of the colored polypeptides ranging in molecular weight from 13,300 to 19,500 were identified as the ..cap alpha.. and ..beta.. subunits of allophycocyanin, R-phycocyanin, and phycoerythrin. Three others (29,000-30,500) were orange and are probably related to the ..gamma.. subunit of phycoerythrin. Sequential dissociation of phycobilisomes, and analysis of the polypeptides in each fraction, revealed the association of a 32,500 molecular weight colorless polypeptide with a phycoerythrin fraction. The remaining eight colorless polypeptides were in the core fraction of the phycobilisome, which also was enriched in allophycocyanin.

  5. Cytochrome P450 1D1: A novel CYP1A-related gene that is not transcriptionally activated by PCB126 or TCDD

    DEFF Research Database (Denmark)

    Goldstone, J.V.; Jönsson, M.E.; Behrendt, Lars

    2009-01-01

    expressed in liver and is relatively highly expressed in brain. CYP1D1 transcript levels were higher at 9 h post-fertilization than at later developmental times. Treatment of zebrafish with potent aryl hydrocarbon receptor (AHR) agonists (3,3',4,4',5-pentachlorobiphenyl or 2,3,7,8-tetrachlorodibenzo...

  6. Disruption of the AMPK-TBC1D1 nexus increases lipogenic gene expression and causes obesity in mice via promoting IGF1 secretion.

    Science.gov (United States)

    Chen, Liang; Chen, Qiaoli; Xie, Bingxian; Quan, Chao; Sheng, Yang; Zhu, Sangsang; Rong, Ping; Zhou, Shuilian; Sakamoto, Kei; MacKintosh, Carol; Wang, Hong Yu; Chen, Shuai

    2016-06-28

    Tre-2/USP6, BUB2, cdc16 domain family member 1 (the TBC domain is the GTPase activating protein domain) (TBC1D1) is a Rab GTPase activating protein that is phosphorylated on Ser(231) by the AMP-activated protein kinase (AMPK) in response to intracellular energy stress. However, the in vivo role and importance of this phosphorylation event remains unknown. To address this question, we generated a mouse model harboring a TBC1D1(Ser231Ala) knockin (KI) mutation and found that the KI mice developed obesity on a normal chow diet. Mechanistically, TBC1D1 is located on insulin-like growth factor 1 (IGF1) storage vesicles, and the KI mutation increases endocrinal and paracrinal/autocrinal IGF1 secretion in an Rab8a-dependent manner. Hypersecretion of IGF1 causes increased expression of lipogenic genes via activating the protein kinase B (PKB; also known as Akt)-mammalian target of rapamycin (mTOR) pathway in adipose tissues, which contributes to the development of obesity, diabetes, and hepatic steatosis as the KI mice age. Collectively, these findings demonstrate that the AMPK-TBC1D1 signaling nexus interacts with the PKB-mTOR pathway via IGF1 secretion, which consequently controls expression of lipogenic genes in the adipose tissue. These findings also have implications for drug discovery to combat obesity.

  7. [Exploring the Correlation between Pi and Shen from the Excretion of AA-I and Expressions of Or- ganic Anion Transporting Polypeptide 2al and 2 b1 in Pi Deficiency Model Rats].

    Science.gov (United States)

    Xiang, Ting; Ren, Bin; Yang, Zhang-bin; Sun, Bao-guo; Chen, Ze-xiong; Chen, Yan; Zhang, Shi-jun

    2015-10-01

    To explore the correlation between Pi and Shen by observing the relationship between the metabolism of aristolochic acid (AA) and mRNA and protein expression levels of organic anion transporting polypeptide (oatp) superfamily member 2a1 and 2 b1 (oatp2al and oatp2bl) in renal, small intestinal, and large intestinal tissues of Pi deficiency syndrome (PDS) model rats. Totally 46 Sprague-Dawley (SD) rats were randomly divided into four groups, i.e., the blank group (n = 12), the PDS group (n = 22), the AA-I group (n = 6), and the PDS AA-I group (n = 6). PDS model was established by subcutaneously injecting Reserpine at the daily dose of 5 mg/kg for 16 successive days. Carotid intubation was performed in 6 rats selected from the blank group and the PDS group. Pharmacokinetics of AA-I were detected at 5, 15, 30, 45, and 60 min after gastrogavage of AA-I. AA-I concentrations in renal, small intestinal, and large intestinal tissues of 10 rats selected from the PDS group were determined. Normal saline was administered to 6 rats selected from the PDS group and the blank group by gastrogavage. Renal, small intestinal, and large intestinal tissues were collected in the AA-I group and the PDS AA-I group at 60 min after gastrogavage of AA-I. mRNA and protein expression levels of oatp2a1 and oatp2b1 in each tissue were detected using real-time polymerase chain reaction (RT- PCR) and Western blot. Compared with the blank group, plasma concentrations of in vivo AA-I were obviously higher in the PDS group at 15, 30, 45, and 60 min after gastrogavage of AA-I with statistical difference (P AA-I were obviously decreased at 60 min after gastrogavage of AA-I; AA-I concentrations in renal and large intestinal tissues were elevated; AA-I concentrations in small intestinal tissues were obviously reduced in the PDS group. There was no statistical difference in mRNA expression levels of oatp2a1 and oatp2b1 in the aforesaid three tissues of rats between the blank group and the PDS group

  8. Recombinant expression of backbone-cyclized polypeptides.

    Science.gov (United States)

    Borra, Radhika; Camarero, Julio A

    2013-09-01

    Here we review the different biochemical approaches available for the expression of backbone-cyclized polypeptides, including peptides and proteins. These methods allow for the production of circular polypeptides either in vitro or in vivo using standard recombinant DNA expression techniques. Polypeptide circularization provides a valuable tool to study the effects of topology on protein stability and folding kinetics. Furthermore, having biosynthetic access to backbone-cyclized polypeptides makes the production of genetically encoded libraries of cyclic polypeptides possible. The production of such libraries, which was previously restricted to the domain of synthetic chemistry, now offers biologists access to highly diverse and stable molecular libraries that can be screened using high-throughput methods for the rapid selection of novel cyclic polypeptide sequences with new biological activities. Copyright © 2013 Wiley Periodicals, Inc.

  9. Acute exercise and physiological insulin induce distinct phosphorylation signatures on TBC1D1 and TBC1D4 in human skeletal muscle

    DEFF Research Database (Denmark)

    Treebak, Jonas Thue; Pehmøller, Christian; Kristensen, Jonas Møller

    2014-01-01

    We investigated the phosphorylation signatures of two Rab GTPase activating proteins TBC1D1 and TBC1D4 in human skeletal muscle in response to physical exercise and physiological insulin levels induced by a carbohydrate rich meal using a paired experimental design. Eight healthy male volunteers...... in response to physiological stimuli in human skeletal muscle and support the idea that Akt and AMPK are upstream kinases. TBC1D1 phosphorylation signatures were comparable between in vitro contracted mouse skeletal muscle and exercised human muscle, and we show that AMPK was regulating phosphorylation...... of these sites in mouse muscle. Contraction and exercise elicited a different phosphorylation pattern of TBC1D4 in mouse compared with human muscle, and although different circumstances in our experimental setup may contribute to this difference, the observation exemplifies that transferring findings between...

  10. Production of Elastomeric Polypeptides for Materials Characterizations

    National Research Council Canada - National Science Library

    Urry, Dan

    2004-01-01

    .... Specifically, this effort is to provide 100 gram quantities of six and 10 gram quantities of an additional nine elastomeric polypeptides for conventional and specialized materials characterizations...

  11. Methods for engineering polypeptide variants via somatic hypermutation and polypeptide made thereby

    Science.gov (United States)

    Tsien, Roger Y; Wang, Lei

    2015-01-13

    Methods using somatic hypermutation (SHM) for producing polypeptide and nucleic acid variants, and nucleic acids encoding such polypeptide variants are disclosed. Such variants may have desired properties. Also disclosed are novel polypeptides, such as improved fluorescent proteins, produced by the novel methods, and nucleic acids, vectors, and host cells comprising such vectors.

  12. Ordered biological nanostructures formed from chaperonin polypeptides

    Science.gov (United States)

    Trent, Jonathan D. (Inventor); McMillan, R. Andrew (Inventor); Kagawa, Hiromi (Inventor); Paavola, Chad D. (Inventor)

    2010-01-01

    The following application relates to nanotemplates, nanostructures, nanoarrays and nanodevices formed from wild-type and mutated chaperonin polypeptides, methods of producing such compositions, methods of using such compositions and particular chaperonin polypeptides that can be utilized in producing such compositions.

  13. Polypeptides having catalase activity and polynucleotides encoding same

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Ye; Duan, Junxin; Zhang, Yu; Tang, Lan

    2017-05-02

    Provided are isolated polypeptides having catalase activity and polynucleotides encoding the polypeptides. Also provided are nucleic acid constructs, vectors and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides.

  14. Polypeptides having cellobiohydrolase activity and polynucleotides encoding same

    Science.gov (United States)

    Spodsberg, Nikolaj

    2015-07-14

    The present invention relates to isolated polypeptides having cellobiohydrolase activity and polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides.

  15. Hybrid polypeptides having cellobiohydrolase activity and polynucleotides encoding same

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Ye; Shaghasi, Tarana

    2016-11-01

    The present invention provides hybrid polypeptides having cellobiohydrolase activity. The present invention also provides polynucleotides encoding the hybrid polypeptides; nucleic acid constructs, vectors and host cells comprising the polynucleotides; and processes of using the hybrid polypeptides.

  16. Polypeptides having beta-xylosidase activity and polynucleotides encoding same

    Science.gov (United States)

    Liu, Ye; Tang, Lan; Zhang, Yu; Duan, Junxin

    2017-04-18

    Provided are isolated polypeptides having beta-xylosidase activity and polynucleotides encoding the polypeptides. Also provided are nucleic acid constructs, vectors and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides.

  17. Polypeptides having beta-glucosidase activity and polynucleotides encoding same

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Ye; Duan, Junxin; Zhang, Yu; Tang, Lan

    2017-09-26

    Provided are isolated polypeptides having beta-glucosidase activity and polynucleotides encoding the polypeptides. Also provided are nucleic acid constructs, vectors and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides.

  18. Polypeptides having cellobiohydrolase activity and polynucleotides encoding same

    Energy Technology Data Exchange (ETDEWEB)

    Spodsberg, Nikolaj

    2016-06-28

    The present invention relates to isolated polypeptides having cellobiohydrolase activity and polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides.

  19. Polypeptides having cellobiohydrolase activity and polynucleotides encoding same

    Energy Technology Data Exchange (ETDEWEB)

    Spodsberg, Nikolaj

    2016-12-13

    The present invention relates to isolated polypeptides having cellobiohydrolase activity and polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides.

  20. Polypeptides having cellobiohydrolase activity and polynucleotides encoding same

    Energy Technology Data Exchange (ETDEWEB)

    Spodsberg, Nikolaj

    2017-11-21

    The present invention relates to isolated polypeptides having cellobiohydrolase activity and polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides.

  1. Polypeptides having endoglucanase activity and polynucleotides encoding same

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Yu; Liu, Ye; Duan, Junxin; Tang, Lan

    2017-07-18

    Provided are isolated polypeptides having endoglucanase activity and isolated polynucleotides encoding the polypeptides. Also provided are nucleic acid constructs, vectors and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides.

  2. Polypeptides having cellobiohydrolase activity and polynucleotides encoding same

    Science.gov (United States)

    Spodsberg, Nikolaj

    2015-11-17

    The present invention relates to isolated polypeptides having cellobiohydrolase activity and polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides.

  3. Polypeptides having cellulolytic enhancing activity and polynucleotides encoding same

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Yu; Tang, Lan; Henriksen, Svend Hostgaard Bang

    2016-05-17

    The present invention provides isolated polypeptides having cellulolytic enhancing activity and isolated polynucleotides encoding the polypeptides. The invention also provides nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides.

  4. Polypeptides having xylanase activity and polynucleotides encoding same

    Energy Technology Data Exchange (ETDEWEB)

    Spodsberg, Nikolaj

    2017-05-02

    The present invention relates to isolated polypeptides having xylanase activity and polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides.

  5. Polypeptides having cellobiohydrolase activitiy and polynucleotides encoding same

    Science.gov (United States)

    Liu, Ye; Tang, Lan; Duan, Junxin

    2015-12-15

    The present invention provides isolated polypeptides having cellobiohydrolase activity and isolated polynucleotides encoding the polypeptides. The invention also provides nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides.

  6. Polypeptides having xylanase activity and polynucleotides encoding same

    Energy Technology Data Exchange (ETDEWEB)

    Spodsberg, Nikolaj

    2018-02-06

    The present invention relates to isolated polypeptides having xylanase activity and polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides.

  7. K1D1 METAR

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — METAR is a routine scheduled observation and is the primary observation code used in the United States to satisfy requirements for reporting surface meteorological...

  8. Preparation of polypeptides comprising multiple TAA peptides.

    Science.gov (United States)

    Ni, Bing; Jia, Zhengcai; Wu, Yuzhang

    2014-01-01

    Polypeptides consisting of multiple tumor-associated antigen epitopes (multiepitope peptides) are commonly used as therapeutic peptide cancer vaccines in experimental studies and clinical trials. These methods include polypeptides composed of multiple major histocompatibility complex (MHC) class I-restricted cytotoxic T cell (CTL) epitopes and those containing multiple CTL epitopes and one T helper (Th) epitope. This chapter describes a complete set of methods for preparing multiepitope peptides and branched multiple antigen peptides (MAPs), including sequence design, peptide synthesis, purification, preservation, and the preparation of polypeptide solutions.

  9. Tissue polypeptide antigen activity in cerebrospinal fluid

    DEFF Research Database (Denmark)

    Bach, F; Söletormos, Georg; Dombernowsky, P

    1991-01-01

    Tissue polypeptide antigen (TPpA) in the cerebrospinal fluid (CSF) was measured in 59 consecutive breast cancer patients with suspected central nervous system (CNS) metastases. Subsequently, we determined that 13 patients had parenchymal brain metastases, 10 had leptomeningeal carcinomatosis...

  10. Biolubricant Polypeptides and Therapeutic Uses Thereof

    NARCIS (Netherlands)

    Sharma, Prashant; Herrmann, Andreas; Kolbe, Anke; Veeregowda, Deepak; van der Mei, Henderina; Busscher, Hendrik

    2016-01-01

    The invention relates to the field of medicine. In particular, it relates to recombinant cationic polypeptides and their use as biolubricant. Provided is a biolubricant substance comprising the amino acid sequence[(GKGVP)9]n, wherein n is ≧5.

  11. Polypeptides having laccase activity and polynucleotides encoding same

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Ye; Tang, Lan; Duan, Junxin; Zhang, Yu

    2017-08-22

    The present invention relates to isolated polypeptides having laccase activity and polynucleotides encoding the polypeptides and polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides.

  12. Analysis of cyclins A, B1, D1 and E in breast cancer in relation to tumour grade and other prognostic factors

    Directory of Open Access Journals (Sweden)

    Collan Yrjö

    2009-07-01

    Full Text Available Abstract Background The cell cycle is promoted by activation of cyclin dependent kinases (Cdks, which are regulated positively by cyclins and negatively by Cdk inhibitors. Proliferation of carcinoma is associated with altered regulation of the cell cycle. Little is known on the combined alterations of cyclins A, B1, D1 and E in breast cancer in relation to the tumour grade and other prognostic factors. Findings Immunohistochemical analysis of cyclins A, B1, D1 and E, estrogen receptor, progesterone receptor, Ki-67, Her-2/neu and CK5/6 was performed on 53 breast carcinomas. mRNA levels of the cyclins were analysed of 12 samples by RT-PCR. The expression of cyclins A, B1 and E correlated with each other, while cyclin D1 correlated with none of these cyclins. Cyclins A, B1 and E showed association with tumour grade, Her-2/neu and Ki-67. Cyclin E had a negative correlation with hormone receptors and a positive correlation with triple negative carcinomas. Cyclin D1 had a positive correlation with ER, PR and non-basal breast carcinomas. Conclusion Cyclin A, B1 and E overexpression correlates to grade, Ki-67 and Her2/neu expression. Overexpression of cyclin D1 has a positive correlation with receptor status and non-basal carcinomas suggesting that cyclin D1 expression might be a marker of good prognosis. Combined analysis of cyclins indicates that cyclin A, B and E expression is similarly regulated, while other factors regulate cyclin D1 expression. The results suggest that the combined immunoreactivity of cyclins A, B1, D and E might be a useful prognostic factor in breast cancer.

  13. Coulomb repulsion in short polypeptides.

    Science.gov (United States)

    Norouzy, Amir; Assaf, Khaleel I; Zhang, Shuai; Jacob, Maik H; Nau, Werner M

    2015-01-08

    Coulomb repulsion between like-charged side chains is presently viewed as a major force that impacts the biological activity of intrinsically disordered polypeptides (IDPs) by determining their spatial dimensions. We investigated short synthetic models of IDPs, purely composed of ionizable amino acid residues and therefore expected to display an extreme structural and dynamic response to pH variation. Two synergistic, custom-made, time-resolved fluorescence methods were applied in tandem to study the structure and dynamics of the acidic and basic hexapeptides Asp6, Glu6, Arg6, Lys6, and His6 between pH 1 and 12. (i) End-to-end distances were obtained from the short-distance Förster resonance energy transfer (sdFRET) from N-terminal 5-fluoro-l-tryptophan (FTrp) to C-terminal Dbo. (ii) End-to-end collision rates were obtained for the same peptides from the collision-induced fluorescence quenching (CIFQ) of Dbo by FTrp. Unexpectedly, the very high increase of charge density at elevated pH had no dynamical or conformational consequence in the anionic chains, neither in the absence nor in the presence of salt, in conflict with the common view and in partial conflict with accompanying molecular dynamics simulations. In contrast, the cationic peptides responded to ionization but with surprising patterns that mirrored the rich individual characteristics of each side chain type. The contrasting results had to be interpreted, by considering salt screening experiments, N-terminal acetylation, and simulations, in terms of an interplay of local dielectric constant and peptide-length dependent side chain charge-charge repulsion, side chain functional group solvation, N-terminal and side chain charge-charge repulsion, and side chain-side chain as well as side chain-backbone interactions. The common picture that emerged is that Coulomb repulsion between water-solvated side chains is efficiently quenched in short peptides as long as side chains are not in direct contact with each

  14. Carbohydrate degrading polypeptide and uses thereof

    Science.gov (United States)

    Sagt, Cornelis Maria Jacobus; Schooneveld-Bergmans, Margot Elisabeth Francoise; Roubos, Johannes Andries; Los, Alrik Pieter

    2015-10-20

    The invention relates to a polypeptide having carbohydrate material degrading activity which comprises the amino acid sequence set out in SEQ ID NO: 2 or an amino acid sequence encoded by the nucleotide sequence of SEQ ID NO: 1 or SEQ ID NO: 4, or a variant polypeptide or variant polynucleotide thereof, wherein the variant polypeptide has at least 96% sequence identity with the sequence set out in SEQ ID NO: 2 or the variant polynucleotide encodes a polypeptide that has at least 96% sequence identity with the sequence set out in SEQ ID NO: 2. The invention features the full length coding sequence of the novel gene as well as the amino acid sequence of the full-length functional protein and functional equivalents of the gene or the amino acid sequence. The invention also relates to methods for using the polypeptide in industrial processes. Also included in the invention are cells transformed with a polynucleotide according to the invention suitable for producing these proteins.

  15. Anharmonic Theoretical Vibrational Spectroscopy of Polypeptides.

    Science.gov (United States)

    Panek, Paweł T; Jacob, Christoph R

    2016-08-18

    Because of the size of polypeptides and proteins, the quantum-chemical prediction of their vibrational spectra presents an exceptionally challenging task. Here, we address one of these challenges, namely, the inclusion of anharmonicities. By performing the expansion of the potential energy surface in localized-mode coordinates instead of the normal-mode coordinates, it becomes possible to calculate anharmonic vibrational spectra of polypeptides efficiently and reliably. We apply this approach to calculate the infrared, Raman, and Raman optical activity spectra of helical alanine polypeptides consisting of up to 20 amino acids. We find that while anharmonicities do not alter the band shapes, simple scaling procedures cannot account for the different shifts found for the individual bands. This closes an important gap in theoretical vibrational spectroscopy by making it possible to quantify the anharmonic contributions and opens the door to a first-principles calculation of multidimensional vibrational spectra.

  16. Ribosomal L1 domain and lysine-rich region are essential for CSIG/ RSL1D1 to regulate proliferation and senescence

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Liwei; Zhao, Wenting; Zheng, Quanhui; Chen, Tianda; Qi, Ji; Li, Guodong; Tong, Tanjun, E-mail: tztong@bjmu.edu.cn

    2016-01-15

    The expression change of cellular senescence-associated genes is underlying the genetic foundation of cellular senescence. Using a suppressive subtractive hybridization system, we identified CSIG (cellular senescence-inhibited gene protein; RSL1D1) as a novel senescence-associated gene. CSIG is implicated in various process including cell cycle regulation, apoptosis, and tumor metastasis. We previously showed that CSIG plays an important role in regulating cell proliferation and cellular senescence progression through inhibiting PTEN, however, which domain or region of CSIG contributes to this function? To clarify this question, we investigated the functional importance of ribosomal L1 domain and lysine (Lys) -rich region of CSIG. The data showed that expression of CSIG potently reduced PTEN expression, increased cell proliferation rates, and reduced the senescent phenotype (lower SA-β-gal activity). By contrast, neither the expression of CSIG N- terminal (NT) fragment containing the ribosomal L1 domain nor C-terminal (CT) fragment containing Lys-rich region could significantly altered the levels of PTEN; instead of promoting cell proliferation and delaying cellular senescence, expression of CSIG-NT or CSIG-CT inhibited cell proliferation and accelerated cell senescence (increased SA-β-gal activity) compared to either CSIG over-expressing or control (empty vector transfected) cells. The further immunofluorescence analysis showed that CSIG-CT and CSIG-NT truncated proteins exhibited different subcellular distribution with that of wild-type CSIG. Conclusively, both ribosomal L1 domain and Lys-rich region of CSIG are critical for CSIG to act as a regulator of cell proliferation and cellular senescence. - Highlights: • The ribosomal L1 domain and lysine-rich region of CSIG were expressed. • They are critical for CSIG to regulate proliferation and senescence. • CSIG and its domains exhibit different subcellular distribution.

  17. Ribosomal L1 domain and lysine-rich region are essential for CSIG/ RSL1D1 to regulate proliferation and senescence

    International Nuclear Information System (INIS)

    Ma, Liwei; Zhao, Wenting; Zheng, Quanhui; Chen, Tianda; Qi, Ji; Li, Guodong; Tong, Tanjun

    2016-01-01

    The expression change of cellular senescence-associated genes is underlying the genetic foundation of cellular senescence. Using a suppressive subtractive hybridization system, we identified CSIG (cellular senescence-inhibited gene protein; RSL1D1) as a novel senescence-associated gene. CSIG is implicated in various process including cell cycle regulation, apoptosis, and tumor metastasis. We previously showed that CSIG plays an important role in regulating cell proliferation and cellular senescence progression through inhibiting PTEN, however, which domain or region of CSIG contributes to this function? To clarify this question, we investigated the functional importance of ribosomal L1 domain and lysine (Lys) -rich region of CSIG. The data showed that expression of CSIG potently reduced PTEN expression, increased cell proliferation rates, and reduced the senescent phenotype (lower SA-β-gal activity). By contrast, neither the expression of CSIG N- terminal (NT) fragment containing the ribosomal L1 domain nor C-terminal (CT) fragment containing Lys-rich region could significantly altered the levels of PTEN; instead of promoting cell proliferation and delaying cellular senescence, expression of CSIG-NT or CSIG-CT inhibited cell proliferation and accelerated cell senescence (increased SA-β-gal activity) compared to either CSIG over-expressing or control (empty vector transfected) cells. The further immunofluorescence analysis showed that CSIG-CT and CSIG-NT truncated proteins exhibited different subcellular distribution with that of wild-type CSIG. Conclusively, both ribosomal L1 domain and Lys-rich region of CSIG are critical for CSIG to act as a regulator of cell proliferation and cellular senescence. - Highlights: • The ribosomal L1 domain and lysine-rich region of CSIG were expressed. • They are critical for CSIG to regulate proliferation and senescence. • CSIG and its domains exhibit different subcellular distribution.

  18. GLYCOSYLATED YGHJ POLYPEPTIDES FROM ENTEROTOXIGENIC ESCHERICHIA COLI (ETEC)

    DEFF Research Database (Denmark)

    2017-01-01

    The present invention relates to glycosylated YghJ polypeptides from or derived from enterotoxigenic Escherichia coli (ETEC) that are immunogenic. In particular, the present invention relates to compositions or vaccines comprising the polypeptides and their application in immunization, vaccination...

  19. Polypeptide electrophoretic pattern of Matricaria chamomilla and ...

    African Journals Online (AJOL)

    In order to study the effects of salinity and Fe-deficiency on electrophoresis pattern of polypeptides in two chamomile genera (Matricaria chamomilla and Anthemis nobilis), a factorial experiment was conducted based on completely randomized block design with three replications, in 2010. The experimental factors were two ...

  20. Recombinant Supercharged Polypeptides Restore and Improve Biolubrication

    NARCIS (Netherlands)

    Veeregowda, Deepak H.; Kolbe, Anke; van der Mei, Henny C.; Busscher, Henk J.; Herrmann, Andreas; Sharma, Prashant K.

    2013-01-01

    Recombinant supercharged polypeptides (SUPs) with low cytotoxicity are developed and applied to rejuvenate the lubrication of naturally occurring salivary conditioning films (SCFs). SUPs with 72 positive charges adsorbed and rigidified the SCFs and recruited mucins to form a hydrated layer. These

  1. Tuning Ice Nucleation with Supercharged Polypeptides

    NARCIS (Netherlands)

    Yang, Huige; Ma, Chao; Li, Kaiyong; Liu, Kai; Loznik, Mark; Teeuwen, Rosalie; van Hest, Jan C. M.; Zhou, Xin; Herrmann, Andreas; Wang, Jianjun

    2016-01-01

    Supercharged unfolded polypeptides (SUPs) are exploited for controlling ice nucleation via tuning the nature of charge and charge density of SUPs. The results show that positively charged SUPs facilitate ice nucleation, while negatively charged ones suppress it. Moreover, the charge density of the

  2. Endogenous pancreatic polypeptide in different vascular beds

    DEFF Research Database (Denmark)

    Henriksen, J H; Schwartz, Tania; Bülow, J B

    1986-01-01

    The plasma concentration of pancreatic polypeptide (PP-like immunoreactivity) was measured in different vascular beds in order to determine regional kinetics of endogenous PP in fasting, supine subjects with normal or moderately decreased kidney function. Patients with kidney disease (n = 10) had...

  3. Polypeptides having xylanase activity and polynucleotides encoding same

    Energy Technology Data Exchange (ETDEWEB)

    Spodsberg, Nikolaj; Shaghasi, Tarana

    2017-06-20

    The present invention relates to polypeptides having xylanase activity, catalytic domains, and carbohydrate binding domains, and polynucleotides encoding the polypeptides, catalytic domains, and carbohydrate binding domains. The present invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides, catalytic domains, and carbohydrate binding domains.

  4. Polypeptides having endoglucanase activity and polynucleotides encoding same

    Science.gov (United States)

    Spodsberg, Nikolaj

    2016-02-23

    The present invention relates to isolated polypeptides having endoglucanase activity and isolated polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides.

  5. Polypeptides having cellulolytic enhancing activity and polynucleotides encoding same

    Science.gov (United States)

    Schnorr, Kirk; Kramer, Randall

    2016-04-05

    The present invention relates to isolated polypeptides having cellulolytic enhancing activity and isolated polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides.

  6. Polypeptides having beta-glucosidase activity and polynucleotides encoding same

    Science.gov (United States)

    Harris, Paul; Golightly, Elizabeth

    2007-07-17

    The present invention relates to isolated polypeptides having beta-glucosidase activity and isolated polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods for producing and using the polypeptides.

  7. Polypeptides having cellulolytic enhancing activity and polynucleotides encoding same

    Energy Technology Data Exchange (ETDEWEB)

    Schnorr, Kirk; Kramer, Randall

    2017-08-08

    The present invention relates to isolated polypeptides having cellulolytic enhancing activity and isolated polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides.

  8. Polypeptides having beta-xylosidase activity and polynucleotides encoding same

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Yu; Liu, Ye; Duan, Junxin; Tang, Lan; McBrayer, Brett

    2017-07-04

    The present invention relates to isolated polypeptides having beta-xylosidase activity and polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides.

  9. Polypeptides having xylanase activity and polynucleotides encoding same

    Energy Technology Data Exchange (ETDEWEB)

    Lopez de Leon, Alfredo; Rey, Michael

    2017-09-26

    The present invention relates to isolated polypeptides having xylanase activity and isolated polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides.

  10. Polypeptides having cellobiohydrolase activity and polynucleotides encoding same

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Ye; Tang, Lan; Duan, Junxin

    2017-02-07

    The present invention relates to isolated polypeptides having cellobiohydrolase activity and isolated polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides.

  11. Polypeptides having cellulolytic enhancing activity and polynucleotides encoding the same

    Science.gov (United States)

    Duan, Junxin; Schnorr, Kirk Matthew; Wu, Wenping

    2013-11-19

    The present invention relates to isolated polypeptides having cellulolytic enhancing activity and isolated polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides.

  12. Chimeric polypeptides having cellulolytic enhancing activity and polynucleotides encoding same

    Science.gov (United States)

    Wogulis, Mark; Sweeney, Matthew; Heu, Tia

    2017-06-14

    The present invention relates to chimeric GH61 polypeptides having cellulolytic enhancing activity. The present invention also relates to polynucleotides encoding the chimeric GH61 polypeptides; nucleic acid constructs, vectors, and host cells comprising the polynucleotides; and methods of using the chimeric GH61 polypeptides.

  13. Polypeptides having cellobiohydrolase activity and polynucleotides encoding same

    Energy Technology Data Exchange (ETDEWEB)

    Stringer, Mary Ann; McBrayer, Brett

    2016-11-29

    The present invention relates to isolated polypeptides having cellobiohydrolase activity, catalytic domains, and cellulose binding domains and polynucleotides encoding the polypeptides, catalytic domains, and cellulose binding domains. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides, catalytic domains, or cellulose binding domains.

  14. Polypeptides having cellulolytic enhancing activity and polynucleotides encoding same

    Energy Technology Data Exchange (ETDEWEB)

    Tang, Lan; Liu, Ye; Duan, Junxin; Zhang, Yu; Joergensen, Christian; Kramer, Randall

    2016-11-29

    The present invention relates to isolated polypeptides having cellulolytic enhancing activity and isolated polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides.

  15. Polypeptides having xylanase activity and polynucleotides encoding same

    Science.gov (United States)

    Tang, Lan; Liu, Ye; Duan, Junxin; Hanshu, Ding

    2012-10-30

    The present invention relates to isolated polypeptides having xylanase activity and isolated polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides.

  16. Polynucleotides encoding polypeptides having beta-glucosidase activity

    Science.gov (United States)

    Harris, Paul; Golightly, Elizabeth

    2010-03-02

    The present invention relates to isolated polypeptides having beta-glucosidase activity and isolated polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods for producing and using the polypeptides.

  17. Polypeptides having cellulolytic enhancing activity and polynucleotides encoding same

    Science.gov (United States)

    Maiyuran, Suchindra; Kramer, Randall; Harris, Paul

    2013-10-29

    The present invention relates to isolated polypeptides having cellulolytic enhancing activity and isolated polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides.

  18. Polypeptides having cellulolytic enhancing activity and polynucleotides encoding same

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Yu; Duan, Junxin; Tang, Lan; Wu, Wenping

    2016-11-22

    The present invention relates to isolated polypeptides having cellulolytic enhancing activity and isolated polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides.

  19. Polypeptides having cellulolytic enhancing activity and nucleic acids encoding same

    Science.gov (United States)

    Brown, Kimberly; Harris, Paul; Zaretsky, Elizabeth; Re, Edward; Vlasenko, Elena; McFarland, Keith; Lopez de Leon, Alfredo

    2012-10-16

    The present invention relates to isolated polypeptides having cellulolytic enhancing activity and isolated polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods for producing and using the polypeptides.

  20. Polypeptides having xylanase activity and polynucleotides encoding same

    Energy Technology Data Exchange (ETDEWEB)

    Lopez de Leon, Alfredo; Rey, Michael

    2016-05-31

    The present invention relates to isolated polypeptides having xylanase activity and isolated polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides.

  1. Polypeptides having cellulolytic enhancing activity and polynucleotides encoding same

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Yu; Duan, Junxin; Tang, Lan; Wu, Wenping

    2016-06-14

    The present invention relates to isolated polypeptides having cellulolytic enhancing activity and isolated polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides.

  2. Polypeptides having cellulolytic enhancing activity and polynucleotides encoding same

    Energy Technology Data Exchange (ETDEWEB)

    Tang, Lan; Liu, Ye; Duan, Junxin; Wu, Wenping; Kramer, Randall

    2017-09-19

    The present invention relates to isolated polypeptides having cellulolytic enhancing activity and isolated polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides.

  3. Polypeptides having endoglucanase activity and polynucleotides encoding same

    Energy Technology Data Exchange (ETDEWEB)

    Spodsberg, Nikolaj; Shagasi, Tarana

    2017-05-30

    The present invention relates to isolated polypeptides having endoglucanase activity, catalytic domains, cellulose binding domains and polynucleotides encoding the polypeptides, catalytic domains or cellulose binding domains. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides, catalytic domains or cellulose binding domains.

  4. Polypeptides having endoglucanase activity and polynucleotides encoding same

    Science.gov (United States)

    Harris, Paul; Lopez de Leon, Alfredo; Rey, Michael; Ding, Hanshu; Vlasenko, Elena

    2010-11-02

    The present invention relates to isolated polypeptides having endoglucanase activity and isolated polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods for producing and using the polypeptides.

  5. Polypeptides having cellulolytic enhancing activity and nucleic acids encoding same

    Energy Technology Data Exchange (ETDEWEB)

    Brown, Kimberly; Harris, Paul; Zaretsky, Elizabeth; Re, Edward; Vlasenko, Elena; McFarland, Keith; Lopez de Leon, Alfredo

    2016-08-09

    The present invention relates to isolated polypeptides having cellulolytic enhancing activity and isolated polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods for producing and using the polypeptides.

  6. Polypeptides having cellulolytic enhancing activity and nucleic acids encoding same

    Energy Technology Data Exchange (ETDEWEB)

    Brown, Kimberly; Harris, Paul; Zaretsky, Elizabeth; Re, Edward; Vlasenko, Elena; McFarland, Keith; Lopez de Leon, Alfredo

    2017-09-05

    The present invention relates to isolated polypeptides having cellulolytic enhancing activity and isolated polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods for producing and using the polypeptides.

  7. Polypeptides having cellulolytic enhancing activity and polynucleotides encoding same

    Energy Technology Data Exchange (ETDEWEB)

    Schnorr, Kirk; Kramer, Randall

    2016-08-09

    The present invention relates to isolated polypeptides having cellulolytic enhancing activity and isolated polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides.

  8. Polypeptides having xylanase activity and polynucleotides encoding the same

    Science.gov (United States)

    Spodsberg, Nikolaj [Bagsvaed, DK

    2014-01-07

    The present invention relates to isolated polypeptides having xylanase activity and isolated polynucleotides encoding the polypeptides. The inventino also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides.

  9. Polypeptides having beta-glucosidase activity and polynucleotides encoding same

    Science.gov (United States)

    Morant, Marc Dominique

    2014-10-14

    The present invention relates to isolated polypeptides having beta-glucosidase activity, beta-xylosidase activity, or beta-glucosidase and beta-xylosidase activity and isolated polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides.

  10. Polypeptide from a cellulolytic fungus having cellulolytic enhancing activity

    Science.gov (United States)

    Brown, Kimberly [Elk Grove, CA; Harris, Paul [Carnation, WA; Zaretsky, Elizabeth [Reno, NV; Re, Edward [Davis, CA; Vlasenko, Elena [Davis, CA; McFarland, Keith [Davis, CA; Lopez de Leon, Alfredo [Davis, CA

    2008-04-22

    The present invention relates to isolated polypeptides having cellulolytic enhancing activity and isolated polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods for producing and using the polypeptides.

  11. Polypeptides having endoglucanase activity and polynucleotides encoding same

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Yu; Liu, Ye; Duan, Junxin; Tang, Lan

    2018-01-30

    The present invention relates to isolated polypeptides having endoglucanase activity and isolated polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides.

  12. Measles virus polypeptides in purified virions and in infected cells

    International Nuclear Information System (INIS)

    Vainionpaeae, R.; Ziola, B.; Salmi, A.

    1978-01-01

    A wild-type measles virus was radiolabeled during growth in VERO cells and purified by two successive potassium tartrate gradient centrifugations. The virion polypeptide composition was determined by SDS-polyacrylamide gel electrophoresis employing two different buffer systems. Six virus-specific polypeptides were consistently detected. The largest (L) had a molecular weight (MW) of greater than 150,000. The second largest polypeptide, G (MW 79,000), was the only glycoprotein found. The proteins designated polypeptide 2 (MW 66 to 70,000) and nucleocapsid protein or NP (MW 61,000) were phosphorylated. The remaining virus-coded proteins were polypeptide 5 (MW 40,000) and the matrix or M protein (MW 37,000). Measles virions also contained a polypeptide (MW 42,000) thought to be actin due to co-migration with this component of uninfected cells. Analysis of in vitro 3 H-acetic anhydride radiolabeled virions confirmed the presence of these seven polypeptides. Acetic anhydride also labeled a protein designated polypeptide 4 (MW 53,000) which was not consistently radiolabeled in vivo, as well as several other minor proteins believed to be cellular in origin. Synthesis of the six virus-specific structural polypeptides was detected in lysates of infected cells by SDS-polyacrylamide slab gel electrophoresis. Virus specificity of polypeptide 4 could not be confirmed due to the similar MW of several cellular polypeptides. Two non-virion, but virus-specified polypeptides, of MW 38,000 and 18,000 were also detected. Synthesis of the virus structural proteins was in the same proportions as the polypeptides found in virions except for under production of polypeptide G and over production of polypeptide 2. (author)

  13. POLYPEPTIDE AND POLYSACCHARIDE PROCESSING IN HYPERTHERMOPHILIC MICROORGANISMS

    Energy Technology Data Exchange (ETDEWEB)

    KELLY, ROBERT M.

    2008-12-22

    This project focused on the microbial physiology and biochemistry of heterotrophic hyperthermophiles with respect to mechanisms by which these organisms process polypeptides and polysaccharides under normal and stressed conditions. Emphasis is on two model organisms, for which completed genome sequences are available: Pyrococcus furiosus (growth Topt of 98°C), an archaeon, and Thermotoga maritima (growth Topt of 80°C), a bacterium. Both organisms are obligately anaerobic heterotrophs that reduce sulfur facultatively. Whole genome cDNA spotted microarrays were used to follow transcriptional response to a variety of environmental conditions in order to identify genes encoding proteins involved in the acquisition, synthesis, processing and utilization of polypeptides and polysaccharides. This project provided new insights into the physiological aspects of hyperthermophiles as these relate to microbial biochemistry and biological function in high temperature habitats. The capacity of these microorganisms to produce biohydrogen from renewable feedstocks makes them important for future efforts to develop biofuels.

  14. Nanostructured complexes of polyelectrolytes and charged polypeptides

    Czech Academy of Sciences Publication Activity Database

    Müller, M.; Ouyang, W.; Bohatá, Karolína; Kessler, B.

    2010-01-01

    Roč. 12, Sp. Iss. 9 (2010), B519-B528 ISSN 1438-1656. [Sino-German Symposium on Advanced Biomedical Nanostructures /1./. Jena, 26.10.2009-30.10.2009] Institutional research plan: CEZ:AV0Z40500505 Keywords : situ ATR-FTIR * alpha-helical polypeptides * multilayer films Subject RIV: CD - Macromolecular Chemistry Impact factor: 1.746, year: 2010

  15. Improved docking of polypeptides with Glide.

    Science.gov (United States)

    Tubert-Brohman, Ivan; Sherman, Woody; Repasky, Matt; Beuming, Thijs

    2013-07-22

    Predicting the binding mode of flexible polypeptides to proteins is an important task that falls outside the domain of applicability of most small molecule and protein-protein docking tools. Here, we test the small molecule flexible ligand docking program Glide on a set of 19 non-α-helical peptides and systematically improve pose prediction accuracy by enhancing Glide sampling for flexible polypeptides. In addition, scoring of the poses was improved by post-processing with physics-based implicit solvent MM-GBSA calculations. Using the best RMSD among the top 10 scoring poses as a metric, the success rate (RMSD ≤ 2.0 Å for the interface backbone atoms) increased from 21% with default Glide SP settings to 58% with the enhanced peptide sampling and scoring protocol in the case of redocking to the native protein structure. This approaches the accuracy of the recently developed Rosetta FlexPepDock method (63% success for these 19 peptides) while being over 100 times faster. Cross-docking was performed for a subset of cases where an unbound receptor structure was available, and in that case, 40% of peptides were docked successfully. We analyze the results and find that the optimized polypeptide protocol is most accurate for extended peptides of limited size and number of formal charges, defining a domain of applicability for this approach.

  16. Conversion of Human Steroid 5[beta]-Reductase (AKR1D1) into 3[beta]-Hydroxysteroid Dehydrogenase by Single Point Mutation E120H: Example of Perfect Enzyme Engineering

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Mo; Drury, Jason E.; Christianson, David W.; Penning, Trevor M. (UPENN)

    2012-10-10

    Human aldo-keto reductase 1D1 (AKR1D1) and AKR1C enzymes are essential for bile acid biosynthesis and steroid hormone metabolism. AKR1D1 catalyzes the 5{beta}-reduction of {Delta}{sup 4}-3-ketosteroids, whereas AKR1C enzymes are hydroxysteroid dehydrogenases (HSDs). These enzymes share high sequence identity and catalyze 4-pro-(R)-hydride transfer from NADPH to an electrophilic carbon but differ in that one residue in the conserved AKR catalytic tetrad, His120 (AKR1D1 numbering), is substituted by a glutamate in AKR1D1. We find that the AKR1D1 E120H mutant abolishes 5{beta}-reductase activity and introduces HSD activity. However, the E120H mutant unexpectedly favors dihydrosteroids with the 5{alpha}-configuration and, unlike most of the AKR1C enzymes, shows a dominant stereochemical preference to act as a 3{beta}-HSD as opposed to a 3{alpha}-HSD. The catalytic efficiency achieved for 3{beta}-HSD activity is higher than that observed for any AKR to date. High resolution crystal structures of the E120H mutant in complex with epiandrosterone, 5{beta}-dihydrotestosterone, and {Delta}{sup 4}-androstene-3,17-dione elucidated the structural basis for this functional change. The glutamate-histidine substitution prevents a 3-ketosteroid from penetrating the active site so that hydride transfer is directed toward the C3 carbonyl group rather than the {Delta}{sup 4}-double bond and confers 3{beta}-HSD activity on the 5{beta}-reductase. Structures indicate that stereospecificity of HSD activity is achieved because the steroid flips over to present its {alpha}-face to the A-face of NADPH. This is in contrast to the AKR1C enzymes, which can invert stereochemistry when the steroid swings across the binding pocket. These studies show how a single point mutation in AKR1D1 can introduce HSD activity with unexpected configurational and stereochemical preference.

  17. Polypeptide having carbohydrate degrading activity and uses thereof

    Science.gov (United States)

    Schooneveld-Bergmans, Margot Elisabeth Francoise; Heijne, Wilbert Herman Marie; Vlasie, Monica Diana; Damveld, Robbertus Antonius

    2015-08-18

    The invention relates to a polypeptide comprising the amino acid sequence set out in SEQ ID NO: 2 or an amino acid sequence encoded by the nucleotide sequence of SEQ ID NO: 1, or a variant polypeptide or variant polynucleotide thereof, wherein the variant polypeptide has at least 73% sequence identity with the sequence set out in SEQ ID NO: 2 or the variant polynucleotide encodes a polypeptide that has at least 73% sequence identity with the sequence set out in SEQ ID NO: 2. The invention features the full length coding sequence of the novel gene as well as the amino acid sequence of the full-length functional polypeptide and functional equivalents of the gene or the amino acid sequence. The invention also relates to methods for using the polypeptide in industrial processes. Also included in the invention are cells transformed with a polynucleotide according to the invention suitable for producing these proteins.

  18. Polypeptide having acetyl xylan esterase activity and uses thereof

    Energy Technology Data Exchange (ETDEWEB)

    Schoonneveld-Bergmans, Margot Elisabeth Francoise; Heijne, Wilbert Herman Marie; Los, Alrik Pieter

    2015-10-20

    The invention relates to a polypeptide comprising the amino acid sequence set out in SEQ ID NO: 2 or an amino acid sequence encoded by the nucleotide sequence of SEQ ID NO: 1, or a variant polypeptide or variant polynucleotide thereof, wherein the variant polypeptide has at least 82% sequence identity with the sequence set out in SEQ ID NO: 2 or the variant polynucleotide encodes a polypeptide that has at least 82% sequence identity with the sequence set out in SEQ ID NO: 2. The invention features the full length coding sequence of the novel gene as well as the amino acid sequence of the full-length functional polypeptide and functional equivalents of the gene or the amino acid sequence. The invention also relates to methods for using the polypeptide in industrial processes. Also included in the invention are cells transformed with a polynucleotide according to the invention suitable for producing these proteins.

  19. Thermophilic and thermoacidophilic sugar transporter genes and enzymes from Alicyclobacillus acidocaldarius and related organisms, methods

    Science.gov (United States)

    Thompson, David N.; Apel, William A.; Thompson, Vicki S.; Reed, David W.; Lacey, Jeffrey A.

    2013-01-29

    Isolated and/or purified polypeptides and nucleic acid sequences encoding polypeptides from Alicyclobacillus acidocaldarius are provided. Further provided are methods for transporting sugars across cell membranes using isolated and/or purified polypeptides and nucleic acid sequences from Alicyclobacillus acidocaldarius.

  20. Ordered Nanostructures Made Using Chaperonin Polypeptides

    Science.gov (United States)

    Trent, Jonathan; McMillan, Robert; Paavola, Chad; Mogul, Rakesh; Kagawa, Hiromi

    2004-01-01

    A recently invented method of fabricating periodic or otherwise ordered nanostructures involves the use of chaperonin polypeptides. The method is intended to serve as a potentially superior and less expensive alternative to conventional lithographic methods for use in the patterning steps of the fabrication of diverse objects characterized by features of the order of nanometers. Typical examples of such objects include arrays of quantum dots that would serve as the functional building blocks of future advanced electronic and photonic devices. A chaperonin is a double-ring protein structure having a molecular weight of about 60 plus or minus 5 kilodaltons. In nature, chaperonins are ubiquitous, essential, subcellular structures. Each natural chaperonin molecule comprises 14, 16, or 18 protein subunits, arranged as two stacked rings approximately 16 to 18 nm tall by approximately 15 to 17 nm wide, the exact dimensions depending on the biological species in which it originates. The natural role of chaperonins is unknown, but they are believed to aid in the correct folding of other proteins, by enclosing unfolded proteins and preventing nonspecific aggregation during assembly. What makes chaperonins useful for the purpose of the present method is that under the proper conditions, chaperonin rings assemble themselves into higher-order structures. This method exploits such higher-order structures to define nanoscale devices. The higher-order structures are tailored partly by choice of chemical and physical conditions for assembly and partly by using chaperonins that have been mutated. The mutations are made by established biochemical techniques. The assembly of chaperonin polypeptides into such structures as rings, tubes, filaments, and sheets (two-dimensional crystals) can be regulated chemically. Rings, tubes, and filaments of some chaperonin polypeptides can, for example, function as nano vessels if they are able to absorb, retain, protect, and release gases or

  1. Phase transitions in polypeptides: analysis of energy fluctuations

    DEFF Research Database (Denmark)

    Yakubovich, Alexander V.; Solov'yov, Ilia; Solov'yov, Andrey V.

    2009-01-01

    The helix random coil transition in alanine, valine, and leucine polypeptides consisting of 30 amino acids is studied in vacuo using the Langevin molecular dynamics approach. The influence of side chain radicals on internal energy and heat capacity of the polypeptides is discussed. The heat...... capacity of these polypeptides is calculated as a function of temperature using two different methods, namely, as the derivative of the energy with respect to temperature, and on the basis of energy fluctuations in the system. The convergence of the fluctuations based approach is analyzed as a function...... of simulation time. This study provides a comparison of methods for the description of structural transitions in polypeptides....

  2. [New drug developments of snake venom polypeptides and progress].

    Science.gov (United States)

    Fu, Sihai; Feng, Mei; Xiong, Yan

    2017-11-28

    The value of snake venom polypeptides in clinical application has drawn extensive attention, and the development of snake polypeptides into new drugs with anti-tumor, anti-inflammatory, antithrombotic, analgesic or antihypertensive properties has become the recent research hotspot. With the rapid development of molecular biology and biotechnology, the mechanisms of snake venom polypeptides are also gradually clarified. Numerous studies have demonstrated that snake venom polypeptides exert their pharmacological effects by regulating ion channels, cell proliferation, apoptosis, intracellular signaling pathway, and expression of cytokine as well as binding to relevant active sites or receptors.

  3. Detection of Specific Polypeptide(s Synthesized during the Sequential Stages of Differentiation in Dioscorea species

    Directory of Open Access Journals (Sweden)

    Ashwani Kumar

    2015-10-01

    Full Text Available ABSTRACTThe present investigation was aimed to detect the specific polypeptide(s appeared during the sequential stages of differentiation. Among different explants, only nodal explants showed good results for callusing. Depending on the fresh and dry weight, best callus growth was observed on MS medium supplemented with NAA (2.5 mg/L inDioscorea alata and 2, 4-D (2.0 mg/L inD. deltoidea, respectively. This callus was used for the regeneration. Roots differentiation was observed on MS medium + NAA (2.0 mg/L + IBA (0.5 mg/L and shoots on MS medium + BAP (2.0 mg/L + NAA (0.5 mg/L in D. alata while in D. deltoidea, roots on RT medium + IAA (1.0 mg/L and shoots on RT medium + BAP (1.0 mg/L + NAA (0.5 mg/L. Continuous decrease was seen in the total soluble protein during the differentiation inD. alatawhereas inD. deltoidea, the protein content decreased upto initiation stage. Four root specific polypeptides (MW 25.56, 24.35, 19.13 and 18.2 kDa and three shoot specific polypeptides (MW 53.7, 25.12 and 19.13 kDa were synthesized during the differentiation inD. alata. Similarly, two root specific (MW 33.9 and 31.69 kDa and one shoot specific (MW 16.98 kDa polypeptide band were appeared during differentiation in D. deltoidea.

  4. Nuclear localization and function of polypeptide ligands and their receptors: a new paradigm for hormone specificity within the mammary gland?

    International Nuclear Information System (INIS)

    Clevenger, Charles V

    2003-01-01

    The specific effects triggered by polypeptide hormone/growth factor stimulation of mammary cells were considered mediated solely by receptor-associated signaling networks. A compelling body of new data, however, clearly indicates that polypeptide ligands and/or their receptors are transported into the nucleus, where they function directly to regulate the expression of specific transcription factors and gene loci. The intranuclear function of these complexes may contribute to the explicit functions associated with a given ligand, and may serve as new targets for pharmacologic intervention

  5. In vitro and in vivo phosphorylation of polypeptides in plasma membrane and tonoplast-enriched fractions from barley roots

    International Nuclear Information System (INIS)

    Garbarino, J.E.; Hurkman, W.J.; Tanaka, C.K.; DuPont, F.M.

    1991-01-01

    Phosphorylation of polypeptides in membrane fractions from barley (Hordeum vulgare L. cv CM 72) roots was compared in in vitro and in vivo assays to assess the potential role of protein kinases in modification of membrane transport. Membrane fractions enriched in endoplasmic reticulum, tonoplast, and plasma membrane were isolated using sucrose gradients and the membrane polypeptides separated using sodium dodecyl sulfate polyacrylamide gel electrophoresis. When the membrane fractions were incubated with γ[p 32 P]ATP, phosphorylation occurred almost exclusively in the plasma membrane fraction. Phosphorylation of a band at 38 kilodaltons increased as the concentration of Mg 2+ was decreased from millimolar to micromolar levels. Phosphorylation of bands at 125, 86, 58, 46 and 28 kilodaltons required millimolar Mg 2+ concentrations and was greatly enhanced by Ca 2+ . When roots of intact plants were labeled with [ 32 P]orthophosphate, polypeptides at approximately 135, 166, 90, 46 to 53, 32, 28, and 19 kilodaltons were labeled in the plasma membrane fraction and polypeptides at approximately 73, 66, and 48 kilodaltons were labeled in the tonoplast fraction. Treatment of the roots of intact plants with 150 millimolar NaCl resulted in increased phosphorylation of some polypeptides while treatment with 100 mM NaCl had no effect

  6. Interaction of ApoA-IV with NR4A1 and NR1D1 Represses G6Pase and PEPCK Transcription: Nuclear Receptor-Mediated Downregulation of Hepatic Gluconeogenesis in Mice and a Human Hepatocyte Cell Line.

    Science.gov (United States)

    Li, Xiaoming; Xu, Min; Wang, Fei; Ji, Yong; DavidsoN, W Sean; Li, Zongfang; Tso, Patrick

    2015-01-01

    We have previously shown that the nuclear receptor, NR1D1, is a cofactor in ApoA-IV-mediated downregulation of gluconeogenesis. Nuclear receptor, NR4A1, is involved in the transcriptional regulation of various genes involved in inflammation, apoptosis, and glucose metabolism. We investigated whether NR4A1 influences the effect of ApoA-IV on hepatic glucose metabolism. Our in situ proximity ligation assays and coimmunoprecipitation experiments indicated that ApoA-IV colocalized with NR4A1 in human liver (HepG2) and kidney (HEK-293) cell lines. The chromatin immunoprecipitation experiments and luciferase reporter assays indicated that the ApoA-IV and NR4A1 colocalized at the RORα response element of the human G6Pase promoter, reducing its transcriptional activity. Our RNA interference experiments showed that knocking down the expression of NR4A1 in primary mouse hepatocytes treated with ApoA-IV increased the expression of NR1D1, G6Pase, and PEPCK, and that knocking down NR1D1 expression increased the level of NR4A1. We also found that ApoA-IV induced the expression of endogenous NR4A1 in both cultured primary mouse hepatocytes and in the mouse liver, and decreased glucose production in primary mouse hepatocytes. Our findings showed that ApoA-IV colocalizes with NR4A1, which suppresses G6Pase and PEPCK gene expression at the transcriptional level, reducing hepatic glucose output and lowering blood glucose. The ApoA-IV-induced increase in NR4A1 expression in hepatocytes mediates further repression of gluconeogenesis. Our findings suggest that NR1D1 and NR4A1 serve similar or complementary functions in the ApoA-IV-mediated regulation of gluconeogenesis.

  7. Interplay between Folding and Assembly of Fibril-Forming Polypeptides

    NARCIS (Netherlands)

    Ni, R.; Abeln, S.; Schor, M.; Cohen Stuart, M.A.; Bolhuis, P.G.

    2013-01-01

    Polypeptides can self-assemble into hierarchically organized fibrils consisting of a stack of individually folded polypeptides driven together by hydrophobic interaction. Using a coarse-grained model, we systematically studied this self-assembly as a function of temperature and hydrophobicity of the

  8. Enzyme-catalyzed synthesis of polyamides and polypeptides

    Science.gov (United States)

    Polyamides and polypeptides are important polymers in biological systems and industrial processes. Usually polyamides are produced via chemical synthesis, whereas polypeptides and proteins are isolated from living systems or produced from Merrifield synthesis. An area of active research is to use ...

  9. Measles virus-specified polypeptides in infected cells

    International Nuclear Information System (INIS)

    Vainionpaepae, R.

    1979-01-01

    The synthesis of wild-type measles virus-specified polypeptides in Vero cells in pulse-chase experiments, in cells with synchronized protein synthesis by high salt concentration, and in the presence of proteolytic enzyme inhibitors was analyzed by polyacrylamide slab-gel electrophoresis. Six major (L, G, 2, NP, 5 and M) structural polypeptides were identified in infected cells. The results of pulse-chase experiments suggested that most of the structural polypeptides were synthesized at their final length. Polypeptide M was found to be sensitive to trypsin. In TLCK-treated cells its molecular weight was about 1000-2000 daltons higher than in untreated cells. A minor virus-specific polypeptide with a molecular weight of about 23,000 was found as a very faint and diffuse band. In addition, three nonstructural polypeptides with molecular weights of 65,000, 38,000 and 18,000 were also detected. The experiments with proteolytic enzyme inhibitors and with synchronized protein synthesis suggested that the polypeptide with a molecular weight of 65,000 might be a precursor of the structural polypeptide 5. (author)

  10. Engineered Solution-Liquid-Solid Growth of a "Treelike" 1D/1D TiO2Nanotube-CdSe Nanowire Heterostructure: Photoelectrochemical Conversion of Broad Spectrum of Solar Energy.

    Science.gov (United States)

    Mukherjee, Bratindranath; Sarker, Swagotom; Crone, Eric; Pathak, Pawan; Subramanian, Vaidyanathan R

    2016-12-07

    This work presents a hitherto unreported approach to assemble a 1D oxide-1D chalcogenide heterostructured photoactive film. As a representative system, bismuth (Bi) catalyzed 1D CdSe nanowires are directly grown on anodized 1D TiO 2 nanotube (T_NT). A combination of the reductive successive-ionic-layer-adsorption-reaction (R-SILAR) and the solution-liquid-solid (S-L-S) approach is implemented to fabricate this heterostructured assembly, reported in this 1D/1D form for the first time. XRD, SEM, HRTEM, and elemental mapping are performed to systematically characterize the deposition of bismuth on T_NT and the growth of CdSe nanowires leading to the evolution of the 1D/1D heterostructure. The resulting "treelike" photoactive architecture demonstrates UV-visible light-driven electron-hole pair generation. The photoelectrochemical results highlight: (i) the formation of a stable n-n heterojunction between TiO 2 nanotube and CdSe nanowire, (ii) an excellent correlation between the absorbance vis-à-vis light conversion efficiency (IPCE), and (iii) a photocurrent density of 3.84 mA/cm 2 . This proof-of-concept features the viability of the approach for designing such complex 1D/1D oxide-chalcogenide heterostructures that can be of interest to photovoltaics, photocatalysis, environmental remediation, and sensing.

  11. Chirality-selected phase behaviour in ionic polypeptide complexes

    Science.gov (United States)

    Perry, Sarah L.; Leon, Lorraine; Hoffmann, Kyle Q.; Kade, Matthew J.; Priftis, Dimitrios; Black, Katie A.; Wong, Derek; Klein, Ryan A.; Pierce, Charles F.; Margossian, Khatcher O.; Whitmer, Jonathan K.; Qin, Jian; de Pablo, Juan J.; Tirrell, Matthew

    2015-01-01

    Polyelectrolyte complexes present new opportunities for self-assembled soft matter. Factors determining whether the phase of the complex is solid or liquid remain unclear. Ionic polypeptides enable examination of the effects of stereochemistry on complex formation. Here we demonstrate that chirality determines the state of polyelectrolyte complexes, formed from mixing dilute solutions of oppositely charged polypeptides, via a combination of electrostatic and hydrogen-bonding interactions. Fluid complexes occur when at least one of the polypeptides in the mixture is racemic, which disrupts backbone hydrogen-bonding networks. Pairs of purely chiral polypeptides, of any sense, form compact, fibrillar solids with a β-sheet structure. Analogous behaviour occurs in micelles formed from polypeptide block copolymers with polyethylene oxide, where assembly into aggregates with either solid or fluid cores, and eventually into ordered phases at high concentrations, is possible. Chirality is an exploitable tool for manipulating material properties in polyelectrolyte complexation. PMID:25586861

  12. Fibrillar dimer formation of islet amyloid polypeptides

    Energy Technology Data Exchange (ETDEWEB)

    Chiu, Chi-cheng [Univ. of Chicago, IL (United States); Argonne National Lab. (ANL), Argonne, IL (United States); de Pablo, Juan J. [Univ. of Chicago, IL (United States); Argonne National Lab. (ANL), Argonne, IL (United States)

    2015-05-08

    Amyloid deposits of human islet amyloid polypeptide (hIAPP), a 37-residue hormone co-produced with insulin, have been implicated in the development of type 2 diabetes. Residues 20 – 29 of hIAPP have been proposed to constitute the amyloidogenic core for the aggregation process, yet the segment is mostly unstructured in the mature fibril, according to solid-state NMR data. Here we use molecular simulations combined with bias-exchange metadynamics to characterize the conformational free energies of hIAPP fibrillar dimer and its derivative, pramlintide. We show that residues 20 – 29 are involved in an intermediate that exhibits transient β-sheets, consistent with recent experimental and simulation results. By comparing the aggregation of hIAPP and pramlintide, we illustrate the effects of proline residues on inhibition of the dimerization of IAPP. The mechanistic insights presented here could be useful for development of therapeutic inhibitors of hIAPP amyloid formation.

  13. Fibrillar dimer formation of islet amyloid polypeptides

    Science.gov (United States)

    Chiu, Chi-cheng; de Pablo, Juan J.

    2015-09-01

    Amyloid deposits of human islet amyloid polypeptide (hIAPP), a 37-residue hormone co-produced with insulin, have been implicated in the development of type 2 diabetes. Residues 20 - 29 of hIAPP have been proposed to constitute the amyloidogenic core for the aggregation process, yet the segment is mostly unstructured in the mature fibril, according to solid-state NMR data. Here we use molecular simulations combined with bias-exchange metadynamics to characterize the conformational free energies of hIAPP fibrillar dimer and its derivative, pramlintide. We show that residues 20 - 29 are involved in an intermediate that exhibits transient β-sheets, consistent with recent experimental and simulation results. By comparing the aggregation of hIAPP and pramlintide, we illustrate the effects of proline residues on inhibition of the dimerization of IAPP. The mechanistic insights presented here could be useful for development of therapeutic inhibitors of hIAPP amyloid formation.

  14. Protein Encapsulation via Polypeptide Complex Coacervation

    Energy Technology Data Exchange (ETDEWEB)

    Black, Katie A.; Priftis, Dimitrios; Perry, Sarah L.; Yip, Jeremy; Byun, William Y.; Tirrell, Matthew

    2014-10-21

    Proteins have gained increasing success as therapeutic agents; however, challenges exist in effective and efficient delivery. In this work, we present a simple and versatile method for encapsulating proteins via complex coacervation with oppositely charged polypeptides, poly(L-lysine) (PLys) and poly(D/L-glutamic acid) (PGlu). A model protein system, bovine serum albumin (BSA), was incorporated efficiently into coacervate droplets via electrostatic interaction up to a maximum loading of one BSA per PLys/PGlu pair and could be released under conditions of decreasing pH. Additionally, encapsulation within complex coacervates did not alter the secondary structure of the protein. Lastly the complex coacervate system was shown to be biocompatible and interact well with cells in vitro. A simple, modular system for encapsulation such as the one presented here may be useful in a range of drug delivery applications.

  15. Transportation

    International Nuclear Information System (INIS)

    Anon.

    1998-01-01

    Here is the decree of the thirtieth of July 1998 relative to road transportation, to trade and brokerage of wastes. It requires to firms which carry out a road transportation as well as to traders and to brokers of wastes to declare their operations to the prefect. The declaration has to be renewed every five years. (O.M.)

  16. Transportation

    National Research Council Canada - National Science Library

    Allshouse, Michael; Armstrong, Frederick Henry; Burns, Stephen; Courts, Michael; Denn, Douglas; Fortunato, Paul; Gettings, Daniel; Hansen, David; Hoffman, Douglas; Jones, Robert

    2007-01-01

    .... The ability of the global transportation industry to rapidly move passengers and products from one corner of the globe to another continues to amaze even those wise to the dynamics of such operations...

  17. Cancer Nano technology Using Elastin-Like Polypeptides

    International Nuclear Information System (INIS)

    Siti Najila Mohd Janib

    2014-01-01

    Despite progress in understanding cancer biology, this knowledge has not translated into comparable advances in the clinic. Two fundamental problems currently stalling the efficient treatment of cancer have been detecting cancer early enough for successful treatment and avoiding excessive toxicity to normal tissues. In view of this, cancer still remains one of the leading causes of mortality worldwide, affecting over 10 million new patients every year. Clearly the development of novel approaches for early detection and treatment of cancer is urgently needed to increase patient survival. Recently, nano technology-based systems have emerged as novel therapeutic modalities for cancer treatment. Tiny man made nanoparticles, much smaller than a virus, are being developed to package, transport, and deliver imaging and therapeutic agents. Co-inclusion of these agents, into nano carriers might be advantageous because they increase solubility of hydrophobic drugs, enhance permeability across physiological barriers, alter drug biodistribution, increase local bioavailability and reduce side effects. Initial findings have been promising and nanoparticles have been shown to deliver therapeutic agents to target cells and effect tumor growth. To this end our lab is investigating a class of biodegradable and biocompatible polymers known as elastin-like polypeptides (ELP). Elastin like polypeptide is a bio polymer derived from the structural motif found in mammalian elastin protein and has a sequence dependent transition temperature that can be used as nano carriers to treat diseases. ELPs are characterized by the pentameric repeat VPGXG, where X can be any amino acid. All functional ELPs undergo inverse phase transition whereby below its transition temperature, they exist in a solubilized form while above its transition temperature they undergo phase separation which leads to their aggregation in solution. This process is reversible. Phase transition can also be triggered by other

  18. Selective posttranslational modification of phage-displayed polypeptides

    Science.gov (United States)

    Tsao, Meng-Lin; Tian, Feng; Schultz, Peter

    2013-02-05

    The invention relates to posttranslational modification of phage-displayed polypeptides. These displayed polypeptides comprise at least one unnatural amino acid, e.g., an aryl-azide amino acid such as p-azido-L-phenylalanine, or an alkynyl-amino acid such as para-propargyloxyphenylalanine, which are incorporated into the phage-displayed fusion polypeptide at a selected position by using an in vivo orthogonal translation system comprising a suitable orthogonal aminoacyl-tRNA synthetase and a suitable orthogonal tRNA species. These unnatural amino acids advantageously provide targets for posttranslational modifications such as azide-alkyne [3+2]cycloaddition reactions and Staudinger modifications.

  19. Islet Amyloid Polypeptide: Structure, Function, and Pathophysiology

    Directory of Open Access Journals (Sweden)

    Rehana Akter

    2016-01-01

    Full Text Available The hormone islet amyloid polypeptide (IAPP, or amylin plays a role in glucose homeostasis but aggregates to form islet amyloid in type-2 diabetes. Islet amyloid formation contributes to β-cell dysfunction and death in the disease and to the failure of islet transplants. Recent work suggests a role for IAPP aggregation in cardiovascular complications of type-2 diabetes and hints at a possible role in type-1 diabetes. The mechanisms of IAPP amyloid formation in vivo or in vitro are not understood and the mechanisms of IAPP induced β-cell death are not fully defined. Activation of the inflammasome, defects in autophagy, ER stress, generation of reactive oxygen species, membrane disruption, and receptor mediated mechanisms have all been proposed to play a role. Open questions in the field include the relative importance of the various mechanisms of β-cell death, the relevance of reductionist biophysical studies to the situation in vivo, the molecular mechanism of amyloid formation in vitro and in vivo, the factors which trigger amyloid formation in type-2 diabetes, the potential role of IAPP in type-1 diabetes, the development of clinically relevant inhibitors of islet amyloidosis toxicity, and the design of soluble, bioactive variants of IAPP for use as adjuncts to insulin therapy.

  20. Biomedical applications of polypeptide multilayer nanofilms and microcapsules

    Science.gov (United States)

    Rudra, Jai Simha S.

    The past few years have witnessed considerable growth in synthetic polymer chemistry and physics, biomaterials science, and nano-scale engineering. Research on polypeptide multilayer films, coatings, and microcapsules is located at the intersection of these areas and are promising materials for applications in medicine, biotechnology, environmental science. Most envisioned applications of polypeptide multilayers have a biomedical bent. This dissertation on polypeptide multilayer film applications covers key points of polypeptides as materials, means of polymer production, film preparation, film characterization methods, and key points of current research in basic science. Both commercial and designed peptides have been used to fabricate films for in-vitro applications such as antimicrobial coatings and cell culture coatings and also microcapsules for drug delivery applications. Other areas of product development include artificial red blood cells, anisotropic coatings, enantioselective membranes, and artificial viruses.

  1. Controlling assembly of helical polypeptides via PEGylation strategies†

    Science.gov (United States)

    Top, Ayben; Zhong, Sheng; Yan, Congqi

    2013-01-01

    Recent studies in our laboratories have demonstrated that a helical polypeptide (17H6), equipped with a histidine tag and a helical alanine-rich, glutamic-acid-containing domain, exhibits pH-responsive assembly behavior useful in the production of polymorphological nanostructures. In this study, the histidine tag in these polypeptides was replaced by polyethylene glycol (PEG) with different molecular masses (5 kDa, or 10 kDa), and the self-association behavior of 17H6 and the PEGylated conjugates was characterized via dynamic light scattering (DLS), small angle neutron scattering (SANS), and cryogenic transmission electron microscopy (cryo-TEM). DLS experiments illustrated that the polypeptide and its PEG-conjugates undergo reversible assembly under acidic conditions, suggesting that the aggregation state of the polypeptide and the conjugates is controlled by the charged state of the glutamic acid residues. Nanoscale aggregates were detected at polypeptide/conjugate concentrations as low as 20 μM (∼0.3–0.5 mg ml−1) at physiological and ambient temperatures. Scattering and microscopy results showed that the size, the aggregation number, and the morphology of the aggregates can be tuned by the size and the nature of the hydrophilic tag. This tunable nature of the morphology of the aggregates, along with their low critical aggregation concentration, suggests that PEG-alanine-rich polypeptide conjugates may be useful as drug delivery vehicles in which the alanine-rich block serves as a drug attachment domain. PMID:24039625

  2. Biosynthesis of the neural cell adhesion molecule: characterization of polypeptide C

    DEFF Research Database (Denmark)

    Nybroe, O; Albrechtsen, M; Dahlin, J

    1985-01-01

    The biosynthesis of the neural cell adhesion molecule (N-CAM) was studied in primary cultures of rat cerebral glial cells, cerebellar granule neurons, and skeletal muscle cells. The three cell types produced different N-CAM polypeptide patterns. Glial cells synthesized a 135,000 Mr polypeptide B...... and a 115,000 Mr polypeptide C, whereas neurons expressed a 200,000 Mr polypeptide A as well as polypeptide B. Skeletal muscle cells produced polypeptide B. The polypeptides synthesized by the three cell types were immunochemically identical. The membrane association of polypeptide C was investigated...... with methods that distinguish peripheral and integral membrane proteins. Polypeptide C was found to be a peripheral membrane protein, whereas polypeptides A and B were integral membrane proteins with cytoplasmic domains of approximately 50,000 and approximately 25,000 Mr, respectively. The affinity...

  3. Mapping of polypeptides encoded by the Epstein-Barr virus genome in productive infection.

    OpenAIRE

    Hummel, M; Kieff, E

    1982-01-01

    Over 30 viral-specified polypeptides are translated in vitro from RNA of cells productively infected with Epstein-Barr virus (EBV). The polypeptides map to sites in EBV DNA by hybrid selection. Almost all of the polypeptides are reactive with EBV immune human serum. Several of the polypeptides are part of the early antigen complex. Two others are likely to be major structural components of the virus. Genes encoding persistent early and late polypeptides are intermixed through most of the EBV ...

  4. Surface active complexes formed between keratin polypeptides and ionic surfactants.

    Science.gov (United States)

    Pan, Fang; Lu, Zhiming; Tucker, Ian; Hosking, Sarah; Petkov, Jordan; Lu, Jian R

    2016-12-15

    Keratins are a group of important proteins in skin and hair and as biomaterials they can provide desirable properties such as strength, biocompatibility, and moisture regaining and retaining. The aim of this work is to develop water-soluble keratin polypeptides from sheep wool and then explore how their surface adsorption behaves with and without surfactants. Successful preparation of keratin samples was demonstrated by identification of the key components from gel electrophoresis and the reproducible production of gram scale samples with and without SDS (sodium dodecylsulphate) during wool fibre dissolution. SDS micelles could reduce the formation of disulphide bonds between keratins during extraction, reducing inter-molecular crosslinking and improving keratin polypeptide solubility. However, Zeta potential measurements of the two polypeptide batches demonstrated almost identical pH dependent surface charge distributions with isoelectric points around pH 3.5, showing complete removal of SDS during purification by dialysis. In spite of different solubility from the two batches of keratin samples prepared, very similar adsorption and aggregation behavior was revealed from surface tension measurements and dynamic light scattering. Mixing of keratin polypeptides with SDS and C 12 TAB (dodecyltrimethylammonium bromide) led to the formation of keratin-surfactant complexes that were substantially more effective at reducing surface tension than the polypeptides alone, showing great promise in the delivery of keratin polypeptides via the surface active complexes. Neutron reflection measurements revealed the coexistence of surfactant and keratin polypeptides at the interface, thus providing the structural support to the observed surface tension changes associated with the formation of the surface active complexes. Copyright © 2016. Published by Elsevier Inc.

  5. Further investigations on the polypeptides and reconstitution of prasinophycean ejectisomes.

    Science.gov (United States)

    Ammermann, Silke; Hillebrand, Helmut; Rhiel, Erhard

    2014-06-01

    Ejectisome fragments were isolated from the prasinophyte Pyramimonas grossii and subjected to different treatments, i.e. Percoll density gradient centrifugation, incubation at pH 2.5 or at pH 10.8, or incubation in 6M guanidine hydrochloride. Sodium dodecyl sulfate polyacrylamide gel electrophoresis revealed that Percoll density gradient centrifugation did not improve the purity of the ejectisome fragment-enriched fractions. The ejectisome fragments withstood pH 2.5 and pH 10.8 treatment, and no loosely bound polypeptides became detached. The disintegration of ejectisome fragments was achieved in 6M guanidine hydrochloride, and reassembly into filamentous, ejectisome-like structures occurred after dialysis against distilled water. Fractions enriched either in ejectisome fragments or in reconstituted ejectisome-like structures were dominated by three polypeptides with relative molecular weights of approximately 12.5-19kDa and two additional polypeptides of 23 and 26kDa. A polyclonal antiserum directed against an ejectisome fragment-enriched fraction weakly cross-reacted with these polypeptides, and no significant immuno-labelling of ejectisome fragments was registered. A positive immuno-label was achieved using immunoglobulin (IgG) fractions which were gained by selectively incubating nitrocellulose stripes of these polypeptides with the antiserum. Copyright © 2014 Elsevier GmbH. All rights reserved.

  6. Calculation of the Isotope Cluster for Polypeptides by Probability Grouping

    Science.gov (United States)

    Olson, Matthew T.; Yergey, Alfred L.

    2014-01-01

    This paper presents a novel theoretical basis for accurately calculating the isotope cluster of polypeptides. In contrast to previous approaches to this problem, which consider exhaustive or near exhaustive combinations of isotopic species, the program, Neutron Cluster, groups probabilities to yield highly accurate information without elucidating any fine structure within a nominal mass unit. This is a fundamental difference from any previously described algorithm for calculating the isotope cluster. As a result of this difference, the accurate isotope clusters for high molecular weight polypeptides can be calculated rapidly without any pruning. When applied to isotope enriched polypeptides, the algorithm introduces “grouping error”, which is described, quantified, and avoided by using probability partitioning. PMID:19026561

  7. Separation, antitumor activities, and encapsulation of polypeptide from Chlorella pyrenoidosa.

    Science.gov (United States)

    Wang, Xiaoqin; Zhang, Xuewu

    2013-01-01

    Chlorella pyrenoidosa is a unicellular green algae and has been a popular foodstuff worldwide. However, no reports on the antitumor peptides from such a microalgae are available in the literature. In this study, using low-temperature high-pressure extraction, enzymatic hydrolysis, ion exchange, and gel filtration chromatography, we separated a polypeptide that exhibited inhibitory activity on human liver cancer HepG2 cells, and named the polypeptide CPAP (C. pyrenoidosa antitumor polypeptide). Furthermore, the micro- and nanoencapsulation of CPAP were investigated by using two methods: complex coacervation and ionotropic gelation. The in vitro release tests revealed that CPAP was well preserved against gastric enzymatic degradation after micro/nanoencapsulation and the slowly controlled release in the intestine could be potentially achieved. These results suggest that CPAP may be a useful ingredient in food, nutraceutical, and pharmaceutical applications. © 2013 American Institute of Chemical Engineers.

  8. On the theory of phase transitions in polypeptides

    DEFF Research Database (Denmark)

    Yakubovich, Alexander V.; Solov'yov, Ilia; Solov'yov, Andrey V.

    2008-01-01

    We suggest a theoretical method based on the statistical mechanics for treating the alpha-helix random coil transition in polypeptides. This process is considered as a first-order-like phase transition. The developed theory is free of model parameters and is based solely on fundamental physical...... principles. We apply the developed formalism for the description of thermodynamical properties of alanine polypeptides of different length. We analyze the essential thermodynamical properties of the system such as heat capacity, phase transition temperature and latent heat of the phase transition...

  9. Identification of polypeptides by using SOM neural networks

    Science.gov (United States)

    Liu, Jianwei; He, Ting; Zhang, Bo; Shen, Jingling

    2014-11-01

    Sample with no characteristic absorption can be identified by refractive index features. In this work, qualitative and quantitative identification of THz spectra of polypeptides using self-organization feature map (SOM) artificial neural network has been demonstrated. The absorption and refractive index features of three polypeptides, including Argreline Acetate, Alarelin Acetate, and Bivalirudin Trifluoroacetate, were measured by using the terahertz time-domain spectroscopy technique in the range 0.2-2.2 THz. The experimental results show that the three measured polypeptides present high similarity in absorption spectra but difference in refractive index spectra. After the network training process, the collected spectra were identified by the well-trained SOM network at another time. Analyzing the result we can see that the refractive index spectra are clustered and identify much better than the THz spectra of polypeptides. The study indicates that refractive index spectra can also be clustered by the SOM artificial neural network for identification of THz spectra especially when there is no obvious difference in absorption but significant difference in refractive index spectra.

  10. Vasoactive intestinal polypeptide (VIP) in the pig pancreas

    DEFF Research Database (Denmark)

    Poulsen, Steen Seier

    1984-01-01

    Vasoactive intestinal polypeptide (VIP) in the pig pancreas is localized to nerves, many of which travel along the pancreatic ducts. VIP stimulates pancreatic fluid and bicarbonate secretion like secretin. Electrical vagal stimulation in the pig causes an atropine-resistant profuse secretion...

  11. CLE polypeptide signaling gene expression in Arabidopsis embryos

    Science.gov (United States)

    Technical Abstract: The CLAVATA3 (CLV3)/ESR-related (CLE) family of small polypeptides mediate intercellular signaling events in plants. The biological roles of several CLE family members have been characterized, but the function of the majority still remains elusive. We recently performed a system...

  12. Discovery and Characterization of A Novel Class of Functional Polypeptides

    Science.gov (United States)

    Chu, Qian; Ma, Jiao; Saghatelian, Alan

    2015-01-01

    Molecular biology, genomics and proteomics methods have been utilized to reveal a non-annotated class of endogenous polypeptides (small proteins and peptides) encoded by short open reading frames (sORFs), or small open reading frames (smORFs). We refer to these polypeptides as s(m)ORF-encoded polypeptides or SEPs. The early SEPs were identified via genetic screens, and many of the RNAs that contain s(m)ORFs were originally considered to be non-coding; however, elegant work in bacteria and flies demonstrated that these s(m)ORFs code for functional polypeptides as small as 11-amino acids in length. The discovery of these initial SEPs led to searches for these molecules using methods such as ribosome profiling and proteomics, which have revealed the existence of many SEPs, including novel human SEPs. Unlike screens, –omics methods do not necessarily link a SEP to a cellular or biological function, but functional genomic and proteomic strategies have demonstrated that at least some of these newly discovered SEPs have biochemical and cellular functions. Here, we provide an overview of these results and discuss the future directions in this emerging field. PMID:25857697

  13. Immunohistochemical localization of pancreatic spasmolytic polypeptide (PSP) in the pig

    DEFF Research Database (Denmark)

    Raaberg, Lasse; Poulsen, Steen Seier; Thim, L

    1992-01-01

    Pancreatic spasmolytic polypeptide (PSP) is a peptide that is isolated from the porcine pancreas and that affects intestinal motility and growth of intestinal tumour cells in vitro. The peptide was recently demonstrated to be present in large amounts in pancreatic juice. The cellular origin...

  14. Identification and characterization of sORF-encoded polypeptides.

    Science.gov (United States)

    Chu, Qian; Ma, Jiao; Saghatelian, Alan

    2015-01-01

    Molecular biology, genomics and proteomics methods have been utilized to reveal a non-annotated class of endogenous polypeptides (small proteins and peptides) encoded by short open reading frames (sORFs), or small open reading frames (smORFs). We refer to these polypeptides as s(m)ORF-encoded polypeptides or SEPs. The early SEPs were identified via genetic screens, and many of the RNAs that contain s(m)ORFs were originally considered to be non-coding; however, elegant work in bacteria and flies demonstrated that these s(m)ORFs code for functional polypeptides as small as 11-amino acids in length. The discovery of these initial SEPs led to search for these molecules using methods such as ribosome profiling and proteomics, which have revealed the existence of many SEPs, including novel human SEPs. Unlike screens, omics methods do not necessarily link a SEP to a cellular or biological function, but functional genomic and proteomic strategies have demonstrated that at least some of these newly discovered SEPs have biochemical and cellular functions. Here, we provide an overview of these results and discuss the future directions in this emerging field.

  15. Chirality-selected phase behavior in ionic polypeptide complexes

    Science.gov (United States)

    Tirrell, Matthew

    2015-03-01

    We demonstrate that chirality determines the phase state of polyelectrolyte complexes formed from mixing dilute solutions of oppositely charged polypeptides. In these systems, the physical state of the resultant complex is determined by the combination of electrostatic and hydrogen bonding interactions. The formation of fluid complexes occurs when at least one of the polypeptides in the mixture is racemic, which disrupts backbone hydrogen bonding networks. Pairs of purely chiral polypeptides, of any sense, form compact, fibrillar solids with a β-sheet structure on mixing. Analogous behavior occurs in micellar cores formed from polypeptide block copolymers with polyethylene oxide, where microphase separation into discrete, self-assembled aggregates with either solid or fluid cores, and eventually into ordered phases at high concentrations, is possible. Chirality is an exploitable tool for manipulating material properties in systems based on polyelectrolyte complexation. Its role in these systems gives insight into polyelectrolyte complex phase behavior more broadly. This work was supported by the U.S. Department of Energy Office of Science Program in Basic Energy Sciences, Materials Sciences and Engineering Division.

  16. Research progress of active polypeptides of Cordyceps militaris

    Directory of Open Access Journals (Sweden)

    Xu Guangyu

    2017-01-01

    Full Text Available It is recognized at home and abroad that Cordyceps militaris is a fungus that can be edible and used for medicinal application, and also a common cordyceps taishanensis that is widely distributed and with very high medicinal value in China. Active Cordyceps militaris polypeptide has shown several highlights in its absorption mechanism, such as directly absorbed without the need for digestion, and absorbed quickly and completely, and more and more international researchers are attaching great importance to it. Physiological and pharmacological activities of Cordyceps militaris polypeptide are mainly to activate related enzyme systems, promote intermediary metabolisms or control the DNA transcription and translation, simultaneously activate the reticuloendothelial system and macrophage, promote the transformation of lymphocytes, and as a nonspecific immune enhancer and regulator, activate the immune competent cells, especially lymphocytes, lymphokines, mononuclear macrophage system and NK cells, thereby attacking the target cells to play an antitumor role, and also exerting its anti-aging, anticoagulant, hypolipidemic to enhance the immunity, improve the liver function and delay the aging. In this paper, the immunity improvement, anticancer, antioxidation and antimicrobial activities of active polypeptides from Cordyceps militaris are reviewed, in order to provide a solid theoretical help for the further development and application of active polypeptides of Cordyceps militaris.

  17. Revisiting the Helical Cooperativity of Synthetic Polypeptides in Solution.

    Science.gov (United States)

    Ren, Yuan; Baumgartner, Ryan; Fu, Hailin; van der Schoot, Paul; Cheng, Jianjun; Lin, Yao

    2017-08-14

    Using synthetic polypeptides as a model system, the theories of helix-coil transition were developed into one of the most beautiful and fruitful subjects in macromolecular science. The classic models proposed by Schellman and Zimm-Bragg more than 50 years ago, differ in the assumption on whether the configuration of multiple helical sequences separated by random coil sections is allowed in a longer polypeptide chain. Zimm also calculated the critical chain lengths that facilitate such interrupted helices in different solvent conditions. The experimental validation of Zimm's prediction, however, was not carefully examined at that time. Herein, we synthesize a series of homopolypeptide samples with different lengths, to systematically examine their helix-coil transition and folding cooperativity in solution. We find that for longer chains, polypeptides do exist as interrupted helices with scattered coil sections even in helicogenic solvent conditions, as predicted in the Zimm-Bragg model. The critical chain lengths that facilitate such interrupted helices, however, are substantially smaller than Zimm's original estimation. The inaccuracy is in part due to an approximation that Zimm made in simplifying the calculation. But more importantly, we find there exist intramolecular interactions between different structural segments in the longer polypeptides, which are not considered in the classic helix-coil theories. As such, even the Zimm-Bragg model in its exact form cannot fully describe the transition behavior and folding cooperativity of longer polypeptides. The results suggest that long "all-helix" chains may be much less prevalent in solution than previously imagined, and a revised theory is required to accurately account for the helix-coil transition of the longer chains with potential "non-local" intramolecular interactions.

  18. Polypeptides having beta-glucosidase activity and polynucleotides encoding the same

    Science.gov (United States)

    Brown, Kimberly; Harris, Paul

    2013-12-17

    The present invention relates to isolated polypeptides having beta-glucosidase activity and isolated polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides.

  19. Polypeptides having beta-glucosidase and beta-xylosidase activity and polynucleotides encoding same

    Science.gov (United States)

    Morant, Marc Dominique

    2014-05-06

    The present invention relates to isolated polypeptides having beta-glucosidase activity, beta-xylosidase activity, or beta-glucosidase and beta-xylosidase activity and isolated polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides.

  20. Recombinant host cells and nucleic acid constructs encoding polypeptides having cellulolytic enhancing activity

    Science.gov (United States)

    Schnorr, Kirk; Kramer, Randall

    2017-03-28

    The present invention relates to isolated polypeptides having cellulolytic enhancing activity and isolated polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides.

  1. Polypeptides having beta-glucosidase activity and beta-xylosidase activity and polynucleotides encoding same

    Science.gov (United States)

    Morant, Marc Dominique

    2014-04-29

    The present invention relates to isolated polypeptides having beta-glucosidase activity, beta-xylosidase activity, or beta-glucosidase and beta-xylosidase activity and isolated polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides.

  2. Biophysical studies of membrane channel polypeptides

    CERN Document Server

    Galbraith, T P

    2001-01-01

    Membrane channels facilitate the flow of ions across biological membranes, a process which is important in numerous cellular functions. The study of large integral membrane proteins is made difficult by identification, production and purification problems, and detailed knowledge of their three-dimensional structures is relatively scarce. The study of simple 'model' membrane proteins has given valuable insight into the structures and dynamics of membrane proteins in general. The bacterial peptide gramicidin has been the subject of intense study for many years, and has provided important information into the structural basis of channel function. Peptaibols, a class of fungal membrane peptides which includes alamethicin and antiamoebin, have also been useful in relating structural details to molecular ion transport processes. Gramicidin crystals were grown in the presence of phospholipids with various headgroups and acyl chains. The diffraction patterns of the crystals obtained were processed, but found to be in...

  3. An engineered coiled-coil polypeptide assembled onto quantum dots for targeted cell imaging

    Science.gov (United States)

    Yao, Ming-Hao; Yang, Jie; Song, Ji-Tao; Zhang, Lin; Fang, Bi-Yun; Zhao, Dong-Hui; Xia, Rui-Xue; Jin, Rui-Mei; Zhao, Yuan-Di; Liu, Bo

    2015-12-01

    Quantum dot (QD)-polypeptide probes have been developed through the specific metal-affinity interaction between polypeptides appended with N-terminal polyhistidine sequences and CdSe/ZnS core-shell QDs. The size and charge of a QD-polypeptide can be tuned by using different coiled-coil polypeptides. Compared to glutathione-capped QDs (QD-GSH), QD-polypeptide probes showed an approximately two- to three-fold luminescence increase, and the luminescence increase was not obviously related to the charge of the polypeptide. QD-polypeptide probes with different charge have a great effect on nonspecific cellular uptake. QD-polypeptide probes with negative charge exhibited lower nonspecific cellular uptake in comparison to the QD-GSH, while positively charged QD-polypeptide probes presented higher cellular uptake than the QD-GSH. A targeted QD-ARGD probe can obviously increase targeted cellular uptake in α v β 3 overexpressing HeLa cells compared to QD-A. In addition, QD-polypeptide probes showed lower in vitro cytotoxicity compared to the original QDs. These results demonstrate that these QD-polypeptide probes with high specific cellular uptake, high fluorescence intensity and low background noise are expected to have great potential applications in targeted cell imaging.

  4. High molecular weight polypeptide bands specific for equine herpesvirus 4.

    Science.gov (United States)

    Zheng, M; Love, D N; Sabine, M

    1995-09-01

    Serum neutralisation (SN) and immunoblotting were used in attempts to distinguish between natural infections with the closely related viruses equine herpesvirus 1 (EHV-1) and equine herpes-virus 4 (EHV-4). Horse sera (n = 323) collected in 1990 from studs with no experience of EHV-1 abortions as well as 197 sera collected in 1992 from studs with a history of EHV-1 abortions were tested by SN. The two groups differed in the proportion with measurable EHV-1 antibody, the 1992 group being significantly higher. Both groups had high proportions with EHV-4 antibody and no serum had antibody to EHV-1 alone. Pools of positive sera were prepared as probes in immunoblots. High molecular weight (> 200 kDa) polypeptide bands specific for EHV-4 were detected. No bands specific for EHV-1 only were found. The specific EHV-4 polypeptides shared some properties with gp2 of EHV-1.

  5. Compositions and methods for making selenocysteine containing polypeptides

    Energy Technology Data Exchange (ETDEWEB)

    Soll, Dieter; Aldag, Caroline; Hohn, Michael

    2016-10-11

    Non-naturally occurring tRNA.sup.Sec and methods of using them for recombinant expression of proteins engineered to include one or more selenocysteine residues are disclosed. The non-naturally occurring tRNA.sup.Sec can be used for recombinant manufacture of selenocysteine containing polypeptides encoded by mRNA without the requirement of an SECIS element. In some embodiments, selenocysteine containing polypeptides are manufactured by co-expressing a non-naturally occurring tRNA.sup.Sec a recombinant expression system, such as E. coli, with SerRS, EF-Tu, SelA, or PSTK and SepSecS, and an mRNA with at least one codon that recognizes the anticodon of the non-naturally occurring tRNA.sup.Sec.

  6. Imparting large macroscopic changes with small changes in polypeptide composition

    Science.gov (United States)

    Sing, Michelle; McKinley, Gareth; Olsen, Bradley

    Block copolymers composed of polypeptides provide an excellent platform for exploring the underlying physics surrounding macroscopic associative network behavior. Previous work in our group has elucidated a difference in the mechanical properties of two nearly identical elastin-like polypeptide (ELP) endblocks. In poly(ELP)s, this substitution is known to result in tighter beta turns. These beta turns exhibit slower responses to changes in temperature within the material. Under shear, the modulus for the alanine-containing ELP triblock is almost three times higher than the glycine-containing ELP. Additionally, preliminary tensile tests show higher stress and strain at break for the alanine ELP triblock. We are able to explain the reasons for this behavior using a variety of spectroscopic and analytical techniques. Small angle neutron and x-ray scattering indicate differences in ordering between the alanine and glycine containing ELP materials both in shear and in stagnant flow.

  7. NMR study of the cooperative behavior of thermotropic model polypeptides

    Czech Academy of Sciences Publication Activity Database

    Kurková, Dana; Kříž, Jaroslav; Rodríguez-Cabello, J. C.; Arias, F. J.

    2007-01-01

    Roč. 56, č. 2 (2007), s. 186-194 ISSN 0959-8103 R&D Projects: GA AV ČR IAA400500604 Grant - others:Spanish Ministry of Science and Culture (ES) A002/02; MAT2000-1764-C02; MAT2001-1853-C02-01; MAT2003- Institutional research plan: CEZ:AV0Z40500505 Keywords : thermotropic polymers * cooperativity * synthetic polypeptides Subject RIV: CD - Macromolecular Chemistry Impact factor: 1.557, year: 2007

  8. Inhibition of the coated vesicle proton pump and labeling of a 17,000-dalton polypeptide by N,N'-dicyclohexylcarbodiimide

    International Nuclear Information System (INIS)

    Arai, H.; Berne, M.; Forgac, M.

    1987-01-01

    N,N'-Dicyclohexylcarbodiimide (DCCD) inhibits 100% of proton transport and 80-85% of (Mg2+)-ATPase activity in clathrin-coated vesicles. Half-maximum inhibition of proton transport is observed at 10 microM DCCD after 30 min. Although treatment of the coated vesicle (H+)-ATPase with DCCD has no effect on ATP hydrolysis in the detergent-solubilized state, sensitivity of proton transport and ATPase activity to DCCD is restored following reconstitution into phospholipid vesicles. In addition, treatment of the detergent-solubilized enzyme with DCCD followed by reconstitution gives a preparation that is blocked in both proton transport and ATP hydrolysis. These results suggest that although the coated vesicle (H+)-ATPase can react with DCCD in either a membrane-bound or detergent-solubilized state, inhibition of ATPase activity is only manifested when the pump is present in sealed membrane vesicles. To identify the subunit responsible for inhibition of the coated vesicle (H+)-ATPase by DCCD, we have labeled the partially purified enzyme with [ 14 C]DCCD. A single polypeptide of molecular weight 17,000 is labeled. The extremely hydrophobic nature of this polypeptide is indicated by its extraction with chloroform:methanol. The 17,000-dalton protein can be labeled to a maximum stoichiometry of 0.99 mol of DCCD/mol of protein with 100% inhibition of proton transport occurring at a stoichiometry of 0.15-0.20 mol of DCCD/mol of protein. Amino acid analysis of the chloroform:methanol extracted 17,000-dalton polypeptide reveals a high percentage of nonpolar amino acids. The similarity in properties of this protein and the DCCD-binding subunit of the coupling factor (H+)-ATPases suggests that the 17,000-dalton polypeptide may function as part of a proton channel in the coated vesicle proton pump

  9. Generation of polypeptide-templated gold nanoparticles using ionizing radiation.

    Science.gov (United States)

    Walker, Candace Rae; Pushpavanam, Karthik; Nair, Divya Geetha; Potta, Thrimoorthy; Sutiyoso, Caesario; Kodibagkar, Vikram D; Sapareto, Stephen; Chang, John; Rege, Kaushal

    2013-08-13

    Ionizing radiation, including γ rays and X-rays, are high-energy electromagnetic radiation with diverse applications in nuclear energy, astrophysics, and medicine. In this work, we describe the use of ionizing radiation and cysteine-containing elastin-like polypeptides (C(n)ELPs, where n = 2 or 12 cysteines in the polypeptide sequence) for the generation of gold nanoparticles. In the presence of C(n)ELPs, ionizing radiation doses higher than 175 Gy resulted in the formation of maroon-colored gold nanoparticle dispersions, with maximal absorbance at 520 nm, from colorless metal salts. Visible color changes were not observed in any of the control systems, indicating that ionizing radiation, gold salt solution, and C(n)ELPs were all required for nanoparticle formation. The hydrodynamic diameters of nanoparticles, determined using dynamic light scattering, were in the range of 80-150 nm, while TEM imaging indicated the formation of gold cores 10-20 nm in diameter. Interestingly, C2ELPs formed 1-2 nm diameter gold nanoparticles in the absence of radiation. Our results describe a facile method of nanoparticle formation in which nanoparticle size can be tailored based on radiation dose and C(n)ELP type. Further improvements in these polypeptide-based systems can lead to colorimetric detection of ionizing radiation in a variety of applications.

  10. Separation and nanoencapsulation of antitumor polypeptide from Spirulina platensis.

    Science.gov (United States)

    Zhang, Bochao; Zhang, Xuewu

    2013-01-01

    Spirulina platensis is a multicellular edible blue-green alga with abundant proteins (∼ 60%). No report is available on the antitumor polypeptides from the whole proteins of S. platensis. In this study, for the first time, an antitumor polypeptide Y2 from trypsin digest of S. platensis proteins was obtained by using freeze-thawing plus ultrasonication extraction, hydrolysis with four enzymes (trypsin, alcalase, papain, and pepsin), and gel filtration chromatography. The results showed that the degree of hydrolysis can be ordered as: trypsin (38.5%) > alcalase (31.2%) > papain (27.8%) > pepsin (7.1%). For MCF-7 and HepG2 cells, at 250 µg/mL, the maximum inhibitory rate of Y2 was 97%, while standard drug 5-FU was 55 and 97%, respectively. Furthermore, the nanoencapsulation of Y2 with chitosan (CS) was also investigated. After nanoencapsulation, the maximum encapsulation efficiency and polypeptides contents are 49 and 15%, respectively; and the antitumor activity is basically not lost. These data demonstrated the potential of nanopolypeptides (Y2-CS) in food and pharmaceutical applications. © 2013 American Institute of Chemical Engineers.

  11. Polypeptide having or assisting in carbohydrate material degrading activity and uses thereof

    Science.gov (United States)

    Schooneveld-Bergmans, Margot Elisabeth Francoise; Heijne, Wilbert Herman Marie; Los, Alrik Pieter

    2016-02-16

    The invention relates to a polypeptide which comprises the amino acid sequence set out in SEQ ID NO: 2 or an amino acid sequence encoded by the nucleotide sequence of SEQ ID NO: 1, or a variant polypeptide or variant polynucleotide thereof, wherein the variant polypeptide has at least 76% sequence identity with the sequence set out in SEQ ID NO: 2 or the variant polynucleotide encodes a polypeptide that has at least 76% sequence identity with the sequence set out in SEQ ID NO: 2. The invention features the full length coding sequence of the novel gene as well as the amino acid sequence of the full-length functional polypeptide and functional equivalents of the gene or the amino acid sequence. The invention also relates to methods for using the polypeptide in industrial processes. Also included in the invention are cells transformed with a polynucleotide according to the invention suitable for producing these proteins.

  12. Basal serum pancreatic polypeptide is dependent on age and gender in an adult population

    DEFF Research Database (Denmark)

    Brimnes Damholt, M; Rasmussen, B K; Hilsted, L

    1997-01-01

    This study is the first epidemiologically based study of basal levels of serum pancreatic polypeptide (s-PP). The basal level of serum PP has become a field of interest mainly due to the role of PP as an endocrine tumour marker, and as a marker of pancreatic neuroendocrine function after pancreas...... a monospecific radioimmunoassay. Fasting serum pancreatic polypeptide depended on age and gender. The results demonstrated that fasting pancreatic polypeptide levels increase exponentially with age. Fitted separately for each sex, basal serum pancreatic polypeptide was found to increase by approximately 3% per...... reports on the fasting levels of serum pancreatic polypeptide are most likely due to lack of adjustment for age and gender. Thus, variation due to age and gender should be considered in evaluating fasting levels of serum pancreatic polypeptide. Whether similar considerations are important when evaluating...

  13. Solvent-free liquid crystals and liquids based on genetically engineered supercharged polypeptides with high elasticity.

    Science.gov (United States)

    Liu, Kai; Pesce, Diego; Ma, Chao; Tuchband, Michael; Shuai, Min; Chen, Dong; Su, Juanjuan; Liu, Qing; Gerasimov, Jennifer Y; Kolbe, Anke; Zajaczkowski, Wojciech; Pisula, Wojciech; Müllen, Klaus; Clark, Noel A; Herrmann, Andreas

    2015-04-17

    A series of solvent-free elastin-like polypeptide liquid crystals and liquids are developed by electrostatic complexation of supercharged elastin-like polypeptides with surfactants. The smectic mesophases exhibit a high elasticity and the values can be easily tuned by varying the alkyl chain lengths of the surfactants or the lengths of the elastin-like polypeptides. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Well-defined (co)polypeptides bearing pendant alkyne groups

    KAUST Repository

    Zhao, Wei

    2016-03-18

    A novel metal-free strategy, using hydrogen-bonding catalytic ring opening polymerization of acetylene-functionalized N-carboxy anhydrites of α-amino acids, was developed for the synthesis of well-defined polypeptides bearing pendant alkyne groups. This method provides an efficient way to synthesize novel alkyne-functionalized homopolypeptides (A) and copolypeptides, such as AB diblock (B: non-functionalized), ABA triblock and star-AB diblock, as well as linear and star random copolypeptides, precursors of a plethora complex macromolecular architectures by click chemistry.

  15. Ab initio study of alanine polypeptide chain twisting

    DEFF Research Database (Denmark)

    Solov'yov, Ilia; Yakubovich, Alexander V.; Solov'yov, Andrey V.

    2006-01-01

    We have investigated the potential energy surfaces for alanine chains consisting of three and six amino acids. For these molecules we have calculated potential energy surfaces as a function of the Ramachandran angles ph$ and psi, which are widely used for the characterization of the polypeptide...... and with the available experimental data extracted from the Protein Data Base. This comparison demonstrates a reasonable correspondence of the most prominent minima on the calculated potential energy surfaces to the experimentally measured angles phi and psi for alanine chains appearing in native proteins. We have also...

  16. Functional Modification of Thioether Groups in Peptides, Polypeptides, and Proteins.

    Science.gov (United States)

    Deming, Timothy J

    2017-03-15

    Recent developments in the modification of methionine and other thioether-containing residues in peptides, polypeptides, and proteins are reviewed. Properties and potential applications of the resulting functionalized products are also discussed. While much of this work is focused on natural Met residues, modifications at other side-chain residues have also emerged as new thioether-containing amino acids have been incorporated into peptidic materials. Functional modification of thioether-containing amino acids has many advantages and is a complementary methodology to the widely utilized methods for modification at cysteine residues.

  17. Reaction mechanisms in the radiolysis of peptides, polypeptides and proteins

    International Nuclear Information System (INIS)

    Garrison, W.M.

    1985-01-01

    The purpose of this review is to bring together and to correlate the wide variety of experimental studies that provide information on the reaction products and reaction mechanisms involved in the radiolysis of peptides, polypeptides and proteins (including chromosomal proteins) in both aqueous and solid-state systems. The comparative radiation chemistry of these systems is developed in terms of specific reactions of the peptide main-chain and the aliphatic, aromatic-unsaturated and sulfur-containing side-chains. Information obtained with the various experimental techniques of product analysis, competition kinetics, spin-trapping, pulse radiolysis and ESR spectroscopy is included. 147 refs

  18. Reaction mechanisms in the radiolysis of peptides, polypeptides and proteins

    Energy Technology Data Exchange (ETDEWEB)

    Garrison, W.M.

    1985-01-01

    The purpose of this review is to bring together and to correlate the wide variety of experimental studies that provide information on the reaction products and reaction mechanisms involved in the radiolysis of peptides, polypeptides and proteins (including chromosomal proteins) in both aqueous and solid-state systems. The comparative radiation chemistry of these systems is developed in terms of specific reactions of the peptide main-chain and the aliphatic, aromatic-unsaturated and sulfur-containing side-chains. Information obtained with the various experimental techniques of product analysis, competition kinetics, spin-trapping, pulse radiolysis and ESR spectroscopy is included. 147 refs.

  19. Compositions comprising a polypeptide having cellulolytic enhancing activity and a bicycle compound and uses thereof

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Feng; Sweeney, Matthew; Quinlan, Jason

    2015-06-16

    The present invention relates to compositions comprising: a polypeptide having cellulolytic enhancing activity and a bicyclic compound. The present invention also relates to methods of using the compositions.

  20. Compositions comprising a polypeptide having cellulolytic enhancing activity and a quinone compound and uses thereof

    Science.gov (United States)

    Quinlan, Jason; Xu, Feng; Sweeney, Matthew

    2016-03-01

    The present invention relates to compositions comprising: a polypeptide having cellulolytic enhancing activity and a quinone compound. The present invention also relates to methods of using the compositions.

  1. Thermal aggregation behaviour of soy protein: characteristics of different polypeptides and sub-units.

    Science.gov (United States)

    He, Xiu-Ting; Yuan, De-Bao; Wang, Jin-Mei; Yang, Xiao-Quan

    2016-03-15

    Due to the differences in structure and composition of glycinin and β-conglycinin, they exhibit different characteristics during heat treatment. In present study, the thermal aggregation behaviour of glycinin, β-conglycinin and their isolated sub-units was investigated at pH 7.0. Acidic polypeptides, basic polypeptides, αα' and β sub-units of soy protein were denatured during the isolation process. The degree of aggregation of protein fractions after heat treatment was in the order: denatured basic polypeptides > native glycinin > denatured β sub-unit > native β-conglycinin > denatured acidic polypeptides > denatured αα' sub-units. Glycinin, β-conglycinin, acidic polypeptides and αα'/β sub-units exhibited different changing trends of surface hydrophobicity with increasing temperature. The αα' sub-units showed higher ability to suppress thermal aggregation of basic polypeptides than β sub-units during heat treatment. The β sub-units were shown to form soluble aggregates with glycinin after heating. The interaction mechanism of αα' and β sub-units heated with basic polypeptides was proposed. For the β sub-units-basic polypeptides mixed system, more hydrophobic chains were binding together and buried inside during heat treatment, which resulted in lower surface hydrophobicity. The αα' sub-units-basic polypeptides mixed system was considered to be a stable system with higher surface hydrophobicity after being heated. © 2015 Society of Chemical Industry.

  2. Vasoactive intestinal polypeptide and other preprovasoactive intestinal polypeptide-derived peptides in the female and male genital tract: localization, biosynthesis, and functional and clinical significance

    DEFF Research Database (Denmark)

    Ottesen, B; Fahrenkrug, J

    1995-01-01

    in the control of erection. Vasoactive intestinal polypeptide has been suggested as a causative factor in some diseases of the genital organs (e.g., it may play a pathophysiologic role in male impotence and the peptide is currently used in the treatment of this condition). Vasoactive intestinal polypeptide may...... be important for control of the low resistance in the fetomaternal vascular bed and is therefore a putative factor involved in the development of preeclampsia. The therapeutic potential of vasoactive intestinal polypeptide and future agonists and antagonists will be revealed by ongoing and forthcoming studies....

  3. CDNA encoding a polypeptide including a hevein sequence

    Science.gov (United States)

    Raikhel, Natasha V.; Broekaert, Willem F.; Chua, Nam-Hai; Kush, Anil

    1995-03-21

    A cDNA clone (HEV1) encoding hevein was isolated via polymerase chain reaction (PCR) using mixed oligonucleotides corresponding to two regions of hevein as primers and a Hevea brasiliensis latex cDNA library as a template. HEV1 is 1018 nucleotides long and includes an open reading frame of 204 amino acids. The deduced amino acid sequence contains a putative signal sequence of 17 amino acid residues followed by a 187 amino acid polypeptide. The amino-terminal region (43 amino acids) is identical to hevein and shows homology to several chitin-binding proteins and to the amino-termini of wound-induced genes in potato and poplar. The carboxyl-terminal portion of the polypeptide (144 amino acids) is 74-79% homologous to the carboxyl-terminal region of wound-inducible genes of potato. Wounding, as well as application of the plant hormones abscisic acid and ethylene, resulted in accumulation of hevein transcripts in leaves, stems and latex, but not in roots, as shown by using the cDNA as a probe. A fusion protein was produced in E. coli from the protein of the present invention and maltose binding protein produced by the E. coli.

  4. Effects of snake venom polypeptides on central nervous system.

    Science.gov (United States)

    Osipov, Alexey; Utkin, Yuri

    2012-12-01

    The nervous system is a primary target for animal venoms as the impairment of its function results in the fast and efficient immobilization or death of a prey. There are numerous evidences about effects of crude snake venoms or isolated toxins on peripheral nervous system. However, the data on their interactions with the central nervous system (CNS) are not abundant, as the blood-brain barrier (BBB) impedes penetration of these compounds into brain. This updated review presents the data about interaction of snake venom polypeptides with CNS. Such data will be described according to three main modes of interactions: - Direct in vivo interaction of CNS with venom polypeptides either capable to penetrate BBB or injected into the brain. - In vitro interactions of cell or sub-cellular fractions of CNS with crude venoms or purified toxins. - Indirect effects of snake venoms or their components on functioning of CNS under different conditions. Although the venom components penetrating BBB are not numerous, they seem to be the most suitable candidates for the leads in drug design. The compounds with other modes of action are more abundant and better studied, but the lack of the data about their ability to penetrate BBB may substantially aggravate the potentials for their medical perspectives. Nevertheless, many such compounds are used for research of CNS in vitro. These investigations may give invaluable information for understanding the molecular basis of CNS diseases and thus lay the basis for targeted drug design. This aspect also will be outlined in the review.

  5. cDNA encoding a polypeptide including a hevein sequence

    Energy Technology Data Exchange (ETDEWEB)

    Raikhel, N.V.; Broekaert, W.F.; Chua, N.H.; Kush, A.

    2000-07-04

    A cDNA clone (HEV1) encoding hevein was isolated via polymerase chain reaction (PCR) using mixed oligonucleotides corresponding to two regions of hevein as primers and a Hevea brasiliensis latex cDNA library as a template. HEV1 is 1018 nucleotides long and includes an open reading frame of 204 amino acids. The deduced amino acid sequence contains a putative signal sequence of 17 amino acid residues followed by a 187 amino acid polypeptide. The amino-terminal region (43 amino acids) is identical to hevein and shows homology to several chitin-binding proteins and to the amino-termini of wound-induced genes in potato and poplar. The carboxyl-terminal portion of the polypeptide (144 amino acids) is 74--79% homologous to the carboxyl-terminal region of wound-inducible genes of potato. Wounding, as well as application of the plant hormones abscisic acid and ethylene, resulted in accumulation of hevein transcripts in leaves, stems and latex, but not in roots, as shown by using the cDNA as a probe. A fusion protein was produced in E. coli from the protein of the present invention and maltose binding protein produced by the E. coli.

  6. Immunogenicity in dogs and protection against visceral leishmaniasis induced by a 14 kDa Leishmania infantum recombinant polypeptide

    Directory of Open Access Journals (Sweden)

    Claudia Abeijon

    2016-01-01

    Full Text Available In areas were human visceral leishmaniasis (VL is endemic, the domestic dog is the main parasite reservoir in the infectious cycle of Leishmania infantum. Development of prophylactic strategies to lower the parasite burden in dogs would reduce sand fly transmission thus lowering the incidence of zoonotic VL. Here we demonstrate that vaccination of dogs with a recombinant 14 kDa polypeptide of L. infantum nuclear transport factor 2 (Li-ntf2 mixed with adjuvant BpMPLA-SE resulted in the production of specific anti-Li-ntf2 IgG antibodies as well as IFN-γ release by the animals’ peripheral blood mononuclear cells stimulated with the antigen. In addition, immunization with this single and small 14 kDa polypeptide resulted in protracted progression of the infection of the animals after challenging with a high dose of virulent L. infantum. Five months after challenge the parasite load was lower in the bone marrow of immunized dogs compared to non-immunized animals. The antibody response to K39, a marker of active VL, at ten months after challenge was strong and significantly higher in the control dogs than in vaccinated animals. At the study termination vaccinated animals showed significantly more liver granulomas and lymphoid hyperplasia than non-vaccinated animals, which are both histological markers of resistance to infection. Together, these results indicate that the 14 kDa polypeptide is an attractive protective molecule that can be easily incorporated in a leishmanial polyprotein vaccine candidate to augment/complement the overall protective efficacy of the final product.

  7. Thymus Polypeptide Preparation Tactivin Restores Learning and Memory in Thymectomied Rats.

    Science.gov (United States)

    Novoseletskaya, A V; Kiseleva, N M; Zimina, I V; Bystrova, O V; Belova, O V; Inozemtsev, A N; Arion, V Ya; Sergienko, V I

    2015-09-01

    We studied the effects of tactivin and splenic polypeptides on learning and memory of thymectomized animals. In 3-week rats, thymectomy blocked active avoidance conditioning. Injections of tactivin (0.5 mg/kg) during 1 month after surgery restored learning capacity; splenic polypeptides were ineffective.

  8. Biosynthesis of the neural cell adhesion molecule: characterization of polypeptide C

    DEFF Research Database (Denmark)

    Nybroe, O; Albrechtsen, M; Dahlin, J

    1985-01-01

    The biosynthesis of the neural cell adhesion molecule (N-CAM) was studied in primary cultures of rat cerebral glial cells, cerebellar granule neurons, and skeletal muscle cells. The three cell types produced different N-CAM polypeptide patterns. Glial cells synthesized a 135,000 Mr polypeptide B...

  9. Competition between surface adsorption and folding of fibril-forming polypeptides

    NARCIS (Netherlands)

    Ni, R.; Kleijn, J.M.; Cohen Stuart, M.A.; Bolhuis, P.G.

    2015-01-01

    Self-assembly of polypeptides into fibrillar structures can be initiated by planar surfaces that interact favorably with certain residues. Using a coarse-grained model, we systematically studied the folding and adsorption behavior of a ß -roll forming polypeptide. We find that there are two

  10. Competition between surface adsorption and folding of fibril-forming polypeptides

    NARCIS (Netherlands)

    Ni, R.; de Kleijn, M.; Abeln, S.; Cohen Stuart, M.A.; Bolhuis, P.G.

    2015-01-01

    Self-assembly of polypeptides into fibrillar structures can be initiated by planar surfaces that interact favorably with certain residues. Using a coarse-grained model, we systematically studied the folding and adsorption behavior of a β-roll forming polypeptide. We find that there are two different

  11. Synthesis of peptide-grafted comb polypeptides via polymerisation of NCA-peptides.

    Science.gov (United States)

    Enomoto, Hiroshi; Nottelet, Benjamin; Halifa, Soultan Al; Enjalbal, Christine; Dupré, Mathieu; Tailhades, Julien; Coudane, Jean; Subra, Gilles; Martinez, Jean; Amblard, Muriel

    2013-01-14

    A straightforward synthesis of comb-polypeptides of repeated peptide sequences was developed. These polypeptides were obtained by ROP of defined NCA without any post-polymerization grafting. The key to this strategy relies on the preparation of pure NCA bearing a peptide sequence on its side chain, by an original solid supported methodology.

  12. Ontogeny of αA and αB crystallin polypeptides during Rana temporaria lens development

    NARCIS (Netherlands)

    Brahma, S.K.; McDevitt, D.S.; DeFize, L.H.K.

    The ontogeny and localization of αA and αB polypeptide chains of α-crystallin were investigated in the developing lens of Rana temporaria, an anuran amphibian, using the indirect immunofluorescence staining method with heterologous antibodies directed against these two polypeptides. αA and αB

  13. High-performance liquid chromatography of rat and mouse islet polypeptides

    DEFF Research Database (Denmark)

    Linde, S; Hansen, B; Welinder, B S

    1990-01-01

    supported its suspected identity as methionine sulphoxide insulin II. We have examined the formation of Met-O derivatives of insulin II, glucagon and pancreatic polypeptide during sample preparation (Sep-Pak and Speed-Vac concentrating). The oxidation of methionine residues was found to depend very much......-O derivatives is important for the quantitation of methionine-containing polypeptides....

  14. Self-assembly of α-helical polypeptides driven by complex coacervation.

    Science.gov (United States)

    Priftis, Dimitrios; Leon, Lorraine; Song, Ziyuan; Perry, Sarah L; Margossian, Khatcher O; Tropnikova, Anna; Cheng, Jianjun; Tirrell, Matthew

    2015-09-14

    Reported is the ability of α-helical polypeptides to self-assemble with oppositely-charged polypeptides to form liquid complexes while maintaining their α-helical secondary structure. Coupling the α-helical polypeptide to a neutral, hydrophilic polymer and subsequent complexation enables the formation of nanoscale coacervate-core micelles. While previous reports on polypeptide complexation demonstrated a critical dependence of the nature of the complex (liquid versus solid) on chirality, the α-helical structure of the positively charged polypeptide prevents the formation of β-sheets, which would otherwise drive the assembly into a solid state, thereby, enabling coacervate formation between two chiral components. The higher charge density of the assembly, a result of the folding of the α-helical polypeptide, provides enhanced resistance to salts known to inhibit polypeptide complexation. The unique combination of properties of these materials can enhance the known potential of fluid polypeptide complexes for delivery of biologically relevant molecules. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Characterisation of the nascent polypeptide-associated complex in fission yeast

    DEFF Research Database (Denmark)

    Andersen, Katrine M; Semple, Colin A; Hartmann-Petersen, Rasmus

    2007-01-01

    The nascent polypeptide-associated complex (NAC) is an abundant and phylogenetically conserved protein complex. It is composed of two subunits and interacts with nascent polypeptide chains emerging from the ribosome. It has been proposed to protect the nascent chains from premature interaction...

  16. Competition between surface adsorption and folding of fibril-forming polypeptides

    NARCIS (Netherlands)

    Ni, R.; Kleijn, J.M.; Abeln, S.; Cohen Stuart, M.A.; Bolhuis, P.G.

    2015-01-01

    Self-assembly of polypeptides into fibrillar structures can be initiated by planar surfaces that interact favorably with certain residues. Using a coarse-grained model, we systematically studied the folding and adsorption behavior of a beta-roll forming polypeptide. We find that there are two

  17. Ring-Opening Polymerization of N-Carboxyanhydrides for Preparation of Polypeptides and Polypeptide-Based Hybrid Materials with Various Molecular Architectures

    KAUST Repository

    Pahovnik, David

    2015-09-01

    Different synthetic approaches utilizing ring-opening polymerization of N-carboxyanhydrides for preparation of polypeptide and polypeptide-based hybrid materials with various molecular architectures are described. An overview of polymerization mechanisms using conventional (various amines) as well as some recently developed initiators (hexamethyldisilazane, N-heterocyclic persistent carbenes, etc.) is presented, and their benefits and drawbacks for preparation of polypeptides with well-defined chain lengths and chain-end functionality are discussed. Recent examples from literature are used to illustrate different possibilities for synthesis of pure polypeptide materials with different molecular architectures bearing various functional groups, which are introduced either by modification of amino acids, before they are transformed into corresponding Ncarboxyanhydrides, or by post-polymerization modifications using protective groups and/or orthogonal functional groups. Different approaches for preparation of polypeptide-based hybrid materials are discussed as well using examples from recent literature. Syntheses of simple block copolymers or copolymers with more complex molecular architectures (graft and star copolymers) as well as modifications of nanoparticles and other surfaces with polypeptides are described.

  18. Inhibition of gastric inhibitory polypeptide signaling prevents obesity

    DEFF Research Database (Denmark)

    Miyawaki, Kazumasa; Yamada, Yuichiro; Ban, Nobuhiro

    2002-01-01

    Secretion of gastric inhibitory polypeptide (GIP), a duodenal hormone, is primarily induced by absorption of ingested fat. Here we describe a novel pathway of obesity promotion via GIP. Wild-type mice fed a high-fat diet exhibited both hypersecretion of GIP and extreme visceral and subcutaneous fat...... deposition with insulin resistance. In contrast, mice lacking the GIP receptor (Gipr(-/-)) fed a high-fat diet were clearly protected from both the obesity and the insulin resistance. Moreover, double-homozygous mice (Gipr(-/-), Lep(ob)/Lep(ob)) generated by crossbreeding Gipr(-/-) and obese ob/ob (Lep......(ob)/Lep(ob)) mice gained less weight and had lower adiposity than Lep(ob)/Lep(ob) mice. The Gipr(-/-) mice had a lower respiratory quotient and used fat as the preferred energy substrate, and were thus resistant to obesity. Therefore, GIP directly links overnutrition to obesity and it is a potential target for anti-obesity...

  19. Genetic code redundancy and its influence on the encoded polypeptides

    Directory of Open Access Journals (Sweden)

    Paige S Spencer

    2012-04-01

    Full Text Available The genetic code is said to be redundant in that the same amino acid residue can be encoded by multiple, so-called synonymous, codons. If all properties of synonymous codons were entirely equivalent, one would expect that they would be equally distributed along protein coding sequences. However, many studies over the last three decades have demonstrated that their distribution is not entirely random. It has been postulated that certain codons may be translated by the ribosome faster than others and thus their non-random distribution dictates how fast the ribosome moves along particular segments of the mRNA. The reasons behind such segmental variability in the rates of protein synthesis, and thus polypeptide emergence from the ribosome, have been explored by theoretical and experimental approaches. Predictions of the relative rates at which particular codons are translated and their impact on the nascent chain have not arrived at unequivocal conclusions. This is probably due, at least in part, to variation in the basis for classification of codons as “fast” or “slow”, as well as variability in the number and types of genes and proteins analyzed. Recent methodological advances have allowed nucleotide-resolution studies of ribosome residency times in entire transcriptomes, which confirm the non-uniform movement of ribosomes along mRNAs and shed light on the actual determinants of rate control. Moreover, experiments have begun to emerge that systematically examine the influence of variations in ribosomal movement and the fate of the emerging polypeptide chain.

  20. GENETIC CODE REDUNDANCY AND ITS INFLUENCE ON THE ENCODED POLYPEPTIDES

    Directory of Open Access Journals (Sweden)

    Paige S. Spencer

    2012-04-01

    Full Text Available The genetic code is said to be redundant in that the same amino acid residue can be encoded by multiple, so-called synonymous, codons. If all properties of synonymous codons were entirely equivalent, one would expect that they would be equally distributed along protein coding sequences. However, many studies over the last three decades have demonstrated that their distribution is not entirely random. It has been postulated that certain codons may be translated by the ribosome faster than others and thus their non-random distribution dictates how fast the ribosome moves along particular segments of the mRNA. The reasons behind such segmental variability in the rates of protein synthesis, and thus polypeptide emergence from the ribosome, have been explored by theoretical and experimental approaches. Predictions of the relative rates at which particular codons are translated and their impact on the nascent chain have not arrived at unequivocal conclusions. This is probably due, at least in part, to variation in the basis for classification of codons as “fast” or “slow”, as well as variability in the number and types of genes and proteins analyzed. Recent methodological advances have allowed nucleotide-resolution studies of ribosome residency times in entire transcriptomes, which confirm the non-uniform movement of ribosomes along mRNAs and shed light on the actual determinants of rate control. Moreover, experiments have begun to emerge that systematically examine the influence of variations in ribosomal movement and the fate of the emerging polypeptide chain.

  1. Biosynthesis of human sialophorins and analysis of the polypeptide core

    International Nuclear Information System (INIS)

    Remold-O'Donnell, E.; Kenney, D.; Rosen, F.S.

    1987-01-01

    Biosynthesis was examined of sialophorin (formerly called gpL115) which is altered in the inherited immunodeficiency Wiskott-Aldrich syndrome. Sialophorin is greater than 50% carbohydrate, primarily O-linked units of sialic acid, galactose, and galactosamine. Pulse-labeling with [ 35 S]methionine and chase incubation established that sialophorin is synthesized in CEM lymphoblastoid cells as an Mr 62,000 precursor which is converted within 45 min to mature glycosylated sialophorin, a long-lived molecule. Experiments with tunicamycin and endoglycosidase H demonstrated that sialophorin contains N-linked carbohydrate (approximately two units per molecule) and is therefore an N,O-glycoprotein. Pulse-labeling of tunicamycin-treated CEM cells together with immunoprecipitation provided the means to isolate the [ 35 S]-methionine-labeled polypeptide core of sialophorin and determine its molecular weight (58,000). This datum allowed us to express the previously established composition on a per molecule basis and determine that sialophorin molecules contain approximately 520 amino acid residues and greater than or equal to 100 O-linked carbohydrate units. A recent study showed that various blood cells express sialophorin and that there are two molecular forms: lymphocyte/monocyte sialophorin and platelet/neutrophil sialophorin. Biosynthesis of the two forms was compared by using sialophorin of CEM cells and sialophorin of MOLT-4 cells (another lymphoblastoid line) as models for lymphocyte/monocyte sialophorin and platelet/neutrophil sialophorin, respectively. The time course of biosynthesis and the content of N units were found to be identical for the two sialophorin species. [ 35 S]Methionine-labeled polypeptide cores of CEM sialophorin and MOLT sialophorin were isolated and compared by electrophoresis, isoelectrofocusing, and a newly developed peptide mapping technique

  2. Mechanisms of fat-induced gastric inhibitory polypeptide/glucose-dependent insulinotropic polypeptide secretion from K cells.

    Science.gov (United States)

    Yamane, Shunsuke; Harada, Norio; Inagaki, Nobuya

    2016-04-01

    Gastric inhibitory polypeptide/glucose-dependent insulinotropic polypeptide (GIP) is one of the incretins, which are gastrointestinal hormones released in response to nutrient ingestion and potentiate glucose-stimulated insulin secretion. Single fat ingestion stimulates GIP secretion from enteroendocrine K cells; chronic high-fat diet (HFD) loading enhances GIP secretion and induces obesity in mice in a GIP-dependent manner. However, the mechanisms of GIP secretion from K cells in response to fat ingestion and GIP hypersecretion in HFD-induced obesity are not well understood. We generated GIP-green fluorescent protein knock-in (GIP (gfp/+)) mice, in which K cells are labeled by enhanced GIP-green fluorescent protein. Microarray analysis of isolated K cells from GIP (gfp/+) mice showed that both fatty acid-binding protein 5 and G protein-coupled receptor 120 are highly expressed in K cells. Single oral administration of fat resulted in significant reduction of GIP secretion in both fatty acid-binding protein 5- and G protein-coupled receptor 120-deficient mice, showing that fatty acid-binding protein 5 and G protein-coupled receptor 120 are involved in acute fat-induced GIP secretion. Furthermore, the transcriptional factor, regulatory factor X6 (Rfx6), is highly expressed in K cells. In vitro experiments using the mouse enteroendocrine cell line, STC-1, showed that GIP messenger ribonucleic acid levels are upregulated by Rfx6. Expression levels of Rfx6 messenger ribonucleic acid as well as that of GIP messenger ribonucleic acid were augmented in the K cells of HFD-induced obese mice, in which GIP content in the small intestine is increased compared with that in lean mice fed a control diet. These results suggest that Rfx6 is involved in hypersecretion of GIP in HFD-induced obese conditions by increasing GIP gene expression.

  3. Domed Silica Microcylinders Coated with Oleophilic Polypeptides and Their Behavior in Lyotropic Cholesteric Liquid Crystals of the Same Polypeptide.

    Science.gov (United States)

    Rosu, Cornelia; Jacobeen, Shane; Park, Katherine; Reichmanis, Elsa; Yunker, Peter; Russo, Paul S

    2016-12-13

    Liquid crystals can organize dispersed particles into useful and exotic structures. In the case of lyotropic cholesteric polypeptide liquid crystals, polypeptide-coated particles are appealing because the surface chemistry matches that of the polymeric mesogen, which permits a tighter focus on factors such as extended particle shape. The colloidal particles developed here consist of a magnetic and fluorescent cylindrically symmetric silica core with one rounded, almost hemispherical end. Functionalized with helical poly(γ-stearyl-l-glutamate) (PSLG), the particles were dispersed at different concentrations in cholesteric liquid crystals (ChLC) of the same polymer in tetrahydrofuran (THF). Defects introduced by the particles to the director field of the bulk PSLG/THF host led to a variety of phases. In fresh mixtures, the cholesteric mesophase of the PSLG matrix was distorted, as reflected in the absence of the characteristic fingerprint pattern. Over time, the fingerprint pattern returned, more quickly when the concentration of the PSLG-coated particles was low. At low particle concentration the particles were "guided" by the PSLG liquid crystal to organize into patterns similar to that of the re-formed bulk chiral nematic phase. When their concentration increased, the well-dispersed PSLG-coated particles seemed to map onto the distortions in the bulk host's local director field. The particles located near the glass vial-ChLC interfaces were stacked lengthwise into architectures with apparent two-dimensional hexagonal symmetry. The size of these "crystalline" structures increased with particle concentration. They displayed remarkable stability toward an external magnetic field; hydrophobic interactions between the PSLG polymers in the shell and those in the bulk LC matrix may be responsible. The results show that bio-inspired LCs can assemble suitable colloidal particles into soft crystalline structures.

  4. Ejectisins: tough and tiny polypeptides are a major component of cryptophycean ejectisomes.

    Science.gov (United States)

    Ammermann, Silke; Schneider, Tristan; Westermann, Martin; Hillebrand, Helmut; Rhiel, Erhard

    2013-04-01

    Fragments of discharged ejectisomes were isolated from two Cryptomonas and a Chroomonas species by detergent treatment followed by Percoll density gradient centrifugation. The fragments withstand high concentrated detergent solutions, reducing agents and freeze-thawing. Disintegration was achieved in 6 M guanidine hydrochloride. Reassembly into long, filamentous, ejectisome-like structures occurred after dialysis. Sodium dodecyl sulfate polyacrylamide gel electrophoresis revealed that the polypeptide patterns of isolated ejectisome fragments and of reconstituted ejectisome-like structures were dominated by polypeptides with relative molecular weights of approximately 6 kDa. The polypeptides were not glycosylated and did not cross-react with antisera directed against recombinant Reb polypeptides which constitute the R-bodies of Caedibacter taeniospiralis. A polyclonal antiserum directed against reconstituted, ejectisome-like filaments cross-reacted with the 6-kDa polypeptides and immunolabeled extruded ejectisome filaments. Twenty amino acid residues, obtained by N-terminal amino acid sequence analysis, matched to polypeptide sequences deduced from cDNA sequences of the cryptophyte Guillardia theta. The term "ejectisins" is introduced for the 6-kDa polypeptides which represent a major component of cryptophycean ejectisomes.

  5. Peptides and polypeptides as scaffolds for optoelectronics and biomaterials applications

    Science.gov (United States)

    Charati, Manoj B.

    Peptides and polypeptides are emerging as a new class of biomaterials due to their unique structural, physiochemical, mechanical, and biological properties. The development of peptide and protein-based biomaterials is driven by the convergence of convenient techniques for peptide/protein engineering and its importance in applications as smart biomaterials. The thesis is divided in two parts; the first part highlights the importance of incorporation of non-natural amino acids into peptides and proteins. In particular, incorporation on p-bromophenylalanine in short alpha-helical peptide templates to control the association of chromophores is discussed. In the second part, design of a multi-component, biocompatible polypeptide with superior elasticity is discussed. Part 1. Novel peptide templates to control association of chromophores. Tailor made peptide and protein materials have many versatile applications, as both conformation and functional group position can be controlled. Such control may have intriguing applications in the development of hybrid materials for electroactive applications. A critical need in fabricating devices from organic semiconducting materials is to achieve control over the conformation and distance between two conjugated chains. Controlling chromophore spacing and orientation with required precision over nanometer length scale poses a greater challenge. Here we propose a peptide based template to control the alignment of the methylstilbene and Oxa-PPV chromophores with desired orientations and spacing. The hybrid peptides were characterized via CD, exciton coupled CD, 1H NMR and photoluminescence experiments. It is observed that slight change in the orientation of molecules has pronounced effect on the photo-physical behavior of the molecules. Characterization of the hybrid peptides via circular dichroism (CD) confirmed the helical character of the designed peptides and indicated that inclusion of non-natural amino acids has significant

  6. Anatomical localization and some pharmacological effects of vasoactive intestinal polypeptide in human and monkey corpus cavernosum.

    Science.gov (United States)

    Steers, W D; McConnell, J; Benson, G S

    1984-11-01

    Vasoactive intestinal polypeptide is hypothesized to be a nonadrenergic, noncholinergic neurotransmitter important in the physiology of penile erection. To further explore this concept, anatomical localization of vasoactive intestinal polypeptide, in vitro muscle bath studies and in vivo injection experiments were undertaken in the monkey and man. Using immunohistochemical techniques vasoactive intestinal polypeptide was localized at the light microscopic level to nerves within the monkey and human penis. Ultrastructurally, a modified peroxidase-antiperoxidase technique was used to identify large vasoactive intestinal polypeptide-positive vesicles within peptidergic and cholinergic varicosities. In the in vitro muscle bath, the addition of 10(-7) M vasoactive intestinal polypeptide did not alter the baseline tension of strips of monkey and human corpus cavernosum. During contraction produced by norepinephrine stimulation, however, vasoactive intestinal polypeptide (10(-7) M) caused relaxation of the monkey (41 +/- 18 per cent, no. = 8) and human (23 +/- 8 per cent, no. = 5) corpus cavernosum. Intracorporal injection of vasoactive intestinal polypeptide (0.75 X 10(-9) to 3.75 X 10(-9) moles/kg.) had no effect on the monkey penis. Administration of vasoactive intestinal polypeptide (1.25 X 10(-9) to 2.5 X 10(-9) moles/kg.) into the internal iliac artery of the monkey, while having no effect on the flaccid penis, caused detumescence of the erect penis obtained by cavernous nerve stimulation (2-5 V, 40 Hz, 2 msec.). Although vasoactive intestinal polypeptide can be found within the nerves of the penis, its apparent in vitro and in vivo effects raise further questions concerning the role of this peptide in penile erection.

  7. Effect of sequence on the ionization behavior of a series of amphiphilic polypeptides.

    Science.gov (United States)

    Fowler, Michael; Siddique, Bushra; Duhamel, Jean

    2013-04-09

    The behavior of five polypeptides made of hydrophilic and pH-responsive aspartic acid (Asp) and hydrophobic phenylalanine (Phe), which had been prepared by stitching together short well-defined sequences of Asp and Phe, was studied as a function of pH. The effect of pH on these polypeptides referred to as (Asp3Phe1)n, (Asp2Phe1)n, (Asp1Phe1)n, (Asp1Phe2)n, and (Asp1Phe3)n varied dramatically depending on their constituting sequence. The more hydrophobic polypeptides (Asp1Phe2)n and (Asp1Phe3)n behaved as if the Asp's were isolated from each other and showed an apparent pKa (pKa(app)) that remained constant with level of ionization (α = [Asp(-)]/[Asp]total) and equaled 5.4 and 6.4, respectively. The more hydrophilic polypeptides (Asp3Phe1)n and (Asp2Phe1)n behaved like weak polyacids showing a linear increase in pKa(app) with increasing α. The pKa(app) of (Asp1Phe1)n showed a trend as a function of α intermediate between the Asp-rich and Phe-rich polypeptides, behaving as if the Asp's were isolated at low α values (0.35). The effect that α, and thus the charge density of the polypeptides, had on the collapse and aggregation of the polypeptides was characterized by conducting static light scattering and fluorescence measurements. Static light scattering measurements demonstrated that all polypeptides precipitated and aggregated in solution at a critical charge density of 0.2. Fluorescence measurements with pyrene indicated that this behavior was due to the formation of Phe aggregates in water. Together, these experiments provide a complete description of how pH affects the behavior of a series of unique amphiphilic polypeptides designed with a well-defined sequence.

  8. The Research on the Impact of Maca Polypeptide on Sport Fatigue.

    Science.gov (United States)

    Miao, Hua

    2015-01-01

    In order to study the effect of maca polypeptide on sport fatigue, this paper selected 40 male mice, and they were randomly divided into group A, B, C and D. group A, B and C were fed food with different concentrations of maca polypeptide, and group D was control group. After two weeks of feeding, measured physiological indexes of mice, including blood glucose, urea nitrogen and creatinine. At last gived the experimental results, as well as the analysis. Experimental results show that maca polypeptide can improve the ability of anti-fatigue mice, and in a certain concentration range, the higher the concentration, the better the resistance to fatigue.

  9. The polymerization of amino acid adenylates on sodium-montmorillonite with preadsorbed polypeptides

    Science.gov (United States)

    Paecht-Horowitz, Mella; Eirich, Frederick R.

    1988-01-01

    The spontaneous polymerization of amino acid adenylates on Na-montmorillonite in dilute, neutral suspension, after polypeptides were adsorbed on the clay, is studied. It is found that the degrees of polymerization of the oligopeptides and polypeptides obtained is dependent on the amounts of polypeptides that were preadsorbed. It is concluded that a catalytic activity may derive from c-spacings that offer adsorption sites for the reagent amino acid adenylate within the peripheral recesses of irregularly stacked clay platelets by bringing the anhydride bonds and neutral amino groups into favorable reaction distances.

  10. Processes for the production of hydroxycinnamic acids using polypeptides having tyrosine ammonia lyase activity

    DEFF Research Database (Denmark)

    2016-01-01

    The present invention generally relates to the field of biotechnology as it applies to the production of hydroxycinnamic acids using polypeptides having tyrosine ammonia lyase activity. More particularly, the present invention pertains to polypeptides having tyrosine ammonia lyase activity and high...... substrate specificity towards tyrosine, which makes them particularly suitable in the production of p-coumaric acid and other hydroxycinnamic acids. The present invention thus provides processes for the production of p-coumaric acid and other hydroxycinnamic acids employing these polypeptides as well...

  11. Intestinal mucosa is a target tissue for pancreatic polypeptide

    International Nuclear Information System (INIS)

    Gilbert, W.R.; Kramer, J.L.; Frank, B.H.; Gingerich, R.L.

    1986-01-01

    Studies were carried out to identify mammalian tissues capable of specifically binding mammalian pancreatic polypeptide (PP). Bovine PP (bPP) radiolabeled with 125 I was purified by HPLC to yield [ 125 I]iodo-(Tyr-27) bPP. The label was injected into three pairs of fasted littermate dogs and allowed to circulate for 5 min. One of the dogs was a control which received an excess of unlabeled porcine PP to provide competition for receptor binding. Unbound bPP was removed by perfusion with Krebs-Ringer bicarbonate and the tissue fixed in situ with Karnovsky's fixative. Tissue samples from various organs were removed, weighed, and counted. The entire gastrointestinal tract demonstrated high levels of 125 I after injection of the labeled peptide. The duodenum, jejunum, ileum, and colon were the only tissues to exhibit specific binding of bPP. These tissues (mucosal and muscle layers) from experimental animals exhibited 31-76% higher binding than the corresponding tissues from the control animals. Sections of the gastrointestinal tract were scraped to separate the mucosal layer from the underlying muscle layer. The mucosal layer of the duodenum, jejunum, and ileum exhibited 145-162% increases in binding compared to the control animals. The muscle layer of these tissues demonstrated no significant increase. These findings demonstrate that mucosal layer of the small intestine is a target tissue for mammalian PP

  12. TRAP display: a high-speed selection method for the generation of functional polypeptides.

    Science.gov (United States)

    Ishizawa, Takahiro; Kawakami, Takashi; Reid, Patrick C; Murakami, Hiroshi

    2013-04-10

    Here, we describe a novel method that enables high-speed in vitro selection of functional peptides, peptidomimetics, and proteins via a simple procedure. We first developed a new cell-free translation system, the TRAP system (transcription-translation coupled with association of puromycin linker), which automatically produces a polypeptide library through a series of sequential reactions: transcription, association of puromycin-DNA linker, translation, and conjugation between the nascent polypeptide and puromycin-DNA linker. We then applied the TRAP system for the selection of macrocyclic peptides against human serum albumin. Six rounds of selection using TRAP display were performed in approximately 14 h, yielding macrocyclic peptides with nanomolar affinity to their target protein. Because TRAP display enables high-speed selection of functional polypeptides, it will facilitate the generation of various polypeptides that are useful for biological and therapeutic applications.

  13. Variants of polypeptides having cellulolytic enhancing activity and polynucleotides encoding same

    Energy Technology Data Exchange (ETDEWEB)

    Sweeney, Matt; Wogulis, Mark

    2017-11-14

    The present invention relates to polypeptide having cellulolytic enhancing activity variants. The present invention also relates to polynucleotides encoding the variants; nucleic acid constructs, vectors, and host cells comprising the polynucleotides; and methods of using the variants.

  14. Papain-Catalyzed Chemoenzymatic Synthesis of Telechelic Polypeptides Using Bis(Leucine Ethyl Ester) Initiator.

    Science.gov (United States)

    Tsuchiya, Kousuke; Numata, Keiji

    2016-07-01

    In order to construct unique polypeptide architectures, a novel telechelic-type initiator with two leucine ethyl ester units is designed for chemoenzymatic polymerization. Glycine or alanine ethyl ester is chemoenzymatically polymerized using papain in the presence of the initiator, and the propagation occurs at each leucine ethyl ester unit to produce the telechelic polypeptide. The formation of the telechelic polypeptides is confirmed by (1) H NMR and MALDI-TOF mass spectroscopies. It is revealed by AFM observation that long nanofibrils are formed from the telechelic polyalanine, whereas a conventional linear polyalanine with a similar degree of polymerization shows granule-like structures. The telechelic polyglycine and polyalanine show the crystalline structures of Polyglycine II and antiparallel β-sheet, respectively. It is demonstrated that this method to synthesize telechelic-type polypeptides potentially opens up a pathway to construct novel hierarchical structures by self-assembly. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Star-Shaped Polypeptides: Synthesis and Opportunities for Delivery of Therapeutics.

    Science.gov (United States)

    Byrne, Mark; Murphy, Robert; Kapetanakis, Antonios; Ramsey, Joanne; Cryan, Sally-Ann; Heise, Andreas

    2015-09-17

    Significant advances in the synthesis of polypeptides by N-carboxyanhydride (NCA) polymerisation over the last decade have enabled the design of advanced polypeptide architectures such as star-shaped polypeptides. These materials combine the functionality offered by amino acids with the flexibility of creating stable nanoparticles with adjustable cargo space for therapeutic delivery. This review highlights recent advances in the synthesis of star polypeptides by NCA polymerisation followed by a critical review of the applications of this class of polymer in the delivery of therapeutic agents. This includes examples of traditional small-molecule drugs as well as the emerging class of biologics such as genetic therapeutics (gene delivery). © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Zwitterionic states in gas-phase polypeptide ions revealed by 157-nm ultra-violet photodissociation

    DEFF Research Database (Denmark)

    Kjeldsen, Frank; Silivra, Oleg A; Zubarev, Roman A

    2006-01-01

    within polypeptide clusters. Collision-activated dissociation (CAD) of decarboxylated cations localizes the position of deprotonation. Fragment abundances can be used for the semiquantitative assessment of the branching ratio of deprotonation among different acidic sites, however, the mechanism...

  17. Induction of protein body formation in plant leaves by elastin-like polypeptide fusions

    Directory of Open Access Journals (Sweden)

    Joensuu Jussi J

    2009-08-01

    Full Text Available Abstract Background Elastin-like polypeptides are synthetic biopolymers composed of a repeating pentapeptide 'VPGXG' sequence that are valuable for the simple non-chromatographic purification of recombinant proteins. In addition, elastin-like polypeptide fusions have been shown to enhance the accumulation of a range of different recombinant proteins in plants, thus addressing the major limitation of plant-based expression systems, which is a low production yield. This study's main objectives were to determine the general utility of elastin-like polypeptide protein fusions in various intracellular compartments and to elucidate elastin-like polypeptide's mechanism of action for increasing recombinant protein accumulation in the endoplasmic reticulum of plants. Results The effect of elastin-like polypeptide fusions on the accumulation of green fluorescent protein targeted to the cytoplasm, chloroplasts, apoplast, and endoplasmic reticulum was evaluated. The endoplasmic reticulum was the only intracellular compartment in which an elastin-like polypeptide tag was shown to significantly enhance recombinant protein accumulation. Interestingly, endoplasmic reticulum-targeted elastin-like polypeptide fusions induced the formation of a novel type of protein body, which may be responsible for elastin-like polypeptide's positive effect on recombinant protein accumulation by excluding the heterologous protein from normal physiological turnover. Although expressed in the leaves of plants, these novel protein bodies appeared similar in size and morphology to the prolamin-based protein bodies naturally found in plant seeds. The elastin-like polypeptide-induced protein bodies were highly mobile organelles, exhibiting various dynamic patterns of movement throughout the cells, which were dependent on intact actin microfilaments and a functional actomyosin motility system. Conclusion An endoplasmic reticulum-targeted elastin-like polypeptide fusion approach

  18. Rubella virion polypeptides. Characterization by polyacrylamide gel electrophoresis, isoelectric focusing and peptide mapping

    Energy Technology Data Exchange (ETDEWEB)

    Ho-Terry, L.; Cohen, A. (University Coll. Hospital Medical School, London (UK))

    1982-01-01

    Four polypeptides with molecular weights of 55K, 47K, 45K, and 33K have been resolved by polyacrylamide gel electrophoresis of immune precipitated rubella virus. The 47K and 45K components have similar peptide maps but different isoelectric points so that the same polypeptide may exist in more than one charged form. The 55K and 45K components have similar isoelectric points but different peptide maps showing that similarity of isoelectric point is not evidence of identity.

  19. Vasoactive Intestinal Polypeptide and Muscarinic Receptors: Supersensitivity Induced by Long-Term Atropine Treatment

    Science.gov (United States)

    Hedlund, Britta; Abens, Janis; Bartfai, Tamas

    1983-04-01

    Long-term treatment of rats with atropine induced large increases in the numbers of muscarinic receptors and receptors for vasoactive intestinal polypeptide in the salivary glands. Since receptors for vasoactive intestinal polypeptide coexist with muscarinic receptors on the same neurons in this preparation, the results suggest that a drug that alters the sensitivity of one receptor may also affect the sensitivity of the receptor for a costored transmitter and in this way contribute to the therapeutic or side effects of the drug.

  20. Glucagon-like peptide 1 and glucose-dependent insulinotropic polypeptide: new advances

    DEFF Research Database (Denmark)

    Asmar, Meena; Holst, Jens Juul

    2010-01-01

    This article highlights recent advances in our understanding of glucagon-like peptide 1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP) physiology and their various sites of action beyond the incretin effect.......This article highlights recent advances in our understanding of glucagon-like peptide 1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP) physiology and their various sites of action beyond the incretin effect....

  1. Metal ion-dependent, reversible, protein filament formation by designed beta-roll polypeptides

    Science.gov (United States)

    Scotter, Andrew J; Guo, Meng; Tomczak, Melanie M; Daley, Margaret E; Campbell, Robert L; Oko, Richard J; Bateman, David A; Chakrabartty, Avijit; Sykes, Brian D; Davies, Peter L

    2007-01-01

    Background A right-handed, calcium-dependent β-roll structure found in secreted proteases and repeat-in-toxin proteins was used as a template for the design of minimal, soluble, monomeric polypeptides that would fold in the presence of Ca2+. Two polypeptides were synthesised to contain two and four metal-binding sites, respectively, and exploit stacked tryptophan pairs to stabilise the fold and report on the conformational state of the polypeptide. Results Initial analysis of the two polypeptides in the presence of calcium suggested the polypeptides were disordered. The addition of lanthanum to these peptides caused aggregation. Upon further study by right angle light scattering and electron microscopy, the aggregates were identified as ordered protein filaments that required lanthanum to polymerize. These filaments could be disassembled by the addition of a chelating agent. A simple head-to-tail model is proposed for filament formation that explains the metal ion-dependency. The model is supported by the capping of one of the polypeptides with biotin, which disrupts filament formation and provides the ability to control the average length of the filaments. Conclusion Metal ion-dependent, reversible protein filament formation is demonstrated for two designed polypeptides. The polypeptides form filaments that are approximately 3 nm in diameter and several hundred nm in length. They are not amyloid-like in nature as demonstrated by their behaviour in the presence of congo red and thioflavin T. A capping strategy allows for the control of filament length and for potential applications including the "decoration" of a protein filament with various functional moieties. PMID:17908326

  2. Cholecystokinin, secretin, pancreatic polypeptide in relation to gallbladder dynamics and gastrointestinal interdigestive motility

    DEFF Research Database (Denmark)

    Qvist, N; Oster-Jørgensen, E; Rasmussen, L

    1990-01-01

    Using a combined technique of hepatobiliary scintigraphy and gastrointestinal motility recordings, the changes in blood concentrations of cholecystokinin (CCK), secretin and pancreatic polypeptide (PP) were studied in relation to gastrointestinal motility and gallbladder dynamics in the interdige......Using a combined technique of hepatobiliary scintigraphy and gastrointestinal motility recordings, the changes in blood concentrations of cholecystokinin (CCK), secretin and pancreatic polypeptide (PP) were studied in relation to gastrointestinal motility and gallbladder dynamics...

  3. Correlation between ovarian growth, vitellogenin titer, and yolk polypeptide pattern in the haemolymph of Calliphora vicina

    DEFF Research Database (Denmark)

    Sørensen, Ilona Kryspin; Jensen, P. V.

    1982-01-01

    During the first egg maturation cycle ofCalliphora vicina changes in the vitellogenin titer and yolk polypeptide pattern of the haemolymph are correlated with the intensity of follicular growth, and the rate of yolk deposition.......During the first egg maturation cycle ofCalliphora vicina changes in the vitellogenin titer and yolk polypeptide pattern of the haemolymph are correlated with the intensity of follicular growth, and the rate of yolk deposition....

  4. New Kunitz-Type HCRG Polypeptides from the Sea Anemone Heteractis crispa

    Directory of Open Access Journals (Sweden)

    Irina Gladkikh

    2015-09-01

    Full Text Available Sea anemones are a rich source of Kunitz-type polypeptides that possess not only protease inhibitor activity, but also Kv channels toxicity, analgesic, antihistamine, and anti-inflammatory activities. Two Kunitz-type inhibitors belonging to a new Heteractis crispa RG (HCRG polypeptide subfamily have been isolated from the sea anemone Heteractis crispa. The amino acid sequences of HCRG1 and HCRG2 identified using the Edman degradation method share up to 95% of their identity with the representatives of the HCGS polypeptide multigene subfamily derived from H. crispa cDNA. Polypeptides are characterized by positively charged Arg at the N-terminus as well as P1 Lys residue at their canonical binding loop, identical to those of bovine pancreatic trypsin inhibitor (BPTI. These polypeptides are shown by our current evidence to be more potent inhibitors of trypsin than the known representatives of the HCGS subfamily with P1Thr. The kinetic and thermodynamic characteristics of the intermolecular interactions between inhibitors and serine proteases were determined by the surface plasmon resonance (SPR method. Residues functionally important for polypeptide binding to trypsin were revealed using molecular modeling methods. Furthermore, HCRG1 and HCRG2 possess anti-inflammatory activity, reducing tumor necrosis factor-α (TNF-α and interleukin 6 (IL-6 secretions, as well as proIL-1β expression in lipopolysaccharide (LPS-activated macrophages. However, there was no effect on nitric oxide (NO generation.

  5. New Kunitz-Type HCRG Polypeptides from the Sea Anemone Heteractis crispa.

    Science.gov (United States)

    Gladkikh, Irina; Monastyrnaya, Margarita; Zelepuga, Elena; Sintsova, Oksana; Tabakmakher, Valentin; Gnedenko, Oksana; Ivanov, Alexis; Hua, Kuo-Feng; Kozlovskaya, Emma

    2015-09-24

    Sea anemones are a rich source of Kunitz-type polypeptides that possess not only protease inhibitor activity, but also Kv channels toxicity, analgesic, antihistamine, and anti-inflammatory activities. Two Kunitz-type inhibitors belonging to a new Heteractis crispa RG (HCRG) polypeptide subfamily have been isolated from the sea anemone Heteractis crispa. The amino acid sequences of HCRG1 and HCRG2 identified using the Edman degradation method share up to 95% of their identity with the representatives of the HCGS polypeptide multigene subfamily derived from H. crispa cDNA. Polypeptides are characterized by positively charged Arg at the N-terminus as well as P1 Lys residue at their canonical binding loop, identical to those of bovine pancreatic trypsin inhibitor (BPTI). These polypeptides are shown by our current evidence to be more potent inhibitors of trypsin than the known representatives of the HCGS subfamily with P1Thr. The kinetic and thermodynamic characteristics of the intermolecular interactions between inhibitors and serine proteases were determined by the surface plasmon resonance (SPR) method. Residues functionally important for polypeptide binding to trypsin were revealed using molecular modeling methods. Furthermore, HCRG1 and HCRG2 possess anti-inflammatory activity, reducing tumor necrosis factor-α (TNF-α) and interleukin 6 (IL-6) secretions, as well as proIL-1β expression in lipopolysaccharide (LPS)-activated macrophages. However, there was no effect on nitric oxide (NO) generation.

  6. Effects of side group functionality and molecular weight on the activity of synthetic antimicrobial polypeptides.

    Science.gov (United States)

    Engler, Amanda C; Shukla, Anita; Puranam, Sravanthi; Buss, Hilda G; Jreige, Nina; Hammond, Paula T

    2011-05-09

    The rapid emergence of antibiotic-resistant bacteria along with increasing difficulty in biofilm treatment has caused an immediate need for the development of new classes of antimicrobial therapeutics. We have developed a library of antimicrobial polypeptides, prepared by the ring-opening polymerization of γ-propargyl-L-glutamate N-carboxyanhydride and the alkyne-azide cycloaddition click reaction, which mimic the favorable characteristics of naturally occurring antimicrobial peptides (AmPs). AmPs are known not to cause drug resistance as well as prevent bacteria attachment on surfaces. The ease and scale of synthesis of the antimicrobial polypeptides developed here are significantly improved over the traditional Merrifield synthetic peptide approaches needed for naturally occurring antimicrobial peptides and avoids the unique challenges of biosynthetic pathways. The polypeptides range in length from 30 to 140 repeat units and can have varied side group functionality, including primary, secondary, tertiary, and quaternary amines with hydrocarbon side chains ranging from 1 to 12 carbons long. Overall, we find these polypeptides to exhibit broad-spectrum activity against both Gram positive and Gram negative bacteria, namely, S. aureus and E. coli , while having very low hemolytic activity. Many of the polypeptides can also be used as surface coatings to prevent bacterial attachment. The polypeptide library developed in this work addresses the need for effective biocompatible therapeutics for drug delivery and medical device coatings.

  7. Algorithm to design inhibitors using stereochemically mixed l,d polypeptides: Validation against HIV protease.

    Science.gov (United States)

    Gupta, Pooja; Durani, Susheel

    2015-11-01

    Polypeptides have potential to be designed as drugs or inhibitors against the desired targets. In polypeptides, every chiral α-amino acid has enantiomeric structural possibility to become l or d amino acids and can be used as design monomer. Among the various possibilities, use of stereochemistry as a design tool has potential to determine both functional specificity and metabolic stability of the designed polypeptides. The polypeptides with mixed l,d amino acids are a class of peptidomimitics, an attractive drug like molecules and also less susceptible to proteolytic activities. Therefore in this study, a three step algorithm is proposed to design the polypeptides against desired drug targets. For this, all possible configurational isomers of mixed l,d polyleucine (Ac-Leu8-NHMe) structure were randomly modeled with simulated annealing molecular dynamics and the resultant library of discrete folds were scored against HIV protease as a model target. The best scored folds of mixed l,d structures were inverse optimized for sequences in situ and the resultant sequences as inhibitors were validated for conformational integrity using molecular dynamics. This study presents and validates an algorithm to design polypeptides of mixed l,d structures as drugs/inhibitors by inverse fitting them as molecular ligands against desired target. Copyright © 2015 Elsevier B.V. All rights reserved.

  8. Stimuli responsive synthetic polypeptides derived from N-carboxyanhydride (NCA) polymerisation.

    Science.gov (United States)

    Huang, Jin; Heise, Andreas

    2013-09-07

    The progress in NCA polymerisation combined with advanced orthogonal functionalization techniques as well as the integration with other controlled polymerisation techniques significantly widened the scope of polypeptide building blocks in a variety of material designs. Well-defined synthetic stimuli-responsive polypeptides ("smart" polypeptides) with incorporated different functionalities have been extensively explored over the past decades. Their significant potential lies in the fact that they combine natural and synthetic elements both contributing to their properties. These novel materials have potential applications in biomedicine and biotechnology including tissue engineering, drug delivery and biodiagnostics. Responsive polypeptides are capable of undergoing conformational changes and phase transition accompanied by variations in the chemical and physical changes of the polypeptides in response to an external stimulus such as biologically relevant species (i.e. biomolecules), the environment (i.e. temperature, pH), irradiation with light or exposure to a magnetic field. In this review, the recent developments including synthetic strategies and applications of synthetic stimuli-responsive homo- and block polypeptides are reviewed.

  9. PODAAC-SST00-1D1M1

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set contains sea surface temperature (SST) data on a monthly 1 degree grid from the Advanced Microwave Scanning Radiometer (AMSR-E) aboard NASA's Aqua...

  10. PODAAC-DYNTO-1D1M1

    Data.gov (United States)

    National Aeronautics and Space Administration — The absolute dynamic topography data (similar to sea level but with respect to the geoid) are on monthly 1 degree grids. These data were generated to help support...

  11. PODAAC-SSTNO-1D1M1

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set contains the number of observations corresponding to sea surface temperature (SST) data on monthly 1 degree grids from the Advanced Microwave Scanning...

  12. Binary polypeptide system for permanent and oriented protein immobilization

    Directory of Open Access Journals (Sweden)

    Bailes Julian

    2010-05-01

    Full Text Available Abstract Background Many techniques in molecular biology, clinical diagnostics and biotechnology rely on binary affinity tags. The existing tags are based on either small molecules (e.g., biotin/streptavidin or glutathione/GST or peptide tags (FLAG, Myc, HA, Strep-tag and His-tag. Among these, the biotin-streptavidin system is most popular due to the nearly irreversible interaction of biotin with the tetrameric protein, streptavidin. The major drawback of the stable biotin-streptavidin system, however, is that neither of the two tags can be added to a protein of interest via recombinant means (except for the Strep-tag case leading to the requirement for chemical coupling. Results Here we report a new immobilization system which utilizes two monomeric polypeptides which self-assemble to produce non-covalent yet nearly irreversible complex which is stable in strong detergents, chaotropic agents, as well as in acids and alkali. Our system is based on the core region of the tetra-helical bundle known as the SNARE (soluble N-ethylmaleimide-sensitive factor attachment protein receptor complex. This irreversible protein attachment system (IPAS uses either a shortened syntaxin helix and fused SNAP25-synaptobrevin or a fused syntaxin-synaptobrevin and SNAP25 allowing a two-component system suitable for recombinant protein tagging, capture and immobilization. We also show that IPAS is suitable for use with traditional beads and chromatography, planar surfaces and Biacore, gold nanoparticles and for protein-protein interaction in solution. Conclusions IPAS offers an alternative to chemical cross-linking, streptavidin-biotin system and to traditional peptide affinity tags and can be used for a wide range of applications in nanotechnology and molecular sciences.

  13. Binary polypeptide system for permanent and oriented protein immobilization.

    Science.gov (United States)

    Ferrari, Enrico; Darios, Frédéric; Zhang, Fan; Niranjan, Dhevahi; Bailes, Julian; Soloviev, Mikhail; Davletov, Bazbek

    2010-05-12

    Many techniques in molecular biology, clinical diagnostics and biotechnology rely on binary affinity tags. The existing tags are based on either small molecules (e.g., biotin/streptavidin or glutathione/GST) or peptide tags (FLAG, Myc, HA, Strep-tag and His-tag). Among these, the biotin-streptavidin system is most popular due to the nearly irreversible interaction of biotin with the tetrameric protein, streptavidin. The major drawback of the stable biotin-streptavidin system, however, is that neither of the two tags can be added to a protein of interest via recombinant means (except for the Strep-tag case) leading to the requirement for chemical coupling. Here we report a new immobilization system which utilizes two monomeric polypeptides which self-assemble to produce non-covalent yet nearly irreversible complex which is stable in strong detergents, chaotropic agents, as well as in acids and alkali. Our system is based on the core region of the tetra-helical bundle known as the SNARE (soluble N-ethylmaleimide-sensitive factor attachment protein receptor) complex. This irreversible protein attachment system (IPAS) uses either a shortened syntaxin helix and fused SNAP25-synaptobrevin or a fused syntaxin-synaptobrevin and SNAP25 allowing a two-component system suitable for recombinant protein tagging, capture and immobilization. We also show that IPAS is suitable for use with traditional beads and chromatography, planar surfaces and Biacore, gold nanoparticles and for protein-protein interaction in solution. IPAS offers an alternative to chemical cross-linking, streptavidin-biotin system and to traditional peptide affinity tags and can be used for a wide range of applications in nanotechnology and molecular sciences.

  14. Self-assembled micelles of amphiphilic poly(L-phenylalanine)-b-poly(L-serine) polypeptides for tumor-targeted delivery.

    Science.gov (United States)

    Zhao, Ziming; Wang, Yu; Han, Jin; Wang, Keli; Yang, Dan; Yang, Yihua; Du, Qian; Song, Yuanjian; Yin, Xiaoxing

    2014-01-01

    The aim of this work was to design, synthesize, and characterize self-assembled micelles based on polypeptides as a potential antitumor drug carrier. Amphiphilic poly(L-phenylalanine)-b-poly(L-serine) (PFS) polypeptides were obtained through the polymerization of N-carboxyanhydride. As a novel hydrophilic segment, poly(L-serine) was utilized to enhance tumor targeting due to a large demand of tumors for serine. PFS could self-assemble into micelles with an average diameter of 110-240 nm and a slightly negative charge. PFS polypeptides adopted random coil in pH 7.4 phosphate-buffered saline and could partly transform to α-helix induced by trifluoroethanol. PFS micelles with a low critical micelle concentration of 4.0 μg mL(-1) were stable in pH 5-9 buffers and serum albumin solution. PFS micelles had a loading capacity of 3.8% for coumarin-6 and exhibited a sustained drug release. Coumarin-6 loaded rhodamine B isothiocyanate-labeled PFS micelles were incubated with Huh-7 tumor cells to study the correlation between drugs and carriers during endocytosis. The uptake of drugs was consistent with the micelles, illustrating that the intracellular transport of drugs highly depended on the micelles. PFS micelles diffused in whole cytoplasm while coumarin-6 assumed localized distribution, suggesting that the micelles could release the loaded drugs in particular areas. The internalization mechanism of PFS micelles was involved with clathrin-mediated endocytosis and macropinocytosis. Excess serine inhibited the uptake of PFS micelles, which demonstrated that serine receptors played a positive role in the internalization of PFS. The more interesting thing was that the uptake inhibition impacted on normal cells but not on tumor cells at the physiological concentration of serine. The difference in the uptake of PFS micelles was fourfold as high between the tumor cells and the normal cells, which indicated that PFS micelles had good tumor targeting in vitro. In conclusion, PFS

  15. Side-chain-controlled self-assembly of polystyrene-polypeptide miktoarm star copolymers

    KAUST Repository

    Junnila, Susanna

    2012-03-27

    We show how the self-assembly of miktoarm star copolymers can be controlled by modifying the side chains of their polypeptide arms, using A 2B and A 2B 2 type polymer/polypeptide hybrids (macromolecular chimeras). Initially synthesized PS 2PBLL and PS 2PBLL 2 (PS, polystyrene; PBLL, poly(ε-tert-butyloxycarbonyl-l-lysine) ) miktoarms were first deprotected to PS 2PLLHCl and PS 2PLLHCl 2 miktoarms (PLLHCl, poly(l-lysine hydrochloride)) and then complexed ionically with sodium dodecyl sulfonate (DS) to give the supramolecular complexes PS 2PLL(DS) and PS 2(PLL(DS)) 2. The solid-state self-assemblies of these six miktoarm systems were studied by transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), and small- and wide-angle X-ray scattering (SAXS, WAXS). The side chains of the polypeptide arms were observed to have a large effect on the solubility, polypeptide conformation, and self-assembly of the miktoarms. Three main categories were observed: (i) lamellar self-assemblies at the block copolymer length scale with packed layers of α-helices in PS 2PBLL and PS 2PBLL 2; (ii) charge-clustered polypeptide micelles with less-defined conformations in a nonordered lattice within a PS matrix in PS 2PLLHCl and PS 2PLLHCl 2; (iii) lamellar polypeptide-surfactant self-assemblies with β-sheet conformation in PS 2PLL(DS) and PS 2(PLL(DS)) 2 which dominate over the formation of block copolymer scale structures. Differences between the 3- and 4-arm systems illustrate how packing frustration between the coil-like PS arms and rigid polypeptide conformations can be relieved by the right number of arms, leading to differences in the extent of order. © 2012 American Chemical Society.

  16. The mining of toxin-like polypeptides from EST database by single residue distribution analysis

    Science.gov (United States)

    2011-01-01

    Background Novel high throughput sequencing technologies require permanent development of bioinformatics data processing methods. Among them, rapid and reliable identification of encoded proteins plays a pivotal role. To search for particular protein families, the amino acid sequence motifs suitable for selective screening of nucleotide sequence databases may be used. In this work, we suggest a novel method for simplified representation of protein amino acid sequences named Single Residue Distribution Analysis, which is applicable both for homology search and database screening. Results Using the procedure developed, a search for amino acid sequence motifs in sea anemone polypeptides was performed, and 14 different motifs with broad and low specificity were discriminated. The adequacy of motifs for mining toxin-like sequences was confirmed by their ability to identify 100% toxin-like anemone polypeptides in the reference polypeptide database. The employment of novel motifs for the search of polypeptide toxins in Anemonia viridis EST dataset allowed us to identify 89 putative toxin precursors. The translated and modified ESTs were scanned using a special algorithm. In addition to direct comparison with the motifs developed, the putative signal peptides were predicted and homology with known structures was examined. Conclusions The suggested method may be used to retrieve structures of interest from the EST databases using simple amino acid sequence motifs as templates. The efficiency of the procedure for directed search of polypeptides is higher than that of most currently used methods. Analysis of 39939 ESTs of sea anemone Anemonia viridis resulted in identification of five protein precursors of earlier described toxins, discovery of 43 novel polypeptide toxins, and prediction of 39 putative polypeptide toxin sequences. In addition, two precursors of novel peptides presumably displaying neuronal function were disclosed. PMID:21281459

  17. The effect of gastric inhibitory polypeptide on intestinal glucose absorption and intestinal motility in mice

    Energy Technology Data Exchange (ETDEWEB)

    Ogawa, Eiichi [Department of Diabetes and Clinical Nutrition, Graduate School of Medicine, Kyoto University (Japan); Hosokawa, Masaya [Department of Diabetes and Clinical Nutrition, Graduate School of Medicine, Kyoto University (Japan); Faculty of Human Sciences, Tezukayama Gakuin University, Osaka (Japan); Harada, Norio; Yamane, Shunsuke; Hamasaki, Akihiro; Toyoda, Kentaro; Fujimoto, Shimpei; Fujita, Yoshihito; Fukuda, Kazuhito [Department of Diabetes and Clinical Nutrition, Graduate School of Medicine, Kyoto University (Japan); Tsukiyama, Katsushi; Yamada, Yuichiro [Department of Diabetes and Clinical Nutrition, Graduate School of Medicine, Kyoto University (Japan); Department of Internal Medicine, Division of Endocrinology, Diabetes and Geriatric Medicine, Akita University School of Medicine, Akita (Japan); Seino, Yutaka [Department of Diabetes and Clinical Nutrition, Graduate School of Medicine, Kyoto University (Japan); Kansai Electric Power Hospital, Osaka (Japan); Inagaki, Nobuya, E-mail: inagaki@metab.kuhp.kyoto-u.ac.jp [Department of Diabetes and Clinical Nutrition, Graduate School of Medicine, Kyoto University (Japan); CREST of Japan Science and Technology Cooperation (JST), Kyoto (Japan)

    2011-01-07

    Research highlights: {yields} Exogenous GIP inhibits intestinal motility through a somatostatin-mediated pathway. {yields} Exogenous GIP inhibits intestinal glucose absorption by reducing intestinal motility. {yields} The GIP-receptor-mediated action in intestine does not involve in GLP-1-mediated pathway. -- Abstract: Gastric inhibitory polypeptide (GIP) is released from the small intestine upon meal ingestion and increases insulin secretion from pancreatic {beta} cells. Although the GIP receptor is known to be expressed in small intestine, the effects of GIP in small intestine are not fully understood. This study was designed to clarify the effect of GIP on intestinal glucose absorption and intestinal motility. Intestinal glucose absorption in vivo was measured by single-pass perfusion method. Incorporation of [{sup 14}C]-glucose into everted jejunal rings in vitro was used to evaluate the effect of GIP on sodium-glucose co-transporter (SGLT). Motility of small intestine was measured by intestinal transit after oral administration of a non-absorbed marker. Intraperitoneal administration of GIP inhibited glucose absorption in wild-type mice in a concentration-dependent manner, showing maximum decrease at the dosage of 50 nmol/kg body weight. In glucagon-like-peptide-1 (GLP-1) receptor-deficient mice, GIP inhibited glucose absorption as in wild-type mice. In vitro examination of [{sup 14}C]-glucose uptake revealed that 100 nM GIP did not change SGLT-dependent glucose uptake in wild-type mice. After intraperitoneal administration of GIP (50 nmol/kg body weight), small intestinal transit was inhibited to 40% in both wild-type and GLP-1 receptor-deficient mice. Furthermore, a somatostatin receptor antagonist, cyclosomatostatin, reduced the inhibitory effect of GIP on both intestinal transit and glucose absorption in wild-type mice. These results demonstrate that exogenous GIP inhibits intestinal glucose absorption by reducing intestinal motility through a somatostatin

  18. The effect of gastric inhibitory polypeptide on intestinal glucose absorption and intestinal motility in mice

    International Nuclear Information System (INIS)

    Ogawa, Eiichi; Hosokawa, Masaya; Harada, Norio; Yamane, Shunsuke; Hamasaki, Akihiro; Toyoda, Kentaro; Fujimoto, Shimpei; Fujita, Yoshihito; Fukuda, Kazuhito; Tsukiyama, Katsushi; Yamada, Yuichiro; Seino, Yutaka; Inagaki, Nobuya

    2011-01-01

    Research highlights: → Exogenous GIP inhibits intestinal motility through a somatostatin-mediated pathway. → Exogenous GIP inhibits intestinal glucose absorption by reducing intestinal motility. → The GIP-receptor-mediated action in intestine does not involve in GLP-1-mediated pathway. -- Abstract: Gastric inhibitory polypeptide (GIP) is released from the small intestine upon meal ingestion and increases insulin secretion from pancreatic β cells. Although the GIP receptor is known to be expressed in small intestine, the effects of GIP in small intestine are not fully understood. This study was designed to clarify the effect of GIP on intestinal glucose absorption and intestinal motility. Intestinal glucose absorption in vivo was measured by single-pass perfusion method. Incorporation of [ 14 C]-glucose into everted jejunal rings in vitro was used to evaluate the effect of GIP on sodium-glucose co-transporter (SGLT). Motility of small intestine was measured by intestinal transit after oral administration of a non-absorbed marker. Intraperitoneal administration of GIP inhibited glucose absorption in wild-type mice in a concentration-dependent manner, showing maximum decrease at the dosage of 50 nmol/kg body weight. In glucagon-like-peptide-1 (GLP-1) receptor-deficient mice, GIP inhibited glucose absorption as in wild-type mice. In vitro examination of [ 14 C]-glucose uptake revealed that 100 nM GIP did not change SGLT-dependent glucose uptake in wild-type mice. After intraperitoneal administration of GIP (50 nmol/kg body weight), small intestinal transit was inhibited to 40% in both wild-type and GLP-1 receptor-deficient mice. Furthermore, a somatostatin receptor antagonist, cyclosomatostatin, reduced the inhibitory effect of GIP on both intestinal transit and glucose absorption in wild-type mice. These results demonstrate that exogenous GIP inhibits intestinal glucose absorption by reducing intestinal motility through a somatostatin-mediated pathway rather

  19. Recent advances in amino acid N-carboxyanhydrides and synthetic polypeptides: chemistry, self-assembly and biological applications.

    Science.gov (United States)

    Lu, Hua; Wang, Jing; Song, Ziyuan; Yin, Lichen; Zhang, Yanfeng; Tang, Haoyu; Tu, Chunlai; Lin, Yao; Cheng, Jianjun

    2014-01-07

    Polypeptides are fascinating materials with unique properties for various biological materials. We highlight here recent advances in amino acid N-carboxyanhydrides (NCAs) and synthetic polypeptides from the aspects of chemistry, self-assembly and biological applications. New synthetic methodologies, mechanistic studies and optimization of polymerization conditions for the preparation of well-defined novel polypeptides are comprehensively reviewed and evaluated. Functional polypeptides, mostly prepared from novel NCA monomers, with ultra-stable helical conformation, stimuli-sensitive properties, or glycoprotein mimetics are summarized. We also highlight a number of interesting self-assembled structures of polypeptides in solid state and solution, with particular emphasis on those structures other than amphiphilic self-assembly. The biological applications of polypeptides in drug and gene delivery are also reviewed. Future directions and perspectives are discussed in the conclusion.

  20. Principles Governing the Self Assembly of Polypeptide Nanoparticles

    Science.gov (United States)

    Wahome, Newton

    Self assembling systems on the nanometer scale afford the advantage of being able to control submicron level events. In this study, we focus on the self-assembling polypeptide nanoparticles (SAPN). The SAPN scaffold is made up of oligomerizing domains that align along the principle rotational axes of icosahedral symmetry. By aligning them along these axes, a particle with spherical geometry can be achieved. This particle can be utilized as a vaccine, as a drug delivery vehicle, or as a biomedical imaging device. This research will try to answer why the SAPN self-assembles into distinct molecular weight ranges while mostly maintaining a spherical morphology. The first means will be theoretical and computational, where we will utilize a mathematical formalism to find out how the packing of SAPN's monomeric units can occur within symmetric space. Then molecular dynamics will be run within this symmetric space to test the per amino acid residue susceptibility of SAPN towards becoming polymorphic in nature. Means for examining the aggregation propensity of SAPN will be also be tested. Specifically, the relationship of different sequences of SAPN with pH will be elucidated. Co-assembly of SAPN to reduce the surface density of an aggregation prone epitope will be tested. Also, aggregation reduction consisting of the exchange of an anionic denaturant with a positively charged suppressor in order to mitigate a priori peptide association and misfolding, will also be attempted. SAPN has been shown to be an immunogenic platform for the presentation of pathogen derived antigens. We will attempt to show the efficacy of presenting an antigen from HIV-1 which is structurally restrained to best match the native conformation on the virus. Immunological studies will be performed to test the effect of this approach, as well testing the antigenicity of the nanoparticle in the absence of adjuvant. Finally, the antigen presenting nanoparticles will undergo formulation testing, to measure

  1. Polycondensation of Asparagine-comprising Dipeptides in Aqueous Media-A Simulation of Polypeptide Formation in Primordial Earth Hydrosphere

    Science.gov (United States)

    Munegumi, Toratane; Tanikawa, Naoya

    2017-09-01

    Asparagine and aspartic acid might have mutually transformed in the primordial hydrosphere of the earth, if ammonia and aspartic acid had existed in equilibrium. These amino acids seem to contribute to polypeptides, while the simple amino acids glycine and alanine easily form cyclic dipeptides and do not achieve long peptide chains. Asparagine-comprising dipeptides contribute some kinds of activation forms of dipeptides because these can polymerize faster than asparagine only. The new finding of polypeptide formation suggests a pathway of sequential polypeptides to evolve a diversity of polypeptides.

  2. Brachytherapy Using Elastin-Like Polypeptides with (131)I Inhibit Tumor Growth in Rabbits with VX2 Liver Tumor.

    Science.gov (United States)

    Liu, Xinpei; Shen, Yiming; Zhang, Xuqian; Lin, Rui; Jia, Qiang; Chang, Yixiang; Liu, Wenge; Liu, Wentian

    2016-10-01

    Brachytherapy is a targeted type of radiotherapy utilized in the treatment of cancers. Elastin-like polypeptides are a unique class of genetically engineered peptide polymers that have several attractive properties for brachytherapy. To explore the feasibility and application of brachytherapy for VX2 liver tumor using elastin-like polypeptides with (131)I so as to provide reliable experimental evidence for a new promising treatment of liver cancer. Elastin-like polypeptide as carrier was labeled with (131)I using the iodogen method. Ten eligible rabbits with VX2 liver tumor were randomly divided into the treatment group (n = 5) and control group (n = 5). The treatment group received brachytherapy using elastin-like polypeptide with (131)I, and in the control group, elastin-like polypeptide was injected into the VX2 liver tumor as a control. Periodic biochemical and imaging surveillances were required to assess treatment efficacy. The stability of elastin-like polypeptide with (131)I in vitro was maintained at over 96.8 % for 96 h. Biochemistry and imaging indicated brachytherapy using elastin-like polypeptide with (131)I for liver tumor can improve liver function and inhibit tumor growth (P polypeptide can be an ideal carrier of (131)I and have high labeling efficiency, radiochemical purity and stability. Brachytherapy using elastin-like polypeptide with (131)I for liver tumor is a useful therapy that possesses high antitumor efficacy advantages.

  3. Fabrication of genetically engineered polypeptide@quantum dots hybrid nanogels for targeted imaging

    Science.gov (United States)

    Yang, Jie; Yao, Ming-Hao; Zhao, Dong-Hui; Zhang, Xiao-Shuai; Jin, Rui-Mei; Zhao, Yuan-Di; Liu, Bo

    2017-08-01

    Nanogels have been widely used as multifunctional drug delivery carriers because of high water content, biocompatibility, and high loading capability. We designed and biosynthesized two triblock artificial polypeptides PC10A and PC10ARGD as vehicles for encapsulating hydrophobic materials. These polypeptides can form nanogels by self-assembly when the concentration is below 2% ( w/ v). The physical properties of nanogels, including size, surface potential, and targeting domain, are able to be tuned. Hydrophobic materials from molecular size to nano-size can be loaded into the polypeptide nanogels to form hybrid nanogels. Hydrophobic quantum dots CdSe@ZnS below 10 nM were loaded into the polypeptide nanogels by ultrasonic treatment. Encapsulation endows hydrophobic QDs with good tunability of size, water solubility, stability, targeting, and biocompatibility. PC10ARGD nanogels and PC10ARGD@QDs hybrid nanogels showed excellent biocompatibility, which the cellular viabilities of HeLa and MCF-7 cells treated with 1% PC10ARGD nanogels and PC10ARGD@QDs hybrid nanogels contained 20 nM QDs were above 90 and 80%, respectively. PC10ARGD@QDs hybrid nanogels with an arginine-glycine-aspartic acid motif present efficient receptor-mediated endocytosis in α v β 3 overexpressing HeLa cells but not in the control MCF-7 cells as analyzed by confocal microscopy. These results demonstrate that such polypeptide nanogels as nanocarriers are expected to have great potential applications in biomedicine.

  4. Congenital deficiency of two polypeptide subunits of the iron-protein fragment of mitochondrial complex I.

    Science.gov (United States)

    Moreadith, R W; Cleeter, M W; Ragan, C I; Batshaw, M L; Lehninger, A L

    1987-02-01

    Recently, we described a patient with severe lactic acidosis due to congenital complex I (NADH-ubiquinone oxidoreductase) deficiency. We now report further enzymatic and immunological characterizations. Both NADH and ferricyanide titrations of complex I activity (measured as NADH-ferricyanide reductase) were distinctly altered in the mitochondria from the patient's tissues. In addition, antisera against complex I immunoprecipitated NADH-ferricyanide reductase from the control but not the patient's mitochondria. However, immunoprecipitation and sodium dodecyl sulfate-polyacrylamide gel electrophoresis of complex I polypeptides demonstrated that the majority of the 25 polypeptides comprising complex I were present in the affected mitochondria. A more detailed analysis using subunit selective antisera against the main polypeptides of the iron-protein fragments of complex I revealed a selective absence of the 75- and 13-kD polypeptides. These findings suggest that the underlying basis for this patient's disease was a congenital deficiency of at least two polypeptides comprising the iron-protein fragment of complex I, which resulted in the inability to correctly assemble a functional enzyme complex.

  5. Competition between surface adsorption and folding of fibril-forming polypeptides.

    Science.gov (United States)

    Ni, Ran; Kleijn, J Mieke; Abeln, Sanne; Cohen Stuart, Martien A; Bolhuis, Peter G

    2015-02-01

    Self-assembly of polypeptides into fibrillar structures can be initiated by planar surfaces that interact favorably with certain residues. Using a coarse-grained model, we systematically studied the folding and adsorption behavior of a β-roll forming polypeptide. We find that there are two different folding pathways depending on the temperature: (i) at low temperature, the polypeptide folds in solution into a β-roll before adsorbing onto the attractive surface; (ii) at higher temperature, the polypeptide first adsorbs in a disordered state and folds while on the surface. The folding temperature increases with increasing attraction as the folded β-roll is stabilized by the surface. Surprisingly, further increasing the attraction lowers the folding temperature again, as strong attraction also stabilizes the adsorbed disordered state, which competes with folding of the polypeptide. Our results suggest that to enhance the folding, one should use a weakly attractive surface. They also explain the recent experimental observation of the nonmonotonic effect of charge on the fibril formation on an oppositely charged surface [C. Charbonneau et al., ACS Nano 8, 2328 (2014)].

  6. Ultrastructural and biochemical detection of biotin and biotinylated polypeptides in Schistosoma mansoni

    Directory of Open Access Journals (Sweden)

    Santos P.R.P.

    1997-01-01

    Full Text Available Biotinylation is proposed for the identification of surface proteins in Schistosoma mansoni using the streptavidin-HRP conjugate for the detection of labeled polypeptides. However, control samples also showed several endogenous biotinylated polypeptides. In an attempt to determine the possibility of nonspecific binding between the streptavidin-HRP conjugate and polypeptides from S. mansoni, the conjugate was blocked with biotinamidecaproate-N-hydroxysuccinimide ester (BcapNHS before biotin-streptavidin blotting. No bands were detected on the nitrocellulose sheet, demonstrating the specific recognition of biotin by the streptavidin present in the conjugate. Whole cercariae and cercarial bodies and tails showed several endogenous biotinylated polypeptides. The biotin concentration was 13 µg/190,000 cercariae. Adult worms presented less endogenous biotinylated polypeptides than cercariae. These results may be due to changes in the environment from aerobic to anaerobic conditions when cercarial bodies (schistosomula are transformed into adult worms and a decrease in CO2 production may occur. Cercariae, cercarial bodies and adult male worms were examined by transmission electron microscopy employing an avidin-colloidal gold conjugate for the detection of endogenous biotin. Gold particles were distributed mainly on the muscle fibers, but dispersed granules were observed in the tegument, mitochondria and cytosol. The discovery of endogenous biotin in S. mansoni should be investigated in order to clarify the function of this vitamin in the parasite

  7. Competition between surface adsorption and folding of fibril-forming polypeptides

    Science.gov (United States)

    Ni, Ran; Kleijn, J. Mieke; Abeln, Sanne; Cohen Stuart, Martien A.; Bolhuis, Peter G.

    2015-02-01

    Self-assembly of polypeptides into fibrillar structures can be initiated by planar surfaces that interact favorably with certain residues. Using a coarse-grained model, we systematically studied the folding and adsorption behavior of a β -roll forming polypeptide. We find that there are two different folding pathways depending on the temperature: (i) at low temperature, the polypeptide folds in solution into a β -roll before adsorbing onto the attractive surface; (ii) at higher temperature, the polypeptide first adsorbs in a disordered state and folds while on the surface. The folding temperature increases with increasing attraction as the folded β -roll is stabilized by the surface. Surprisingly, further increasing the attraction lowers the folding temperature again, as strong attraction also stabilizes the adsorbed disordered state, which competes with folding of the polypeptide. Our results suggest that to enhance the folding, one should use a weakly attractive surface. They also explain the recent experimental observation of the nonmonotonic effect of charge on the fibril formation on an oppositely charged surface [C. Charbonneau et al., ACS Nano 8, 2328 (2014), 10.1021/nn405799t].

  8. Fluorescence probe of polypeptide conformational dynamics in gas phase and in solution

    Science.gov (United States)

    Iavarone, Anthony T.; Meinen, Jan; Schulze, Susanne; Parks, Joel H.

    2006-07-01

    Fluorescence measurements of polypeptides derivatized with the fluorescent dye BODIPY TMR have been used to probe the polypeptide conformational dynamics as a function of temperature and charge state. Measurements of (BODIPY TMR)-[Pro]n-Arg-Trp and (BODIPY TMR)-[Gly-Ser]m-Arg-Trp have been performed for charge states 1+ and 2+ of n = 4 and 10 and m = 2 and 5. The 2+ charge states of both of these polypeptides exhibit similar temperature dependences for equal chain lengths (n = 4, m = 2 and n = 10, m = 5) and suggest conformations dominated by Coulomb repulsion. In the absence of such Coulomb repulsion, the 1+ charge state conformations appear to be characterized by the flexibility of the polypeptide chain for which [Gly-Ser]m > [Pro]n. Comparisons of these gas phase polypeptide measurements with corresponding measurements in solution provide a direct measure of the effects of solvent on the conformational dynamics. The change in fluorescence as a function of temperature in the gas phase is two orders of magnitude greater than that in solution, a dramatic result we attribute to the restrictions on intramolecular dynamics imposed by diffusion-limited kinetics and the lack of shielding by solvent. Measurements were also made of unsolvated Pron peptides without the tryptophan (Trp) residue to isolate the interaction of the fluorescent dye with charges.

  9. Comparison between the polypeptide profile of halophilic bacteria and salt tolerant plants.

    Science.gov (United States)

    Muñoz, G; González, C; Flores, P; Prado, B; Campos, V

    1997-12-01

    Changes in the polypeptide profile induced by salt stress in halotolerant and halophilic bacteria, isolated from the Atacama desert (northern Chile), were compared with those in the cotyledons of Prosopis chilensis (Leguminoseae) seedlings, a salt tolerant plant. SDS-PAGE analyses show the presence of four predominant polypeptides, with molecular weights around 78, 70, 60 and 44 kDa respectively, both in bacteria and in cotyledons from P. chilensis seedlings raised under salt stress conditions. Moreover, the 60 and 44 kDa polypeptides seem to be salt responsive, since their concentration increases with increasing NaCl in the growth medium. Our results suggest a common mechanism for salt tolerance in prokaryotes and in eukaryotes.

  10. Polypeptides with quaternary phosphonium side chains: synthesis, characterization, and cell-penetrating properties.

    Science.gov (United States)

    Song, Ziyuan; Zheng, Nan; Ba, Xiaochu; Yin, Lichen; Zhang, Rujing; Ma, Liang; Cheng, Jianjun

    2014-04-14

    Polypeptides bearing quaternary phosphonium side chains were synthesized via controlled ring-opening polymerization of chlorine-functionalized amino acid N-carboxyanhydride monomers followed by one-step nucleophilic substitution reaction with triethylphosphine. The conformation of the resulting polypeptides can be controlled by modulating the side-chain length and α-carbon stereochemistry. The phosphonium-based poly(l-glutamate) derivatives with 11 σ-bond backbone-to-charge distance adopt stable α-helical conformation against pH and ionic strength changes. These helical, quaternary phosphonium-bearing polypeptides exhibit higher cell-penetrating capability than their racemic and random-coiled analogues. They enter cells mainly via an energy-independent, nonendocytic cell membrane transduction mechanism and exhibit low cytotoxicity, substantiating their potential use as a safe and effective cell-penetrating agent.

  11. Effect of oxygen on morphogenesis and polypeptide expression by Mucor racemosus

    International Nuclear Information System (INIS)

    Phillips, G.J.; Borgia, P.T.

    1985-01-01

    The morphology of Mucor racemosus in cultures continuously sparged with nitrogen gas was investigated. When appropriate precautions were taken to prevent oxygen from entering the cultures, the morphology of the cells was uniformly yeastlike irrespective of the N 2 flow rate. When small amounts of oxygen entered the cultures the resulting microaerobic conditions evoked mycelial development. Polypeptides synthesized by aerobic mycelia, microaerobic mycelia, anaerobic yeasts, and yeasts grown in a CO 2 atmosphere were compared by two-dimensional gel electrophoresis. The results indicated that a large number of differences in polypeptide expression exist when microaerobic mycelia or anaerobic yeasts are compared with aerobic mycelia and that these alterations correlate with a change from an oxidative to a fermentative metabolic mode. The authors hypothesize that oxygen regulates the expression of polypeptides involved in both the metabolic mode and in morphogenesis

  12. Analysis of urine composition in type Ⅱ diabetic mice after intervention therapy using holothurian polypeptides

    Science.gov (United States)

    Li, Yanyan; Xu, Jiajie; Su, Xiurong

    2017-07-01

    Hydrolysates and peptide fractions (PF) obtained from sea cucumber with commercial enzyme were studied on the hpyerglycemic and renal protective effects on db/db rats using urine metabolomics. Compared with the control group the polypeptides from the two species could significantly reduce the urine glucose and urea. We also tried to address the compositions of highly expressed urinary proteins using a proteomics approach. They were serum albumins, AMBP proteins, negative trypsin, elastase and urinary protein, GAPDH, a receptor of urokinase-type plasminogen activator (uPAR), and Ig kappa chain C region. We used the electronic nose to quickly detect changes in the volatile substances in mice urine after holothurian polypeptides fed, and the results show it can identify the difference between treatment groups with the control group without overlapping. The protein express mechanism of holothurian polypeptides treating diabetes was discussed, and we suggested these two peptides with the hypoglycemic and renal protective activity might be utilized as nutraceuticals.

  13. The Generation of Dehydroalanine Residues in Protonated Polypeptides: Ion/Ion Reactions for Introducing Selective Cleavages

    Science.gov (United States)

    Peng, Zhou; Bu, Jiexun; McLuckey, Scott A.

    2017-09-01

    We examine a gas-phase approach for converting a subset of amino acid residues in polypeptide cations to dehydroalanine (Dha). Subsequent activation of the modified polypeptide ions gives rise to specific cleavage N-terminal to the Dha residue. This process allows for the incorporation of selective cleavages in the structural characterization of polypeptide ions. An ion/ion reaction within the mass spectrometer between a multiply protonated polypeptide and the sulfate radical anion introduces a radical site into the multiply protonated polypeptide reactant. Subsequent collisional activation of the polypeptide radical cation gives rise to radical side chain loss from one of several particular amino acid side chains (e.g., leucine, asparagine, lysine, glutamine, and glutamic acid) to yield a Dha residue. The Dha residues facilitate preferential backbone cleavages to produce signature c- and z-ions, demonstrated with cations derived from melittin, mechano growth factor (MGF), and ubiquitin. The efficiencies for radical side chain loss and for subsequent generation of specific c- and z-ions have been examined as functions of precursor ion charge state and activation conditions using cations of ubiquitin as a model for a small protein. It is noted that these efficiencies are not strongly dependent on ion trap collisional activation conditions but are sensitive to precursor ion charge state. Moderate to low charge states show the greatest overall yields for the specific Dha cleavages, whereas small molecule losses (e.g., water/ammonia) dominate at the lowest charge states and proton catalyzed amide bond cleavages that give rise to b- and y-ions tend to dominate at high charge states. [Figure not available: see fulltext.

  14. Drug trafficking in mice: In vivo functions of OATP uptake and ABC efflux transporters

    NARCIS (Netherlands)

    Iusuf, D.

    2013-01-01

    In recent years, there has been increasing attention for drug uptake transporters of the Organic Anion-Transporting Polypeptide (human OATP, mouse Oatp, gene names SLCO, Slco) superfamily. Especially the OATP1A and OATP1B subfamilies turn out to have important physiological and pharmacological

  15. Hordein polypeptide patterns in relation to malting quality in Brazilian barley varieties

    Directory of Open Access Journals (Sweden)

    Echart-Almeida Cinara

    2001-01-01

    Full Text Available Since there is evidence that malting quality is related to the storage protein (hordein fraction, in the present work the hordein polypeptide patterns from 13 barley (Hordeum vulgare L. varieties of different malting quality were analysed in order to explore the feasibility of using hordein electrophoresis to assist in the selection of malting barleys. The formation of clusters separating the varieties with higher malting quality from the others with lower quality suggests that there is a relationship between the general hordein polypeptide pattern and malting quality in the varieties analysed. By the Sperman's correlation test three hordein bands correlated negatively with malting quality in the germplasm studied.

  16. Phase transition in polypeptides: a step towards the understanding of protein folding

    DEFF Research Database (Denmark)

    Yakubovich, Alexander V.; Solov'yov, Ilia; Solov'yov, Andrey V.

    2006-01-01

    We present a formalism which turns out to be very successful in the description of the polypeptide folding. We consider this process as a first-order phase transition and develop a theory which is free of model parameters and is based solely on fundamental physical principles. It describes...... essential thermodynamical properties of the system such as heat capacity, the phase transition temperature and others from the analysis of the polypeptide potential energy surface calculated within ab initio density functional theory and parameterized by two dihedral angles. This problem is viewed...

  17. Protective effect of Cordyceps militaris polypeptide against acute alcoholic liver injury in rats

    Directory of Open Access Journals (Sweden)

    CAI Qi

    2016-04-01

    Full Text Available ObjectiveTo investigate the protective effect of Cordyceps militaris polypeptide against acute alcoholic liver injury in rats and related mechanism. MethodsA total of 60 Wistar rats were randomly divided into blank control group, model group, and low-, medium-, and high-dose Cordyceps militaris polypeptide groups. All rats except those in the blank control group were given 10 ml/kg 56° liquor by gavage once a day; the rats in the blank control group were given distilled water of the same dose by gavage once a day. At 1 hour after gavage with liquor, the rats in the model group and low-, medium-, and high-dose Cordyceps militaris polypeptide groups were given distilled water or Cordyceps militaris polypeptide solution (6 ml/kg by gavage. Blood samples were collected from the orbit 4 weeks later. The serum levels of alanine aminotransferase (ALT and aspartate aminotransferase (AST and the activity of superoxide dismutase (SOD and level of malondialdehyde (MDA in the liver were measured for each group, and the pathological changes in the liver were observed under a light microscope. Analysis of variance was applied for comparison between multiple groups, and the SNK-q test was applied for comparison between any two groups. ResultsCompared with the model group, the low-, medium-, and high-dose Cordyceps militaris polypeptide groups showed significant reductions in the serum levels of ALT and AST and the level of MDA in the liver (all P<0.05, as well as a significant increase in the activity of SOD in the liver (all P<0.05, while these indices showed significant differences between the low-, medium-, and high-dose Cordyceps militaris polypeptide groups (all P<0.05. The liver pathological sections from the low-, medium-, and high-dose Cordyceps militaris polypeptide groups showed alleviated hepatocyte fatty degeneration and necrosis induced by alcohol under a light microscope. ConclusionCordyceps militaris polypeptide has a protective effect

  18. Non-chromatographic purification of recombinant elastin-like polypeptides and their fusions with peptides and proteins from Escherichia coli.

    Science.gov (United States)

    MacEwan, Sarah R; Hassouneh, Wafa; Chilkoti, Ashutosh

    2014-06-09

    Elastin-like polypeptides are repetitive biopolymers that exhibit a lower critical solution temperature phase transition behavior, existing as soluble unimers below a characteristic transition temperature and aggregating into micron-scale coacervates above their transition temperature. The design of elastin-like polypeptides at the genetic level permits precise control of their sequence and length, which dictates their thermal properties. Elastin-like polypeptides are used in a variety of applications including biosensing, tissue engineering, and drug delivery, where the transition temperature and biopolymer architecture of the ELP can be tuned for the specific application of interest. Furthermore, the lower critical solution temperature phase transition behavior of elastin-like polypeptides allows their purification by their thermal response, such that their selective coacervation and resolubilization allows the removal of both soluble and insoluble contaminants following expression in Escherichia coli. This approach can be used for the purification of elastin-like polypeptides alone or as a purification tool for peptide or protein fusions where recombinant peptides or proteins genetically appended to elastin-like polypeptide tags can be purified without chromatography. This protocol describes the purification of elastin-like polypeptides and their peptide or protein fusions and discusses basic characterization techniques to assess the thermal behavior of pure elastin-like polypeptide products.

  19. The interdomain flexible linker of the polypeptide GalNAc transferases dictates their long-range glycosylation preferences

    DEFF Research Database (Denmark)

    Rivas, Matilde De Las; Lira-Navarrete, Erandi; Daniel, Earnest James Paul

    2017-01-01

    The polypeptide GalNAc-transferases (GalNAc-Ts), that initiate mucin-type O-glycosylation, consist of a catalytic and a lectin domain connected by a flexible linker. In addition to recognizing polypeptide sequence, the GalNAc-Ts exhibit unique long-range N- A nd/or C-terminal prior glycosylation ...

  20. Antipeptide antibodies that can distinguish specific subunit polypeptides of glutamine synthetase from bean (Phaseolus vulgaris L.)

    Science.gov (United States)

    Cai, X.; Henry, R. L.; Takemoto, L. J.; Guikema, J. A.; Wong, P. P.; Spooner, B. S. (Principal Investigator)

    1992-01-01

    The amino acid sequences of the beta and gamma subunit polypeptides of glutamine synthetase from bean (Phaseolus vulgaris L.) root nodules are very similar. However, there are small regions within the sequences that are significantly different between the two polypeptides. The sequences between amino acids 2 and 9 and between 264 and 274 are examples. Three peptides (gamma 2-9, gamma 264-274, and beta 264-274) corresponding to these sequences were synthesized. Antibodies against these peptides were raised in rabbits and purified with corresponding peptide-Sepharose affinity chromatography. Western blot analysis of polyacrylamide gel electrophoresis of bean nodule proteins demonstrated that the anti-beta 264-274 antibodies reacted specifically with the beta polypeptide and the anti-gamma 264-274 and anti-gamma 2-9 antibodies reacted specifically with the gamma polypeptide of the native and denatured glutamine synthetase. These results showed the feasibility of using synthetic peptides in developing antibodies that are capable of distinguishing proteins with similar primary structures.

  1. Effects on DPPH inhibition of egg-white protein polypeptides treated by pulsed electric field technology.

    Science.gov (United States)

    Wang, Ke; Wang, Jia; Liu, Bolong; Lin, Songyi; Zhao, Ping; Liu, Jingbo; Jones, Gregory; Huang, Hsiang-Chi

    2013-05-01

    Egg-white protein polypeptides are potentially used as a functional ingredient in food products. In this study, the effects on DPPH inhibition of egg-white protein polypeptides ranging from 10 to 30 kDa treated by pulsed electric field (PEF) technology were investigated. 2, 2-Diphenyl-1-picrylhydrazyl (DPPH) inhibition (%) was used to evaluate the antioxidant activity of polypeptides. In order to develop and optimize a pulsed electric field (PEF) mathematical model for improving the antioxidant activity, we have investigated three variables, including concentration (6, 8 and 10 mg mL(-1)), electric field intensity (10, 20 and 30 kV cm(-1)) and pulse frequency (2000, 2350 and 2700 Hz) and subsequently optimized them by response surface methodology (RSM). The concentration (8 mg mL(-1)), electric field intensity (10 kV cm(-1)) and pulse frequency (2000 Hz) were found to be the optimal conditions under which the DPPH inhibition increased 28.44%, compared to the sample without PEF treatment. Both near-infrared spectroscopy (NIR) and mid-infrared spectroscopy (MIR) were used to analyze the change of functional groups. The results showed that PEF technology could improve the antioxidant activity of antioxidant polypeptides from egg-white protein under the optimized conditions. © 2012 Society of Chemical Industry.

  2. Noncanonical self-assembly of highly asymmetric genetically encoded polypeptide amphiphiles into cylindrical micelles.

    Science.gov (United States)

    McDaniel, Jonathan R; Weitzhandler, Isaac; Prevost, Sylvain; Vargo, Kevin B; Appavou, Marie-Sousai; Hammer, Daniel A; Gradzielski, Michael; Chilkoti, Ashutosh

    2014-11-12

    Elastin-like polypeptides (ELPs) are a class of biopolymers consisting of the pentameric repeat (VPGαG)n based on the sequence of mammalian tropoelastin that display a thermally induced soluble-to-insoluble phase transition in aqueous solution. We have discovered a remarkably simple approach to driving the spontaneous self-assembly of high molecular weight ELPs into nanostructures by genetically fusing a short 1.5 kDa (XGy)z assembly domain to one end of the ELP. Classical theories of self-assembly based on the geometric mass balance of hydrophilic and hydrophobic block copolymers suggest that these highly asymmetric polypeptides should form spherical micelles. Surprisingly, when sufficiently hydrophobic amino acids (X) are presented in a periodic sequence such as (FGG)8 or (YG)8, these highly asymmetric polypeptides self-assemble into cylindrical micelles whose length can be tuned by the sequence of the morphogenic tag. These nanostructures were characterized by light scattering, tunable resistive pulse sensing, fluorescence spectrophotometry, and thermal turbidimetry, as well as by cryogenic transmission electron microscopy (cryo-TEM) and small-angle neutron scattering (SANS). These short assembly domains provide a facile strategy to control the size, shape, and stability of stimuli responsive polypeptide nanostructures.

  3. Identification of flagellar and associated polypeptides of Helicobacter (formerly Campylobacter) pylori.

    Science.gov (United States)

    Luke, C J; Kubiak, E; Cockayne, A; Elliott, T S; Penn, C W

    1990-09-01

    Flagella of Helicobacter pylori were isolated from intact organisms by shearing and differential centrifugation. Treatment of the flagella with the detergent Triton X-100 removed the flagellar sheath, which was confirmed by electron microscopy, and the remaining naked flagella were shown by sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) to consist primarily of a single 54 kilodalton (kDa) polypeptide. This was confirmed by immunogold labelling and electron microscopy of detergent treated whole organisms, using a mouse antiserum specific for the 54 kDa polypeptide. Polypeptides solubilised from crude flagellar preparations by detergent treatment were found to have molecular weights of 26, 30, 58, 62, 66 and 80 kDa. These polypeptides are possible components of the flagellar sheath and they may represent outer membrane proteins, based on the assumption that the flagellar sheath is related in composition to the outer membrane of the organism. Analysis and definition of these components of the surface structures of the organism are important in understanding the interaction between the organism and its host in pathogenesis.

  4. Structural variation and inhibitor binding in polypeptide deformylase from four different bacterial species.

    Science.gov (United States)

    Smith, Kathrine J; Petit, Chantal M; Aubart, Kelly; Smyth, Martin; McManus, Edward; Jones, Jo; Fosberry, Andrew; Lewis, Ceri; Lonetto, Michael; Christensen, Siegfried B

    2003-02-01

    Polypeptide deformylase (PDF) catalyzes the deformylation of polypeptide chains in bacteria. It is essential for bacterial cell viability and is a potential antibacterial drug target. Here, we report the crystal structures of polypeptide deformylase from four different species of bacteria: Streptococcus pneumoniae, Staphylococcus aureus, Haemophilus influenzae, and Escherichia coli. Comparison of these four structures reveals significant overall differences between the two Gram-negative species (E. coli and H. influenzae) and the two Gram-positive species (S. pneumoniae and S. aureus). Despite these differences and low overall sequence identity, the S1' pocket of PDF is well conserved among the four enzymes studied. We also describe the binding of nonpeptidic inhibitor molecules SB-485345, SB-543668, and SB-505684 to both S. pneumoniae and E. coli PDF. Comparison of these structures shows similar binding interactions with both Gram-negative and Gram-positive species. Understanding the similarities and subtle differences in active site structure between species will help to design broad-spectrum polypeptide deformylase inhibitor molecules.

  5. ca 15-3, ceruloplasmin and tissue polypeptide specific antigen as a ...

    African Journals Online (AJOL)

    hi-tech

    2000-06-01

    Jun 1, 2000 ... CA 15-3, CERULOPLASMIN AND TISSUE POLYPEPTIDE SPECIFIC ANTIGEN AS A TUMOUR MARKER PANEL IN BREAST CANCER. Ö. Özyilkan ... The most commonly used breast cancer antigen is CA 15-3. Objective: ..... circulation CA 15-3 and carcinoembryonic antigen levels in patients with breast ...

  6. TISSUE POLYPEPTIDE-SPECIFIC ANTIGEN - A DISCRIMINATIVE PARAMETER BETWEEN PROSTATE-CANCER AND BENIGN PROSTATIC HYPERTROPHY

    NARCIS (Netherlands)

    MARRINK, J; OOSTEROM, R; BONFRER, HMG; SCHRODER, FH; MENSINK, HJA

    1993-01-01

    The serum concentration of the cell proliferation marker TPS (tissue polypeptide-specific antigen) was compared with the tumour marker PSA (prostate specific antigen). PSA was found elevated in 50% of the benign prostatic hypertrophy (BPH) patients, in 88% of the patients with active prostate cancer

  7. Postnatally disturbed pancreatic islet cell distribution in human islet amyloid polypeptide transgenic mice

    NARCIS (Netherlands)

    Wong, HY; Ahren, B; Lips, CJM; Hoppener, JWM; Sundler, F

    2003-01-01

    Objective: Islet amyloid polypeptide (IAPP)/amylin is produced by the pancreatic islet beta-cells, which also produce insulin. To study potential functions of IAPP, we have generated transgenic mice overexpressing human IAPP (hIAPP) in the beta-cells. These mice show a diabetic phenotype when

  8. Creating cellular patterns using genetically engineered, gold- and cell-binding polypeptides.

    Science.gov (United States)

    Li, Linying; Mo, Chia-Kuei; Chilkoti, Ashutosh; Lopez, Gabriel P; Carroll, Nick J

    2016-06-27

    Patterning cells on material surfaces is an important tool for the study of fundamental cell biology, tissue engineering, and cell-based bioassays. Here, the authors report a simple approach to pattern cells on gold patterned silicon substrates with high precision, fidelity, and stability. Cell patterning is achieved by exploiting adsorbed biopolymer orientation to either enhance (gold regions) or impede (silicon oxide regions) cell adhesion at particular locations on the patterned surface. Genetic incorporation of gold binding domains enables C-terminal chemisorption of polypeptides onto gold regions with enhanced accessibility of N-terminal cell binding domains. In contrast, the orientation of polypeptides adsorbed on the silicon oxide regions limit the accessibility of the cell binding domains. The dissimilar accessibility of cell binding domains on the gold and silicon oxide regions directs the cell adhesion in a spatially controlled manner in serum-free medium, leading to the formation of well-defined cellular patterns. The cells are confined within the polypeptide-modified gold regions and are viable for eight weeks, suggesting that bioactive polypeptide modified surfaces are suitable for long-term maintenance of patterned cells. This study demonstrates an innovative surface-engineering approach for cell patterning by exploiting distinct ligand accessibility on heterogeneous surfaces.

  9. Circulating endogenous vasoactive intestinal polypeptide (VIP) in patients with uraemia and liver cirrhosis

    DEFF Research Database (Denmark)

    Henriksen, Jens Henrik Sahl; Staun-Olsen, P; Borg Mogensen, N

    1986-01-01

    The concentration of vasoactive intestinal polypeptide (VIP) in peripheral venous plasma was median 6.0 pmol l-1 (range 0-20) in 112 normal subjects. In fifty-three patients with decreased kidney function plasma VIP was significantly increased (median 15.0 pmol l-1, range 0.5-70, P less than 0...

  10. The Beads of Translation: Using Beads to Translate mRNA into a Polypeptide Bracelet

    Science.gov (United States)

    Dunlap, Dacey; Patrick, Patricia

    2012-01-01

    During this activity, by making beaded bracelets that represent the steps of translation, students simulate the creation of an amino acid chain. They are given an mRNA sequence that they translate into a corresponding polypeptide chain (beads). This activity focuses on the events and sites of translation. The activity provides students with a…

  11. Effects of surface hydrophobicity on the conformational changes of polypeptides of different length.

    Science.gov (United States)

    Mu, Yan

    2011-09-01

    We studied the effects of surface hydrophobicity on the conformational changes of different length polypeptides by calculating the free energy difference between peptide structures using the bias-potential Monte Carlo technique and the probability ratio method. It was found that the hydrophobic surface plays an important role in the stability of secondary structures of the polypeptides with hydrophobic side chains. For short GAAAAG peptides, the hydrophobic surface destabilizes the α helix but stabilizes the β hairpin in the entire temperature region considered in our study. Interestingly, when the surface hydrophobic strength ε(hpsf)≥ε(hp), the most stable structure in the low temperature region changes from α helix to β hairpin, and the corresponding phase transition temperature increases slightly. For longer GAAAAAAAAAAG peptides, the effects of the relatively weak hydrophobic surface (ε(hpsf) ε(hp)) may further disturb the formation of both α-helical and β structures. Moreover, the phase transition temperature between α-helical structures and random coils significantly decreases due to the helicity loss when ε(hpsf)>ε(hp). Our findings provide a basic and quantitative picture for understanding the effects of a hydrophobic surface on the conformational changes of the polypeptides with hydrophobic side chains. From an application viewpoint, the present study is helpful in developing alternative strategies of producing high-quality biological fibrillar materials and functional nanoscale devices by the self-assembly of the polypeptides on hydrophobic surfaces.

  12. Proline-rich polypeptides in Alzheimer's disease and neurodegenerative disorders - Therapeutic potential or a mirage?

    NARCIS (Netherlands)

    Gladkevich, A.; Bosker, F.; Korf, J.; Yenkoyan, K.; Vahradyan, H.; Aghajanov, M.

    2007-01-01

    The development of effective and safe drugs for a growing Alzheimer disease population is an increasing need at present. Both experimental and clinical evidence support a beneficial effect of proline-rich polypeptides in a number of neurodegenerative diseases, including Alzheimer disease.

  13. Parasympathetic blockade attenuates augmented pancreatic polypeptide but not insulin secretion in Pima Indians

    DEFF Research Database (Denmark)

    de Courten, Barbora; Weyer, Christian; Stefan, Norbert

    2004-01-01

    of pancreatic polypeptide (PP), an islet hormone considered a surrogate marker of parasympathetic nervous system (PNS) drive to the pancreas. To test if hyperinsulinemia in Pima Indians is due to increased vagal input to the beta-cell, we examined the effect of PNS blockade in 17 Caucasian (aged 35 +/- 8 years...

  14. CA 15-3, Ceruloplasmin and tissue polypeptide specific antigen as a ...

    African Journals Online (AJOL)

    Objective: To examine the value of CA 15-3, ceruloplasmin and tissue polypeptide specific antigen (TPS) panel in the monitoring of breast cancer. Subjects: Serum concentrations of CA 15-3, ceruloplasmin and TPS were measured in 90 women: Fifteen controls, sixteen patients with benign breast disease (BBD), thirty one ...

  15. Impaired pancreatic polypeptide response to a meal in type 1 diabetic patients

    DEFF Research Database (Denmark)

    Rasmussen, M H; Carstensen, H; List, S

    1993-01-01

    The pancreatic polypeptide (PP) response to a mixed meal was investigated in seven insulin-dependent diabetics without measurable signs of diabetic autonomic neuropathy, and in seven healthy subjects. Since acute changes in metabolic regulation might influence the meal-induced PP response...

  16. Self-assemble nanoparticles based on polypeptides containing C-terminal luminescent Pt-cysteine complex

    Science.gov (United States)

    Vlakh, E. G.; Grachova, E. V.; Zhukovsky, D. D.; Hubina, A. V.; Mikhailova, A. S.; Shakirova, J. R.; Sharoyko, V. V.; Tunik, S. P.; Tennikova, T. B.

    2017-02-01

    The growing attention to the luminescent nanocarriers is strongly stimulated by their potential application as drug delivery systems and by the necessity to monitor their distribution in cells and tissues. In this communication we report on the synthesis of amphiphilic polypeptides bearing C-terminal phosphorescent label together with preparation of nanoparticles using the polypeptides obtained. The approach suggested is based on a unique and highly technological process where the new phosphorescent Pt-cysteine complex serves as initiator of the ring-opening polymerization of α-amino acid N-carboxyanhydrides to obtain the polypeptides bearing intact the platinum chromophore covalently bound to the polymer chain. It was established that the luminescent label retains unchanged its emission characteristics not only in the polypeptides but also in more complicated nanoaggregates such as the polymer derived amphiphilic block-copolymers and self-assembled nanoparticles. The phosphorescent nanoparticles display no cytotoxicity and hemolytic activity in the tested range of concentrations and easily internalize into living cells that makes possible in vivo cell visualization, including prospective application in time resolved imaging and drug delivery monitoring.

  17. Reference intervals for glucose, beta-cell polypeptides and counterregulatory factors during prolonged fasting

    DEFF Research Database (Denmark)

    Højlund, Kurt; Wildner-Christensen, M; Eshøj, O

    2001-01-01

    decreased from the second to third day of fasting (P = 0.03). Males had higher glucose and glucagon levels and lower FFA levels during the fast (P polypeptides was observed. A high body mass index resulted in higher insulin and C-peptide levels during...

  18. Molecular cloning and protein structure of a human blood group Rh polypeptide

    International Nuclear Information System (INIS)

    Cherif-Zahar, B.; Bloy, C.; Le Van Kim, C.; Blanchard, D.; Bailly, P.; Hermand, P.; Salmon, C.; Cartron, J.P.; Colin, Y.

    1990-01-01

    cDNA clones encoding a human blood group Rh polypeptide were isolated from a human bone marrow cDNA library by using a polymerase chain reaction-amplified DNA fragment encoding the known common N-terminal region of the Rh proteins. The entire primary structure of the Rh polypeptide has been deduced from the nucleotide sequence of a 1384-base-pair-long cDNA clone. Translation of the open reading frame indicates that the Rh protein is composed of 417 amino acids, including the initiator methionine, which is removed in the mature protein, lacks a cleavable N-terminal sequence, and has no consensus site for potential N-glycosylation. The predicted molecular mass of the protein is 45,500, while that estimated for the Rh protein analyzed in NaDodSO 4 /polyacrylamide gels is in the range of 30,000-32,000. These findings suggest either that the hydrophobic Rh protein behaves abnormally on NaDodSO 4 gels or that the Rh mRNA may encode a precursor protein, which is further matured by a proteolytic cleavage of the C-terminal region of the polypeptide. Hydropathy analysis and secondary structure predictions suggest the presence of 13 membrane-spanning domains, indicating that the Rh polypeptide is highly hydrophobic and deeply buried within the phospholipid bilayer. These results suggest that the expression of the Rh gene(s) might be restricted to tissues or cell lines expressing erythroid characters

  19. Pituitary adenylate cyclase-activating polypeptide stimulates renin secretion via activation of PAC1 receptors

    DEFF Research Database (Denmark)

    Hautmann, Matthias; Friis, Ulla G; Desch, Michael

    2007-01-01

    Besides of its functional role in the nervous system, the neuropeptide pituitary adenylate cyclase-activating polypeptide (PACAP) is involved in the regulation of cardiovascular function. Therefore, PACAP is a potent vasodilator in several vascular beds, including the renal vasculature. Because...

  20. Improvement of Learning and Memory Induced by Cordyceps Polypeptide Treatment and the Underlying Mechanism

    Directory of Open Access Journals (Sweden)

    Guangxin Yuan

    2018-01-01

    Full Text Available Our previous research revealed that Cordyceps militaris can improve the learning and memory, and although the main active ingredient should be its polypeptide complexes, the underlying mechanism of its activity remains poorly understood. In this study, we explored the mechanisms by which Cordyceps militaris improves learning and memory in a mouse model. Mice were given scopolamine hydrobromide intraperitoneally to establish a mouse model of learning and memory impairment. The effects of Cordyceps polypeptide in this model were tested using the Morris water maze test; serum superoxide dismutase activity; serum malondialdehyde levels; activities of acetyl cholinesterase, Na+-k+-ATPase, and nitric oxide synthase; and gamma aminobutyric acid and glutamate contents in brain tissue. Moreover, differentially expressed genes and the related cellular signaling pathways were screened using an mRNA expression profile chip. The results showed that the genes Pik3r5, Il-1β, and Slc18a2 were involved in the effects of Cordyceps polypeptide on the nervous system of these mice. Our findings suggest that Cordyceps polypeptide may improve learning and memory in the scopolamine-induced mouse model of learning and memory impairment by scavenging oxygen free radicals, preventing oxidative damage, and protecting the nervous system.

  1. Initial characterization of the nascent polypeptide-associated complex in yeast.

    Science.gov (United States)

    Reimann, B; Bradsher, J; Franke, J; Hartmann, E; Wiedmann, M; Prehn, S; Wiedmann, B

    1999-03-30

    The three subunits of the nascent polypeptide-associated complex (alpha, beta1, beta3) in Saccharomyces cerevisiae are encoded by three genes (EGD2, EGD1, BTT1). We found the complex bound to ribosomes via the beta-subunits in a salt-sensitive manner, in close proximity to nascent polypeptides. Estimation of the molecular weight of the complex of wild-type cells and cells lacking one or two subunits revealed that the composition of the complex is variable and that as yet unknown proteins might be included. Regardless of the variability, a certain balance of the subunits has to be maintained: the deletion of one subunit causes downregulation of the remaining subunits at physiological growth temperature. Cells lacking both beta-subunits are unable to grow at 37 degrees C, most likely due to a toxic effect of the alpha-subunit. Based on in vitro experiments, it has been proposed that the function of mammalian nascent-polypeptide associated complexes (NAC) is to prevent inappropriate targeting of non-secretory nascent polypeptides. In vivo, however, the lack of NAC does not cause secretion of signal-less invertase in yeast. This result and the lack of a drastic phenotype of cells missing one, two or three subunits at optimal conditions (28 degrees C, YPD-medium) suggest either the existence of a substitute for NAC or that cells tolerate or 'repair' the damage caused by the absence of NAC.

  2. On the role of glucose-dependent insulintropic polypeptide in postprandial metabolism in humans

    DEFF Research Database (Denmark)

    Asmar, Meena; Tangaa, Winnie; Madsbad, Sten

    2010-01-01

    We investigated the role of glucose-dependent insulintropic polypeptide (GIP) in the regulation of gastric emptying (GE), appetite, energy intake (EI), energy expenditure (EE), plasma levels of triglycerides (TAG), and free fatty acids (FFA) in humans. First, 20 healthy males received intravenous...

  3. Adhesive polypeptides of Staphylococcus aureus identified using a novel secretion library technique in Escherichia coli

    Directory of Open Access Journals (Sweden)

    Holm Liisa

    2011-05-01

    Full Text Available Abstract Background Bacterial adhesive proteins, called adhesins, are frequently the decisive factor in initiation of a bacterial infection. Characterization of such molecules is crucial for the understanding of bacterial pathogenesis, design of vaccines and development of antibacterial drugs. Because adhesins are frequently difficult to express, their characterization has often been hampered. Alternative expression methods developed for the analysis of adhesins, e.g. surface display techniques, suffer from various drawbacks and reports on high-level extracellular secretion of heterologous proteins in Gram-negative bacteria are scarce. These expression techniques are currently a field of active research. The purpose of the current study was to construct a convenient, new technique for identification of unknown bacterial adhesive polypeptides directly from the growth medium of the Escherichia coli host and to identify novel proteinaceous adhesins of the model organism Staphylococcus aureus. Results Randomly fragmented chromosomal DNA of S. aureus was cloned into a unique restriction site of our expression vector, which facilitates secretion of foreign FLAG-tagged polypeptides into the growth medium of E. coli ΔfliCΔfliD, to generate a library of 1663 clones expressing FLAG-tagged polypeptides. Sequence and bioinformatics analyses showed that in our example, the library covered approximately 32% of the S. aureus proteome. Polypeptides from the growth medium of the library clones were screened for binding to a selection of S. aureus target molecules and adhesive fragments of known staphylococcal adhesins (e.g coagulase and fibronectin-binding protein A as well as polypeptides of novel function (e.g. a universal stress protein and phosphoribosylamino-imidazole carboxylase ATPase subunit were detected. The results were further validated using purified His-tagged recombinant proteins of the corresponding fragments in enzyme-linked immunoassay and

  4. Manipulating the membrane penetration mechanism of helical polypeptides via aromatic modification for efficient gene delivery.

    Science.gov (United States)

    Zheng, Nan; Song, Ziyuan; Yang, Jiandong; Liu, Yang; Li, Fangfang; Cheng, Jianjun; Yin, Lichen

    2017-08-01

    The delivery performance of non-viral gene vectors is greatly related to their intracellular kinetics. Cationic helical polypeptides with potent membrane penetration properties and gene transfection efficiencies have been recently developed by us. However, they suffer from severe drawbacks in terms of their membrane penetration mechanisms that mainly include endocytosis and pore formation. The endocytosis mechanism leads to endosomal entrapment of gene cargos, while the charge- and helicity-induced pore formation causes appreciable cytotoxicity at high concentrations. With the attempt to overcome such critical challenges, we incorporated aromatic motifs into the design of helical polypeptides to enhance their membrane activities and more importantly, to manipulate their membrane penetration mechanisms. The aromatically modified polypeptides exhibited higher cellular internalization level than the unmodified analogue by up to 2.5 folds. Such improvement is possibly because aromatic domains promoted the polypeptides to penetrate cell membranes via direct transduction, a non-endocytosis and non-pore formation mechanism. As such, gene cargos were more efficiently delivered into cells by bypassing endocytosis and subsequently avoiding endosomal entrapment, and the material toxicity associated with excessive pore formation was also reduced. The top-performing aromatic polypeptide containing naphthyl side chains at the incorporated content of 20mol% revealed notably higher transfection efficiencies than commercial reagents in melanoma cells in vitro (by 11.7 folds) and in vivo (by 9.1 folds), and thus found potential utilities toward topical gene delivery for cancer therapy. Cationic helical polypeptides, as efficient gene delivery materials, suffer from severe drawbacks in terms of their membrane penetration mechanisms. The main cell penetration mechanisms involved are endocytosis and pore formation. However, the endocytosis mechanism has the limitation of endosomal

  5. Biosynthesis and characterization of a non-repetitive polypeptide derived from silk fibroin heavy chain

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Gaoqiang; Wu, Mingyang; Yi, Honggen; Wang, Jiannan, E-mail: wangjn@suda.edu.cn

    2016-02-01

    Silk fibroin heavy chain is the major protein component of Bombyx mori silk fibroin and is composed of 12 repetitive and 11 non-repetitive regions, with the non-repetitive domain consisting of a hydrophilic polypeptide chain. In order to determine the biomedical function of the non-repetitive domain or potentially use it to modify hydrophobic biomaterials, high-purity isolation is necessary. Previously, we cloned and extended a gene motif (f(1)) encoding the non-repetitive domain. Here, this motif and its multimers are inserted into a glutathione S-transferase (GST)-tagged fusion-protein expression vector. Motif f(1) and multimers f(4) and f(8) were expressed in Escherichia coli BL21 cells following isopropyl β-D-1-thiogalactopyranoside induction, purified by GST-affinity chromatography, and single bands of purified fusion proteins GST-F(1), GST-F(4), and GST-F(8), were visualized by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Target polypeptides F(1), F(4), and F(8), were cleaved clearly from the GST-fusion tag following thrombin digestion. Mass spectrometry results indicate that the molecular weights associated with fusion proteins GST-F(1), GST-F(4), and GST-F(8) are 31.5, 43.8, and 59.0 kDa, respectively, and with the cleaved polypeptides F(1), F(4), and F(8) are 4.8, 16.8, and 32.8 kDa, respectively. The F(1), F(4), and F(8) polypeptide chains are negatively charged with isoelectric points (pI) of 3.3, 3.2, and 3.0, respectively. The molecular weight and pI values of the polypeptide chains are consistent with the predicted values and the amino acid compositions similar to predicted sequences. FTIR and CD results show the molecular conformation of F(1) was mainly random coil, and more stable α-helix structure formed in longer molecular chain. - Highlights: • A non-repetitive domain and its multimers of silk fibroin were expressed by E. coli. • The corresponding target polypeptides F(1), F(4) and F(8) were cleaved clearly. • Their

  6. Zonadhesin D3-polypeptides vary among species but are similar in Equus species capable of interbreeding.

    Science.gov (United States)

    Tardif, Steve; Brady, Heidi A; Breazeale, Kelly R; Bi, Ming; Thompson, Leslie D; Bruemmer, Jason E; Bailey, Laura B; Hardy, Daniel M

    2010-02-01

    Zonadhesin is a rapidly evolving protein in the sperm acrosome that confers species specificity to sperm-zona pellucida adhesion. Though structural variation in zonadhesin likely contributes to its species-specific function, the protein has not previously been characterized in organisms capable of interbreeding. Here we compared properties of zonadhesin in several animals, including the horse (Equus caballus), donkey (E. asinus), and Grevy's zebra (E. grevyi) to determine if variation in zonadhesin correlates with ability of gametes to cross-fertilize. Zonadhesin localized to the apical acrosomes of spermatozoa from all three Equus species, similar to its localization in other animals. Likewise, in horse and donkey testis, zonadhesin was detected only in germ cells, first in the acrosomal granule of round spermatids and then in the developing acrosomes of elongating spermatids. Among non-Equus species, D3-domain polypeptides of mature, processed zonadhesin varied markedly in size and detergent solubility. However, zonadhesin D3-domain polypeptides in horse, donkey, and zebra spermatozoa exhibited identical electrophoretic mobility and detergent solubility. Equus zonadhesin D3-polypeptides (p110/p80 doublet) were most similar in size to porcine and bovine zonadhesin D3-polypeptides (p105). Sequence comparisons revealed that the horse zonadhesin precursor's domain content and arrangement are similar to those of zonadhesin from other large animals. Partial sequences of horse and donkey zonadhesin were much more similar to each other (>99% identity) than they were to orthologous sequences of human, pig, rabbit, and mouse zonadhesin (52%-72% identity). We conclude that conservation of zonadhesin D3-polypeptide properties correlates with ability of Equus species to interbreed.

  7. pH responsiveness of fibrous assemblies of repeat-sequence amphipathic α-helix polypeptides.

    Science.gov (United States)

    Takei, Toshiaki; Tsumoto, Kouhei; Okonogi, Atsuhito; Kimura, Akiko; Kojima, Shuichi; Yazaki, Kazumori; Takei, Tsunetomo; Ueda, Takuya; Miura, Kin-ichiro

    2015-05-01

    We reported previously that our designed polypeptide α3 (21 residues), which has three repeats of a seven-amino-acid sequence (LETLAKA)3, forms not only an amphipathic α-helix structure but also long fibrous assemblies in aqueous solution. To address the relationship between the electrical states of the polypeptide and its α-helix and fibrous assembly formation, we characterized mutated polypeptides in which charged amino acid residues of α3 were replaced with Ser. We prepared the following polypeptides: 2Sα3 (LSTLAKA)3, in which all Glu residues were replaced with Ser residues; 6Sα3 (LETLASA)3, in which all Lys residues were replaced with Ser; and 2S6Sα3 (LSTLASA)3; in which all Glu and Lys residues were replaced with Ser. In 0.1M KCl, 2Sα3 formed an α-helix under basic conditions and 6Sα3 formed an α-helix under acid conditions. In 1M KCl, they both formed α-helices under a wide pH range. In addition, 2Sα3 and 6Sα3 formed fibrous assemblies under the same buffer conditions in which they formed α-helices. α-Helix and fibrous assembly formation by these polypeptides was reversible in a pH-dependent manner. In contrast, 2S6Sα3 formed an α-helix under basic conditions in 1M KCl. Taken together, these findings reveal that the charge states of the charged amino acid residues and the charge state of the Leu residue located at the terminus play an important role in α-helix formation. © 2015 The Protein Society.

  8. Polypeptides having beta-glucosidase activity, beta-xylosidase activity, or beta-glucosidase and beta-xylosidase activity and polynucleotides encoding same

    Energy Technology Data Exchange (ETDEWEB)

    Morant, Marc

    2017-02-07

    The present invention relates to isolated polypeptides having beta-glucosidase activity, beta-xylosidase activity, or beta-glucosidase and beta-xylosidase activity and isolated polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides.

  9. Synthesis of conformation switchable cationic polypeptides based on poly(S-propargyl-cysteine) for use as siRNA delivery.

    Science.gov (United States)

    Yi, Ling; Wang, Yisi; Lin, Guanliang; Lin, Danling; Chen, Wenliang; Huang, Yugang; Ye, Guodong

    2017-08-01

    Ring-opening polymerization of S-propargyl-cysteine-N-carboxyanhydride has been used to synthesize conformation switchable poly(S-propargyl-cysteine) starting with l-cysteine, dl- and d-cysteine. Then cationic polypeptides with different backbone chirality are obtained by nearly 100% side-chain grafting of cysteamine via thiol-yne click chemistry. The cationic polypeptides containing mixed conformations of β-sheets, β-turns and random coils are stable against pH, salt and temperature variations. The cationic polypeptides can condense siRNA at a low polypeptide/siRNA weight ratio to form nanoparticles with size depending on the backbone chirality. The cationic polypeptides derived from poly(S-propargyl-l or d-cysteine) are non-cytotoxic to HeLa and HepG2 cells, but interrupting the backbone chirality enhances the cytotoxicity sharply. The cationic polypeptides used for siRNA delivery show good transfection efficiency, but cell internalization process depends on the backbone chirality. The cationic polypeptide derived from the poly(S-propargyl-l-cysteine) is an appropriate siRNA vector with advantages of non-cytotoxicity and high transfection efficiency. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. A signaling polypeptide derived from an innate immune adaptor molecule can be harnessed as a new class of vaccine adjuvant.

    Science.gov (United States)

    Kobiyama, Kouji; Takeshita, Fumihiko; Ishii, Ken J; Koyama, Shohei; Aoshi, Taiki; Akira, Shizuo; Sakaue-Sawano, Asako; Miyawaki, Atsushi; Yamanaka, Yuko; Hirano, Hisashi; Suzuki, Koichi; Okuda, Kenji

    2009-02-01

    Modulation of intracellular signaling using cell-permeable polypeptides is a promising technology for future clinical applications. To develop a novel approach to activate innate immune signaling by synthetic polypeptides, we characterized several different polypeptides derived from the caspase recruitment domain (CARD) of IFN-beta promoter stimulator 1, each of which localizes to a different subcellular compartment. Of particular interest was, N'-CARD, which consisted of the nuclear localization signal of histone H2B and the IFN-beta promoter stimulator 1CARD and which localized to the nucleus. This polypeptide led to a strong production of type I IFNs and molecular and genetic analyses showed that nuclear DNA helicase II is critically involved in this response. N'-CARD polypeptide fused to a protein transduction domain (N'-CARD-PTD) readily transmigrated from the outside to the inside of the cell and triggered innate immune signaling. Administration of N'-CARD-PTD polypeptide elicited production of type I IFNs, maturation of bone marrow-derived dendritic cells, and promotion of vaccine immunogenicity by enhancing Ag-specific Th1-type immune responses, thereby protecting mice from lethal influenza infection and from outgrowth of transplanted tumors in vivo. Thus, our results indicate that the N'-CARD-PTD polypeptide belongs to a new class of vaccine adjuvant that directly triggers intracellular signal transduction by a distinct mechanism from those engaged by conventional vaccine adjuvants, such as TLR ligands.

  11. Contrasting effects of stanniocalcin-related polypeptides on macrophage foam cell formation and vascular smooth muscle cell migration.

    Science.gov (United States)

    Yamamoto, Keigo; Tajima, Yukie; Hasegawa, Akinori; Takahashi, Yui; Kojima, Miho; Watanabe, Rena; Sato, Kengo; Shichiri, Masayoshi; Watanabe, Takuya

    2016-08-01

    Stanniocalcin (STC) is a calcium- and phosphate-regulating hormone secreted by the corpuscles of Stannius, an endocrine gland of bony fish. Its human homologues, STC1 and STC2 showing 34% amino acid identity each other, are expressed in a variety of human tissues. To clarify their roles in atherosclerosis, we investigated the effects of their full-length proteins, STC1(18-247) and STC2(25-302), and STC2-derived fragment peptides, STC2(80-100) and STC2(85-99), on inflammatory responses in human umbilical vein endothelial cells (HUVECs), human macrophage foam cell formation, the migration and proliferation of human aortic smooth muscle cells (HASMCs) and the extracellular matrix expression. All these polypeptides suppressed lipopolysaccharide-induced expressions of interleukin-6, monocyte chemotactic protein-1, and intercellular adhesion molecule-1 in HUVECs. Oxidized low-density lipoprotein-induced foam cell formation was significantly decreased by STC1(18-247) and increased by STC2(80-100) and STC2(85-99), but not STC2(25-302), in human macrophages. Expression of acyl-CoA:cholesterol acyltransferase-1 (ACAT1) was significantly suppressed by STC1(18-247) but stimulated by STC2(80-100) and STC2(85-99). Expression of ATP-binding cassette transporter A1 was significantly stimulated by STC1(18-247). Neither STC1(18-247) nor STC2-derived peptides significantly affected CD36 expression in human macrophages or HASMC proliferation. STC2(80-100) and STC2(85-99) significantly increased HASMC migration, whereas STC1(18-247) significantly suppressed the angiotensin II-induced HASMC migration. Expressions of collagen-1, fibronectin, matrix metalloproteinase-2, and elastin were mostly unchanged with the exception of fibronectin up-regulation by STC2(80-100). Our results demonstrated the contrasting effects of STC1 and STC2-derived peptides on human macrophage foam cell formation associated with ACAT1 expression and on HASMC migration. Thus, STC-related polypeptides could serve as

  12. Effect of polypeptides from sea anemone Heteractis crispa on the rodent blood pressure, heart rate, and hemostasis.

    Science.gov (United States)

    Skobtsova, L A; Dyachenko, I A; Andreev, Ya A; Logashina, Yu A; Murashev, A N; Grishin, E V

    2016-09-01

    АРНС1-3 peptides, modulators of TRPV1 receptors, have been administered to SD rats to study their influence on the animal hemostatic system, heart rate, and blood pressure. None of АЗРС1-3 polypeptides have any effect on the hemostatic system. Both АРНС1 and АРНС2 polypeptides increased significantly the heart rate, but they did not affect blood pressure, which was probably caused by an ability of these polypeptides to modify animal thermoregulation.

  13. The role of transporters on drug therapy

    Directory of Open Access Journals (Sweden)

    . Ngatidjan

    2016-02-01

    Full Text Available ABSTRACT Pharmacodynamical studies showed that most drugs elicit their effects by acting on 3 kinds of protein molecules known as receptors, enzymes or transporters. Although their detail properties had not been explained for decades the roles of transporters in drug kinetics and dynamics has been well understood, even have been applied in the therapy. Transporters are classified into 2 major classes, the solute carriers (SLC and ATP-binding cassette (ABC families. SLC transporters do not possess ATP binding site property as those of ABC transporters. SLC transporters consist of 3 SLC subfamilies i.e. organic cation transporters (OCTs, organic anion transporters (OATs and organic anion transporting polypeptides (OATPs. In contrast, ABC transporters require ATP hydrolysis to transport substrate across cell membrane. Human ABC-transporters consist of ABCA1- 13, ABCB1-11, ABCC1-12, ABCD1-4, ABCE1, ABCF1-3 and ABCG1-8 subfamily. Although the originally funtion of transporter is to transport specific physiological substrate such as nutrient, hormone, cytokines, neurotransmitters and other physiological subtances across cell membrane the specificity is not restricted to each substrate. Drugs and other xenobiotics which have structural similarity to the physiological substrates are recognized and transported by the related transporters. The competition of them on transporters therefore may lead to the occurence of drug-drug interactions (DDI or drugphysiological substrate interaction in the drug-kinetics phase. Many transporters located in the liver, intestinal and renal epithelial cell membranes involve in the transport of endogenous substance or xenobiotics including drugs play important roles as protective barrier. Since transporters also serve as the targets of drug action it is understood that transporters play important role in the pathogenesis of diseases as well as in the drug therapy of diseases.

  14. Dynamic enzyme docking to the ribosome coordinates N-terminal processing with polypeptide folding.

    Science.gov (United States)

    Sandikci, Arzu; Gloge, Felix; Martinez, Michael; Mayer, Matthias P; Wade, Rebecca; Bukau, Bernd; Kramer, Günter

    2013-07-01

    Newly synthesized polypeptides undergo various cotranslational maturation steps, including N-terminal enzymatic processing, chaperone-assisted folding and membrane targeting, but the spatial and temporal coordination of these steps is unclear. We show that Escherichia coli methionine aminopeptidase (MAP) associates with ribosomes through a charged loop that is crucial for nascent-chain processing and cell viability. MAP competes with peptide deformylase (PDF), the first enzyme to act on nascent chains, for binding sites at the ribosomal tunnel exit. PDF has extremely fast association and dissociation kinetics, which allows it to frequently sample ribosomes and ensure the processing of nascent chains after their emergence. Premature recruitment of the chaperone trigger factor, or polypeptide folding, negatively affect processing efficiency. Thus, the fast ribosome association kinetics of PDF and MAP are crucial for the temporal separation of nascent-chain processing from later maturation events, including chaperone recruitment and folding.

  15. Thermodynamic Approach to Enhanced Dispersion and Physical Properties in a Carbon Nanotube/Polypeptide Nanocomposite

    Science.gov (United States)

    Lovell, Conrad S.; Wise, Kristopher E.; Kim, Jae-Woo; Lillehei, Peter T.; Harrison, Joycelyn S.; Park, Cheol

    2009-01-01

    A high molecular weight synthetic polypeptide has been designed which exhibits favorable interactions with single wall carbon nanotubes (SWCNTs). The enthalpic and entropic penalties of mixing between these two molecules are reduced due to the polypeptide's aromatic sidechains and helical secondary structure, respectively. These enhanced interactions result in a well dispersed SWCNT/Poly (L-Leucine-ran-L-Phenylalanine) nanocomposite with enhanced mechanical and electrical properties using only shear mixing and sonication. At 0.5 wt% loading of SWCNT filler, the nanocomposite exhibits simultaneous increases in the Young's modulus, failure strain, and toughness of 8%, 120%, and 144%, respectively. At one kHz, the same nanotube loading level also enhances the dielectric constant from 2.95 to 22.81, while increasing the conductivity by four orders of magnitude.

  16. [Relations of regulatory polypeptide and syndrome differentiation of traditional Chinese medicine of angina pectoris patients].

    Science.gov (United States)

    Huang, H Y; Zhu, W F; Li, B X

    1996-08-01

    Ninety cases of angina pectoris patients with the Deficiency of Heart Qi Syndrome (DHQS), Deficiency of Heart-Yin Syndrome (DHYS) and blood stasis in Heart vessels Syndrome (BSHVS) were studied. The number of patients were 30 for each group. Their regulatory polypeptides:atrial natri-uretic polypeptide (ANP), beta-Endorphine (beta-EP), Endothelin (ET), Angiotensin (A-II) were tested. Results showed that in comparing with normal level, P BSHVS > normal group > DHYS. ET and A-II of them: DHYS > BSHVS > normal group > DHQS. And the comparison between groups revealed that P < 0.05 or < 0.01. So ANP, beta-EP, ET and A-II were the principal material basis, and they could be the specific objective parameters of the Syndrome Differentiation.

  17. Elastin-like polypeptides: Therapeutic applications for an emerging class of nanomedicines.

    Science.gov (United States)

    Despanie, Jordan; Dhandhukia, Jugal P; Hamm-Alvarez, Sarah F; MacKay, J Andrew

    2016-10-28

    Elastin-like polypeptides (ELPs) constitute a genetically engineered class of 'protein polymers' derived from human tropoelastin. They exhibit a reversible phase separation whereby samples remain soluble below a transition temperature (T t ) but form amorphous coacervates above T t . Their phase behavior has many possible applications in purification, sensing, activation, and nanoassembly. As humanized polypeptides, they are non-immunogenic, substrates for proteolytic biodegradation, and can be decorated with pharmacologically active peptides, proteins, and small molecules. Recombinant synthesis additionally allows precise control over ELP architecture and molecular weight, resulting in protein polymers with uniform physicochemical properties suited to the design of multifunctional biologics. As such, ELPs have been employed for various uses including as anti-cancer agents, ocular drug delivery vehicles, and protein trafficking modulators. This review aims to offer the reader a catalogue of ELPs, their various applications, and potential for commercialization across a broad spectrum of fields. Copyright © 2015. Published by Elsevier B.V.

  18. Islet amyloid polypeptide in the control of food intake : An experimental study in the rat

    OpenAIRE

    Arnelo, Urban

    1997-01-01

    Control of food intake and satiety are physiologically complex processes, thatonly partly are understood. Several hormonal peptides have been proposed to mediatesatiety. Islet amyloid polypeptide (IAPP) is a recently discovered 37 amino acidpeptide, mainly produced by the pancreatic ß-cells. Initially, IAPP was shownto impair glucose tolerance at supra-physiological plasma concentrations and wasspeculated to be involved in the development of type-2 diabetes. More recent stud...

  19. Gene delivery of therapeutic polypeptides into brain capillary endothelial cells for protein secretion

    DEFF Research Database (Denmark)

    Larsen, Annette Burkhart; Thomsen, Louiza Bohn; Moos, Torben

    Chronic neurodegenerative and neuropsychiatric diseases are becoming more prevalent. Unfortunately, treatment of such diseases often gets complicated by the inability of many drugs of therapeutic relevance to cross the blood brain barrier (BBB), formed by non-fenestrated brain capillary endothelial...... cells (BCECs) and their intermingling tight junctions. Polypeptides like brain derived neurotropic factor (BDNF), erythropoietin (EPO), and FGL peptide (part of Neuronal adhesion molecule (NCAM)) are acknowledged for their neuroprotective and neurogenerative effects. Generally, however...

  20. Anion and pH-dependent conformational transition of an amphiphilic polypeptide.

    Science.gov (United States)

    Goto, Y; Aimoto, S

    1991-03-20

    While several proteins, including beta-lactamase, cytochrome c and apomyoglobin, are maximally unfolded at pH 2 by HCl in the absence of salt, the addition of anions, either from salt or acid, co-operatively induces the unfolded proteins to refold to a molten globule state, because anions bind preferentially to the compact molten globule state compared to the extended unfolded state. To study the role of the anion-dependent conformational transition at neutral pH, we synthesized a model polypeptide of 51 amino acid residues, consisting of tandem repeats of a Lys-Lys-Leu-Leu sequence and containing a turn sequence, Asn-Pro-Gly, at the center of the molecule. The model polypeptide showed no significant conformation by circular dichroism under conditions of low salt at neutral pH. However, addition of anions, either from salt or acid, induced the folding transition to an alpha-helical conformational state. The order of effectiveness of various anions in inducing the folding transition was consistent with the series of anions in inducing the molten globule of the acid-denatured protein. This suggests that the helical state of the model polypeptide is equivalent to the molten globule state. At pH values above 9, the model polypeptide also took an alpha-helical conformation, which was very similar to that induced by anions. On the basis of the chloride and pH-dependent conformational transitions, a phase diagram for the conformational states was constructed. The phase diagram was explained simply by assuming that the conformational transition is linked to the proton and the anion bindings to a limited number of amino groups and that anions bind only to the protonated groups.

  1. Wall-associated kinase-like polypeptide mediates nutritional status perception and response

    Science.gov (United States)

    Yang, Zhenbiao; Karr, Stephen

    2014-02-11

    The disclosure relates to methods for modulating plant growth and organogenesis using dominant-negative receptor-like kinases. The disclosure further provides a method for increasing plant yield relative to corresponding wild type plants comprising modulating the expression in a plant of a nucleic acid encoding a Wall-Associated Kinase-like 14 polypeptide or a homolog thereof, and selecting for plants having increased yield or growth on a nutrient deficient substrate.

  2. Folding and self-assembly of polypeptides: Dynamics and thermodynamics from molecular simulation

    Science.gov (United States)

    Fluitt, Aaron Michael

    Empowered by their exquisite three-dimensional structures, or "folds," proteins carry out biological tasks with high specificity, efficiency, and fidelity. The fold that optimizes biological function represents a stable configuration of the constituent polypeptide molecule(s) under physiological conditions. Proteins and polypeptides are not static, however: battered by thermal motion, they explore a distribution of folds that is determined by the sequence of amino acids, the presence and identity of other molecules, and the thermodynamic conditions. In this dissertation, we apply molecular simulation techniques to the study of two polypeptides that have unusually diffuse distributions of folds under physiological conditions: polyglutamine (polyQ) and islet amyloid polypeptide (IAPP). Neither polyQ nor IAPP adopts a predominant fold in dilute aqueous solution, but at sufficient concentrations, both are prone to self-assemble into stable, periodic, and highly regular aggregate structures known as amyloid. The appearance of amyloid deposits of polyQ in the brain, and of IAPP in the pancreas, are associated with Huntington's disease and type 2 diabetes, respectively. A molecular view of the mechanism(s) by which polyQ and IAPP fold and self-assemble will enhance our understanding of disease pathogenesis, and it has the potential to accelerate the development of therapeutics that target early-stage aggregates. Using molecular simulations with spatial and temporal resolution on the atomic scale, we present analyses of the structural distributions of polyQ and IAPP under various conditions, both in and out of equilibrium. In particular, we examine amyloid fibers of polyQ, the IAPP dimer in solution, and single IAPP fragments at a lipid bilayer. We also benchmark the molecular models, or "force fields," available for such studies, and we introduce a novel simulation algorithm.

  3. The ribosome quality control pathway can access nascent polypeptides stalled at the Sec61 translocon.

    Science.gov (United States)

    von der Malsburg, Karina; Shao, Sichen; Hegde, Ramanujan S

    2015-06-15

    Cytosolic ribosomes that stall during translation are split into subunits, and nascent polypeptides trapped in the 60S subunit are ubiquitinated by the ribosome quality control (RQC) pathway. Whether the RQC pathway can also target stalls during cotranslational translocation into the ER is not known. Here we report that listerin and NEMF, core RQC components, are bound to translocon-engaged 60S subunits on native ER membranes. RQC recruitment to the ER in cultured cells is stimulated by translation stalling. Biochemical analyses demonstrated that translocon-targeted nascent polypeptides that subsequently stall are polyubiquitinated in 60S complexes. Ubiquitination at the translocon requires cytosolic exposure of the polypeptide at the ribosome-Sec61 junction. This exposure can result from either failed insertion into the Sec61 channel or partial backsliding of translocating nascent chains. Only Sec61-engaged nascent chains early in their biogenesis were relatively refractory to ubiquitination. Modeling based on recent 60S-RQC and 80S-Sec61 structures suggests that the E3 ligase listerin accesses nascent polypeptides via a gap in the ribosome-translocon junction near the Sec61 lateral gate. Thus the RQC pathway can target stalled translocation intermediates for degradation from the Sec61 channel. © 2015 von der Malsburg et al. This article is distributed by The American Society for Cell Biology under license from the author(s). Two months after publication it is available to the public under an Attribution–Noncommercial–Share Alike 3.0 Unported Creative Commons License (http://creativecommons.org/licenses/by-nc-sa/3.0).

  4. Cellular Uptake Mechanism of Cationic Branched Polypeptides with Poly[l-Lys] Backbone.

    Science.gov (United States)

    Szabó, Rita; Sebestyén, Mónika; Kóczán, György; Orosz, Ádám; Mező, Gábor; Hudecz, Ferenc

    2017-04-10

    Cationic macromolecular carriers can be effective carriers for small molecular compounds, drugs, epitopes, or nucleic acids. Polylysine-based polymeric branched polypeptides have been systematically studied on the level of cells and organisms as well. In the present study, we report our findings on the cellular uptake characteristics of nine structurally related polylysine-based polypeptides with cationic side chains composed of (i) single amino acid (poly[Lys(X i )], X i K) or (ii) oligo[dl-alanine] (poly[Lys(dl-Ala m )], AK) or (iii) oligo[dl-alanine] with an additional amino acid (X) at the terminal position (poly[Lys(X i -dl-Ala m )] (XAK)) or (iv) at the position next to the polylysine backbone (poly[Lys(dl-Ala m -X i )] (AXK)). In vitro cytotoxicity and cellular uptake were characterized on HT-29 human colon carcinoma and HepG2 human hepatocarcinoma cell lines. Data indicate that the polycationic polypeptides studied are essentially nontoxic in the concentration range studied, and their uptake is very much dependent on the side chain structure (length, identity of amino acid X, and distance between the terminal positive charges) and also on the cell lines. Our findings in uptake inhibition studies suggest that predominantly macropinocytosis and caveole/lipid raft mediated endocytosis are involved. The efficacy of their internalization is markedly influenced by the hydrophobicity and charge properties of the amino acid X. Interestingly, the uptake properties of the these polypeptides show certain similarities to the entry pathways of several cell penetrating peptides.

  5. High-performance liquid chromatography of rat and mouse islet polypeptides

    DEFF Research Database (Denmark)

    Linde, S; Hansen, B; Welinder, B S

    1990-01-01

    on the buffer, the organic modifier and the procedure. In particular the use of methanol-trifluoroacetic acid resulted in extensive oxidation. The oxidation could be minimized by adding 2 mM dithiothreitol to the buffer and by degassing and/or nitrogen-bubbling of the buffer. Minimal formation of Met......-O derivatives is important for the quantitation of methionine-containing polypeptides....

  6. Specific photoaffinity labeling of two plasma membrane polypeptides with an azido auxin

    Science.gov (United States)

    Hicks, G. R.; Rayle, D. L.; Jones, A. M.; Lomax, T. L.

    1989-01-01

    Plasma membrane vesicles were isolated from zucchini (Cucurbita pepo) hypocotyl tissue by aqueous phase partitioning and assessed for homogeneity by the use of membrane-specific enzyme assays. The highly pure (ca. 95%) plasma membrane vesicles maintained a pH differential across the membrane and accumulated a tritiated azido analogue of 3-indoleacetic acid (IAA), 5-azido-[7-3H]IAA ([3H]N3IAA), in a manner similar to the accumulation of [3H]IAA. The association of the [3H]N3IAA with membrane vesicles was saturable and subject to competition by IAA and auxin analogues. Auxin-binding proteins were photoaffinity labeled by addition of [3H]N3IAA to plasma membrane vesicles prior to exposure to UV light (15 sec; 300 nm) and detected by subsequent NaDodSO4/PAGE and fluorography. When the reaction temperature was lowered to -196 degrees C, high-specific-activity labeling of a 40-kDa and a 42-kDa polypeptide was observed. Triton X-100 (0.1%) increased the specific activity of labeling and reduced the background, which suggests that the labeled polypeptides are intrinsic membrane proteins. The labeled polypeptides are of low abundance, as expected for auxin receptors. Further, the addition of IAA and auxin analogues to the photoaffinity reaction mixture resulted in reduced labeling that was qualitatively similar to their effects on the accumulation of radiolabeled IAA in membrane vesicles. Collectively, these results suggest that the radiolabeled polypeptides are auxin receptors. The covalent nature of the label should facilitate purification and further characterization of the receptors.

  7. Glucose‐dependent insulinotropic polypeptide and glucagon‐like peptide‐1: Incretin actions beyond the pancreas

    OpenAIRE

    Seino, Yutaka; Yabe, Daisuke

    2013-01-01

    Abstract Glucose‐dependent insulinotropic polypeptide (GIP) and glucagon‐like peptide‐1 (GLP‐1) are the two primary incretin hormones secreted from the intestine on ingestion of various nutrients to stimulate insulin secretion from pancreatic β‐cells glucose‐dependently. GIP and GLP‐1 undergo degradation by dipeptidyl peptidase‐4 (DPP‐4), and rapidly lose their biological activities. The actions of GIP and GLP‐1 are mediated by their specific receptors, the GIP receptor (GIPR) and the GLP‐1 r...

  8. Investigation of the pathophysiological mechanisms of migraine attacks induced by pituitary adenylate cyclase-activating polypeptide-38

    DEFF Research Database (Denmark)

    Amin, Faisal Mohammad; Hougaard, Anders; Schytz, Henrik W

    2014-01-01

    samples (plasma PACAP38 and vasoactive intestinal polypeptide and serum tryptase), and vital signs (blood pressure, heart rate, respiratory frequency, and end-tidal pressure of CO2) was recorded before and up to 5 h after infusion. Twenty-two patients [mean age 24 years (range 19-36)] completed the study...... on both days. Sixteen patients (73%) reported migraine-like attacks after PACAP38 and four after vasoactive intestinal polypeptide (18%) infusion (P = 0.002). Three of four patients, who reported migraine-like attacks after vasoactive intestinal polypeptide, also reported attacks after PACAP38. Both...... the start of PACAP38 infusion only in those patients who later reported migraine attacks. Blood levels of vasoactive intestinal polypeptide and tryptase were unchanged after PACAP38 infusion. In conclusion, PACAP38-induced migraine was associated with sustained dilatation of extracranial arteries...

  9. Salt- and pH-Triggered Helix-Coil Transition of Ionic Polypeptides under Physiology Conditions.

    Science.gov (United States)

    Yuan, Jingsong; Zhang, Yi; Sun, Yue; Cai, Zhicheng; Yang, Lijiang; Lu, Hua

    2018-03-26

    Controlling the helix-coil transition of polypeptides under physiological conditions is an attractive way toward smart functional materials. Here we report the synthesis of a series of tertiary amine-functionalized ethylene glycol (EGx)-linked polypeptide electrolytes with their secondary structures tunable under physiological conditions. The resultant polymers, denoted as P(EGxDMA-Glu) (x =1, 2, and 3), show excellent aqueous solubility (> 10 mg/mL) regardless of their charge states. Unlike poly-L-lysine that can form helix only at pH above 10, P(EGxDMA-Glu) undergo a pH-dependent helix-coil switch with their transition points within physiological range (~ pH 5.3-6.5). Meanwhile, P(EGxDMA-Glu) exhibit unusual salt-induced helical conformation presumably owing to the unique properties of EGx linkers. Together, the current work highlights the importance of fine-tuning the linker chemistry in achieving conformation-switchable polypeptides, and represents a facile approach towards stimuli-responsive biopolymers for advanced biological applications.

  10. Labelling polypeptide with 99mTc and bioactivity get back

    International Nuclear Information System (INIS)

    Li Shaolin; Jiang Xiaofei; Pang Hua; Liu Fangxin; Shi Qiong

    2001-01-01

    A method for labelling polypeptide (insulin) with technetium-99 ( 99m Tc) was established without marked loss of biological activity. Following reduction of intrinsic disulfide bonds by mercaptoethanol and purification on a Sephadex G50 column, the polypeptide was labelled with 99m Tc by trans-chelation from methylene diphosphonate (MDP). 99m Tc labelled insulin was identified by thin layer chromatography (TLC) and the change of blood sugar of mice injected, their hypo-glycemic shock symptom was also observed. Six hours after labelling, the dissociation of labelled insulin was only 3%, From then on to 24 h, there was no more dissociation. The blood sugar concentration of mice injected with the mercaptoethanol-reduced insulin was (5.0 +- 3.2) μmol·L -1 , while those injected with the original insulin was (1.4 +- 1.2) μmol·L -1 , the difference was significant (Q test, p -1 for the labelled insulin, and was about the same with that for the original insulin. The labelling efficiency was 74.31% for the labelled insulin, whereas the original insulin cannot be labelled with 99m Tc. The result suggests that while disulfide bonds of polypeptide were reduced by mercaptoethanol, it became free sulfhydryl group, and its bioactivity descended. Then free sulfhydryl group was chelated with 99m Tc under mild condition, re-establishing the disulfide bond, therefore, the bioactivity came back. The 99m Tc-labelled insulin was stable during 24 h

  11. Strategies to Fabricate Polypeptide-Based Structures via Ring-Opening Polymerization of N-Carboxyanhydrides

    Directory of Open Access Journals (Sweden)

    Carmen M. González-Henríquez

    2017-10-01

    Full Text Available In this review, we provide a general and clear overview about the different alternatives reported to fabricate a myriad of polypeptide architectures based on the ring-opening polymerization of N-carbonyanhydrides (ROP NCAs. First of all, the strategies for the preparation of NCA monomers directly from natural occurring or from modified amino acids are analyzed. The synthetic alternatives to prepare non-functionalized and functionalized NCAs are presented. Protection/deprotection protocols, as well as other functionalization chemistries are discussed in this section. Later on, the mechanisms involved in the ROP NCA polymerization, as well as the strategies developed to reduce the eventually occurring side reactions are presented. Finally, a general overview of the synthetic strategies described in the literature to fabricate different polypeptide architectures is provided. This part of the review is organized depending on the complexity of the macromolecular topology prepared. Therefore, linear homopolypeptides, random and block copolypeptides are described first. The next sections include cyclic and branched polymers such as star polypeptides, polymer brushes and highly branched structures including arborescent or dendrigraft structures.

  12. Polypept(o)ides: Hybrid Systems Based on Polypeptides and Polypeptoids.

    Science.gov (United States)

    Klinker, Kristina; Barz, Matthias

    2015-11-01

    Polypept(o)ides combine the multifunctionality and intrinsic stimuli-responsiveness of synthetic polypeptides with the "stealth"-like properties of the polypeptoid polysarcosine (poly(N-methyl glycine)). This class of block copolymers can be synthesized by sequential ring opening polymerization of α-amino acid N-carboxy-anhydrides (NCAs) and correspondingly of the N-substituted glycine N-carboxyanhydride (NNCA). The resulting block copolymers are characterized by Poisson-like molecular weight distributions, full end group integrity, and dispersities below 1.2. While polysarcosine may be able to tackle the currently arising issues regarding the gold standard PEG, including storage diseases in vivo and immune responses, the polypeptidic block provides the functionalities for a specific task. Additionally, polypeptides are able to form secondary structure motives, e.g., α-helix or β-sheets, which can be used to direct self-assembly in solution. In this feature article, we review the relatively new field of polypept(o)ides with respect to synthesis, characterization, and first data on the application of block copolypept(o)ides in nanomedicine. The summarized data already indicates the great potential of polypept(o)ides. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Construction of ultrasonic nanobubbles carrying CAIX polypeptides to target carcinoma cells derived from various organs.

    Science.gov (United States)

    Zhu, Lianhua; Guo, Yanli; Wang, Luofu; Fan, Xiaozhou; Xiong, Xingyu; Fang, Kejing; Xu, Dan

    2017-09-29

    Ultrasound molecular imaging is a novel diagnostic approach for tumors, whose key link is the construction of targeted ultrasound contrast agents. However, available targeted ultrasound contrast agents for molecular imaging of tumors are only achieving imaging in blood pool or one type tumor. No targeted ultrasound contrast agents have realized targeted ultrasound molecular imaging of tumor parenchymal cells in a variety of solid tumors so far. Carbonic anhydrase IX (CAIX) is highly expressed on cell membranes of various malignant solid tumors, so it's a good target for ultrasound molecular imaging. Here, targeted nanobubbles carrying CAIX polypeptides for targeted binding to a variety of malignant tumors were constructed, and targeted binding ability and ultrasound imaging effect in different types of tumors were evaluated. The mean diameter of lipid targeted nanobubbles was (503.7 ± 78.47) nm, and the polypeptides evenly distributed on the surfaces of targeted nanobubbles, which possessed the advantages of homogenous particle size, high stability, and good safety. Targeted nanobubbles could gather around CAIX-positive cells (786-O and Hela cells), while they cannot gather around CAIX-negative cells (BxPC-3 cells) in vitro, and the affinity of targeted nanobubbles to CAIX-positive cells were significantly higher than that to CAIX-negative cells (P polypeptides can specifically enhance ultrasound imaging in CAIX-positive transplanted tumor tissues and could potentially be used in early diagnosis of a variety of solid tumors derived from various organs.

  14. High-yield recombinant expression and purification of marginally soluble, short elastin-like polypeptides.

    Science.gov (United States)

    Bahniuk, Markian S; Alshememry, Abdullah K; Unsworth, Larry D

    2016-12-01

    The protocol described here is designed as an extension of existing techniques for creating elastin-like polypeptides. It allows for the expression and purification of elastin-like polypeptide (ELP) constructs that are poorly expressed or have very low transition temperatures. DNA concatemerization has been modified to reduce issues caused by methylation sensitivity and inefficient cloning. Linearization of the modified expression vector has been altered to greatly increase cleavage efficiency. The purification regimen is based upon using denaturing metal affinity chromatography to fully solubilize and, if necessary, pre-concentrate the target peptide before purification by inverse temperature cycling (ITC). This protocol has been used to express multiple leucine-containing elastin-like polypeptides, with final yields of 250-660 mg per liter of cells, depending on the specific construct. This was considerably greater than previously reported yields for similar ELPs. Due to the relative hydrophobicity of the tested constructs, even compared with commonly employed ELPs, conventional methods would not have been able to be purify these peptides.

  15. Beaded nanofibers assembled from double-hydrophobic elastin-like block polypeptides: Effects of trifluoroethanol.

    Science.gov (United States)

    Le, Duc H T; Okubo, Tatsuya; Sugawara-Narutaki, Ayae

    2015-03-01

    A "double-hydrophobic" elastin-like triblock polypeptide GPG has been constructed by mimicking the localization of proline- and glycine-rich hydrophobic domains of native elastin, a protein that provides elasticity and resilience to connective tissues. In this study, the effects of trifluoroethanol (TFE), an organic solvent that strongly affects secondary structures of polypeptides on self-assembly of GPG in aqueous solutions were systematically studied. Beaded nanofiber formation of GPG, where nanoparticles are initially formed by coacervation of the polypeptides followed by their connection into one-dimensional nanostructures, is accelerated by the addition of TFE at the concentrations up to 30% (v/v), whereas aggregates of nanoparticles are formed at 60% TFE. The concentration-dependent assembly pattern discussed is based on the influence of TFE on the secondary structures of GPG. Well-defined nanofibers whose diameter and secondary structures are controlled by TFE concentration may be ideal building blocks for constructing bioelastic materials in tissue engineering. © 2014 Wiley Periodicals, Inc.

  16. Thermal expansivities of peptides, polypeptides and proteins as measured by pressure perturbation calorimetry.

    Science.gov (United States)

    Pandharipande, Pranav P; Makhatadze, George I

    2015-04-01

    The main goal of this work was to provide direct experimental evidence that the expansivity of peptides, polypeptides and proteins as measured by pressure perturbation calorimetry (PPC), can serve as a proxy to characterize relative compactness of proteins, especially the denatured state ensemble. This is very important as currently only small angle X-ray scattering (SAXS), intrinsic viscosity and, to a lesser degree, fluorescence resonance transfer (FRET) experiments are capable of reporting on the compactness of denatured state ensembles. We combined the expansivity measurements with other biophysical methods (far-UV circular dichroism spectroscopy, differential scanning calorimetry, and small angle X-ray scattering). Three case studies of the effects of conformational changes on the expansivity of polypeptides in solution are presented. We have shown that expansivity appears to be insensitive to the helix-coil transition, and appears to reflect the changes in hydration of the side-chains. We also observed that the expansivity is sensitive to the global conformation of the polypeptide chain and thus can be potentially used to probe hydration of different collapsed states of denatured or even intrinsically disordered proteins. Copyright © 2015 Elsevier Inc. All rights reserved.

  17. Common spectrum of polypeptides occurs in secretion granule membranes of different exocrine glands

    International Nuclear Information System (INIS)

    Cameron, R.S.; Cameron, P.L.; Castle, J.D.

    1986-01-01

    A highly purified membrane preparation from rat parotid secretion granules has been used as a comparative probe to examine the extent of compositional overlap in granule membranes of three other exocrine secretory tissues - pancreatic, lacrimal, and submandibular - from several standpoints. First, indirect immunofluorescent studies using a polyclonal polyspecific anti-parotid granule membrane antiserum has indicated a selective staining of granule membrane profiles in all acinar cells of all tissues. Second, highly purified granule membrane subfractions have been isolated from each exocrine tissue; comparative two-dimensional (isoelectric focusing; SDS) PAGE of radioiodinated granule membranes has identified 10-15 polypeptides of identical pI and apparent molecular mass. These species are likely to be integral membrane components since they are not extracted by either saponin-sodium sulfate or sodium carbonate (pH 11.5) treatments, and they do not have counterparts in the granule content. Finally, the identity among selected parotid and pancreatic radioiodinated granule membrane polypeptides has been documented using two-dimensional peptide mapping of chymotryptic and tryptic digests. These findings clearly indicate that exocrine secretory granules, irrespective of the nature of stored secretion, comprise a type of vesicular carrier with a common (and probably refined) membrane composition. Conceivably, the polypeptides identified carry out general functions related to exocrine secretion

  18. Cross antigenicity of immunodominant polypeptides of somatic antigen of Oesophagostomum columbianum with other helminths by western blotting.

    Science.gov (United States)

    Dalal, Sunita; Prasad, Arvind; Nasir, Abdul; Saini, Vijesh Kumar

    2015-11-01

    Oesophagostomum columbianum in small ruminants in India is found as mixed infection commonly in sheep and goat. Haemonchus contortus, an abomasal nematode is found as concurrent infection with it. Eggs of Haemonchus and O. columbianum cannot be easily distinguished. Diagnosis of O. columbianum may only be possible if a non-cross antigenic polypeptide was available for immunodiagnosis. Somatic antigen (SoAg) of O. columbianum was fractionated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and immunodominant polypeptides were identified by western blotting with homologous hyperimmune serum (HIS) and experimental sera of sheep or goat infected with other helminths. SoAg of O. columbianum was immunoaffinity purified. Sharp polypeptide bands of 130, 72 and 68 KDa were observed along with several faint bands of lower molecular weight. Western blot of purified SoAg of O. columbianum with homologous HIS showed reaction with all the protein bands of 17, 28, 30, 32, 35, 38, 50, 68, 100, 130, 150, and 170 kDa. For identification of non-cross antigenic polypeptide, immunoaffinity purified SoAg of O. columbianum was reacted to heterologous HIS against H. contortus, Paramphistomum epiclitum, and Fasciola gigantica in western blotting utilizing completely dry method (i-blot). Among high molecular weight polypeptides 100 and 150 kDa were non-cross antigenic and among low molecular weight except 50 kDa polypeptide, 17, 30, 32, 35, and 38 kDa of O. columbianum were not cross antigenic with other helminths. Hence, polypeptides of 17, 30, 32, 35 and 38 kDa as well as 100 and 150 kDa polypeptides of O. columbianum may be exploited for immunodiagnosis of the infection in sheep and goat with extensive studies on cross antigenicity.

  19. CRIF1 is essential for the synthesis and insertion of oxidative phosphorylation polypeptides in the mammalian mitochondrial membrane.

    Science.gov (United States)

    Kim, Soung Jung; Kwon, Min-chul; Ryu, Min Jeong; Chung, Hyo Kyun; Tadi, Surendar; Kim, Yong Kyung; Kim, Jin Man; Lee, Sang Hee; Park, Ji Hoon; Kweon, Gi Ryang; Ryu, Seung-Wook; Jo, Young Suk; Lee, Chul-Ho; Hatakeyama, Hideyuki; Goto, Yu-ichi; Yim, Yong-Hyeon; Chung, Jongkyeong; Kong, Young-Yun; Shong, Minho

    2012-08-08

    Although substantial progress has been made in understanding the mechanisms underlying the expression of mtDNA-encoded polypeptides, the regulatory factors involved in mitoribosome-mediated synthesis and simultaneous insertion of mitochondrial oxidative phosphorylation (OXPHOS) polypeptides into the inner membrane of mitochondria are still unclear. In the present study, disruption of the mouse Crif1 gene, which encodes a mitochondrial protein, resulted in a profound deficiency in OXPHOS caused by the disappearance of OXPHOS subunits and complexes in vivo. CRIF1 was associated with large mitoribosomal subunits that were located close to the polypeptide exit tunnel, and the elimination of CRIF1 led to both aberrant synthesis and defective insertion of mtDNA-encoded nascent OXPHOS polypeptides into the inner membrane. CRIF1 interacted with nascent OXPHOS polypeptides and molecular chaperones, e.g., Tid1. Taken together, these results suggest that CRIF1 plays a critical role in the integration of OXPHOS polypeptides into the mitochondrial membrane in mammals. Copyright © 2012 Elsevier Inc. All rights reserved.

  20. Multidentate Comb-Shaped Polypeptides Bearing Trithiocarbonate Functionality: Synthesis and Application for Water-Soluble Quantum Dots.

    Science.gov (United States)

    Zhang, Hang; Chen, Jinlong; Zhang, Xiaojie; Xiao, Chunsheng; Chen, Xuesi; Tao, Youhua; Wang, Xianhong

    2017-03-13

    We describe here the synthesis of multidentate comb-shaped polypeptides bearing trithiocarbonate functionality and their application in the preparation of water-soluble quantum dots (QDs). A new l-lysine-based N-carboxyanhydride monomer containing trithiocarbonate functionality was designed and synthesized. Ring-opening polymerization of the resulting monomer initiated by hexamethyldisilazane affords polypeptides bearing pendent trithiocarbonate groups (P(TTCLys)) with controllable molecular weights. P(TTCLys) was then applied to mediate the reversible addition-fragmentation chain-transfer polymerization of oligo(ethylene glycol)acrylate for the metal-free preparation of hydrophilic comb-shaped polypeptides. Simple reduction of trithiocarbonate functionality enabled the introduction of multiple thiol anchoring groups to the above-mentioned comb-shaped polypeptides. Finally, the obtained multidentate polypeptide-based ligands were successfully applied in the ligand exchange procedures to generate water-soluble QDs. The fluorescent microscopic images suggested that the resultant water-soluble QDs could be effectively internalized into HeLa cells to realize bright cellular imaging. Therefore, our work can result in a new kind of valuable polypeptide-based QDs with hydrophilic character and biocompatibility for cellular imaging.

  1. Stimuli-Triggered Sol-Gel Transitions of Polypeptides Derived from α-Amino Acid N-Carboxyanhydride (NCA) Polymerizations.

    Science.gov (United States)

    He, Xun; Fan, Jingwei; Wooley, Karen L

    2016-02-18

    The past decade has witnessed significantly increased interest in the development of smart polypeptide-based organo- and hydrogel systems with stimuli responsiveness, especially those that exhibit sol-gel phase-transition properties, with an anticipation of their utility in the construction of adaptive materials, sensor designs, and controlled release systems, among other applications. Such developments have been facilitated by dramatic progress in controlled polymerizations of α-amino acid N-carboxyanhydrides (NCAs), together with advanced orthogonal functionalization techniques, which have enabled economical and practical syntheses of well-defined polypeptides and peptide hybrid polymeric materials. One-dimensional stacking of polypeptides or peptide aggregations in the forms of certain ordered conformations, such as α helices and β sheets, in combination with further physical or chemical cross-linking, result in the construction of three-dimensional matrices of polypeptide gel systems. The macroscopic sol-gel transitions, resulting from the construction or deconstruction of gel networks and the conformational changes between secondary structures, can be triggered by external stimuli, including environmental factors, electromagnetic fields, and (bio)chemical species. Herein, the most recent advances in polypeptide gel systems are described, covering synthetic strategies, gelation mechanisms, and stimuli-triggered sol-gel transitions, with the aim of demonstrating the relationships between chemical compositions, supramolecular structures, and responsive properties of polypeptide-based organo- and hydrogels. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Investigation of nonfouling polypeptides of poly(glutamic acid) with lysine side chains synthesized by EDC·HCl/HOBt chemistry.

    Science.gov (United States)

    Yang, Qinghua; Li, Wenchen; Wang, Longgang; Wang, Guangzhi; Wang, Zhen; Liu, Lingyun; Chen, Shengfu

    2014-01-01

    Nonfouling polypeptides with homogenous alternating charges draw peoples' attentions for their potential capability in biodegradation. Homogenous glutamic acid (E) and lysine (K) polypeptides were proposed and synthesized before. In this work, a new polypeptide formed by poly(glutamic acid) with lysine side chains (poly(E)-K) was synthesized by facile EDC·HCl/HOBt chemistry and investigated. Results show that these polypeptides also have good nonspecific protein resistance determined by enzyme-linked immunosorbent assay. The lowest nonspecific adsorption of the model proteins, anti-IgG and fibrinogen (Fg), on the self-assembling monolayers (SAMs) surface of poly(E)-K was only 3.3 ± 1.8 and 4.4 ± 1.6%, respectively, when protein adsorption on tissue culture polystyrene surface was set as 100%. And, the relative nonspecific protein adsorption increases when the polypeptide molecular weight increases due to the repression of low density polymer brushes. Moreover, almost no obvious cytotoxicity and hemolytic activity in vitro were detected. This work suggests that polypeptides with various formats of homogenous balanced charges could achieve excellent nonspecific protein resistance, which might be the intrinsic reason for the coexistence of high concentration serum proteins in blood.

  3. Italian legumes: effect of sourdough fermentation on lunasin-like polypeptides.

    Science.gov (United States)

    Rizzello, Carlo Giuseppe; Hernández-Ledesma, Blanca; Fernández-Tomé, Samuel; Curiel, José Antonio; Pinto, Daniela; Marzani, Barbara; Coda, Rossana; Gobbetti, Marco

    2015-10-22

    There is an increasing interest toward the use of legumes in food industry, mainly due to the quality of their protein fraction. Many legumes are cultivated and consumed around the world, but few data is available regarding the chemical or technological characteristics, and especially on their suitability to be fermented. Nevertheless, sourdough fermentation with selected lactic acid bacteria has been recognized as the most efficient tool to improve some nutritional and functional properties. This study investigated the presence of lunasin-like polypeptides in nineteen traditional Italian legumes, exploiting the potential of the fermentation with selected lactic acid bacteria to increase the native concentration. An integrated approach based on chemical, immunological and ex vivo (human adenocarcinoma Caco-2 cell cultures) analyses was used to show the physiological potential of the lunasin-like polypeptides. Italian legume varieties, belonging to Phaseulus vulgaris, Cicer arietinum, Lathyrus sativus, Lens culinaris and Pisum sativum species, were milled and flours were chemically characterized and subjected to sourdough fermentation with selected Lactobacillus plantarum C48 and Lactobacillus brevis AM7, expressing different peptidase activities. Extracts from legume doughs (unfermented) and sourdoughs were subjected to western blot analysis, using an anti-lunasin primary antibody. Despite the absence of lunasin, different immunoreactive polypeptide bands were found. The number and the intensity of lunasin-like polypeptides increased during sourdough fermentation, as the consequence of the proteolysis of the native proteins carried out by the selected lactic acid bacteria. A marked inhibitory effect on the proliferation of human adenocarcinoma Caco-2 cells was observed using extracts from legume sourdoughs. In particular, sourdoughs from Fagiolo di Lamon, Cece dell'Alta Valle di Misa, and Pisello riccio di Sannicola flours were the most active, showing a decrease

  4. Polyspecific drug and steroid clearance by an organic anion transporter of mammalian liver

    NARCIS (Netherlands)

    Bossuyt, [No Value; Muller, M; Hagenbuch, B; Meier, PJ

    An organic anion-transporting polypeptide that mediates sodium-independent uptake of negatively charged sulfobromophthalein and bile salts has recently been cloned from rat liver (Jacquemin et al., 1994). In this study we have extended the substrate specificity studies to neutral and positively

  5. The generalized model of polypeptide chain describing the helix-coil transition in biopolymers

    International Nuclear Information System (INIS)

    Mamasakhlisov, E.S.; Badasyan, A.V.; Tsarukyan, A.V.; Grigoryan, A.V.; Morozov, V.F.

    2005-07-01

    In this paper we summarize some results of our theoretical investigations of helix-coil transition both in single-strand (polypeptides) and two-strand (polynucleotides) macromolecules. The Hamiltonian of the Generalized Model of Polypeptide Chain (GMPC) is introduced to describe the system in which the conformations are correlated over some dimensional range Δ (it equals 3 for polypeptide, because one H-bond fixes three pairs of rotation, for double strand DNA it equals to one chain rigidity because of impossibility of loop formation on the scale less than Δ). The Hamiltonian does not contain any parameter designed especially for helix-coil transition and uses pure molecular microscopic parameters (the energy of hydrogen bond formation, reduced partition function of repeated unit, the number of repeated units fixed by one hydrogen bond, the energies of interaction between the repeated units and the solvent molecules). To calculate averages we evaluate the partition function using the transfer-matrix approach. The GMPC allowed to describe the influence of a number of factors, affecting the transition, basing on a unified microscopic approach. Thus we obtained, that solvents change transition temperature and interval in different ways, depending on type of solvent and on energy of solvent- macromolecule interaction; stacking on the background of H-bonding increases stability and decreases cooperativity of melting. For heterogeneous DNA we could analytically derive well known formulae for transition temperature and interval. In the framework of GMPC we calculate and show the difference of two order parameters of helix-coil transition - the helicity degree, and the average fraction of repeated units in helical conformation. Given article has the aim to review the results obtained during twenty years in the context of GMPC. (author)

  6. On the fragmentation of biomolecules: Fragmentation of alanine dipeptide along the polypeptide chain

    International Nuclear Information System (INIS)

    Solov'yov, I. A.; Yakubovich, A. V.; Solov'yov, A. V.; Greiner, W.

    2006-01-01

    The interaction potential between amino acids in alanine dipeptide has been studied for the first time taking into account exact molecular geometry. Ab initio calculation has been performed in the framework of density functional theory taking into account all electrons in the system. The fragmentation of dipeptide along the polypeptide chain, as well as the interaction between alanines, has been considered. The energy of the system has been analyzed as a function of the distance between fragments for all possible dipeptide fragmentation channels. Analysis of the energy barriers makes it possible to estimate the characteristic fragmentation times and to determine the degree of applicability of classical electrodynamics for describing the system energy

  7. Ca-C backbone fragmentation dominates in electron detachment dissociation of gas-phase polypeptide polyanions

    DEFF Research Database (Denmark)

    Kjeldsen, Frank; Silivra, Oleg A; Ivonin, Igor A

    2005-01-01

    the dissociation of oxidized radical anions [M-nH]((n-1)-*. We demonstrate that C(alpha)-C cleavages, which are otherwise rarely observed in tandem mass spectrometry, can account for most of the backbone fragmentation, with even-electron x fragments dominating over radical a* ions. Ab initio calculations at the B3......Fragmentation of peptide polyanions by electron detachment dissociation (EDD) has been induced by electron irradiation of deprotonated polypeptides [M-nH](n-) with >10 eV electrons. EDD has been found to lead preferentially to a* and x fragment ions (C(alpha)-C backbone cleavage) arising from...

  8. Searching for the physiological role of glucose-dependent insulinotropic polypeptide

    DEFF Research Database (Denmark)

    Holst, Jens Juul; Windeløv, Johanne Agerlin; Boer, Geke Aline

    2016-01-01

    Glucose-dependent insulinotropic polypeptide (GIP) was established as a gut hormone more than 40 years ago, and there is good experimental support for its role as an incretin hormone although deletion of the GIP receptor or the GIP cells or GIP receptor mutations have only minor effects on glucose...... in rodent point to effects on bone metabolism. Recent studies revealed pronounced inhibitory effects of GIP on bone resorption markers in humans and suggest that GIP may be (one of the) gastrointestinal regulators of bone turn-over. In support of this, a loss-of-function GIP receptor mutation in humans...

  9. Profile of sequential determinants in tissue polypeptide antigen BrCN:B fragment.

    Science.gov (United States)

    Chersi, A; Camera, M; Trinca, M L; Castelli, M

    1989-02-15

    A synthetic approach has been applied to determine the profile of sequential determinants of one immunodominant region of Tissue Polypeptide Antigen (TPA). Five overlapping peptides, covering 30 of the 32 amino acid residues of this fragment, were chemically synthesized, and their antibody-binding activities for rabbit anti-TPA antibodies determined by enzyme-linked immunoadsorbant assays. Anti-TPA reacted with two overlapping fragments at the COOH-terminal end of the fragment, but not with peptides that include Arg 15 considered as essential for the antigenicity of the whole fragment. This might suggest that this critical residue is involved in the formation of a complex conformational determinant.

  10. Stimulation of antibody formation through polypeptide thymic fraction (TP) in irradiated animals. [X radiation, rabbits

    Energy Technology Data Exchange (ETDEWEB)

    Milcu, S.M.; Potop, I.; Boeru, V.; Olinici, N.

    1975-02-28

    Total sublethal irradiation with x-rays of the rabbits immunized with the Salmonella TH 901 antigen induces a decrease in the serum antibody level as compared with nonirradiated controls. Administration of the polypeptide thymic (TP) extract to rabbits immunized with antigen and x-rayed in similar conditions produces a stimulation of antibody formation in these animals as compared to the nontreated controls. The level of antibodies is altered in the animals irradiated, and treatment with the TP extract shows that it has a protective effect on the organism.

  11. Antimicrobial activity of human islet amyloid polypeptides: an insight into amyloid peptides' connection with antimicrobial peptides.

    Science.gov (United States)

    Wang, Lan; Liu, Qian; Chen, Jin-Chun; Cui, Yi-Xian; Zhou, Bing; Chen, Yong-Xiang; Zhao, Yu-Fen; Li, Yan-Mei

    2012-07-01

    Human islet amyloid polypeptide (hIAPP) shows an antimicrobial activity towards two types of clinically relevant bacteria. The potency of hIAPP varies with its aggregation states. Circular dichroism was employed to determine the interaction between hIAPP and bacteria lipid membrane mimic. The antimicrobial activity of each aggregate species is associated with their ability to induce membrane disruption. Our findings provide new evidence revealing the antimicrobial activity of amyloid peptide, which suggest a possible connection between amyloid peptides and antimicrobial peptides.

  12. Molecular diversity and hypoglycemic polypeptide-P content of Momordica charantia in different accessions and different seasons.

    Science.gov (United States)

    Tian, Miao; Zeng, Xiang-Qing; Song, Huan-Lei; Hu, Shan-Xin; Wang, Fu-Jun; Zhao, Jian; Hu, Zhi-Bi

    2015-04-01

    Momordica charantia (MC) has been used for treating diabetes mellitus from ancient times in Asia, Africa and South America. There are many MC accessions in local markets. Polypeptide-P as a main hypoglycemic component in MC was first studied in this experiment to illustrate the different contents in MC of different accessions and different harvesting times. Nineteen MC accessions collected from different regions were clustered into three groups using random amplified polymorphic DNA (RAPD) and inter-simple sequence repeat (ISSR) molecular markers. Content of polypeptide-P in the tested MC accessions was detected by western blot (WB) method. The WB results revealed that polypeptide-P was detected in MC accessions harvested in June and July but not in September and October. Furthermore, Polypeptide-P content corresponded well with the MC accessions. Our results suggest that the MC accessions and the harvesting times or the weather during harvest play significant roles in high content of polypeptide-P. © 2014 Society of Chemical Industry.

  13. Interactions between organic anions on multiple transporters in Caco-2 cells

    DEFF Research Database (Denmark)

    Grandvuinet, Anne Sophie; Steffansen, Bente

    2011-01-01

    Caco-2 cell line may be used as an overall model to predict interactions on multiple membrane transporters in the intestine. Taurocholic acid (TCA) and estrone-3-sulfate (E1S) were used as model substrates. Possible inhibitors studied were TCA, E1S, taurolithocholic acid, fluvastatin, and glipizide......-dependent bile acid transporter and the organic solute transporter α/β, and to less extent by the organic anion transporting polypeptide 2B1. However, interactions on efflux transporters were not detected, although they were expected from the literature on the investigated compounds. Biosimulation methods may...

  14. Toughening of Thermoresponsive Arrested Networks of Elastin-Like Polypeptides To Engineer Cytocompatible Tissue Scaffolds.

    Science.gov (United States)

    Glassman, Matthew J; Avery, Reginald K; Khademhosseini, Ali; Olsen, Bradley D

    2016-02-08

    Formulation of tissue engineering or regenerative scaffolds from simple bioactive polymers with tunable structure and mechanics is crucial for the regeneration of complex tissues, and hydrogels from recombinant proteins, such as elastin-like polypeptides (ELPs), are promising platforms to support these applications. The arrested phase separation of ELPs has been shown to yield remarkably stiff, biocontinuous, nanostructured networks, but these gels are limited in applications by their relatively brittle nature. Here, a gel-forming ELP is chain-extended by telechelic oxidative coupling, forming extensible, tough hydrogels. Small angle scattering indicates that the chain-extended polypeptides form a fractal network of nanoscale aggregates over a broad concentration range, accessing moduli ranging from 5 kPa to over 1 MPa over a concentration range of 5-30 wt %. These networks exhibited excellent erosion resistance and allowed for the diffusion and release of encapsulated particles consistent with a bicontinuous, porous structure with a broad distribution of pore sizes. Biofunctionalized, toughened networks were found to maintain the viability of human mesenchymal stem cells (hMSCs) in 2D, demonstrating signs of osteogenesis even in cell media without osteogenic molecules. Furthermore, chondrocytes could be readily mixed into these gels via thermoresponsive assembly and remained viable in extended culture. These studies demonstrate the ability to engineer ELP-based arrested physical networks on the molecular level to form reinforced, cytocompatible hydrogel matrices, supporting the promise of these new materials as candidates for the engineering and regeneration of stiff tissues.

  15. Schistosoma mansoni polypeptides immunogenic in mice vaccinated with radiation-attenuated cercariae

    Energy Technology Data Exchange (ETDEWEB)

    Dalton, J.P.; Strand, M.

    1987-10-01

    We compared the humoral immune response of mice protected against Schistosoma mansoni by vaccination with radiation-attenuated cercariae to that of patently infected mice, and we identified antigens that elicit a greater, or unique, immune response in the vaccinated mice. These comparisons were based upon radioimmunoprecipitations and immunodepletion of (/sup 35/S)methionine-labeled schistosomular and adult worm polypeptides, followed by one- and two-dimensional polyacrylamide gel analyses. The humoral responses of patently infected mice and of mice vaccinated once were remarkably similar and were directed against schistosome glycoproteins ranging in molecular size from greater than 300 to less than 10 kDa. Exposing mice to a second vaccination resulted in a marked change in the immune response, to one predominantly directed toward high molecular size glycoproteins. Sequential immunodepletion techniques identified five schistosomular and seven adult worm antigens that showed a greater or unique immunogenicity in vaccinated mice as compared with patently infected mice. These adult worm antigens were purified by preparative sequential immunoaffinity chromatography and used to prepare a polyclonal antiserum, anti-irradiated vaccine. This antiserum bound to the surface of live newly transformed and lung-stage schistosomula, as assessed by immunofluorescence assays, and was reactive with a number of /sup 125/I-labeled schistosomular surface polypeptides, including a doublet of 150 kDa that was also recognized by sera of vaccinated mice but not by sera of patently infected mice.

  16. Specific photoaffinity labeling of two plasma membrane polypeptides with an azido auxin

    International Nuclear Information System (INIS)

    Hicks, G.R.; Rayle, D.L.; Jones, A.M.; Lomax, T.L.

    1989-01-01

    Plasma membrane vesicles were isolated from zucchini (Cucurbita pepo) hypocotyl tissue by aqueous phase partitioning and assessed for homogeneity by the use of membrane-specific enzyme assays. The highly pure plasma membrane vesicles maintained a pH differential across the membrane and accumulated a tritiated azido analogue of 3-indoleacetic acid (IAA), 5-azido-[7- 3 H]IAA([ 3 H]N 3 IAA), in a manner similar to the accumulation of [ 3 H]IAA. The association of the [ 3 H]N 3 IAA with membrane vesicles was saturable and subject to competition by IAA and auxin analogues. Auxin-binding proteins were photoaffinity labeled by addition of [ 3 H]N 3 IAA to plasma membrane vesicles prior to exposure to UV light and detected by subsequent NaDodSO 4 /PAGE and fluorography. When the reaction temperature was lowered to -196 degree C, high-specific-activity labeling of a 40-kDa and a 42-kDa polypeptide was observed. Collectively, these results suggest that the radiolabeled polypeptides are auxin receptors. The covalent nature of the label should facilitate purification and further characterization of the receptors

  17. Temperature-dependent morphology of hybrid nanoflowers from elastin-like polypeptides

    Directory of Open Access Journals (Sweden)

    Koushik Ghosh

    2014-02-01

    Full Text Available We report a method for creating hybrid organic-inorganic “nanoflowers” using calcium or copper ions as the inorganic component and a recombinantly expressed elastin-like polypeptide (ELP as the organic component. Polypeptides provide binding sites for the dynamic coordination with metal ions, and then such noncovalent complexes become nucleation sites for primary crystals of metal phosphates. We have shown that the interaction between the stimuli-responsive ELP and Ca2+ or Cu2+, in the presence of phosphate, leads to the growth of micrometer-sized particles featuring nanoscale patterns shaped like flower petals. The morphology of these flower-like composite structures is dependent upon the temperature of growth and has been characterized by scanning electron microscopy. The composition of nanoflowers has also been analyzed by energy-dispersive X-ray spectroscopy, X-ray photoelectron spectroscopy, and X-ray diffraction. The temperature-dependent morphologies of these hybrid nanostructures, which arise from the controllable phase transition of ELPs, hold potential for morphological control of biomaterials in emerging applications such as tissue engineering and biocatalysis.

  18. Temperature-dependent morphology of hybrid nanoflowers from elastin-like polypeptides

    Energy Technology Data Exchange (ETDEWEB)

    Ghosh, Koushik; Balog, Eva Rose M.; Sista, Prakash; Williams, Darrick J.; Martinez, Jennifer S., E-mail: jenm@lanl.gov, E-mail: rcrocha@lanl.gov; Rocha, Reginaldo C., E-mail: jenm@lanl.gov, E-mail: rcrocha@lanl.gov [Center for Integrated Nanotechnologies, Materials Physics and Applications Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Kelly, Daniel [Chemistry Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)

    2014-02-01

    We report a method for creating hybrid organic-inorganic “nanoflowers” using calcium or copper ions as the inorganic component and a recombinantly expressed elastin-like polypeptide (ELP) as the organic component. Polypeptides provide binding sites for the dynamic coordination with metal ions, and then such noncovalent complexes become nucleation sites for primary crystals of metal phosphates. We have shown that the interaction between the stimuli-responsive ELP and Ca{sup 2+} or Cu{sup 2+}, in the presence of phosphate, leads to the growth of micrometer-sized particles featuring nanoscale patterns shaped like flower petals. The morphology of these flower-like composite structures is dependent upon the temperature of growth and has been characterized by scanning electron microscopy. The composition of nanoflowers has also been analyzed by energy-dispersive X-ray spectroscopy, X-ray photoelectron spectroscopy, and X-ray diffraction. The temperature-dependent morphologies of these hybrid nanostructures, which arise from the controllable phase transition of ELPs, hold potential for morphological control of biomaterials in emerging applications such as tissue engineering and biocatalysis.

  19. Elastin-like polypeptides: the power of design for smart cell encapsulation.

    Science.gov (United States)

    Bandiera, Antonella

    2017-01-01

    Cell encapsulation technology is still a challenging issue. Innovative methodologies such as additive manufacturing, and alternative bioprocesses, such as cell therapeutic delivery, where cell encapsulation is a key tool are rapidly gaining importance for their potential in regenerative medicine. Responsive materials such as elastin-based recombinant expression products have features that are particularly attractive for cell encapsulation. They can be designed and tailored to meet desired requirements. Thus, they represent promising candidates for the development of new concept-based materials that can be employed in this field. Areas covered: An overview of the design and employment of elastin-like polypeptides for cell encapsulation is given to outline the state of the art. Special attention is paid to the design of the macromolecule employed as well as to the method of matrix formation and the biological system involved. Expert opinion: As a result of recent progress in regenerative medicine there is a compelling need for materials that provide specific properties and demonstrate defined functional features. Rationally designed materials that may adapt according to applied external stimuli and that are responsive to biological systems, such as elastin-like polypeptides, belong to this class of smart material. A run through the components described to date represents a good starting point for further advancement in this area. Employment of these components in cell encapsulation application will promote its advance toward 'smart cell encapsulation technology'.

  20. Analysis of Urine Composition in Type II Diabetic Mice after Intervention Therapy Using Holothurian Polypeptides

    Directory of Open Access Journals (Sweden)

    Yanyan Li

    2017-07-01

    Full Text Available Hydrolysates and peptide fractions (PF obtained from sea cucumber with commercial enzyme were studied on the hyperglycemic and renal protective effects on db/db rats using urine metabolomics. Compared with the control group the polypeptides from the two species could significantly reduce the urine glucose and urea. We also tried to address the compositions of highly expressed urinary proteins using a proteomics approach. They were serum albumins, AMBP proteins, negative trypsin, elastase, and urinary protein, GAPDH, a receptor of urokinase-type plasminogen activator (uPAR, and Ig kappa chain C region. We used the electronic nose to quickly detect changes in the volatile substances in mice urine after holothurian polypeptides (HPP fed, and the results show it can identify the difference between treatment groups with the control group without overlapping. The protein express mechanism of HPP treating diabetes was discussed, and we suggested these two peptides with the hypoglycemic and renal protective activity might be utilized as nutraceuticals.

  1. Effects of preheating on ice growth in antifreeze polypeptides solutions in a narrow space

    Science.gov (United States)

    Miyamoto, T.; Nishi, N.; Waku, T.; Tanaka, N.; Hagiwara, Y.

    2016-09-01

    We conducted measurements on the unidirectional freezing of aqueous solutions of polypeptide or of winter flounder antifreeze protein. The polypeptide was based on a part of the antifreeze protein. We measured temperatures in the solutions and ice with a small thermocouple, and defined the interface temperature as the temperature at the tip of the serrated or pectinate interface. It was found that the interface temperature of these solutions was lower than that of pure water. To vary the activity of these solutes, we preheated the solutions and cooled them before conducting the measurements. We found that preheating for several hours caused further decreases in the interface temperature and a decrease in the interface velocity. In addition, the inclined interfaces became wider as a result of the preheating. Thus, the supercooled states in the solutions were enhanced by the preheating. To investigate the reasons for these changes, we measured the aggregates of the solutes in the solutions. These aggregates became larger as a result of preheating. It can therefore be concluded that these large aggregates attenuated the ice growth by their interaction with the ice surfaces.

  2. Peptides, polypeptides and peptide-polymer hybrids as nucleic acid carriers.

    Science.gov (United States)

    Ahmed, Marya

    2017-10-24

    Cell penetrating peptides (CPPs), and protein transduction domains (PTDs) of viruses and other natural proteins serve as a template for the development of efficient peptide based gene delivery vectors. PTDs are sequences of acidic or basic amphipathic amino acids, with superior membrane trespassing efficacies. Gene delivery vectors derived from these natural, cationic and cationic amphipathic peptides, however, offer little flexibility in tailoring the physicochemical properties of single chain peptide based systems. Owing to significant advances in the field of peptide chemistry, synthetic mimics of natural peptides are often prepared and have been evaluated for their gene expression, as a function of amino acid functionalities, architecture and net cationic content of peptide chains. Moreover, chimeric single polypeptide chains are prepared by a combination of multiple small natural or synthetic peptides, which imparts distinct physiological properties to peptide based gene delivery therapeutics. In order to obtain multivalency and improve the gene delivery efficacies of low molecular weight cationic peptides, bioactive peptides are often incorporated into a polymeric architecture to obtain novel 'polymer-peptide hybrids' with improved gene delivery efficacies. Peptide modified polymers prepared by physical or chemical modifications exhibit enhanced endosomal escape, stimuli responsive degradation and targeting efficacies, as a function of physicochemical and biological activities of peptides attached onto a polymeric scaffold. The focus of this review is to provide comprehensive and step-wise progress in major natural and synthetic peptides, chimeric polypeptides, and peptide-polymer hybrids for nucleic acid delivery applications.

  3. cDNA encoding a polypeptide including a hev ein sequence

    Energy Technology Data Exchange (ETDEWEB)

    Raikhel, Natasha V. (Okemos, MI); Broekaert, Willem F. (Dilbeek, BE); Chua, Nam-Hai (Scarsdale, NY); Kush, Anil (New York, NY)

    2000-07-04

    A cDNA clone (HEV1) encoding hevein was isolated via polymerase chain reaction (PCR) using mixed oligonucleotides corresponding to two regions of hevein as primers and a Hevea brasiliensis latex cDNA library as a template. HEV1 is 1018 nucleotides long and includes an open reading frame of 204 amino acids. The deduced amino acid sequence contains a putative signal sequence of 17 amino acid residues followed by a 187 amino acid polypeptide. The amino-terminal region (43 amino acids) is identical to hevein and shows homology to several chitin-binding proteins and to the amino-termini of wound-induced genes in potato and poplar. The carboxyl-terminal portion of the polypeptide (144 amino acids) is 74-79% homologous to the carboxyl-terminal region of wound-inducible genes of potato. Wounding, as well as application of the plant hormones abscisic acid and ethylene, resulted in accumulation of hevein transcripts in leaves, stems and latex, but not in roots, as shown by using the cDNA as a probe. A fusion protein was produced in E. coli from the protein of the present invention and maltose binding protein produced by the E. coli.

  4. Glucose-dependent insulinotropic polypeptide (GIP) receptor deletion leads to reduced bone strength and quality.

    Science.gov (United States)

    Mieczkowska, Aleksandra; Irwin, Nigel; Flatt, Peter R; Chappard, Daniel; Mabilleau, Guillaume

    2013-10-01

    Bone is permanently remodeled by a complex network of local, hormonal and neuronal factors that affect osteoclast and osteoblast biology. In this context, a role for gastro-intestinal hormones has been proposed based on evidence that bone resorption dramatically falls after a meal. Glucose-dependent insulinotropic polypeptide (GIP) is one of the candidate hormones as its receptor, glucose-dependent insulinotropic polypeptide receptor (GIPR), is expressed in bone. In the present study we investigated bone strength and quality by three-point bending, quantitative x-ray microradiography, microCT, qBEI and FTIR in a GIPR knockout (GIPR KO) mouse model and compared with control wild-type (WT) animals. Animals with a deletion of the GIPR presented with a significant reduction in ultimate load (--11%), stiffness (-16%), total absorbed (-28%) and post-yield energies (-27%) as compared with WT animals. Furthermore, despite no change in bone outer diameter, the bone marrow diameter was significantly increased and as a result cortical thickness was significantly decreased by 20% in GIPR deficient animals. Bone resorption at the endosteal surface was significantly increased whilst bone formation was unchanged in GIPR deficient animals. Deficient animals also presented with a pronounced reduction in the degree of mineralization of bone matrix. Furthermore, the amount of mature cross-links of collagen matrix was significantly reduced in GIPR deficient animals and was associated with lowered intrinsic material properties. Taken together, these data support a positive effect of the GIPR on bone strength and quality. © 2013.

  5. Elastin-like polypeptides: the influence of its molecular weight on local hyperthermia-induced tumor accumulation.

    Science.gov (United States)

    Ryu, Jung Su; Raucher, Drazen

    2014-10-01

    Elastin-like polypeptides (ELP) are thermally responsive polypeptides that are soluble in solutions at 37°C, but which aggregate above 42°C. ELP can be used as effective carrier systems of anticancer molecules, because they can be targeted to tumor sites through the application of local hyperthermia. Since molecular size largely influences how successfully therapeutic agents can cross the vasculatures of tumors, it was crucial to determine an optimal molecular size. In this study, we designed and evaluated three ELP macromolecules with varying molecular weights (43, 63, and 122 kDa), with the goal of determining which would optimize the ELP drug delivery system. The N-terminus of the ELP macromolecule was modified with the cell penetrating peptide Bac to enhance intratumoral and intracellular uptake, and it was also confirmed that each polypeptide had the target transition temperature of 37-42°C and the results of the studies, using tumor-bearing mice, showed that the tumor accumulations increased in the case of all three peptides when local hyperthermia was applied, but that the elimination patterns from these tumors varied according to peptide size. Local hyperthermia was found to produce prolonged retention of all ELP conjugates in tumors except Bac-ELP43. In addition, the pharmacokinetic analysis showed that two larger polypeptides with 63 and 122 kDa have increased AUC in comparison with the 43 kDa polypeptide. These results suggest that, when combined with local hyperthermia, the larger ELP conjugates (63 and 122 kDa) have advantages over the smaller Bac-ELP43 polypeptide in terms of enhanced permeability and higher retention effects. Copyright © 2014 Elsevier B.V. All rights reserved.

  6. Molecular analysis of Rh polypeptides in a family with RhD-positive and RhD-negative phenotypes.

    OpenAIRE

    Umenishi, F; Kajii, E; Ikemoto, S

    1994-01-01

    To investigate the genetic basis of the Rh polypeptide gene, we attempted the isolation of cDNA clones for Rh polypeptide from a family with the RhD-positive and RhD-negative phenotypes using the reverse transcription (RT)-PCR method for each reticulocyte RNAs followed by subcloning. The isolated cDNAs showed the existence of another Rh-related clone (RhPII-1 cDNA, tentative designation) besides the RhPI and RhPII cDNA clones reported previously by us. The RhPII-1 cDNA had a single nucleotide...

  7. Primary and secondary thyroid hormone transporters

    Directory of Open Access Journals (Sweden)

    Kinne Anita

    2011-08-01

    Full Text Available Abstract Thyroid hormones (TH are essential for the development of the human brain, growth and cellular metabolism. Investigation of TH transporters became one of the emerging fields in thyroid research after the discovery of inactivating mutations in the Monocarboxylate transporter 8 (MCT8, which was found to be highly specific for TH transport. However, additional transmembrane transporters are also very important for TH uptake and efflux in different cell types. They transport TH as secondary substrates and include the aromatic amino acid transporting MCT10, the organic anion transporting polypeptides (e.g. OATP1C1, OATP1A2, OPTP1A4 and the large neutral amino acid transporters (LAT1 and LAT2. These TH transporters characteristically possess 12 transmembrane spanners but due to the strong differing sequences between the three transporter families we assume an identical conformation is not very likely. In contrast to the others, the LAT family members form a heterodimer with the escort protein 4F2hc/CD98. A comparison of sequence proportions, locations and types of functional sensitive features for TH transport discovered by mutations, revealed that transport sensitive charged residues occur as conserved amino acids only within each family of the transporter types but not in all putative TH transporters. Based on the lack of highly conserved sensitive charged residues throughout the three transporter families as a common counterpart for the amino acid moiety of the substrates, we conclude that the molecular transport mechanism is likely organized either a by different molecular determinants in the divergent transporter types or b the counterparts for the substrates` amino acid moiety at the transporter are not any charged side chains but other proton acceptors or donators. However, positions of transport sensitive residues coincide at transmembrane helix 8 in the TH transporter MCT8, OATP1C1 and another amino acid transporter, the L

  8. Primary Structure of Chlamydomonas reinhardtii Ribulose 1,5-Bisphosphate Carboxylase/Oxygenase Activase and Evidence for a Single Polypeptide 1

    Science.gov (United States)

    Roesler, Keith R.; Ogren, William L.

    1990-01-01

    Immunoblot analysis of ribulose 1,5-bisphosphate carboxylase/oxygenase (rubisco) activase from the green alga Chlamydomonas reinhardtii indicated the presence of a single polypeptide. This observation contrasts with the Spinacea oleracea (spinach) and Arabidopsis thaliana proteins, in which two polypeptide species are generated by alternative pre-mRNA splicing. A Chlamydomonas rubisco activase cDNA clone containing the entire coding region was isolated and sequenced. The open reading frame encoded a 408 amino acid, 45 kilodalton polypeptide that included a chloroplast transit peptide. The presumptive mature polypeptide possessed 62% and 65% amino acid sequence identity, respectively, with the spinach and Arabidopsis mature polypeptides. The Chlamydomonas rubisco activase transit peptide possessed almost no amino acid sequence identity with the higher plant transit peptides. The nucleotide sequence of Chlamydomonas rubisco activase cDNA provided no evidence for alternative mRNA splicing, consistent with the immunoblot evidence for only one polypeptide. Genomic DNA blot analysis indicated the presence of a single Chlamydomonas rubisco activase gene. In the presence of spinach rubisco activase, a lower extent and rate of activation were obtained in vitro with Chlamydomonas rubisco than with spinach rubisco. We conclude Chlamydomonas rubisco activase comprises a single polypeptide which differs considerably from the higher plant polypeptides with respect to primary structure. Images Figure 1 Figure 3 PMID:16667924

  9. Two-dimensional electrophoretic analysis of transformation-sensitive polypeptides during chemically, spontaneously, and oncogene-induced transformation of rat liver epithelial cells

    DEFF Research Database (Denmark)

    Wirth, P J; Luo, L D; Fujimoto, Y

    1992-01-01

    Recently, we described the establishment of a computerized database of rat liver epithelial (RLE) cellular polypeptides (Wirth et al., Electrophoresis, 1991, 12, 931-954). This database has now been expanded to include the analysis of cellular polypeptide alterations during chemically (aflatoxin B1...

  10. An engineered polypeptide around nano-sized manganese-calcium oxide: copying plants for water oxidation.

    Science.gov (United States)

    Najafpour, Mohammad Mahdi; Ghobadi, Mohadeseh Zarei; Sarvi, Bahram; Haghighi, Behzad

    2015-09-14

    Synthesis of new efficient catalysts inspired by Nature is a key goal in the production of clean fuel. Different compounds based on manganese oxide have been investigated in order to find their water-oxidation activity. Herein, we introduce a novel engineered polypeptide containing tyrosine around nano-sized manganese-calcium oxide, which was shown to be a highly active catalyst toward water oxidation at low overpotential (240 mV), with high turnover frequency of 1.5 × 10(-2) s(-1) at pH = 6.3 in the Mn(III)/Mn(IV) oxidation range. The compound is a novel structural and efficient functional model for the water-oxidizing complex in Photosystem II. A new proposed clever strategy used by Nature in water oxidation is also discussed. The new model of the water-oxidizing complex opens a new perspective for synthesis of efficient water-oxidation catalysts.

  11. Comparative assessment of the polypeptide profiles from lateral and primary roots of Phaseolus vulgaris L

    Science.gov (United States)

    Westberg, J.; Odom, W. R.; Guikema, J. A.; Spooner, B. S. (Principal Investigator)

    1994-01-01

    In Phaseolus vulgaris, primary roots show gravitational sensitivity soon after emerging from the seed. In contrast, lateral roots are agravitropic during early development, and become gravitropic after several cm growth. Primary and lateral root tissues were examined by polyacrylamide gel electrophoresis, coupled with western blotting techniques, to compare proteins which may contribute to the acquisition of gravitational sensitivity. Root tips and zones of cell elongation were compared for each root type, using immunological probes for calmodulin, alpha-actin, alpha-tubulin, and proteins of the plastid envelope. Lateral roots contained qualitatively less calmodulin, and showed a slightly different pattern of actin-related epitope proteins, than did primary root tissues, suggesting that polypeptide differences may contribute to the gravitational sensitivity which these root types express.

  12. Expression of a Deschampsia antarctica Desv. Polypeptide with Lipase Activity in a Pichia pastoris Vector

    Directory of Open Access Journals (Sweden)

    Claudia Rabert

    2014-02-01

    Full Text Available The current study isolated and characterized the Lip3F9 polypeptide sequence of Deschampsia antarctica Desv. (GeneBank Accession Number JX846628, which was found to be comprised of 291 base pairs and was, moreover, expressed in Pichia pastoris X-33 cells. The enzyme was secreted after 24 h of P. pastoris culture incubation and through induction with methanol. The expressed protein showed maximum lipase activity (35 U/L with an optimal temperature of 37 °C. The lipase-expressed enzyme lost 50% of its specific activity at 25 °C, a behavior characteristic of a psychrotolerant enzyme. Recombinant enzyme activity was measured in the presence of ionic and non-ionic detergents, and a decrease in enzyme activity was detected for all concentrations of ionic and non-ionic detergents assessed.

  13. Pancreatic polypeptide is involved in the regulation of body weight in pima Indian male subjects

    DEFF Research Database (Denmark)

    Koska, Juraj; DelParigi, Angelo; de Courten, Barbora

    2004-01-01

    negatively associated with body size and adiposity. Prospectively, the change in PP response to the meal was negatively associated with the change in body weight (r = -0.53, P = 0.002). In contrast, a high fasting PP level was positively associated with change in body weight (r = 0.45, P = 0......Pancreatic polypeptide (PP) is released from the pancreas in response to a meal. In humans, low-circulating PP levels have been observed in obesity, and administration of pharmacological doses of PP has been shown to decrease food intake. The aim of the present study was to investigate whether low...... circulating PP is associated with weight gain in Pima Indians. Plasma PP concentrations were measured after an overnight fast and 30 min after a standardized mixed meal in 33 nondiabetic male subjects who had a follow-up visit 4.9 +/- 2.5 years later. Cross-sectionally, fasting and postprandial PP levels were...

  14. l-Cystine-Crosslinked Polypeptide Nanogel as a Reduction-Responsive Excipient for Prostate Cancer Chemotherapy

    Directory of Open Access Journals (Sweden)

    Liang He

    2016-01-01

    Full Text Available Smart polymer nanogel-assisted drug delivery systems have attracted more and more attention in cancer chemotherapy because of their well-defined morphologies and pleiotropic functions in recent years. In this work, an l-cystine-crosslinked reduction-responsive polypeptide nanogel of methoxy poly(ethylene glycol-poly(l-phenylalanine-co-l-cystine (mPEG-P(LP-co-LC was employed as a smart excipient for RM-1 prostate cancer (PCa chemotherapy. Doxorubicin (DOX, as a regular chemotherapy drug, was embedded in the nanogel. The loading nanogel marked as NG/DOX was shown to exhibit glutathione (GSH-induced swelling and GSH-accelerated DOX release. Subsequently, NG/DOX showed efficient cellular uptake and proliferation inhibition. Furthermore, NG/DOX presented enhanced antitumor efficacy and security in an RM-1 PCa-grafted mouse model in vivo, indicating its great potential for clinical treatment.

  15. Development of the kits for RIA simultaneous determination of polypeptide hormones

    International Nuclear Information System (INIS)

    Szybinski, Z.

    1982-12-01

    A simple and universal modification of chloramine T technique has been developed for the radioactive iodination of several polypeptide hormones such as insulin, human growth hormone (HGH), human TSH, synthetic human gastrin and beta-endorphine. The prepared products proved to have good immunoreactivity suitable for RIA purposes. The technique is inexpensive and quick. A new procedure has also been worked out utilizing horse myeloperoxidase in solid state as catalyser. The hormones iodinated with this technique show better parameters (e.g. longer stability, better binding to antibody, more favourable adsorption on dextran-coated charcoal); however the specific activities achieved were lower. The possibilities of simultaneous measurement of insulin and HGH have been studied. In this connection, a comparatively simple method for the determination of the endogenous anti-insulin antibodies was developed and used for the control of patients with diabetes and for the checking of new insulin preparations. However, the technique requires relatively sophisticated equipment and computerized calculations

  16. Preparation of tissue polypeptide antigen (TPA) from sera pools of cancer patients.

    Science.gov (United States)

    Romano, T F; Evangelista, M; Castelli, M; Chersi, A

    1991-11-01

    TPA is a tumor marker characteristic of general cellular proliferation. High serum levels are found in patients with tumor progression. With the aim of bettering the clinical use, the authors have isolated TPA in purer form, in order to develop, in the future, a more specific immunoenzymatic method based on unlabeled antipeptide antibodies. A simple method for the isolation of small amounts of tissue polypeptide antigen (TPA) from the sera of patients suffering from neoplastic diseases is described. The procedure takes advantage of the availability of commercial anti-TPA coated beads; sera pools with high levels of antigen are allowed to react with such beads, then the antibody-antigen complex is dissociated by drastic changes of pH or molarity, and TPA recovered. Such TPA preparations contain low amounts of extraneous proteins, and thus can be utilized in immunoenzymatic tests, or in laboratory investigations.

  17. Improved Identification and Analysis of Small Open Reading Frame Encoded Polypeptides.

    Science.gov (United States)

    Ma, Jiao; Diedrich, Jolene K; Jungreis, Irwin; Donaldson, Cynthia; Vaughan, Joan; Kellis, Manolis; Yates, John R; Saghatelian, Alan

    2016-04-05

    Computational, genomic, and proteomic approaches have been used to discover nonannotated protein-coding small open reading frames (smORFs). Some novel smORFs have crucial biological roles in cells and organisms, which motivates the search for additional smORFs. Proteomic smORF discovery methods are advantageous because they detect smORF-encoded polypeptides (SEPs) to validate smORF translation and SEP stability. Because SEPs are shorter and less abundant than average proteins, SEP detection using proteomics faces unique challenges. Here, we optimize several steps in the SEP discovery workflow to improve SEP isolation and identification. These changes have led to the detection of several new human SEPs (novel human genes), improved confidence in the SEP assignments, and enabled quantification of SEPs under different cellular conditions. These improvements will allow faster detection and characterization of new SEPs and smORFs.

  18. Elastin-like polypeptides and their applications in anticancer drug delivery systems: a review.

    Science.gov (United States)

    Saxena, Rubha; Nanjan, Moola Joghee

    2015-02-01

    Elastin-like polypeptides (ELPs) are large molecular weight biopolymers. They have been widely studied as macromolecular carriers for targeted delivery of drugs. The aim of the present article is to review the available information on ELPs (including our recent investigations), their properties, drug delivery applications to tumor sites and future perspectives. This review also provides information on the use of short synthetic ELPs for making ELP-drug conjugates, for targeted delivery of anticancer drugs. In the present review we also focus on the point that short ELPs can also be used for targeting anticancer drugs to tumor sites as they behave similar to long ELPs regarding their capacity to undergo inverse temperature transition (ITT) behavior.

  19. Recombinant production and purification of short hydrophobic Elastin-like polypeptides with low transition temperatures.

    Science.gov (United States)

    Bataille, Laure; Dieryck, Wilfrid; Hocquellet, Agnès; Cabanne, Charlotte; Bathany, Katell; Lecommandoux, Sébastien; Garbay, Bertrand; Garanger, Elisabeth

    2016-05-01

    Elastin-like polypeptides (ELPs) are biodegradable polymers with interesting physico-chemical properties for biomedical and biotechnological applications. We report herein the recombinant expression of three hydrophobic ELPs (VPGIG)n with variable lengths (n = 20, 40, 60) and sub-ambient transition temperatures. These ELPs were purified from the cytoplasmic soluble fraction of Escherichia coli by inverse transition cycling, and their exact molecular weight was confirmed by various mass spectrometry techniques. Transition temperatures of ELP20, ELP40, and ELP60 were measured at 18.6 °C, 12.4 °C and 11.7 °C, respectively. Copyright © 2016 Elsevier Inc. All rights reserved.

  20. Dithiol amino acids can structurally shape and enhance the ligand-binding properties of polypeptides.

    Science.gov (United States)

    Chen, Shiyu; Gopalakrishnan, Ranganath; Schaer, Tifany; Marger, Fabrice; Hovius, Ruud; Bertrand, Daniel; Pojer, Florence; Heinis, Christian

    2014-11-01

    The disulfide bonds that form between two cysteine residues are important in defining and rigidifying the structures of proteins and peptides. In polypeptides containing multiple cysteine residues, disulfide isomerization can lead to multiple products with different biological activities. Here, we describe the development of a dithiol amino acid (Dtaa) that can form two disulfide bridges at a single amino acid site. Application of Dtaas to a serine protease inhibitor and a nicotinic acetylcholine receptor inhibitor that contain disulfide constraints enhanced their inhibitory activities 40- and 7.6-fold, respectively. X-ray crystallographic and NMR structure analysis show that the peptide ligands containing Dtaas have retained their native tertiary structures. We furthermore show that replacement of two cysteines by Dtaas can avoid the formation of disulfide bond isomers. With these properties, Dtaas are likely to have broad application in the rational design or directed evolution of peptides and proteins with high activity and stability.

  1. The 75-kilodalton cytoplasmic Chlamydia trachomatis L2 polypeptide is a DnaK-like protein

    DEFF Research Database (Denmark)

    Birkelund, Svend; Lundemose, AG; Christiansen, Gunna

    1990-01-01

    ,980-base-pair open reading frame revealed 94% homology with a 75-kilodalton protein from C. trachomatis serovar D and 57% homology with the DnaK proteins of E. coli and of Bacillus megaterium, while amino acid homology with human heat shock protein 70 (hsp70) was 42%. The promoter region was identified......The gene coding for the 75-kilodalton cytoplasmic Chlamydia trachomatis L2 polypeptide has been cloned in Escherichia coli, and the nucleotide sequence has been determined. The cloned DNA fragment contained the coding region as well as the putative promoter. The deduced amino acid sequence of the 1...... by computer search and by primer extension of mRNA synthesized in recombinant E. coli. The promoter region which differed from the putative promoter region in serovar D was shown to be a mixed promoter type in which the -10 region showed a regular TATA box configuration while the -35 region showed high...

  2. Pancreatic polypeptide is involved in the regulation of body weight in pima Indian male subjects

    DEFF Research Database (Denmark)

    Koska, Juraj; DelParigi, Angelo; de Courten, Barbora

    2004-01-01

    Pancreatic polypeptide (PP) is released from the pancreas in response to a meal. In humans, low-circulating PP levels have been observed in obesity, and administration of pharmacological doses of PP has been shown to decrease food intake. The aim of the present study was to investigate whether low...... circulating PP is associated with weight gain in Pima Indians. Plasma PP concentrations were measured after an overnight fast and 30 min after a standardized mixed meal in 33 nondiabetic male subjects who had a follow-up visit 4.9 +/- 2.5 years later. Cross-sectionally, fasting and postprandial PP levels were...... negatively associated with body size and adiposity. Prospectively, the change in PP response to the meal was negatively associated with the change in body weight (r = -0.53, P = 0.002). In contrast, a high fasting PP level was positively associated with change in body weight (r = 0.45, P = 0...

  3. Distribution and protective function of pituitary adenylate cyclase-activating polypeptide (PACAP in the retina

    Directory of Open Access Journals (Sweden)

    Tomoya eNakamachi

    2012-11-01

    Full Text Available Pituitary adenylate cyclase-activating polypeptide (PACAP, which is found in 27- or 38-amino acid forms, belongs to the VIP/glucagon/secretin family. PACAP and its three receptor subtypes are expressed in neural tissues, with PACAP known to exert a protective effect against several types of neural damage. The retina is considered to be part of the central nervous system, and retinopathy is a common cause of profound and intractable loss of vision. This review will examine the expression and morphological distribution of PACAP and its receptors in the retina, and will summarize the current state of knowledge regarding the protective effect of PACAP against different kinds of retinal damage, such as that identified in association with diabetes, ultraviolet light, hypoxia, optic nerve transection, and toxins. This article will also address PACAP-mediated protective pathways involving retinal glial cells.

  4. Disaggregation of human islet amyloid polypeptide fibril formation by ruthenium polypyridyl complexes.

    Science.gov (United States)

    Zhu, Dengsen; Gong, Gehui; Wang, Wenji; Du, Weihong

    2017-05-01

    The toxicity of amyloid proteins is associated with many degenerative and systematic diseases. The aggregation of human islet amyloid polypeptide may induce pancreatic β-cell death, which is linked to type II diabetes. Ruthenium complexes are inhibitors of various proteins and potential anticancer metallodrugs, which can also be used to disaggregate amyloid proteins. This work reported that several ruthenium polypyridyl complexes remarkably affected the peptide aggregation by predominant hydrophobic interaction and metal coordination, as reflected by thermodynamic parameters and mass spectrometry analysis. Morphology and particle size analysis showed that the amyloid fibrils were disaggregated from long fibrils into small nano particles. Addition of these complexes also decreased the cytotoxicity induced by the peptide. The results indicated that ruthenium polypyridyl complexes may be potential metallodrugs to treat amyloidosis. Copyright © 2017 Elsevier Inc. All rights reserved.

  5. Dithiol amino acids can structurally shape and enhance the ligand-binding properties of polypeptides

    Science.gov (United States)

    Chen, Shiyu; Gopalakrishnan, Ranganath; Schaer, Tifany; Marger, Fabrice; Hovius, Ruud; Bertrand, Daniel; Pojer, Florence; Heinis, Christian

    2014-11-01

    The disulfide bonds that form between two cysteine residues are important in defining and rigidifying the structures of proteins and peptides. In polypeptides containing multiple cysteine residues, disulfide isomerization can lead to multiple products with different biological activities. Here, we describe the development of a dithiol amino acid (Dtaa) that can form two disulfide bridges at a single amino acid site. Application of Dtaas to a serine protease inhibitor and a nicotinic acetylcholine receptor inhibitor that contain disulfide constraints enhanced their inhibitory activities 40- and 7.6-fold, respectively. X-ray crystallographic and NMR structure analysis show that the peptide ligands containing Dtaas have retained their native tertiary structures. We furthermore show that replacement of two cysteines by Dtaas can avoid the formation of disulfide bond isomers. With these properties, Dtaas are likely to have broad application in the rational design or directed evolution of peptides and proteins with high activity and stability.

  6. Thermal Synthesis of Polypeptides from N-Butyloxycarbonyl Oligopeptides Containing Aspartyl Residue at C-Terminus

    Directory of Open Access Journals (Sweden)

    Toratane Munegumi

    2017-01-01

    Full Text Available The thermal reactions of amino acids have been investigated for pure organic synthesis, materials preparation in industry, and prebiotic chemistry. N-t-Butyloxycarbonyl aspartic acid (Boc-Asp releases 2-butene and carbon dioxide upon heating without solvents. The resulting mixture of the free molten aspartic acid was dehydrated to give peptide bonds. This study describes the thermal reactions of N-t-butyloxycarbonyl peptides (Boc-Gly-L-Asp, Boc-L-Ala-L-Asp, Boc-L-Val-L-Asp, and Boc-Gly-Gly-L-Asp having an aspartic residue at the carboxyl terminus. The peptides were deprotected upon heating at a constant temperature between 110 and 170°C for 1 to 24 h to afford polypeptides in which the average molecular weight reached 7800.

  7. Vasoactive intestinal polypeptide (VIP) in cirrhosis: arteriovenous extraction in different vascular beds

    DEFF Research Database (Denmark)

    Henriksen, Jens Henrik Sahl; Staun-Olsen, P; Fahrenkrug, J

    1980-01-01

    elimination of VIP from extra-splanchnic areas and from porto-systemic shunting of VIP in cirrhosis. The net splanchnic elimination rate of VIP was estimated to be about 3 pmol/min. The concentration of VIP in ascitic fluid was on the average three times that of arterial plasma. In conclusion, VIP...... is significantly elevated in peripheral plasma from patients with cirrhosis, probably due to porto-systemic shunting and/or compromised hepatic elimination. Hepatic elimination is still likely to account for the inactivation of most of the VIP escaping from the neurosynapses throughout the body in patients......The concentration of vasoactive intestinal polypeptide (VIP) was determined in peripheral venous plasma from 136 patients with liver cirrhosis without gastrointestinal bleeding or coma and from 112 controls. In eight patients (cirrhosis, six; fibrosis, one; steatosis, one) arteriovenous extraction...

  8. Immunohistochemical localization of glucagon and pancreatic polypeptide on rat endocrine pancreas: coexistence in rat islet cells

    Directory of Open Access Journals (Sweden)

    YH Huang

    2009-08-01

    Full Text Available We used immunofluorescence double staining method to investigate the cellular localization of glucagon and pancreatic polypeptide (PP in rat pancreatic islets. The results showed that both A-cells (glucagon-secreting cells and PP-cells (PPsecreting cells were located in the periphery of the islets. However, A-cells and PP-cells had a different regional distribution. Most of A-cells were located in the splenic lobe but a few of them were in the duodenal lobe of the pancreas. In contrast, the majority of PP-cells were found in the duodenal lobe and a few of them were in the splenic lobe of the pancreas. Furthermore, we found that 67.74% A-cells had PP immunoreactivity, 70.92% PP-cells contained glucagon immunoreactivity with immunofluorescence double staining. Our data support the concept of a common precursor stem cell for pancreatic hormone-producing cells.

  9. Pituitary adenylate cyclase-activating polypeptide promotes eccrine gland sweat secretion

    DEFF Research Database (Denmark)

    Sasaki, S; Watanabe, J; Ohtaki, H

    2017-01-01

    BACKGROUND: Sweat secretion is the major function of eccrine sweat glands; when this process is disturbed (paridrosis), serious skin problems can arise. To elucidate the causes of paridrosis, an improved understanding of the regulation, mechanisms and factors underlying sweat production is required...... and several exocrine glands, the effects of PACAP on the process of eccrine sweat secretion have not been examined. OBJECTIVES: To investigate the effect of PACAP on eccrine sweat secretion. METHODS: Reverse transcriptase-polymerase chain reaction and immunostaining were used to determine the expression....... Pituitary adenylate cyclase-activating polypeptide (PACAP) exhibits pleiotropic functions that are mediated via its receptors [PACAP-specific receptor (PAC1R), vasoactive intestinal peptide (VIP) receptor type 1 (VPAC1R) and VPAC2R]. Although some studies have suggested a role for PACAP in the skin...

  10. Mathematical Modelling of Glucose-Dependent Insulinotropic Polypeptide and Glucagon-like Peptide-1 following Ingestion of Glucose

    DEFF Research Database (Denmark)

    Røge, Rikke M; Bagger, Jonatan I; Alskär, Oskar

    2017-01-01

    The incretin hormones, glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1), play an important role in glucose homeostasis by potentiating glucose-induced insulin secretion. Furthermore, GLP-1 has been reported to play a role in glucose homeostasis by inhibiting ...

  11. An acetylation site in lectin domain modulates the biological activity of polypeptide GalNAc-transferase-2

    DEFF Research Database (Denmark)

    Zlocowski, Natacha; Lorenz, Virginia; Bennett, Eric Paul

    2013-01-01

    Abstract Polypeptide GalNAc-transferases (ppGalNAc-Ts) are a family of enzymes that catalyze the initiation of mucin-type O-glycosylation. All ppGalNAc-T family members contain a common (QXW)3 motif which is present in R-type lectin group. Acetylation site K521 is part of the QKW motif of ß...

  12. Genetic Associations of Type 2 Diabetes with Islet Amyloid Polypeptide Processing and Degrading Pathways in Asian Populations

    NARCIS (Netherlands)

    Lam, Vincent Kwok Lim; Ma, Ronald Ching Wan; Lee, Heung Man; Hu, Cheng; Park, Kyong Soo; Furuta, Hiroto; Wang, Ying; Tam, Claudia Ha Ting; Sim, Xueling; Ng, Daniel Peng-Keat; Liu, Jianjun; Wong, Tien-Yin; Tai, E. Shyong; Morris, Andrew P.; Tang, Nelson Leung Sang; Woo, Jean; Leung, Ping Chung; Kong, Alice Pik Shan; Ozaki, Risa; Jia, Wei Ping; Lee, Hong Kyu; Nanjo, Kishio; Xu, Gang; Ng, Maggie Chor Yin; So, Wing-Yee; Chan, Juliana Chung Ngor; Ostaptchouk, Jana; Wijmenga, Cisca

    2013-01-01

    Type 2 diabetes (T2D) is a complex disease characterized by beta cell dysfunctions. Islet amyloid polypeptide (IAPP) is highly conserved and co-secreted with insulin with over 40% of autopsy cases of T2D showing islet amyloid formation due to IAPP aggregation. Dysregulation in IAPP processing,

  13. Transgenic rescue of adipocyte glucose-dependent insulinotropic polypeptide receptor expression restores high fat diet-induced body weight gain

    DEFF Research Database (Denmark)

    Ugleholdt, Randi; Pedersen, Jens; Bassi, Maria Rosaria

    2011-01-01

    The glucose-dependent insulinotropic polypeptide receptor (GIPr) has been implicated in high fat diet-induced obesity and is proposed as an anti-obesity target despite an uncertainty regarding the mechanism of action. To independently investigate the contribution of the insulinotropic effects and...

  14. Immune-tolerant elastin-like polypeptides (iTEPs) and their application as CTL vaccine carriers.

    Science.gov (United States)

    Cho, S; Dong, S; Parent, K N; Chen, M

    2016-01-01

    Cytotoxic T lymphocyte (CTL) vaccine carriers are known to enhance the efficacy of vaccines, but a search for more effective carriers is warranted. Elastin-like polypeptides (ELPs) have been examined for many medical applications but not as CTL vaccine carriers. We aimed to create immune tolerant ELPs using a new polypeptide engineering practice and create CTL vaccine carriers using the ELPs. Four sets of novel ELPs, termed immune-tolerant elastin-like polypeptide (iTEP) were generated according to the principles dictating humoral immunogenicity of polypeptides and phase transition property of ELPs. The iTEPs were non-immunogenic in mice. Their phase transition feature was confirmed through a turbidity assay. An iTEP nanoparticle (NP) was assembled from an amphiphilic iTEP copolymer plus a CTL peptide vaccine, SIINFEKL. The NP facilitated the presentation of the vaccine by dendritic cells (DCs) and enhanced vaccine-induced CTL responses. A new ELP design and development practice was established. The non-canonical motif and the immune tolerant nature of the iTEPs broaden our insights about ELPs. ELPs, for the first time, were successfully used as carriers for CTL vaccines. It is feasible to concurrently engineer both immune-tolerant and functional peptide materials. ELPs are a promising type of CTL vaccine carriers.

  15. HPLC of the Polypeptides in a Hydrolyzate of Egg-White Lysozyme. An Experiment for the Undergraduate Biochemistry Laboratory.

    Science.gov (United States)

    Richardson, W. S., III; Burns, L.

    1988-01-01

    Describes a simple high-performance liquid chromatography experiment for undergraduate biochemistry laboratories. The experiment illustrates the separation of polypeptides by a step gradient elution using a single pump instrument with no gradient attachments. Discusses instrumentation, analysis, a sample preparation, and results. (CW)

  16. Antibody responses to human cytomegalovirus-specific polypeptides studied by immunoblotting in relation to viral load during cytomegalovirus infection

    NARCIS (Netherlands)

    van Zanten, J; van der Giessen, M.; van Son, W. J.; The, T. Hauw

    The humoral immune response to individual proteins of human cytomegalovirus (CMV) was studied by immunoblotting. CMV polypeptides present in an extract of CMV-infected fibroblasts in a late stage of infection were recognized by sera of healthy seropositive individuals and transplant recipients who

  17. The effect of side-chain functionality and hydrophobicity on the gene delivery capabilities of cationic helical polypeptides.

    Science.gov (United States)

    Zhang, Rujing; Zheng, Nan; Song, Ziyuan; Yin, Lichen; Cheng, Jianjun

    2014-03-01

    The rational design of effective and safe non-viral gene vectors is largely dependent on the understanding of the structure-property relationship. We herein report the design of a new series of cationic, α-helical polypeptides with different side charged groups (amine and guanidine) and hydrophobicity, and mechanistically unraveled the effect of polypeptide structure on the gene delivery capability. Guanidine-containing polypeptides displayed superior membrane activities to their amine-containing analogues via the pore formation mechanism, and thus possessed notably higher transfection efficiencies. Elongating the hydrophobic side chain also potentiated the membrane activities of the polypeptides, while at the meantime caused higher cytotoxicities. Upon an optimal balance between membrane activity and cytotoxicity, maximal transfection efficiency was achieved which outperformed commercial reagent Lipofectamine™ 2000 (LPF2000) by 3-6 folds. This study thus provides mechanistic insights into the rational design of non-viral gene delivery vectors, and the best-performing materials identified also serve as a promising addition to the existing systems. Copyright © 2014 Elsevier Ltd. All rights reserved.

  18. Glucose-dependent insulinotropic polypeptide may enhance fatty acid re-esterification in subcutaneous abdominal adipose tissue in lean humans

    DEFF Research Database (Denmark)

    Asmar, Meena; Simonsen, Lene; Madsbad, Sten

    2010-01-01

    Glucose-dependent insulinotropic polypeptide (GIP) has been implicated in lipid metabolism in animals. In humans, however, there is no clear evidence of GIP effecting lipid metabolism. The present experiments were performed in order to elucidate the effects of GIP on regional adipose tissue metab...

  19. Polymer-Block-Polypeptides and Polymer-Conjugated Hybrid Materials as Stimuli-Responsive Nanocarriers for Biomedical Applications.

    Science.gov (United States)

    John, Johnson V; Johnson, Renjith P; Heo, Min Seon; Moon, Byeong Kyu; Byeon, Seong Jin; Kim, Il

    2015-01-01

    Stimuli-responsive nanocarriers are a class of soft materials that includes natural polymers, synthetic polymers, and polypeptides. Recently, modern synthesis tools such as atom transfer radical polymerization, reversible addition-fragmentation chain transfer polymerization, nitroxide-mediated radical polymerization, ring-opening polymerization of α-amino acid N-carboxyanhydrides, and various "click" chemistry strategies were simultaneously employed for the design and synthesis of nanosized drug delivery vehicles. Importantly, the research focused on the improvement of the nanocarrier targetability and the site-specific, triggered release of therapeutics with high drug loading efficiency and minimal drug leakage during the delivery to specific targets. In this context, nanocarriers responsive to common stimuli such as pH, temperature, redox potential, light, etc. have been widely used for the controlled delivery of therapeutics to pathological sites. Currently, different synthesis and self-assembly strategies improved the drug loading efficacy and targeted delivery of therapeutic agents to the desired site. In particular, polypeptide-containing hybrid materials have been developed for the controlled delivery of therapeutic agents. Therefore, stimuli-sensitive synthetic polypeptide-based materials have been extensively investigated in recent years. This review focuses on recent advances in the development of polymer-block-polypeptides and polymer-conjugated hybrid materials that have been designed and evaluated for various stimuli-responsive drug and gene delivery applications.

  20. Tissue polypeptide-specific antigen (TPS) determinations before and during intermittent maximal androgen blockade in patients with metastatic prostatic carcinoma

    NARCIS (Netherlands)

    Kil, P. J. M.; Goldschmidt, H. M. J.; Wieggers, B. J. A.; Kariakine, O. B.; Studer, U. E.; Whelan, P.; Hetherington, J.; de Reijke, Th M.; Hoekstra, J. W.; Collette, L.

    2003-01-01

    To evaluate the prognostic significance of serially measured tissue polypeptide-specific antigen (TPS) levels in patients with metastatic prostatic carcinoma treated with intermittent maximal androgen blockade (MAB). To determine its value with respect to predicting response to treatment and time to

  1. Cloning of a cDNA encoding a developmentally regulated 22 kDa polypeptide from tobacco leaf plasma membrane

    NARCIS (Netherlands)

    Gantet, P; Masson, F; Domergue, O; MarquisMention, M; Bauw, G; Inze, D; Rossignol, M; delaServe, BT

    1996-01-01

    A polypeptide doublet (P18-P19, ca 22 kDa, pI 4.5) has been shown to accumulate in tobacco leaf plasma membrane in a development-dependent way, under constant environmental conditions. P18 and P19 were purified by 2D-PAGE and microsequenced. Microsequences revealed only small differences between the

  2. Secretion of incretin hormones and the insulinotropic effect of gastric inhibitory polypeptide in women with a history of gestational diabetes

    DEFF Research Database (Denmark)

    Meier, J J; Gallwitz, B; Askenas, M

    2005-01-01

    AIMS/HYPOTHESIS: The insulinotropic effect of gastric inhibitory polypeptide (GIP) is reduced in patients with type 2 diabetes and around 50% of their first-degree relatives under hyperglycaemic conditions. It is unknown whether this is a result of a specific defect in GIP action or of a general ...

  3. Polycistronic mRNAs code for polypeptides of the Vibrio harveyi luminescence system

    Energy Technology Data Exchange (ETDEWEB)

    Miyamoto, C.M.; Graham, A.D.; Boylan, M.; Evans, J.F.; Hasel, K.W.; Meighen, E.A.; Graham, A.F.

    1985-03-01

    DNA coding for the ..cap alpha.. and ..beta.. subunits of Vibrio harveyi luciferase, the luxA and luxB genes, and the adjoining chromosomal regions on both sides of these genes (total of 18 kilobase pairs) was cloned into Escherichia coli. Using labeled DNA coding for the ..cap alpha.. subunit as a hybridization probe, the authors identified a set of polycistronic mRNAs (2.6, 4, 7, and 8 kilobases) by Northern blotting; the most prominent of these was the one 4 kilobases long. This set of mRNAs was induced during the development of bioluminescence in V. harveyi. Furthermore, the same set of mRNAs was synthesized in E. coli by a recombinant plasmid that contained a 12-kilobase pair length of V. harveyi DNA and expressed the genes for the luciferase subunits. A cloned DNA segment corresponding to the major 4-kilobase mRNA coded for the ..cap alpha.. and ..beta.. subunits of luciferase, as well as a 32,000-dalton protein upstream from these genes that could be specifically modified by acyl-coenzyme A and is a component of the bioluminescence system. V. harveyi mRNA that was hybridized to the released from cloned DNA encompassing the luxA and luxB genes was translated in vitro. Luciferase ..cap alpha.. and ..beta.. subunits and the 32,000-dalton polypeptide were detected among the products, along with 42,000- and 55,000-dalton polypeptides, which are encoded downstream from the lux genes and are thought to be involved in luminescence.

  4. Morphological variation of stimuli-responsive polypeptide at air–water interface

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Sungchul; Ahn, Sungmin; Cheng, Jie [Department of Biosystems and Biomaterials Science and Engineering, Seoul National University, Seoul 151-921 (Korea, Republic of); Chang, Hyejin; Jung, Dae-Hong [Department of Chemical Education, Seoul National University, Seoul 151-741 (Korea, Republic of); Hyun, Jinho, E-mail: jhyun@snu.ac.kr [Department of Biosystems and Biomaterials Science and Engineering, Seoul National University, Seoul 151-921 (Korea, Republic of); Research Institute of Agriculture and Life Sciences, Seoul National University, Seoul 151-921 (Korea, Republic of); Center for Food and Bioconvergence, Seoul National University, Seoul 151-921, Republic of Korea. (Korea, Republic of)

    2016-12-01

    Graphical abstract: - Highlights: • It is the first report on the interfacial properties of ELP monolayers formed at the air–water interface. • ELP monolayers could be prepared with high stability at the air–water interface. • The compressive behavior of thermo-sensitive ELP monolayers was imaged. • The SERS spectra showed a change in the ELP secondary structure at different preparation conditions. - Abstract: The morphological variation of stimuli-responsive polypeptide molecules at the air–water interface as a function of temperature and compression was described. The surface pressure–area (π–A) isotherms of an elastin-like polypeptide (ELP) monolayer were obtained under variable external conditions, and Langmuir–Blodgett (LB) monolayers were deposited onto a mica substrate for characterization. As the compression of the ELP monolayer increased, the surface pressure increased gradually, indicating that the ELP monolayer could be prepared with high stability at the air–water interface. The temperature in the subphase of the ELP monolayer was critical in the preparation of LB monolayers. The change in temperature induced a shift in the π–A isotherms as well as a change in ELP secondary structures. Surprisingly, the compression of the ELP monolayer influenced the ELP secondary structure due to the reduction in the phase transition temperature with decreasing temperature. The change in the ELP secondary structure formed at the air–water interface was investigated by surface-enhanced Raman scattering. Moreover, the morphology of the ELP monolayer was subsequently imaged using atomic force microscopy. The temperature responsive behavior resulted in changes in surface morphology from relatively flat structures to rugged labyrinth structures, which suggested conformational changes in the ELP monolayers.

  5. Mechanisms Mediating the Biologic Activity of Synthetic Proline, Glycine, and Hydroxyproline Polypeptides in Human Neutrophils

    Science.gov (United States)

    Weinberger, Barry; Hanna, Nazeeh; Laskin, Jeffrey D.; Heck, Diane E.; Gardner, Carol R.; Gerecke, Donald R.; Laskin, Debra L.

    2005-01-01

    The accumulation of neutrophils at sites of tissue injury or infection is mediated by chemotactic factors released as part of the inflammatory process. Some of these factors are generated as a direct consequence of tissue injury or infection, including degradation fragments of connective tissue collagen and bacterial- or viral-derived peptides containing collagen-related structural motifs. In these studies, we examined biochemical mechanisms mediating the biologic activity of synthetic polypeptides consisting of repeated units of proline (Pro), glycine (Gly), and hydroxyproline (Hyp), major amino acids found within mammalian and bacterial collagens. We found that the peptides were chemoattractants for neutrophils. Moreover, their chemotactic potency was directly related to their size and composition. Thus, the pentameric peptides (Pro-Pro-Gly)5 and (Pro-Hyp-Gly)5 were more active in inducing chemotaxis than the corresponding decameric peptides (Pro-Pro-Gly)10 and (Pro-Hyp-Gly)10. In addition, the presence of Hyp in peptides reduced chemotactic activity. The synthetic peptides were also found to reduce neutrophil apoptosis. In contrast to chemotaxis, this activity was independent of peptide size or composition. The effects of the peptides on both chemotaxis and apoptosis were blocked by inhibitors of phosphatidylinositol 3-kinase (PI3-K) and p38 mitogen-activated protein (MAP) kinase. However, only (Pro-Pro-Gly)5 and (Pro-Pro-Gly)10 induced expression of PI3-K and phosphorylation of p38 MAP kinase, suggesting a potential mechanism underlying reduced chemotactic activity of Hyp-containing peptides. Although none of the synthetic peptides tested had any effect on intracellular calcium mobilization, each induced nuclear binding activity of the transcription factor NF-κB. These findings indicate that polymeric polypeptides containing Gly-X-Y collagen-related structural motifs promote inflammation by inducing chemotaxis and blocking apoptosis. However, distinct calcium

  6. Chemical synthesis and characterization of elastin-like polypeptides (ELPs) with variable guest residues.

    Science.gov (United States)

    Aladini, Firouzeh; Araman, Can; Becker, Christian F W

    2016-05-01

    The properties of elastin-like polypeptides (ELPs), specifically the fact that they are soluble in aqueous buffers below and aggregate reversibly above a well-defined transition temperature, are extensively used for protein purification, enzyme recycling, and more recently, for in vivo applications such as drug delivery and tissue engineering. ELPs are artificial but biocompatible polypeptides composed of pentameric repeats (Val-Pro-Gly-Xaa-Gly) containing different guest residues Xaa, derived from mammalian elastin. The temperature-dependent aggregation and desaggregation of ELPs is controlled by composition of the pentameric repeats as well as the number of repetitive units within the ELP. External parameters such as ELP concentration, pH, and most importantly, salt effects heavily influence the transition temperature. Here, we explore the chemical synthesis of a series of 51mer peptides consisting of 10 pentameric ELP repeats with hydrophobic as well as charged guest residues such as isoleucine, leucine, alanine, lysine, and/or glutamate all prepared by Boc-based solid phase peptide synthesis. These guest residues expand the available toolbox of synthetic ELPs and provide ELPs that can be chemically modified and tuned to specific environments. An N-terminal cysteine is added allowing disulfide-based crosslinking of ELPs and to link synthetic ELPs to a recombinantly produced protein using native chemical ligation. Transition temperatures of all synthetic ELPs and the fusion construct were determined by measuring turbidity in solution and spanned a large temperature range between 25 and 70 °C, providing synthetically accessible ELPs with transition temperatures suitable for in vitro and in vivo applications. Cycling between their soluble and aggregate state has been observed at least 6 times without significant loss of material for all synthetic ELPs. Copyright © 2016 European Peptide Society and John Wiley & Sons, Ltd. Copyright © 2016 European Peptide

  7. In vitro gamma irradiation of some purified polypeptide hormones and their biological and radioimmunological activity

    International Nuclear Information System (INIS)

    Hromadova, M.; Macho, L.; Strbak, V.; Vigas, M.; Mikulaj, L.

    1979-01-01

    Some polypeptide hormones (adrenocorticotropin - ACTH, human and bovine growth hormone - GH, human menopausal gonadotropin - HMG, human luteinizing hormone - LH, and bovine thyrotropin - TSH) were irradiated either with 2.5 or 12.5 Mrad (1.1 Mrad/h) or both and their biological activity or immunoreactivity was tested within few days or 3 to 5 months after irradiation. Biological activity of irradiated ACTH (estimation of corticosterone released into medium by incubated adrenals - Saffran and Schally 1955) was not decreased in both time intervals tested. Ten days after irradiation of bovine GH no changes in biological activity (tibia test - Wilhelmi 1973) were found. No decrease of biological activity of irradiated HMG (augmentation of ovarian and uterine weight - Butt 1973) was found 4 months after irradiation and, finaly, no decrease of bovine TSH activity (radioiodine release from prelabelled thyroid in mice - McKenzie 1958) was found 2 to 30 days after irradiation with 2.5 Mrad, while a decrease was observed after 12.5 Mrad. Three to five months after irradiation, however, there was a decrease of biological activity after both doses. The immunological reactivity of irradiated HMG and LH did not differ from that of nonirradiated samples. The same was found with human GH after 2.5 Mrad, while a decrease of reactivity after 12.5 Mrad was detected. It was concluded that, in most of cases, the sterilizing dose of gamma radiation (2.5 Mrad) did not affect the biological activity of polypeptide hormones and that their sensitivity to irradiation appears to differ. (author)

  8. Zonadhesin D3-Polypeptides Vary among Species but Are Similar in Equus Species Capable of Interbreeding1

    Science.gov (United States)

    Tardif, Steve; Brady, Heidi A.; Breazeale, Kelly R.; Bi, Ming; Thompson, Leslie D.; Bruemmer, Jason E.; Bailey, Laura B.; Hardy, Daniel M.

    2009-01-01

    Zonadhesin is a rapidly evolving protein in the sperm acrosome that confers species specificity to sperm-zona pellucida adhesion. Though structural variation in zonadhesin likely contributes to its species-specific function, the protein has not previously been characterized in organisms capable of interbreeding. Here we compared properties of zonadhesin in several animals, including the horse (Equus caballus), donkey (E. asinus), and Grevy's zebra (E. grevyi) to determine if variation in zonadhesin correlates with ability of gametes to cross-fertilize. Zonadhesin localized to the apical acrosomes of spermatozoa from all three Equus species, similar to its localization in other animals. Likewise, in horse and donkey testis, zonadhesin was detected only in germ cells, first in the acrosomal granule of round spermatids and then in the developing acrosomes of elongating spermatids. Among non-Equus species, D3-domain polypeptides of mature, processed zonadhesin varied markedly in size and detergent solubility. However, zonadhesin D3-domain polypeptides in horse, donkey, and zebra spermatozoa exhibited identical electrophoretic mobility and detergent solubility. Equus zonadhesin D3-polypeptides (p110/p80 doublet) were most similar in size to porcine and bovine zonadhesin D3-polypeptides (p105). Sequence comparisons revealed that the horse zonadhesin precursor's domain content and arrangement are similar to those of zonadhesin from other large animals. Partial sequences of horse and donkey zonadhesin were much more similar to each other (>99% identity) than they were to orthologous sequences of human, pig, rabbit, and mouse zonadhesin (52%–72% identity). We conclude that conservation of zonadhesin D3-polypeptide properties correlates with ability of Equus species to interbreed. PMID:19794156

  9. Radiation Transport

    Energy Technology Data Exchange (ETDEWEB)

    Urbatsch, Todd James [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-06-15

    We present an overview of radiation transport, covering terminology, blackbody raditation, opacities, Boltzmann transport theory, approximations to the transport equation. Next we introduce several transport methods. We present a section on Caseology, observing transport boundary layers. We briefly broach topics of software development, including verification and validation, and we close with a section on high energy-density experiments that highlight and support radiation transport.

  10. Chamber transport

    International Nuclear Information System (INIS)

    Olson, Craig L.

    2001-01-01

    Heavy ion beam transport through the containment chamber plays a crucial role in all heavy ion fusion (HIF) scenarios. Here, several parameters are used to characterize the operating space for HIF beams; transport modes are assessed in relation to evolving target/accelerator requirements; results of recent relevant experiments and simulations of HIF transport are summarized; and relevant instabilities are reviewed. All transport options still exist, including (1) vacuum ballistic transport, (2) neutralized ballistic transport, and (3) channel-like transport. Presently, the European HIF program favors vacuum ballistic transport, while the US HIF program favors neutralized ballistic transport with channel-like transport as an alternate approach. Further transport research is needed to clearly guide selection of the most attractive, integrated HIF system

  11. An anti-cancer WxxxE-containing azurin polypeptide inhibits Rac1-dependent STAT3 and ERK/GSK-3β signaling in breast cancer cells.

    Science.gov (United States)

    Zhang, Zhe; Luo, Zhiyong; Min, Wenpu; Zhang, Lin; Wu, Yaqun; Hu, Xiaopeng

    2017-06-27

    In our previous study, we characterized a mycoplasmal small GTPase-like polypeptide of 240 amino acids that possesses an N-terminal WVLGE sequence. The N-terminal WVLGE sequence promotes activation of Rac1 and subsequent host cancer cell proliferation. To investigate the function of the WxxxE motif in the interaction with Rac1 and host tumor progression, we synthesized a 35-amino acid WVLGE-containing polypeptide derived from a cell-penetrating peptide derived from the azurin protein. We verified that the WVLGE-containing polypeptide targeted MCF-7 cells rather than MCF-10A cells. However, the WVLGE-containing polypeptide inhibited activation of Rac1 and induced cellular phenotypes that resulted from inhibition of Rac1. In addition, the WVLGE-containing polypeptide down-regulated phosphorylation of the STAT3 and ERK/GSK-3β signaling pathways, and this effect was abolished by either stimulation or inhibition of Rac1 activity. We also found that the WVLGE-containing polypeptide has a Rac1-dependent potential to suppress breast cancer growth in vitro and in vivo. We suggest that by acting as a Rac1 inhibitor, this novel polypeptide may be useful for the treatment of breast cancer.

  12. Charge Transport Phenomena in Peptide Molecular Junctions

    Directory of Open Access Journals (Sweden)

    Alessandra Luchini

    2008-01-01

    Full Text Available Inelastic electron tunneling spectroscopy (IETS is a valuable in situ spectroscopic analysis technique that provides a direct portrait of the electron transport properties of a molecular species. In the past, IETS has been applied to small molecules. Using self-assembled nanoelectronic junctions, IETS was performed for the first time on a large polypeptide protein peptide in the phosphorylated and native form, yielding interpretable spectra. A reproducible 10-fold shift of the I/V characteristics of the peptide was observed upon phosphorylation. Phosphorylation can be utilized as a site-specific modification to alter peptide structure and thereby influence electron transport in peptide molecular junctions. It is envisioned that kinases and phosphatases may be used to create tunable systems for molecular electronics applications, such as biosensors and memory devices.

  13. Sustainable Transportation

    DEFF Research Database (Denmark)

    Hall, Ralph P.; Gudmundsson, Henrik; Marsden, Greg

    2014-01-01

    that relate to the construction and maintenance of transportation infrastructure and the operation or use of the different transportation modes. The concept of sustainable transportation emerged in response to these concerns as part of the broader notion of sustainable development. Given the transportation...... sector’s significant contribution to global challenges such as climate change, it is often said that sustainable development cannot be achieved without sustainable transportation....

  14. An Investigation of the Polypeptide, Poly - L - Glutamic Acid, Using Neutron Inelastic Scattering

    International Nuclear Information System (INIS)

    Whittemore, W.L.

    1968-01-01

    The polypeptides are synthetic polymers of amino acids with many similarities to natural proteins. In a large number of cases, one of the conformations for both the synthetic and natural proteins is the α - helix. The simplest of the synthetic polymers with no side chains is polyglycine and the simplest of the synthetic polymers with a small side chain (methyl group) is polyalanine. Dispersion curves have been computed by Gupta for both of these polymers. Polyglutamic acid is similar to polyalanine in that the composition of the basic residue and radius of helix is the same. Polyglutamic acid has a more complicated side chain which will contribute a number of additional natural frequencies that are expected to be essentially independent of conformation. On the other hand, the dispersion curves already derived for polyalanine in the α -helix form should be correct in many specific details for polyglutamic acid. An experimental study has been undertaken for polyglutamic acid at room temperature using the techniques of inelastic neutron scattering. In the first measurements, 'cold' neutrons from a reactor were used to investigate the energy level structure up to ≃ 3 kT for both conformations of the polymer. In addition, the scattering of monoenergetic high-energy neutrons ( > 0.15 eV) provided- by an electron Linac was used to study energy levels above 3 kT. These latter measurements permit comparisons to be made between the calculated and measured results for a much larger range of frequencies (and hence permit a check for a larger number of dispersion curves). This extension of the experimental results to higher frequencies has made it possible to check on the earlier assumption that only the lower frequencies are altered when the conformation is changed. This assumption underlies the evaluation of changes in internal energy with conformation from only the 'cold' neutron data, as is done with the present data. An experiment was performed to evaluate the

  15. DNA-interactive properties of crotamine, a cell-penetrating polypeptide and a potential drug carrier.

    Directory of Open Access Journals (Sweden)

    Pei-Chun Chen

    Full Text Available Crotamine, a 42-residue polypeptide derived from the venom of the South American rattlesnake Crotalus durissus terrificus, has been shown to be a cell-penetrating protein that targets chromosomes, carries plasmid DNA into cells, and shows specificity for actively proliferating cells. Given this potential role as a nucleic acid-delivery vector, we have studied in detail the binding of crotamine to single- and double-stranded DNAs of different lengths and base compositions over a range of ionic conditions. Agarose gel electrophoresis and ultraviolet spectrophotometry analysis indicate that complexes of crotamine with long-chain DNAs readily aggregate and precipitate at low ionic strength. This aggregation, which may be important for cellular uptake of DNA, becomes less likely with shorter chain length. 25-mer oligonucleotides do not show any evidence of such aggregation, permitting the determination of affinities and size via fluorescence quenching experiments. The polypeptide binds non-cooperatively to DNA, covering about 5 nucleotide residues when it binds to single (ss or (ds double stranded molecules. The affinities of the protein for ss- vs. ds-DNA are comparable, and inversely proportional to salt levels. Analysis of the dependence of affinity on [NaCl] indicates that there are a maximum of ∼3 ionic interactions between the protein and DNA, with some of the binding affinity attributable to non-ionic interactions. Inspection of the three-dimensional structure of the protein suggests that residues 31 to 35, Arg-Trp-Arg-Trp-Lys, could serve as a potential DNA-binding site. A hexapeptide containing this sequence displayed a lower DNA binding affinity and salt dependence as compared to the full-length protein, likely indicative of a more suitable 3D structure and the presence of accessory binding sites in the native crotamine. Taken together, the data presented here describing crotamine-DNA interactions may lend support to the design of more

  16. Protein transport into the human ER and related diseases, Sec61-channelopathies.

    Science.gov (United States)

    Haßdenteufel, Sarah; Klein, Marie-Christine; Melnyk, Armin; Zimmermann, Richard

    2014-12-01

    Protein transport into the human endoplasmic reticulum (ER) is relevant to the biogenesis of most soluble and membrane proteins of organelles, which are involved in endo- or exo-cytsosis. It involves amino-terminal signal peptides in the precursor polypeptides and various transport components in the cytosol plus the ER, and can occur co- or post-translationally. The two mechanisms merge at the level of the ER membrane, specifically at the level of the heterotrimeric Sec61 complex, which forms a dynamic polypeptide-conducting channel in the ER membrane. Since the mammalian ER is also the main intracellular calcium storage organelle, and the Sec61 complex is calcium permeable, the Sec61 complex is tightly regulated in its equilibrium between the closed and open conformations, or "gated", by ligands, such as signal peptides of the transport substrates and the ER lumenal Hsp70-type molecular chaperone BiP. Furthermore, BiP binding to the incoming polypeptide contributes to the efficiency and unidirectionality of transport. Recent insights into the structure and dynamic equilibrium of the Sec61 complex have various mechanistic as well as medical implications.

  17. A novel signal transduction protein: Combination of solute binding and tandem PAS-like sensor domains in one polypeptide chain: Periplasmic Ligand Binding Protein Dret_0059

    Energy Technology Data Exchange (ETDEWEB)

    Wu, R. [Midwest Center for Structural Genomics, Argonne National Laboratory, Argonne Illinois 60439; Biosciences Division, Argonne National Laboratory, Argonne Illinois 60439; Wilton, R. [Biosciences Division, Argonne National Laboratory, Argonne Illinois 60439; Cuff, M. E. [Midwest Center for Structural Genomics, Argonne National Laboratory, Argonne Illinois 60439; Biosciences Division, Argonne National Laboratory, Argonne Illinois 60439; Structural Biology Center, Argonne National Laboratory, Argonne Illinois 60439; Endres, M. [Midwest Center for Structural Genomics, Argonne National Laboratory, Argonne Illinois 60439; Babnigg, G. [Midwest Center for Structural Genomics, Argonne National Laboratory, Argonne Illinois 60439; Biosciences Division, Argonne National Laboratory, Argonne Illinois 60439; Edirisinghe, J. N. [Mathematics and Computer Science Division, Argonne National Laboratory, Argonne Illinois 60439; Computation Institute, University of Chicago, Chicago Illinois 60637; Henry, C. S. [Mathematics and Computer Science Division, Argonne National Laboratory, Argonne Illinois 60439; Computation Institute, University of Chicago, Chicago Illinois 60637; Joachimiak, A. [Midwest Center for Structural Genomics, Argonne National Laboratory, Argonne Illinois 60439; Biosciences Division, Argonne National Laboratory, Argonne Illinois 60439; Structural Biology Center, Argonne National Laboratory, Argonne Illinois 60439; Department of Biochemistry and Molecular Biology, University of Chicago, Chicago Illinois 60637; Schiffer, M. [Biosciences Division, Argonne National Laboratory, Argonne Illinois 60439; Pokkuluri, P. R. [Biosciences Division, Argonne National Laboratory, Argonne Illinois 60439

    2017-03-06

    We report the structural and biochemical characterization of a novel periplasmic ligand-binding protein, Dret_0059, from Desulfohalobium retbaense DSM 5692, an organism isolated from the Salt Lake Retba in Senegal. The structure of the protein consists of a unique combination of a periplasmic solute binding protein (SBP) domain at the N-terminal and a tandem PAS-like sensor domain at the C-terminal region. SBP domains are found ubiquitously and their best known function is in solute transport across membranes. PAS-like sensor domains are commonly found in signal transduction proteins. These domains are widely observed as parts of many protein architectures and complexes but have not been observed previously within the same polypeptide chain. In the structure of Dret_0059, a ketoleucine moiety is bound to the SBP, whereas a cytosine molecule is bound in the distal PAS-like domain of the tandem PAS-like domain. Differential scanning flourimetry support the binding of ligands observed in the crystal structure. There is significant interaction between the SBP and tandem PAS-like domains, and it is possible that the binding of one ligand could have an effect on the binding of the other. We uncovered three other proteins with this structural architecture in the non-redundant sequence data base, and predict that they too bind the same substrates. The genomic context of this protein did not offer any clues for its function. We did not find any biological process in which the two observed ligands are coupled. The protein Dret_0059 could be involved in either signal transduction or solute transport.

  18. Rapid measurement of 3J(HN-Hα) and 3J(N-Hβ) coupling constants in polypeptides

    International Nuclear Information System (INIS)

    Barnwal, Ravi Pratap; Rout, Ashok K.; Chary, Kandala V. R.; Atreya, Hanudatta S.

    2007-01-01

    We present two NMR experiments, (3,2)D HNHA and (3,2)D HNHB, for rapid and accurate measurement of 3 J(H N -H α ) and 3 J(N-H β ) coupling constants in polypeptides based on the principle of G-matrix Fourier transform NMR spectroscopy and quantitative J-correlation. These experiments, which facilitate fast acquisition of three-dimensional data with high spectral/digital resolution and chemical shift dispersion, will provide renewed opportunities to utilize them for sequence specific resonance assignments, estimation/characterization of secondary structure with/without prior knowledge of resonance assignments, stereospecific assignment of prochiral groups and 3D structure determination, refinement and validation. Taken together, these experiments have a wide range of applications from structural genomics projects to studying structure and folding in polypeptides

  19. Hemoglobin variants as models for investigation of dissociation of intact polypeptide chains by ESI tandem mass spectrometry

    International Nuclear Information System (INIS)

    Light, K.J.; Loo, J.A.; Edmonds, C.G.; Smith, R.D.

    1991-06-01

    Electrospray ionization mass spectroscopy (ESI-MS) is rapidly becoming a practical biochemical tool for peptide and protein sequence analysis. The utility of ESI-MS is through use of Collisionally Activated Dissociation (ESI-CAD-MS). Human hemoglobin (Hb, ∼62 kDa) consists of four polypeptide chains and a prosthetic heme group. There are over 400 Hb variants, characterized by amino acid substitutions in either the alpha or beta polypeptide chains. We investigated ESI-CAD-MS as a tool for rapidly analyzing amino acid substitutions, using eight Hb beta chain variants. The approximate location of the modification can be deduced from comparison of the CAD mass spectra and observance of the mass shifts of the fragment ion containing the substitution. Fragmentation occurs preferentially at the amino terminus of proline residues. For most substitutions, differences in CAD mass spectra were not seen. 2 figs

  20. Influence of Aluminium and EGCG on Fibrillation and Aggregation of Human Islet Amyloid Polypeptide

    Directory of Open Access Journals (Sweden)

    Zhi-Xue Xu

    2016-01-01

    Full Text Available The abnormal fibrillation of human islet amyloid polypeptide (hIAPP has been implicated in the development of type II diabetes. Aluminum is known to trigger the structural transformation of many amyloid proteins and induce the formation of toxic aggregate species. The (−-epigallocatechin gallate (EGCG is considered capable of binding both metal ions and amyloid proteins with inhibitory effect on the fibrillation of amyloid proteins. However, the effect of Al(III/EGCG complex on hIAPP fibrillation is unclear. In the present work, we sought to view insight into the structures and properties of Al(III and EGCG complex by using spectroscopic experiments and quantum chemical calculations and also investigated the influence of Al(III and EGCG on hIAPP fibrillation and aggregation as well as their combined interference on this process. Our studies demonstrated that Al(III could promote fibrillation and aggregation of hIAPP, while EGCG could inhibit the fibrillation of hIAPP and lead to the formation of hIAPP amorphous aggregates instead of the ordered fibrils. Furthermore, we proved that the Al(III/EGCG complex in molar ratio of 1 : 1 as Al(EGCG(H2O2 could inhibit the hIAPP fibrillation more effectively than EGCG alone. The results provide the invaluable reference for the new drug development to treat type II diabetes.

  1. β-Hairpin of Islet Amyloid Polypeptide Bound to an Aggregation Inhibitor

    Science.gov (United States)

    Mirecka, Ewa A.; Feuerstein, Sophie; Gremer, Lothar; Schröder, Gunnar F.; Stoldt, Matthias; Willbold, Dieter; Hoyer, Wolfgang

    2016-01-01

    In type 2 diabetes, the formation of islet amyloid consisting of islet amyloid polypeptide (IAPP) is associated with reduction in β-cell mass and contributes to the failure of islet cell transplantation. Rational design of inhibitors of IAPP amyloid formation has therapeutic potential, but is hampered by the lack of structural information on inhibitor complexes of the conformationally flexible, aggregation-prone IAPP. Here we characterize a β-hairpin conformation of IAPP in complex with the engineered binding protein β-wrapin HI18. The β-strands correspond to two amyloidogenic motifs, 12-LANFLVH-18 and 22-NFGAILS-28, which are connected by a turn established around Ser-20. Besides backbone hydrogen bonding, the IAPP:HI18 interaction surface is dominated by non-polar contacts involving hydrophobic side chains of the IAPP β-strands. Apart from monomers, HI18 binds oligomers and fibrils and inhibits IAPP aggregation and toxicity at low substoichiometric concentrations. The IAPP β-hairpin can serve as a molecular recognition motif enabling control of IAPP aggregation. PMID:27641459

  2. Engineered aggregation inhibitor fusion for production of highly amyloidogenic human islet amyloid polypeptide.

    Science.gov (United States)

    Mirecka, Ewa Agnieszka; Gremer, Lothar; Schiefer, Stephanie; Oesterhelt, Filipp; Stoldt, Matthias; Willbold, Dieter; Hoyer, Wolfgang

    2014-12-10

    Human islet amyloid polypeptide (IAPP) is the major component of pancreatic amyloid deposits in type 2 diabetes. The structural conversion of IAPP from a monomeric state into amyloid assemblies is the subject of intense research. Recombinant production of IAPP is, however, difficult due to its extreme aggregation propensity. Here we describe a novel strategy for expression of IAPP in Escherichia coli, based on an engineered protein tag, which sequesters IAPP monomers and prevents IAPP aggregation. The IAPP-binding protein HI18 was selected by phage display from a β-wrapin library. Fusion of HI18 to IAPP enabled the soluble expression of the construct. IAPP was cleaved from the fusion construct and purified to homogeneity with a yield of 3mg of isotopically labeled peptide per liter of culture. In the monomeric state, IAPP was largely disordered as evidenced by far-UV CD and liquid-state NMR spectroscopy but competent to form amyloid fibrils according to atomic force microscopy. These results demonstrate the ability of the engineered β-wrapin HI18 for shielding the hydrophobic sequence of IAPP during expression and purification. Fusion of aggregation-inhibiting β-wrapins is a suitable approach for the recombinant production of aggregation-prone proteins. Copyright © 2014 Elsevier B.V. All rights reserved.

  3. Effects of microgravity on the crystal quality of a collagen-like polypeptide.

    Science.gov (United States)

    Berisio, R; Vitagliano, L; Sorrentino, G; Carotenuto, L; Piccolo, C; Mazzarella, L; Zagari, A

    2000-01-01

    (Pro-Pro-Gly)(10) is one of the most widely studied collagen polypeptide models. Microgravity crystal growth of (Pro-Pro-Gly)(10) was carried out in the Advanced Protein Crystallization Facility aboard the Space Shuttle Discovery during the STS-95 mission. Crystals were successfully grown in all experiments, using both dialysis and free-interface diffusion methods. The quality of the microgravity-grown crystals and of ground-grown counterparts was assessed by X-ray synchrotron diffraction. Microgravity-grown crystals exhibited a significant improvement in terms of dimensions and resolution limit. As previously reported, crystals were orthorhombic, space group P2(1)2(1)2(1). However, the diffraction pattern showed weak reflections, never previously measured, that were consistent with new unit-cell parameters a = 26.9, b = 26.4, c = 182.5 A. This allowed the derivation of a new model for the arrangement of the triple-helical molecules in the crystals.

  4. The polypeptide in Chlamys farreri can protect human dermal fibroblasts from ultraviolet B damage

    Science.gov (United States)

    Zhang, Yujiang; Zhan, Songmei; Cao, Pengli; Liu, Ning; Chen, Xuehong; Wang, Yuejun; Wang, Chunbo

    2005-09-01

    To investigate the effect of polypeptide from Chlamys farreri (PCF) on NHDF in vitro, we modeled oxidative damage on normal human dermal fibroblasts (NHDF) exposed to ultraviolet B (UVB). In this study, 3-[4,5-Dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) and lactate dehydrogenase (LDH) were tested to measure cell viability. Enzymes including superoxide dismutase (SOD), glutathione peroxidase (GSH-PX), catalase (CAT) and xanthine oxidase (XOD) were determined biochemically. Total antioxidative capacity (T-AOC) and anti-superoxide anion capacity (A-SAC) were also determined. Ultrastructure of fibroblasts was observed under transmission electron microscope. The results showed that: UVB (1.176×10-4 J/cm2) suppressed the growth of fibroblasts and the introduction of PCF (0.25% 1%) before UVB reduced the suppression in a concentration-dependent manner. PCF could enhance the activities of SOD, GSH-PX and T-AOC as well as A-SAC. Also PCF could inhibit XOD activity, while it did not affect CAT activity. Ultrastructure of fibroblasts were damaged after UVB irradiation, concentration-dependent PCF reduced the destructive effect of UVB on cells. These results indicated that PCF can protect human dermal fibroblasts from being harmed by UVB irradiation via its antioxidant proerty.

  5. ThPOD3, a truncated polypeptide from Tamarix hispida, conferred drought tolerance in Escherichia coli.

    Science.gov (United States)

    Guo, Xiao-Hong; Jiang, Jing; Wang, Bai-Chen; Li, Hui-Yu; Wang, Yu-Cheng; Yang, Chuan-Ping; Liu, Gui-Feng

    2010-03-01

    The ThPOD1 gene encodes a peroxidase and was isolated from a Tamarix hispida NaCl-stress root cDNA library. We found that ThPOD1 expression could be induced by abiotic stresses such as cold, salt, drought and exogenous abscisic acid. These findings suggested that ThPOD1 might be involved in the plant response to environmental stresses and ABA treatment. To elucidate the function of this gene, recombinant plasmids expressing full-length ThPOD1 as well as ThPOD2 (aa 41-337), and ThPOD3 (aa 73-337) truncated polypeptides were constructed. SDS-PAGE and Western blot analyses of the fusion proteins revealed that the molecular weights of ThPOD1, ThPOD2 and ThPOD3 were approximately 57, approximately 50 and approximately 47 kDa, respectively. Stress assays of E. coli treated with the recombinant plasmids indicated that ThPOD3 could improve resistance to drought stress. This finding could potentially be used to improve plant tolerance to drought stress via gene transfer.

  6. Expression of Polypeptide N-Acetylgalactosaminyltransferase-6 in Epithelial Ovarian Carcinoma.

    Science.gov (United States)

    Murakami, Midori; Kagami, Seiji; Nguyen, Thuy Thi; Koi, Chiho; Kurita, Tomoko; Hachisuga, Toru

    2017-07-01

    The family of polypeptide N-acetylgalactosanimyltransferases (GalNAc-Ts) are important factors in glycosylation in carcinomas. The purpose of this study was to investigate the clinical significance of GalNAc-T6 and its correlation with the prognosis of epithelial ovarian carcinoma. A total of 150 patients with epithelial ovarian carcinoma were enrolled and the relationship between GalNAc-T6 expression by immunohistochemistry and long-term survival was evaluated. The expression of GalNAc-T6 was positive in 57.6% (34/59) of those with serous carcinoma, 85.3% (29/34) in mucinous carcinoma, 15.6% (5/27) in clear cell carcinoma, and 44% (14/25) in endometrioid carcinoma. In a Kaplan-Meier analysis of patients with grade 1 or 2 serous carcinoma, the 10-year overall survival rates were 47.4% in the GalNAc-T6-positive and 9.1% in the GalNAc-T6-negative groups (p=0.047). GalNAc-T6 expression in epithelial ovarian carcinoma was different according to pathological type. In low-grade serous carcinoma, GalNAc-T6 expression may contribute to improved long-term survival. Copyright© 2017, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.

  7. Role of pancreatic polypeptide in the regulation of pancreatic exocrine secretion in dogs

    International Nuclear Information System (INIS)

    Shiratori, Keiko; Lee, K.Y.; Chang, Tamin; Jo, Y.H.; Coy, D.H.; Chey, W.Y.

    1988-01-01

    The effect of intravenous infusion of synthetic human pancreatic polypeptide (HPP) or a rabbit anti-PP serum on pancreatic exocrine secretion was studied in 10 dogs with gastric and Thomas duodenal cannulas. The infusion of HPP, achieved a plasma PP concentration that mimicked the peak plasma concentration of PP in both interdigestive and postprandial states. This dose of HPP significantly inhibited pancreatic secretion in the interdigestive state. By contrast, immunoneutralization of circulating PP by a rabbit anti-PP serum resulted in significant increases in both interdigestive and postprandial pancreatic secretion, including water, bicarbonate, and protein. The increase in the pancreatic secretion paralleled a decrease in circulating PP level, which lasted for as long as 5 days. Furthermore, the anti-PP serum blocked the inhibitory action of exogenous HPP on pancreatic exocrine secretion. The present study indicates that endogenous PP plays a significant role in the regulation of the pancreatic exocrine secretion in both interdigestive and digestive states. Thus the authors conclude that PP is another hormone regulating pancreatic exocrine secretion in dogs

  8. Glucose-Dependent Insulinotropic Polypeptide Mitigates 6-OHDA-Induced Behavioral Impairments in Parkinsonian Rats

    Directory of Open Access Journals (Sweden)

    Yu-Wen Yu

    2018-04-01

    Full Text Available In the present study, the effectiveness of glucose-dependent insulinotropic polypeptide (GIP was evaluated by behavioral tests in 6-hydroxydopamine (6-OHDA hemi-parkinsonian (PD rats. Pharmacokinetic measurements of GIP were carried out at the same dose studied behaviorally, as well as at a lower dose used previously. GIP was delivered by subcutaneous administration (s.c. using implanted ALZET micro-osmotic pumps. After two days of pre-treatment, male Sprague Dawley rats received a single unilateral injection of 6-OHDA into the medial forebrain bundle (MFB. The neuroprotective effects of GIP were evaluated by apomorphine-induced contralateral rotations, as well as by locomotor and anxiety-like behaviors in open-field tests. Concentrations of human active and total GIP were measured in plasma during a five-day treatment period by ELISA and were found to be within a clinically translatable range. GIP pretreatment reduced behavioral abnormalities induced by the unilateral nigrostriatal dopamine (DA lesion produced by 6-OHDA, and thus may be a novel target for PD therapeutic development.

  9. Degradation of surface-labeled hepatoma membrane polypeptides: effect of inhibitors

    Energy Technology Data Exchange (ETDEWEB)

    Hare, J.F.; Huston, M.

    1984-09-01

    When their membrane proteins were labeled with 125I by lactoperoxidase, dividing hepatoma cells lost radioactivity to the medium in a biphasic manner (T1/2 . 16-26 h, greater than 40 h). Lysosomotropic weak bases, chloroquine, and NH4Cl inhibited the rapid phase by 59%. More than 50% of the radioactivity which accumulates in the media from dividing cells during the first 4 h after labeling was trichloroacetic acid-soluble, and was identified as iodotyrosine. Iodotyrosine release from labeled membrane proteins was 60-71% inhibited by lysosomotropic agents chloroquine and NH4Cl as well as the sodium-proton ionophore, monensin. The inhibitory effect of NH4Cl and monensin was reversible. Inhibitors of microtubule and microfilament function and transglutamination had no effect on release of iodotyrosine to the medium, but trypsin-like protease inhibitors, p-aminobenzamidine, tosyl-L-lysine/chloromethylketone, and phenylmethylsulfonyl fluoride, as well as the cathepsin B inhibitor, leupeptin, inhibited by 21-24%. Iodotyrosine release showed a biphasic Arrhenius plot with an activation energy of 17 kcal/mol above but 27 kcal/mol below 20 degrees C. These results indicate that cell membrane polypeptides require a temperature-limiting event as well as passage through an ion-sensitive compartment prior to their complete degradation to constituent amino acids. In contrast to other lysosomal-mediated events, however, iodinated membrane proteins of dividing cells are degraded in a manner insensitive to agents which disrupt the cytoskeleton.

  10. Understanding the Origins of Time-Dependent Inhibition by Polypeptide Deformylase Inhibitors

    Energy Technology Data Exchange (ETDEWEB)

    Totoritis, Rachel; Duraiswami, Chaya; Taylor, Amy N.; Kerrigan, John J.; Campobasso, Nino; Smith, Katherine J.; Ward, Paris; King, Bryan W.; Murrayz-Thompson, Monique; Jones, Amber D.; Van Aller, Glenn S.; Aubart, Kelly M.; Zalacain, Magdalena; Thrall, Sara H.; Meek, Thomas D.; Schwartz, Benjamin (GSKPA)

    2012-03-15

    The continual bacterial adaptation to antibiotics creates an ongoing medical need for the development of novel therapeutics. Polypeptide deformylase (PDF) is a highly conserved bacterial enzyme, which is essential for viability. It has previously been shown that PDF inhibitors represent a promising new area for the development of antimicrobial agents, and that many of the best PDF inhibitors demonstrate slow, time-dependent binding. To improve our understanding of the mechanistic origin of this time-dependent inhibition, we examined in detail the kinetics of PDF catalysis and inhibition by several different PDF inhibitors. Varying pH and solvent isotope led to clear changes in time-dependent inhibition parameters, as did inclusion of NaCl, which binds to the active site metal of PDF. Quantitative analysis of these results demonstrated that the observed time dependence arises from slow binding of the inhibitors to the active site metal. However, we also found several metal binding inhibitors that exhibited rapid, non-time-dependent onset of inhibition. By a combination of structural and chemical modification studies, we show that metal binding is only slow when the rest of the inhibitor makes optimal hydrogen bonds within the subsites of PDF. Both of these interactions between the inhibitor and enzyme were found to be necessary to observe time-dependent inhibition, as elimination of either leads to its loss.

  11. Lamina Associated Polypeptide 1 (LAP1 Interactome and Its Functional Features

    Directory of Open Access Journals (Sweden)

    Joana B. Serrano

    2016-01-01

    Full Text Available Lamina-associated polypeptide 1 (LAP1 is a type II transmembrane protein of the inner nuclear membrane encoded by the human gene TOR1AIP1. LAP1 is involved in maintaining the nuclear envelope structure and appears be involved in the positioning of lamins and chromatin. To date, LAP1’s precise function has not been fully elucidated but analysis of its interacting proteins will permit unraveling putative associations to specific cellular pathways and cellular processes. By assessing public databases it was possible to identify the LAP1 interactome, and this was curated. In total, 41 interactions were identified. Several functionally relevant proteins, such as TRF2, TERF2IP, RIF1, ATM, MAD2L1 and MAD2L1BP were identified and these support the putative functions proposed for LAP1. Furthermore, by making use of the Ingenuity Pathways Analysis tool and submitting the LAP1 interactors, the top two canonical pathways were “Telomerase signalling” and “Telomere Extension by Telomerase” and the top functions “Cell Morphology”, “Cellular Assembly and Organization” and “DNA Replication, Recombination, and Repair”. Once again, putative LAP1 functions are reinforced but novel functions are emerging.

  12. Fusion and fission of molecular assemblies of amphiphilic polypeptides generating small vesicles from nanotubes.

    Science.gov (United States)

    Watabe, Naoki; Joo Kim, Cheol; Kimura, Shunsaku

    2017-03-01

    Three amphiphilic block polypeptides, (sarcosine) m -b-(l- or d-Leu-Aib) n (L16, D16, D14), having different helical chain lengths or helicity are synthesized. A mixture of L16, D16, and D14 generates vesicles of diameters more than ca. 130 nm by injecting the ethanol solution into water and heating at 90°C for 1 h. On the other hand, when nanotubes composed of L16 and D14 having ca. 50 nm diameter are mixed with nanosheets composed of D16, smaller and homogeneous vesicles of ca. 60 nm diameter are obtained with the heat treatment. The time lapse TEM image analysis of the mixtures revealed some transient structures of nanotubes sticking a nanosheet or a vesicle at the open end of nanotubes. The precise size control of vesicles is therefore attainable by using nanotubes as a structural template regulating the size of vesicles near to the nanotube diameter upon the membrane fission processes. © 2016 Wiley Periodicals, Inc.

  13. Effects of tactile and electrical stimuli upon release of vasoactive intestinal polypeptide in the mammalian penis.

    Science.gov (United States)

    Dixson, A F; Kendrick, K M; Blank, M A; Bloom, S R

    1984-02-01

    Plasma levels of vasoactive intestinal polypeptide (VIP) in the corpora cavernosa penis and dorsal penile veins greatly exceeded those measured in the limb or caudal veins during anaesthesia in various mammals (Bennett's wallaby, Barbary sheep, cheetah, puma, sooty mangabey, pigtail macaque and chimpanzee). Tactile stimulation of the penis immediately before or during collection of blood samples resulted in an increase. In the wallaby, VIP levels (mean +/- S.E.M.) in blood samples collected from the flaccid penis in the absence of tactile stimulation were very low (0.6 +/- 0.5 pmol/l). A 36-fold increase in VIP occurred after manual extension of the flaccid penis (24.8 +/- 3.2 pmol/l) or during manually stimulated erections (25.1 +/- 1.7 pmol/l). Electrical stimulation of erection produced no significant increase in VIP levels (2.3 +/- 0.9 pmol/l) unless accompanied by tactile stimulation (17.5 +/- 1.4 pmol/l). These studies provide the first demonstration that sensory feedback from the penis plays an important role in regulating vasoactive intestinal polypeptidergic activity. Since VIP is a potent vasodilator its release due to tactile stimuli during copulation may play a role in the maintenance of penile erection.

  14. Changes of vasoactive polypeptides during postoperative hypertensive crisis in patients with hypertensive intracerebral hemorrhage.

    Science.gov (United States)

    Wang, Zhi; Wang, Xue-feng; Wang, Chao; Luan, Wen-zhong

    2007-12-05

    Hypertensive crisis could be found after operation in patients with hypertensive intracerebral hemorrhage (HICH). The aim of this study was to explore the changes and the roles of some vasoactive polypeptides during postoperative hypertensive crisis in patients with HICH. A total of 31 patients, who were admitted for craniotomy, were enrolled into this study. After the operation, the patients were divided into three groups. Group I consisted of 9 patients with postoperative hypertensive crisis, and group II was composed of 13 patients without postoperative hypertensive crisis. Nine patients, who denied history of hypertension or HICH, were set as group III. The levels of some vasoactivators in the three groups were measured before and after the operation. The differences in the results among the groups were analyzed using the ANOVA. The data collected before and after the operation in the group I was compared by Wilcoxon test. The concentration of endothelin in group I was significantly higher than that in group III (P 0.05). Postoperative hypertensive crisis may be due to the increased thromboxane A2 and relatively inadequate prostacyclin, especially 6-keto-PGF1a. The increased level of endothelin and intraoperative stimulation also play a certain role in the development of postoperative hypertensive crisis.

  15. Neurofilament heavy polypeptide regulates the Akt-beta-catenin pathway in human esophageal squamous cell carcinoma.

    Directory of Open Access Journals (Sweden)

    Myoung Sook Kim

    2010-02-01

    Full Text Available Aerobic glycolysis and mitochondrial dysfunction are common features of aggressive cancer growth. We observed promoter methylation and loss of expression in neurofilament heavy polypeptide (NEFH in a significant proportion of primary esophageal squamous cell carcinoma (ESCC samples that were of a high tumor grade and advanced stage. RNA interference-mediated knockdown of NEFH accelerated ESCC cell growth in culture and increased tumorigenicity in vivo, whereas forced expression of NEFH significantly inhibited cell growth and colony formation. Loss of NEFH caused up-regulation of pyruvate kinase-M2 type and down-regulation of pyruvate dehydrogenase, via activation of the Akt/beta-catenin pathway, resulting in enhanced aerobic glycolysis and mitochondrial dysfunction. The acceleration of glycolysis and mitochondrial dysfunction in NEFH-knockdown cells was suppressed in the absence of beta-catenin expression, and was decreased by the treatment of 2-Deoxyglucose, a glycolytic inhibitor, or API-2, an Akt inhibitor. Loss of NEFH activates the Akt/beta-catenin pathway and increases glycolysis and mitochondrial dysfunction. Cancer cells with methylated NEFH can be targeted for destruction with specific inhibitors of deregulated downstream pathways.

  16. Unconventional amino acid sequence of the sun anemone (Stoichactis helianthus) polypeptide neurotoxin

    International Nuclear Information System (INIS)

    Kem, W.; Dunn, B.; Parten, B.; Pennington, M.; Price, D.

    1986-01-01

    A 5000 dalton polypeptide neurotoxin (Sh-NI) purified by G50 Sephadex, P-cellulose, and SP-Sephadex chromatography was homogeneous by isoelectric focusing. Sh-NI was highly toxic to crayfish (LD 50 0.6 μg/kg) but without effect upon mice at 15,000 μg/kg (i.p. injection). The reduced, 3 H-carboxymethylated toxin and its fragments were subjected to automatic Edman degradation and the resulting PTH-amino acids were identified by HPLC, back hydrolysis, and scintillation counting. Peptides resulting from proteolytic (clostripain, staphylococcal protease) and chemical (tryptophan) cleavage were sequenced. The sequence is: AACKCDDEGPDIRTAPLTGTVDLGSCNAGWEKCASYYTIIADCCRKKK. This sequence differs considerably from the homologous Anemonia and Anthopleura toxins; many of the identical residues (6 half-cystines, G9, P10, R13, G19, G29, W30) are probably critical for folding rather than receptor recognition. However, the Sh-NI sequence closely resembles Radioanthus macrodactylus neurotoxin III and r. paumotensis II. The authors propose that Sh-NI and related Radioanthus toxins act upon a different site on the sodium channel

  17. Radioimmunoassay of vasoactive intestinal polypeptide (VIP) in plasma. [/sup 125/I tracer techniques

    Energy Technology Data Exchange (ETDEWEB)

    Fahrenkrug, J.; Schaffalitzky de Muckadell, O.B.

    1977-06-01

    A sensitive and specific radioimmunoassay for vasoactive intestinal polypeptide (VIP) has been developed, which can detect 3.3 pmol x L/sup -1/ of the peptide in plasma. Antisera to highly purified porcine VIP coupled to albumin were raised in eight rabbits. The final dilution, the avidity, and the specificity of each antiserum were determined. /sup 125/I-VIP served as label, and highly purified porcine VIP was used as standard. Separation of antibody-bound and free VIP was achieved by plasma-coated charcoal. Nonspecific interference with the assay system was excluded by extraction of plasm samples with ethanol. The reliability of the assay was investigated by recovery experiments, by serial dilution of plasma samples with high concentration of endogenous VIP, and by immunosorption. The within-and between assay reproducibility at a concentration of 18.3 pmol x L/sup -1/ was 1.6 and 2.3 pmol x L/sup -1/ (1 S.D.), respectively. Median fasting concentration of VIP in plasma from 74 normal subjects was 7.3 pmol x L/sup -1/ (range: 0 to 20.0 pmol x L/sup -1/).

  18. Toxic polypeptides of the hydra--a bioinformatic approach to cnidarian allomones.

    Science.gov (United States)

    Sher, Daniel; Knebel, Alin; Bsor, Tamar; Nesher, Nir; Tal, Tzachy; Morgenstern, David; Cohen, Eran; Fishman, Yelena; Zlotkin, Eliahu

    2005-06-01

    Cnidarians such as hydrae and sea anemones are sessile, predatory, soft bodied animals which depend on offensive and defensive allomones for prey capture and survival. These allomones are distributed throughout the entire organism both in specialized stinging cells (nematocytes) and in the body tissues. The cnidarian allomonal system is composed of neurotoxins, cytolysins and toxic phospholipapses. The present bioinformatic survey was motivated by the fact that while hydrae are the most studied model cnidarian, little is known about their allomones. A large-scale EST database from Hydra magnipapillata was searched for orthologs of known cnidarian allomones, as well as for allomones found in other venomous organisms. We show that the hydrae express orthologs of cnidarian phospholipase A2 toxins and cytolysins belonging to the actinoporin family, but could not find orthologs of the 'classic' short chain neurotoxins affecting sodium and potassium conductance. Hydrae also express proteins similar to elapid-like phospholipases, CRISP proteins, Prokineticin-like polypeptides and toxic deoxyribonucleases. Our results illustrate a high level of complexity in the hydra allomonal system, suggest that several toxins represent a basal component of all cnidarian allomones, and raise the intriguing possibility that similar proteins may fulfill both endogenous and allomonal roles in cnidaria.

  19. Protein disulfide isomerase ameliorates β-cell dysfunction in pancreatic islets overexpressing human islet amyloid polypeptide.

    Science.gov (United States)

    Montane, Joel; de Pablo, Sara; Obach, Mercè; Cadavez, Lisa; Castaño, Carlos; Alcarraz-Vizán, Gema; Visa, Montserrat; Rodríguez-Comas, Júlia; Parrizas, Marcelina; Servitja, Joan Marc; Novials, Anna

    2016-01-15

    Human islet amyloid polypeptide (hIAPP) is the major component of amyloid deposits in islets of type 2 diabetic patients. hIAPP misfolding and aggregation is one of the factors that may lead to β-cell dysfunction and death. Endogenous chaperones are described to be important for the folding and functioning of proteins. Here, we examine the effect of the endoplasmic reticulum chaperone protein disulfide isomerase (PDI) on β-cell dysfunction. Among other chaperones, PDI was found to interact with hIAPP in human islet lysates. Furthermore, intrinsically recovered PDI levels were able to restore the effect of high glucose- and palmitate-induced β-cell dysfunction by increasing 3.9-fold the glucose-stimulated insulin secretion levels and restoring insulin content up to basal control values. Additionally, PDI transduction decreased induced apoptosis by glucolipotoxic conditions. This approach could reveal a new therapeutic target and aid in the development of strategies to improve β-cell dysfunction in type 2 diabetic patients. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  20. A paclitaxel-loaded recombinant polypeptide nanoparticle outperforms Abraxane in multiple murine cancer models

    Science.gov (United States)

    Bhattacharyya, Jayanta; Bellucci, Joseph J.; Weitzhandler, Isaac; McDaniel, Jonathan R.; Spasojevic, Ivan; Li, Xinghai; Lin, Chao-Chieh; Chi, Jen-Tsan Ashley; Chilkoti, Ashutosh

    2015-08-01

    Packaging clinically relevant hydrophobic drugs into a self-assembled nanoparticle can improve their aqueous solubility, plasma half-life, tumour-specific uptake and therapeutic potential. To this end, here we conjugated paclitaxel (PTX) to recombinant chimeric polypeptides (CPs) that spontaneously self-assemble into ~60 nm near-monodisperse nanoparticles that increased the systemic exposure of PTX by sevenfold compared with free drug and twofold compared with the Food and Drug Administration-approved taxane nanoformulation (Abraxane). The tumour uptake of the CP-PTX nanoparticle was fivefold greater than free drug and twofold greater than Abraxane. In a murine cancer model of human triple-negative breast cancer and prostate cancer, CP-PTX induced near-complete tumour regression after a single dose in both tumour models, whereas at the same dose, no mice treated with Abraxane survived for >80 days (breast) and 60 days (prostate), respectively. These results show that a molecularly engineered nanoparticle with precisely engineered design features outperforms Abraxane, the current gold standard for PTX delivery.

  1. Maternally Sequestered Therapeutic Polypeptides – A New Approach for the Management of Preeclampsia

    Directory of Open Access Journals (Sweden)

    Eric eGeorge

    2014-09-01

    Full Text Available The last several decades have seen intensive research into the molecular mechanisms underlying the symptoms of preeclampsia. While the underlying cause of preeclampsia is believed to be defective placental development and resulting placental ischemia, it is only recently that the links between the ischemic placenta and maternal symptomatic manifestation have been elucidated. Several different pathways have been implicated in the development of the disorder; most notably production of the anti-angiogenic protein sFlt-1, induction of auto-immunity and inflammation, and production of reactive oxygen species. While the molecular mechanisms are becoming clearer, translating that knowledge into effective therapeutics has proven elusive. Here we describe a number of peptide based therapies we have developed to target theses pathways, and which are currently being tested in preclinical models. These therapeutics are based on a synthetic polymeric carrier elastin-like polypeptide (ELP, which can be synthesized in various sequences and sizes to stabilize the therapeutic peptide and avoid crossing the placental interface. This prevents fetal exposure and potential developmental effects. The therapeutics designed will target known pathogenic pathways, and the ELP carrier could prove to be a versatile delivery system for administration of a variety of therapeutics during pregnancy.

  2. Engineering a recyclable elastin-like polypeptide capturing scaffold for non-chromatographic protein purification.

    Science.gov (United States)

    Liu, Fang; Chen, Wilfred

    2013-01-01

    Previously, we reported a non-chromatographic protein purification method exploiting the highly specific interaction between the dockerin and cohesin domains from Clostridium thermocellum and the reversible aggregation property of elastin-like polypeptide (ELP) to provide fast and cost-effective protein purification. However, the bound dockerin-intein tag cannot be completely dissociated from the ELP-cohesin capturing scaffold due to the high binding affinity, resulting in a single-use approach. In order to further reduce the purification cost by recycling the ELP capturing scaffold, a truncated dockerin domain with the calcium-coordinating function partially impaired was employed. We demonstrated that the truncated dockerin domain was sufficient to function as an effective affinity tag, and the target protein was purified directly from cell extracts in a single binding step followed by intein cleavage. The efficient EDTA-mediated dissociation of the bound dockerin-intein tag from the ELP-cohesin capturing scaffold was realized, and the regenerated ELP capturing scaffold was reused in another purification cycle without any decrease in the purification efficiency. This recyclable non-chromatographic based affinity method provides an attractive approach for efficient and cost-effective protein purification. © 2013 American Institute of Chemical Engineers.

  3. Induction of T-Cell Differentiation In Vitro by Thymin, a Purified Polypeptide Hormone of the Thymus

    Science.gov (United States)

    Basch, Ross S.; Goldstein, Gideon

    1974-01-01

    Thymin, a purified polypeptide isolated from bovine thymus, was shown to induce the expression of differentiation antigens characteristic of thymocytes [TL and Thy-1 (θ)] when incubated in vitro with mouse bone marrow or spleen cells. This induction occurred in 5-10% of the cells from bone marrow after a 2-hr incubation with subnanogram concentrations of thymin. The induced cells expressed more TL and Thy-1 (θ) antigens than average normal thymocytes. PMID:4545430

  4. Induction of a M/sub r/ 21,000 polypeptide in an Arthrobacter Sp. by dye-sensitized photooxidation

    International Nuclear Information System (INIS)

    Franzi, J.J.

    1985-01-01

    Irradiation of aerobic cultures of an Arthrobacter species with near-UV light and oxygen induced synthesis of a cell surface protein, M/sub r/ 21,000 polypeptide. Visible light, oxygen and a sensitizing dye were also effective in induction. Far-UV light, bleomycin and nalidixic acid, all inducers of the recA protein in Escherichia coli, were ineffective inducers of this protein. Furthermore, X-irradiation and radical-generating oxidants failed to induce synthesis of the M/sub r/ 21,000 polypeptide. DNA binding dyes proved to be capable of inducing synthesis of this protein or inhibiting dye-mediated stimulation of synthesis of this protein. For example, dGdC-specific dyes (e.g. methylene blue, neutral red, acridine orange or ethidium bromide) were efficient inducers of the M/sub r/ 21,000 polypeptide. Also methylene blue and neutral red were more efficient inducers than were acridine orange or ethidium bromide, which could be explained by the greater dGdC specificity and, possibly by the greater photoreactivity of methylene blue and neutral red. dAdT-specific dyes such as methyl green or daunomycin effectively inhibited dye-mediated induction. Rose bengal is an anionic dye which does not bind to DNA but does mediate the photooxidation of deoxyguanosine residues in DNA. It is an efficient inducer of the M/sub r/ 21,000 polypeptide. Induction with this dye is nearly eliminated when novobiocin, an inhibitor of DNA gyrase (topoisomerase II) which mediates relaxation, is added in conjunction with rose bengal

  5. Induction of a M/sub r/ 21,000 polypeptide in an Arthrobacter Sp. by dye-sensitized photooxidation

    Energy Technology Data Exchange (ETDEWEB)

    Franzi, J.J.

    1985-01-01

    Irradiation of aerobic cultures of an Arthrobacter species with near-UV light and oxygen induced synthesis of a cell surface protein, M/sub r/ 21,000 polypeptide. Visible light, oxygen and a sensitizing dye were also effective in induction. Far-UV light, bleomycin and nalidixic acid, all inducers of the recA protein in Escherichia coli, were ineffective inducers of this protein. Furthermore, X-irradiation and radical-generating oxidants failed to induce synthesis of the M/sub r/ 21,000 polypeptide. DNA binding dyes proved to be capable of inducing synthesis of this protein or inhibiting dye-mediated stimulation of synthesis of this protein. For example, dGdC-specific dyes (e.g. methylene blue, neutral red, acridine orange or ethidium bromide) were efficient inducers of the M/sub r/ 21,000 polypeptide. Also methylene blue and neutral red were more efficient inducers than were acridine orange or ethidium bromide, which could be explained by the greater dGdC specificity and, possibly by the greater photoreactivity of methylene blue and neutral red. dAdT-specific dyes such as methyl green or daunomycin effectively inhibited dye-mediated induction. Rose bengal is an anionic dye which does not bind to DNA but does mediate the photooxidation of deoxyguanosine residues in DNA. It is an efficient inducer of the M/sub r/ 21,000 polypeptide. Induction with this dye is nearly eliminated when novobiocin, an inhibitor of DNA gyrase (topoisomerase II) which mediates relaxation, is added in conjunction with rose bengal.

  6. Cellulose-binding polypeptides from Cellulomonas fimi: endoglucanase D (CenD), a family A beta-1,4-glucanase.

    Science.gov (United States)

    Meinke, A; Gilkes, N R; Kilburn, D G; Miller, R C; Warren, R A

    1993-01-01

    Five cellulose-binding polypeptides were detected in Cellulomonas fimi culture supernatants. Two of them are CenA and CenB, endo-beta-1,4-glucanases which have been characterized previously; the other three were previously uncharacterized polypeptides with apparent molecular masses of 120, 95, and 75 kDa. The 75-kDa cellulose-binding protein was designated endoglucanase D (CenD). The cenD gene was cloned and sequenced. It encodes a polypeptide of 747 amino acids. Mature CenD is 708 amino acids long and has a predicted molecular mass of 74,982 Da. Analysis of the predicted amino acid sequence of CenD shows that the enzyme comprises four domains which are separated by short linker polypeptides: an N-terminal catalytic domain of 405 amino acids, two repeated sequences of 95 amino acids each, and a C-terminal domain of 105 amino acids which is > 50% identical to the sequences of cellulose-binding domains in Cex, CenA, and CenB from C. fimi. Amino acid sequence comparison placed the catalytic domain of CenD in family A, subtype 1, of beta-1,4-glycanases. The repeated sequences are more than 40% identical to the sequences of three repeats in CenB and are related to the repeats of fibronectin type III. CenD hydrolyzed the beta-1,4-glucosidic bond with retention of anomeric configuration. The activities of CenD towards various cellulosic substrates were quite different from those of CenA and CenB. Images PMID:8458833

  7. Short term aerobic exercise training increases postprandial pancreatic polypeptide but not peptide YY concentrations in obese individuals

    OpenAIRE

    Kanaley, Jill A.; Heden, Timothy D.; Liu, Ying; Whaley-Connell, Adam T.; Chockalingam, Anand; Dellsperger, Kevin C.; Fairchild, Timothy J.

    2013-01-01

    Objective Short-term exercise training improves glycemic control, but the effect of short-term training on postprandial satiety peptide responses or perceived satiety remains unknown. We tested the hypothesis that short-term aerobic exercise training (15 days) would alter postprandial pancreatic and gut peptide [pancreatic polypeptide (PP) and peptide YY (PYY)] responses and perceived appetite and satiety in obese individuals. Subjects Thirteen healthy obese men and women (age: 42±2 y; BMI: 3...

  8. High saturated fatty acid intake induces insulin secretion by elevating gastric inhibitory polypeptide levels in healthy individuals

    DEFF Research Database (Denmark)

    Itoh, Kazue; Moriguchi, Ririko; Yamada, Yuichiro

    2014-01-01

    insulin and gastric inhibitory polypeptide (GIP) secretion. To clarify the effect of ingested fatty acid composition on glucose levels, we conducted an intervention study to investigate the insulin and plasma GIP responses in 11 healthy women, including a dietary control. Subjects were provided daily...... and FB-30 or F-30. However, insulin levels were higher after the FB-30 than after the F-20 (P incremental GIP between FB-30 and F-30 correlated significantly and positively...

  9. Expression and biological activity of two recombinant polypeptides related to subunit 1 of the interferon-a receptor

    Directory of Open Access Journals (Sweden)

    S. Yoon

    2000-07-01

    Full Text Available Abnormal production of interferon alpha (IFN-a has been found in certain autoimmune diseases and can be also observed after prolonged therapy with IFN-a. IFN-a can contribute to the pathogenesis of allograft rejection in bone marrow transplants. Therefore, the development of IFN-a inhibitors as a soluble receptor protein may be valuable for the therapeutic control of these diseases. We have expressed two polypeptides encoding amino acids 93-260 (P1 and 261-410 (P2 of the extracellular domain of subunit 1 of the interferon-a receptor (IFNAR 1-EC in E. coli. The activities of the recombinant polypeptides and of their respective antibodies were evaluated using antiproliferative and antiviral assays. Expression of P1 and P2 polypeptides was achieved by transformation of cloned plasmid pRSET A into E. coli BL21(DE3pLysS and by IPTG induction. P1 and P2 were purified by serial sonication steps and by gel filtration chromatography with 8 M urea and refolded by dialysis. Under reducing SDS-PAGE conditions, the molecular weight of P1 and P2 was 22 and 17 kDa, respectively. Polyclonal anti-P1 and anti-P2 antibodies were produced in mice. P1 and P2 and their respective polyclonal antibodies were able to block the antiproliferative activity of 6.25 nM IFN-aB on Daudi cells, but did not block IFN-aB activity at higher concentrations (>6.25 nM. On the other hand, the polypeptides and their respective antibodies did not inhibit the antiviral activity of IFN-aB on Hep 2/c cells challenged with encephalomyocarditis virus.

  10. A Bio-Inspired Two-Layer Sensing Structure of Polypeptide and Multiple-Walled Carbon Nanotube to Sense Small Molecular Gases

    Directory of Open Access Journals (Sweden)

    Li-Chun Wang

    2015-03-01

    Full Text Available In this paper, we propose a bio-inspired, two-layer, multiple-walled carbon nanotube (MWCNT-polypeptide composite sensing device. The MWCNT serves as a responsive and conductive layer, and the nonselective polypeptide (40 mer coating the top of the MWCNT acts as a filter into which small molecular gases pass. Instead of using selective peptides to sense specific odorants, we propose using nonselective, peptide-based sensors to monitor various types of volatile organic compounds. In this study, depending on gas interaction and molecular sizes, the randomly selected polypeptide enabled the recognition of certain polar volatile chemical vapors, such as amines, and the improved discernment of low-concentration gases. The results of our investigation demonstrated that the polypeptide-coated sensors can detect ammonia at a level of several hundred ppm and barely responded to triethylamine.

  11. Distinct localization of FMRFamide- and bovine pancreatic polypeptide-like material in the brain, retrocerebral complex and suboesophageal ganglion of the cockroach Periplaneta americana L

    DEFF Research Database (Denmark)

    Verhaert, P; Grimmelikhuijzen, C J; De Loof, A

    1985-01-01

    One bovine pancreatic polypeptide (BPP) antiserum and two FMRFamide antisera were applied in the peroxidase-antiperoxidase (PAP) immunohistochemical technique on a complete series of sections of brains, suboesophageal ganglia (SOG), corpora cardiaca (CC) and corpora allata of Periplaneta american...

  12. Preparation of Photocrosslinked Fish Elastin Polypeptide/Microfibrillated Cellulose Composite Gels with Elastic Properties for Biomaterial Applications

    Directory of Open Access Journals (Sweden)

    Shinya Yano

    2015-01-01

    Full Text Available Photocrosslinked hydrogels reinforced by microfibrillated cellulose (MFC were prepared from a methacrylate-functionalized fish elastin polypeptide and MFC dispersed in dimethylsulfoxide (DMSO. First, a water-soluble elastin peptide with a molecular weight of ca. 500 g/mol from the fish bulbus arteriosus was polymerized by N,N′-dicyclohexylcarbodiimide (DCC, a condensation reagent, and then modified with 2-isocyanatoethyl methacrylate (MOI to yield a photocrosslinkable fish elastin polypeptide. The product was dissolved in DMSO and irradiated with UV light in the presence of a radical photoinitiator. We obtained hydrogels successfully by substitution of DMSO with water. The composite gel with MFC was prepared by UV irradiation of the photocrosslinkable elastin polypeptide mixed with dispersed MFC in DMSO, followed by substitution of DMSO with water. The tensile test of the composite gels revealed that the addition of MFC improved the tensile properties, and the shape of the stress–strain curve of the composite gel became more similar to the typical shape of an elastic material with an increase of MFC content. The rheology measurement showed that the elastic modulus of the composite gel increased with an increase of MFC content. The cell proliferation test on the composite gel showed no toxicity.

  13. Preparation of photocrosslinked fish elastin polypeptide/microfibrillated cellulose composite gels with elastic properties for biomaterial applications.

    Science.gov (United States)

    Yano, Shinya; Mori, Megumi; Teramoto, Naozumi; Iisaka, Makoto; Suzuki, Natsumi; Noto, Masanari; Kaimoto, Yasuko; Kakimoto, Masashi; Yamada, Michio; Shiratsuchi, Eri; Shimasaki, Toshiaki; Shibata, Mitsuhiro

    2015-01-09

    Photocrosslinked hydrogels reinforced by microfibrillated cellulose (MFC) were prepared from a methacrylate-functionalized fish elastin polypeptide and MFC dispersed in dimethylsulfoxide (DMSO). First, a water-soluble elastin peptide with a molecular weight of ca. 500 g/mol from the fish bulbus arteriosus was polymerized by N,N'-dicyclohexylcarbodiimide (DCC), a condensation reagent, and then modified with 2-isocyanatoethyl methacrylate (MOI) to yield a photocrosslinkable fish elastin polypeptide. The product was dissolved in DMSO and irradiated with UV light in the presence of a radical photoinitiator. We obtained hydrogels successfully by substitution of DMSO with water. The composite gel with MFC was prepared by UV irradiation of the photocrosslinkable elastin polypeptide mixed with dispersed MFC in DMSO, followed by substitution of DMSO with water. The tensile test of the composite gels revealed that the addition of MFC improved the tensile properties, and the shape of the stress-strain curve of the composite gel became more similar to the typical shape of an elastic material with an increase of MFC content. The rheology measurement showed that the elastic modulus of the composite gel increased with an increase of MFC content. The cell proliferation test on the composite gel showed no toxicity.

  14. Potential immunogenic polypeptides of Burkholderia pseudomallei identified by shotgun expression library and evaluation of their efficacy for serodiagnosis of melioidosis.

    Science.gov (United States)

    Puah, Suat Moi; Puthucheary, S D; Chua, Kek Heng

    2013-01-01

    The search for novel immunogenic polypeptides to improve the accuracy and reliability of serologic diagnostic methods for Burkholderia pseudomallei infection is ongoing. We employed a rapid and efficient approach to identify such polypeptides with sera from melioidosis patients using a small insert genomic expression library created from clinically confirmed local virulent isolates of B. pseudomallei. After 2 rounds of immunoscreening, 6 sero-positive clones expressing immunogenic peptides were sequenced and their identities were: benzoate 1,2-dioxygenase beta subunit, a putative 200 kDa antigen p200, phosphotransferase enzyme family protein, short chain dehydrogenase and 2 hypothetical proteins. These immunogens were then transferred to an ELISA platform for further large scale screening. By combining shotgun expression library and ELISA assays, we identified 2 polypeptides BPSS1904 (benzoate 1,2-dioxygenase beta subunit) and BPSL3130 (hypothetical protein), which had sensitivities of 78.9% and 79.4% and specificities of 88.1% and 94.8%, respectively in ELISA test, thus suggesting that both are potential candidate antigens for the serodiagnosis of infections caused by B. pseudomallei.

  15. Polyphenols and Polypeptides in Chinese Rice Wine Inhibit Homocysteine-induced Proliferation and Migration of Vascular Smooth Muscle Cells.

    Science.gov (United States)

    Meng, Liping; Liu, Longbin; Zhou, Changzuan; Pan, Sunlei; Zhai, Xiaoya; Jiang, Chengjian; Guo, Yan; Ji, Zheng; Chi, Jufang; Peng, Fang; Guo, Hangyuan

    2016-06-01

    The beneficial effect of Chinese rice wine on atherosclerosis has been proved, but the exact components that have the cardiovascular protective effect are still unknown. This study aimed to explore the exact ingredients in Chinese rice wine that could inhibit homocysteine (Hcy)-induced vascular smooth muscle cell (VSMC) proliferation and migration. VSMCs were divided into 7 groups: control, Hcy (1 mmol/L), Hcy + oligosaccharide, Hcy + polypeptides, Hcy + polyphenols, Hcy + alcohol, and Hcy + Chinese rice wine. methyl thiazolyl tetrazolium (MTT) assay, Transwell chambers, and wound-healing assay were used to test the proliferation and migratory ability of the VSMCs. Western blot and gelatin zymography were used to investigate the expressions and activities of metal matrix proteinase 2/9 (MMP-2/9) and tissue inhibitor of metalloproteinase 2 (TIMP-2) in VSMCs. Polypeptides and polyphenols in the Chinese rice wine reduced the proliferation and migration ability of the VSMCs. Furthermore, they also decreased the expression and activity of MMP-2/9 but had no obvious impact on the expression of TIMP-2 in each group. This study further confirms that polypeptides and polyphenols in the Chinese rice wine could inhibit Hcy-induced proliferation and migration of VSMCs and maintain the balance between matrix metalloproteinases (MMPs) and TIMPs.

  16. Bacterial expression and/or solid phase peptide synthesis of 20-40 amino acid long polypeptides and miniproteins, the case study of Class B GPCR ligands.

    Science.gov (United States)

    Stráner, Pál; Taricska, Nóra; Szabó, Mária; Tóth, Gábor K; Perczel, András

    2016-01-01

    By using two different synthetic techniques several polypeptides interacting with Class B type G-protein coupled receptors were prepared. These polypeptides of different lengths (20 ≤ amino acids ≤ 40), structural and aggregation properties, were prepared both by solid phase peptide synthesis (SPPS) and E.coli bacterial expression. Their purity, synthetic yields, by-products and (15)N/(13)Clabelling characteristics were compared as function of i) the applied method, ii) amino acid length and iii) folding propensities. Their tentative yields, costs and "environmental footprints" were analyzed and found as follows. For unlabelled and short polypeptides (n= 20 aa.) the method of choice is the less environmentally friendly however, quick and effective SPPS. If the polypeptide is (un)folded and/or has no aggregation propensity, then SPPS gives relatively good yield (e.g. 14 ± 4%) and a pure product (>97%). For aggregating polypeptides production yields drop for both methods 4 ± 2% (SPPS) and 2 ± 1% (E. coli), respectively. For longer (n≥ 30 aa.) macromolecules (e.g. miniproteins) bacterial expression efficacy gets higher. Moreover biotechnology is "greener", the resulting in raw material is purer (2.8 ± 1.5 mg). All these advantages for at a lower cost: ~4 €/aa. If isotopic labelling is needed for heteronuclear NMR measurements, bacterial expression is the sole option, due to the high cost of (15)N/(13)C labelled Fmoc(Boc)-L-aa-OH starting materials needed for SPPS. In E.coli uniformly double-labelled, pure polypeptides can be obtained for less than 5-700 €/mg, regardless of the length of the polypeptide chain. Thus, chemists are encouraged to use E.coli expression systems when adequate to make not only proteins but polypeptides and miniproteins as well.

  17. “Splicing up” drug discovery. Cell-Based Expression and Screening of Genetically-Encoded Libraries of Backbone Cyclized Polypeptides

    Science.gov (United States)

    Sancheti, Harshkumar; Camarero, Julio A.

    2012-01-01

    The present paper reviews the use of protein splicing for the biosynthesis of backbone cyclic polypeptides. This general method allows the in vivo and in vitro biosynthesis of cyclic polypeptides using recombinant DNA expression techniques. Biosynthetic access to backbone cyclic peptides opens the possibility to generate cell-based combinatorial libraries that can be screened inside living cells for their ability to attenuate or inhibit cellular processes thus providing a new way for finding therapeutic agents. PMID:19628015

  18. Gas transport in graphitic materials

    International Nuclear Information System (INIS)

    Hoinkis, E.

    1995-02-01

    The characterization of the gas transport properties of porous solids is of interest in several fields of science and technology. Many catalysts, adsorbents, soils, graphites and carbons are porous. The gas transport through most porous solids can be well described by the dusty gas model invented by Evans, Watson and Mason. This model includes all modes of gas tranport under steady-state conditions, which are Knudsen diffusion, combined Knudsen/continuum diffusion and continuum diffusion, both for gas pairs with equal and different molecular weights. In the absence of a pressure difference gas transport in a pore system can be described by the combined Knudsen/continuum diffusion coefficient D 1 for component 1 in the pores, the Knudsen diffusion coefficient D 1K in the pores, and the continuum diffusion coefficient D 12 for a binary mixture in the pores. The resistance to stationary continuum diffusion of the pores is characterized by a geometrical factor (ε/τ) 12 = (ε/τ)D 12 , were D 12 is the continuum diffusion coefficient for a binary mixture in free space. The Wicke-Kallenbach method was often used to measure D 1 as function of pressure. D 12 and D 1K can be derived from a plot 1/D 1 νs P, and ε/τcan be calculated since D 12 is known. D 1K and the volume of dead end pores can be derived from transient measurements of the diffusional flux at low pressures. From D 1K the expression (ε/τ c ) anti l por may be calculated, which characterizes the pore system for molecular diffusion, where collisions with the pore walls are predominant. (orig.)

  19. Neurotransmitter transporters

    DEFF Research Database (Denmark)

    Gether, Ulrik; Andersen, Peter H; Larsson, Orla M

    2006-01-01

    The concentration of neurotransmitters in the extracellular space is tightly controlled by distinct classes of membrane transport proteins. This review focuses on the molecular function of two major classes of neurotransmitter transporter that are present in the cell membrane of neurons and....../or glial cells: the solute carrier (SLC)1 transporter family, which includes the transporters that mediate the Na(+)-dependent uptake of glutamate, and the SLC6 transporter family, which includes the transporters that mediate the Na(+)-dependent uptake of dopamine, 5-HT, norepinephrine, glycine and GABA....... Recent research has provided substantial insight into the structure and function of these transporters. In particular, the recent crystallizations of bacterial homologs are of the utmost importance, enabling the first reliable structural models of the mammalian neurotransmitter transporters...

  20. Structural specificity of mucosal-cell transport and metabolism of peptide drugs: implication for oral peptide drug delivery

    Science.gov (United States)

    Bai, J. P.; Amidon, G. L.

    1992-01-01

    The brush border membrane of intestinal mucosal cells contains a peptide carrier system with rather broad substrate specificity and various endo- and exopeptidase activities. Small peptide (di-/tripeptide)-type drugs with or without an N-terminal alpha-amino group, including beta-lactam antibiotics and angiotensin-converting enzyme (ACE) inhibitors, are transported by the peptide transporter. Polypeptide drugs are hydrolyzed by brush border membrane proteolytic enzymes to di-/tripeptides and amino acids. Therefore, while the intestinal brush border membrane has a carrier system facilitating the absorption of di-/tripeptide drugs, it is a major barrier limiting oral availability of polypeptide drugs. In this paper, the specificity of peptide transport and metabolism in the intestinal brush border membrane is reviewed.

  1. Chemical synthesis of a polypeptide backbone derived from the primary sequence of the cancer protein NY-ESO-1 enabled by kinetically controlled ligation and pseudoprolines.

    Science.gov (United States)

    Harris, Paul W R; Brimble, Margaret A

    2015-03-01

    The cancer protein NY-ESO-1 has been shown to be one of the most promising vaccine candidates although little is known about its cellular function. Using a chemical protein strategy, the 180 amino acid polypeptide, tagged with an arginine solubilizing tail, was assembled in a convergent manner from four unprotected peptide α-thioester peptide building blocks and one cysteinyl polypeptide, which were in turn prepared by Boc and Fmoc solid phase peptide synthesis (SPPS) respectively. To facilitate the assembly by ligation chemistries, non-native cysteines were introduced as chemical handles into the polypeptide fragments; pseudoproline dipeptides and microwave assisted Fmoc SPPS were crucial techniques to prepare the challenging hydrophobic C-terminal fragment. Three sequential kinetically controlled ligations, which exploited the reactivity between peptide arylthioesters and peptide alkylthioesters, were then used in order to assemble the more tractable N-terminal region of NY-ESO-1. The ensuing 147 residue polypeptide thioester then underwent successful final native chemical ligation with the very hydrophobic C-terminal polypeptide bearing an N-terminal cysteine affording the 186 residue polypeptide as an advanced intermediate en route to the native NY-ESO-1 protein. © 2015 Wiley Periodicals, Inc.

  2. Interactions driving the collapse of islet amyloid polypeptide: Implications for amyloid aggregation

    Science.gov (United States)

    Cope, Stephanie M.

    Human islet amyloid polypeptide (hIAPP), also known as amylin, is a 37-residue intrinsically disordered hormone involved in glucose regulation and gastric emptying. The aggregation of hIAPP into amyloid fibrils is believed to play a causal role in type 2 diabetes. To date, not much is known about the monomeric state of hIAPP or how it undergoes an irreversible transformation from disordered peptide to insoluble aggregate. IAPP contains a highly conserved disulfide bond that restricts hIAPP(1-8) into a short ring-like structure: N_loop. Removal or chemical reduction of N_loop not only prevents cell response upon binding to the CGRP receptor, but also alters the mass per length distribution of hIAPP fibers and the kinetics of fibril formation. The mechanism by which N_loop affects hIAPP aggregation is not yet understood, but is important for rationalizing kinetics and developing potential inhibitors. By measuring end-to-end contact formation rates, Vaiana et al. showed that N_loop induces collapsed states in IAPP monomers, implying attractive interactions between N_loop and other regions of the disordered polypeptide chain . We show that in addition to being involved in intra-protein interactions, the N_loop is involved in inter-protein interactions, which lead to the formation of extremely long and stable beta-turn fibers. These non-amyloid fibers are present in the 10 muM concentration range, under the same solution conditions in which hIAPP forms amyloid fibers. We discuss the effect of peptide cyclization on both intra- and inter-protein interactions, and its possible implications for aggregation. Our findings indicate a potential role of N_loop-N_loop interactions in hIAPP aggregation, which has not previously been explored. Though our findings suggest that N_loop plays an important role in the pathway of amyloid formation, other naturally occurring IAPP variants that contain this structural feature are incapable of forming amyloids. For example, hIAPP readily

  3. Pituitary adenylate cyclase-activating polypeptide promotes eccrine gland sweat secretion.

    Science.gov (United States)

    Sasaki, S; Watanabe, J; Ohtaki, H; Matsumoto, M; Murai, N; Nakamachi, T; Hannibal, J; Fahrenkrug, J; Hashimoto, H; Watanabe, H; Sueki, H; Honda, K; Miyazaki, A; Shioda, S

    2017-02-01

    Sweat secretion is the major function of eccrine sweat glands; when this process is disturbed (paridrosis), serious skin problems can arise. To elucidate the causes of paridrosis, an improved understanding of the regulation, mechanisms and factors underlying sweat production is required. Pituitary adenylate cyclase-activating polypeptide (PACAP) exhibits pleiotropic functions that are mediated via its receptors [PACAP-specific receptor (PAC1R), vasoactive intestinal peptide (VIP) receptor type 1 (VPAC1R) and VPAC2R]. Although some studies have suggested a role for PACAP in the skin and several exocrine glands, the effects of PACAP on the process of eccrine sweat secretion have not been examined. To investigate the effect of PACAP on eccrine sweat secretion. Reverse transcriptase-polymerase chain reaction and immunostaining were used to determine the expression and localization of PACAP and its receptors in mouse and human eccrine sweat glands. We injected PACAP subcutaneously into the footpads of mice and used the starch-iodine test to visualize sweat-secreting glands. Immunostaining showed PACAP and PAC1R expression by secretory cells from mouse and human sweat glands. PACAP immunoreactivity was also localized in nerve fibres around eccrine sweat glands. PACAP significantly promoted sweat secretion at the injection site, and this could be blocked by the PAC1R-antagonist PACAP6-38. VIP, an agonist of VPAC1R and VPAC2R, failed to induce sweat secretion. This is the first report demonstrating that PACAP may play a crucial role in sweat secretion via its action on PAC1R located in eccrine sweat glands. The mechanisms underlying the role of PACAP in sweat secretion may provide new therapeutic options to combat sweating disorders. © 2016 British Association of Dermatologists.

  4. Human islet amyloid polypeptide fibril binding to catalase: a transmission electron microscopy and microplate study.

    Science.gov (United States)

    Milton, Nathaniel G N; Harris, J Robin

    2010-05-18

    The diabetes-associated human islet amyloid polypeptide (IAPP) is a 37-amino-acid peptide that forms fibrils in vitro and in vivo. Human IAPP fibrils are toxic in a similar manner to Alzheimer's amyloid-beta (A-beta) and prion protein (PrP) fibrils. Previous studies have shown that catalase binds to A-beta fibrils and appears to recognize a region containing the Gly-Ala-Ile-Ile sequence that is similar to the Gly-Ala-Ile-Leu sequence found in human IAPP residues 24-27. This study presents a transmission electron microscopy (TEM)-based analysis of fibril formation and the binding of human erythrocyte catalase to IAPP fibrils. The results show that human IAPP 1-37, 8-37, and 20-29 peptides form fibrils with diverse and polymorphic structures. All three forms of IAPP bound catalase, and complexes of IAPP 1-37 or 8-37 with catalase were identified by immunoassay. The binding of biotinylated IAPP to catalase was high affinity with a KD of 0.77 nM, and could be inhibited by either human or rat IAPP 1-37 and 8-37 forms. Fibrils formed by the PrP 118-135 peptide with a Gly-Ala-Val-Val sequence also bound catalase. These results suggest that catalase recognizes a Gly-Ala-Ile-Leu-like sequence in amyloid fibril-forming peptides. For IAPP 1-37 and 8-37, the catalase binding was primarily directed towards fibrillar rather than ribbon-like structures, suggesting differences in the accessibility of the human IAPP 24-27 Gly-Ala-Ile-Leu region. This suggests that catalase may be able to discriminate between different structural forms of IAPP fibrils. The ability of catalase to bind IAPP, A-beta, and PrP fibrils demonstrates the presence of similar accessible structural motifs that may be targets for antiamyloid therapeutic development.

  5. Protein body formation in stable transgenic tobacco expressing elastin-like polypeptide and hydrophobin fusion proteins.

    Science.gov (United States)

    Gutiérrez, Sonia P; Saberianfar, Reza; Kohalmi, Susanne E; Menassa, Rima

    2013-05-10

    Plants are recognized as an efficient and inexpensive system to produce valuable recombinant proteins. Two different strategies have been commonly used for the expression of recombinant proteins in plants: transient expression mediated by Agrobacterium; or stable transformation of the plant genome. However, the use of plants as bioreactors still faces two main limitations: low accumulation levels of some recombinant proteins and lack of efficient purification methods. Elastin-like polypeptide (ELP), hydrophobin I (HFBI) and Zera® are three fusion partners found to increase the accumulation levels of recombinant proteins and induce the formation of protein bodies (PBs) in leaves when targeted to the endoplasmic reticulum (ER) in transient expression assays. In this study the effects of ELP and HFBI fusion tags on recombinant protein accumulation levels and PB formation was examined in stable transgenic Nicotiana tabacum. The accumulation of recombinant protein and PB formation was evaluated in two cultivars of Nicotiana tabacum transformed with green fluorescent protein (GFP) fused to ELP or HFBI, both targeted and retrieved to the ER. The ELP and HFBI tags increased the accumulation of the recombinant protein and induced the formation of PBs in leaves of stable transgenic plants from both cultivars. Furthermore, these tags induced the formation of PBs in a concentration-dependent manner, where a specific level of recombinant protein accumulation was required for PBs to appear. Moreover, agro-infiltration of plants accumulating low levels of recombinant protein with p19, a suppressor of post-transcriptional gene silencing (PTGS), increased accumulation levels in four independent transgenic lines, suggesting that PTGS might have caused the low accumulation levels in these plants. The use of ELP and HFBI tags as fusion partners in stable transgenic plants of tobacco is feasible and promising. In a constitutive environment, these tags increase the accumulation levels

  6. Renoprotection by pituitary adenylate cyclase-activating polypeptide in multiple myeloma and other kidney diseases.

    Science.gov (United States)

    Li, Min; Maderdrut, Jerome L; Lertora, Juan J L; Arimura, Akira; Batuman, Vecihi

    2008-01-10

    Renal involvement in patients with multiple myeloma complicates their treatment and shortens their life-span. The main renal lesion is a tubulointerstitial transformation with fibrosis, frequently associated with cast formation in the distal nephron that results from co-precipitation of pathological immunoglobulin light chains with Tamm-Horsfall proteins. The human renal proximal tubular reabsorption of excessive light chains by endocytosis causes cellular protein overload and activates the transcription factor nuclear factor kappa B (NFkappaB). The activation of NFkappaB promotes the synthesis of inflammatory cytokines and activates signaling pathways, such as mitogen-activated protein kinases (MAPKs), extracellular signal-regulated kinase 1/2, Jun kinase, and p38 MAPK, thus promoting interstitial inflammation and fibrosis. We tested the concept that pituitary adenylate cyclase-activating polypeptide (PACAP), a member of the secretin/vasoactive intestinal peptide family, could prevent the development of cast nephropathies. PACAP38 inhibited myeloma light chain-induced proinflammatory cytokine expression with greater potency than dexamethasone, and attenuated the resulting cell damage in the renal proximal tubule epithelial cells. The results indicated that its effects are mediated through inhibition of phosphorylation of p38 MAPK and nuclear translocation of the p50 subunit of NFkappaB via both the PAC(1) and VPAC(1) receptors. PACAP was also shown to be efficacious in other common in vivo animal models for kidney hypertrophies, including streptozotocin-induced diabetic nephropathy and gentamicin-induced nephrotoxicity. Thus, our studies suggest that PACAP38 could be used as a cytoprotective agent that would be effective in the treatment of renal tubule injury in multiple myeloma and other chronic kidney diseases.

  7. Pituitary adenylate cyclase activating polypeptide modulates catecholamine storage and exocytosis in PC12 cells.

    Directory of Open Access Journals (Sweden)

    Yan Dong

    Full Text Available A number of efforts have been made to understand how pituitary adenylate cyclase activating polypeptide (PACAP functions as a neurotrophic and neuroprotective factor in Parkinson's disease (PD. Recently its effects on neurotransmission and underlying mechanisms have generated interest. In the present study, we investigate the effects of PACAP on catecholamine storage and secretion in PC12 cells with amperometry and transmission electron microscopy (TEM. PACAP increases quantal release induced by high K+ without significantly regulating the frequency of vesicle fusion events. TEM data indicate that the increased volume of the vesicle is mainly the result of enlargement of the fluidic space around the dense core. Moreover, the number of docked vesicles isn't modulated by PACAP. When cells are acutely treated with L-DOPA, the vesicular volume and quantal release both increase dramatically. It is likely that the characteristics of amperometric spikes from L-DOPA treated cells are associated with increased volume of individual vesicles rather than a direct effect on the mechanics of exocytosis. Treatment with PACAP versus L-DOPA results in different profiles of the dynamics of exocytosis. Release via the fusion pore prior to full exocytosis was observed with the same frequency following treatment with PACAP and L-DOPA. However, release events have a shorter duration and higher average current after PACAP treatment compared to L-DOPA. Furthermore, PACAP reduced the proportion of spikes having rapid decay time and shortened the decay time of both fast and slow spikes. In contrast, the distributions of the amperometric spike decay for both fast and slow spikes were shifted to longer time following L-DOPA treatment. Compared to L-DOPA, PACAP may produce multiple favorable effects on dopaminergic neurons, including protecting dopaminergic neurons against neurodegeneration and potentially regulating dopamine storage and release, making it a promising

  8. Enhancement of +1 frameshift by polyamines during translation of polypeptide release factor 2 in Escherichia coli.

    Science.gov (United States)

    Higashi, Kyohei; Kashiwagi, Keiko; Taniguchi, Shiho; Terui, Yusuke; Yamamoto, Kaneyoshi; Ishihama, Akira; Igarashi, Kazuei

    2006-04-07

    Polypeptide release factor 2 (RF2) in Escherichia coli is known to be synthesized by a +1 frameshift at the 26th UGA codon of RF2 mRNA. Polyamines were found to stimulate the +1 frameshift of RF2 synthesis, an effect that was reduced by excess RF2. Polyamine stimulation of +1 frameshift of RF2 synthesis was observed at the early logarithmic phase, which is the important phase in determination of the overall rate of cell growth. A Shine-Dalgarno-like sequence was necessary for an efficient +1 frameshift of RF2 synthesis, but not for polyamine stimulation. Spectinomycin, tetracycline, streptomycin, and neomycin reduced polyamine stimulation of the +1 frameshift of RF2 synthesis. The results suggest that a structural change of the A site on 30 S ribosomal subunits is important for polyamine stimulation of the +1 frameshift. The level of mRNAs of ribosomal proteins and elongation factors having UAA as termination codon was enhanced by polyamines, and OppA synthesis from OppA mRNA having UAA as termination codon was more enhanced by polyamines than that from OppA mRNA having a UGA termination codon. Furthermore, synthesis of ribosomal protein L20 and elongation factor G from the mRNAs having a UAA termination codon was enhanced by polyamines at the level of translation and transcription. The results suggest that some protein synthesis from mRNAs having a UAA termination codon is enhanced at the level of translation through polyamine stimulation of +1 frameshift of RF2 synthesis. It is concluded that prfB encoding RF2 is a new member of the polyamine modulon.

  9. Vibrational infrared and Raman spectra of polypeptides: Fragments-in-fragments within molecular tailoring approach

    Energy Technology Data Exchange (ETDEWEB)

    Sahu, Nityananda; Gadre, Shridhar R., E-mail: gadre@iitk.ac.in [Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur 208 016 (India)

    2016-03-21

    The present work reports the calculation of vibrational infrared (IR) and Raman spectra of large molecular systems employing molecular tailoring approach (MTA). Further, it extends the grafting procedure for the accurate evaluation of IR and Raman spectra of large molecular systems, employing a new methodology termed as Fragments-in-Fragments (FIF), within MTA. Unlike the previous MTA-based studies, the accurate estimation of the requisite molecular properties is achieved without performing any full calculations (FC). The basic idea of the grafting procedure is implemented by invoking the nearly basis-set-independent nature of the MTA-based error vis-à-vis the respective FCs. FIF has been tested out for the estimation of the above molecular properties for three isomers, viz., β-strand, 3{sub 10}- and α-helix of acetyl(alanine){sub n}NH{sub 2} (n = 10, 15) polypeptides, three conformers of doubly protonated gramicidin S decapeptide and trpzip2 protein (PDB id: 1LE1), respectively, employing BP86/TZVP, M06/6-311G**, and M05-2X/6-31G** levels of theory. For most of the cases, a maximum difference of 3 cm{sup −1} is achieved between the grafted-MTA frequencies and the corresponding FC values. Further, a comparison of the BP86/TZVP level IR and Raman spectra of α-helical (alanine){sub 20} and its N-deuterated derivative shows an excellent agreement with the existing experimental spectra. In view of the requirement of only MTA-based calculations and the ability of FIF to work at any level of theory, the current methodology provides a cost-effective solution for obtaining accurate spectra of large molecular systems.

  10. A New in Vitro Anti-Tumor Polypeptide Isolated from Arca inflata

    Directory of Open Access Journals (Sweden)

    Jian Xu

    2013-12-01

    Full Text Available A new in vitro anti-tumor polypeptide, coded as J2-C3, was isolated from Arca inflata Reeve and purified by diethyl-aminoethanol (DEAE-sepharose Fast Flow anion exchange and phenyl sepharose CL-4B hydrophobic chromatography. J2-C3 was identified to be a homogeneous compound by native polyacrylamide gel electrophoresis (Native-PAGE. The purity of J2-C3 was over 99% in reversed phase-high performance liquid chromatography (RP-HPLC. The molecular weight was determined as 20,538.0 Da by electrospray-ionization mass spectrometry (ESI-MS/MS. J2-C3 was rich in Glx (Gln + Glu, Lys, and Asx (Asp + Asn according to amino acid analysis. Four partial amino acid sequences of this peptide were determined as L/ISMEDVEESR, KNGMHSI/LDVNHDGR, AMKI/LI/LNPKKGI/LVPR and AMGAHKPPKGNEL/IGHR via MALDI-TOF/TOF-MS and de novo sequencing. Secondary structural analysis by CD spectroscopy revealed that J2-C3 had the α-helix (45.2%, β-sheet (2.9%, β-turn (26.0% and random coil (25.9%. The anti-tumor effect of J2-C3 against human tumor cells was measured by 3-(4,5-dimethylthiazol-2-yl-2,5-diphenyltetrazolium bromide (MTT assay, and the IC50 values of J2-C3 were 65.57, 93.33 and 122.95 µg/mL against A549, HT-29 and HepG2 cell lines, respectively. Therefore, J2-C3 might be developed as a potential anti-tumor agent.

  11. Pituitary Adenylate-Cyclase Activating Polypeptide Regulates Hunger- and Palatability-Induced Binge Eating

    Directory of Open Access Journals (Sweden)

    Matthew M. Hurley

    2016-08-01

    Full Text Available While pituitary adenylate cyclase activating polypeptide (PACAP signaling in the hypothalamic ventromedial nuclei (VMN has been shown to regulate feeding, a challenge in unmasking a role for this peptide in obesity is that excess feeding can involve numerous mechanisms including homeostatic (hunger and hedonic-related (palatability drives. In these studies, we first isolated distinct feeding drives by developing a novel model of binge behavior in which homeostatic-driven feeding was temporally separated from feeding driven by food palatability. We found that stimulation of the VMN, achieved by local microinjections of AMPA, decreased standard chow consumption in food-restricted rats (e.g., homeostatic feeding; surprisingly, this manipulation failed to alter palatable food consumption in satiated rats (e.g., hedonic feeding. In contrast, inhibition of the nucleus accumbens (NAc, through local microinjections of GABA receptor agonists baclofen and muscimol, decreased hedonic feeding without altering homeostatic feeding. PACAP microinjections produced the site-specific changes in synaptic transmission needed to decrease feeding via VMN or NAc circuitry. PACAP into the NAc mimicked the actions of GABA agonists by reducing hedonic feeding without altering homeostatic feeding. In contrast, PACAP into the VMN mimicked the actions of AMPA by decreasing homeostatic feeding without affecting hedonic feeding. Slice electrophysiology recordings verified PACAP excitation of VMN neurons and inhibition of NAc neurons. These data suggest that the VMN and NAc regulate distinct circuits giving rise to unique feeding drives, but that both can be regulated by the neuropeptide PACAP to potentially curb excessive eating stemming from either drive.

  12. Studies on the role of insect hemolymph polypeptides: Galleria mellonella anionic peptide 2 and lysozyme.

    Science.gov (United States)

    Sowa-Jasiłek, Aneta; Zdybicka-Barabas, Agnieszka; Stączek, Sylwia; Wydrych, Jerzy; Mak, Paweł; Jakubowicz, Teresa; Cytryńska, Małgorzata

    2014-03-01

    The lysozymes are well known antimicrobial polypeptides exhibiting antibacterial and antifungal activities. Their antibacterial potential is related to muramidase activity and non-enzymatic activity resembling the mode of action of cationic defense peptides. However, the mechanisms responsible for fungistatic and/or fungicidal activity of lysozyme are still not clear. In the present study, the anti-Candida albicans activity of Galleria mellonella lysozyme and anionic peptide 2 (AP2), defense factors constitutively present in the hemolymph, was examined. The lysozyme inhibited C. albicans growth in a dose-dependent manner. The decrease in the C. albicans survival rate caused by the lysozyme was accompanied by a considerable reduction of the fungus metabolic activity, as revealed by LIVE/DEAD staining. In contrast, although AP2 reduced C. albicans metabolic activity, it did not influence its survival rate. Our results suggest fungicidal action of G. mellonella lysozyme and fungistatic activity of AP2 toward C. albicans cells. In the presence of AP2, the anti-C. albicans activity of G. mellonella lysozyme increased. Moreover, when the fungus was incubated with both defense factors, true hyphae were observed besides pseudohyphae and yeast-like C. albicans cells. Atomic force microscopy analysis of the cells exposed to the lysozyme and/or AP2 revealed alterations in the cell surface topography and properties in comparison with the control cells. The results indicate synergistic action of G. mellonella AP2 and lysozyme toward C. albicans. The presence of both factors in the hemolymph of naive larvae suggests their important role in the early stages of immune response against fungi in G. mellonella. Copyright © 2014 Elsevier Inc. All rights reserved.

  13. Vibrational infrared and Raman spectra of polypeptides: Fragments-in-fragments within molecular tailoring approach

    Science.gov (United States)

    Sahu, Nityananda; Gadre, Shridhar R.

    2016-03-01

    The present work reports the calculation of vibrational infrared (IR) and Raman spectra of large molecular systems employing molecular tailoring approach (MTA). Further, it extends the grafting procedure for the accurate evaluation of IR and Raman spectra of large molecular systems, employing a new methodology termed as Fragments-in-Fragments (FIF), within MTA. Unlike the previous MTA-based studies, the accurate estimation of the requisite molecular properties is achieved without performing any full calculations (FC). The basic idea of the grafting procedure is implemented by invoking the nearly basis-set-independent nature of the MTA-based error vis-à-vis the respective FCs. FIF has been tested out for the estimation of the above molecular properties for three isomers, viz., β-strand, 310- and α-helix of acetyl(alanine)nNH2 (n = 10, 15) polypeptides, three conformers of doubly protonated gramicidin S decapeptide and trpzip2 protein (PDB id: 1LE1), respectively, employing BP86/TZVP, M06/6-311G**, and M05-2X/6-31G** levels of theory. For most of the cases, a maximum difference of 3 cm-1 is achieved between the grafted-MTA frequencies and the corresponding FC values. Further, a comparison of the BP86/TZVP level IR and Raman spectra of α-helical (alanine)20 and its N-deuterated derivative shows an excellent agreement with the existing experimental spectra. In view of the requirement of only MTA-based calculations and the ability of FIF to work at any level of theory, the current methodology provides a cost-effective solution for obtaining accurate spectra of large molecular systems.

  14. Chaperones ameliorate beta cell dysfunction associated with human islet amyloid polypeptide overexpression.

    Directory of Open Access Journals (Sweden)

    Lisa Cadavez

    Full Text Available In type 2 diabetes, beta-cell dysfunction is thought to be due to several causes, one being the formation of toxic protein aggregates called islet amyloid, formed by accumulations of misfolded human islet amyloid polypeptide (hIAPP. The process of hIAPP misfolding and aggregation is one of the factors that may activate the unfolded protein response (UPR, perturbing endoplasmic reticulum (ER homeostasis. Molecular chaperones have been described to be important in regulating ER response to ER stress. In the present work, we evaluate the role of chaperones in a stressed cellular model of hIAPP overexpression. A rat pancreatic beta-cell line expressing hIAPP exposed to thapsigargin or treated with high glucose and palmitic acid, both of which are known ER stress inducers, showed an increase in ER stress genes when compared to INS1E cells expressing rat IAPP or INS1E control cells. Treatment with molecular chaperone glucose-regulated protein 78 kDa (GRP78, also known as BiP or protein disulfite isomerase (PDI, and chemical chaperones taurine-conjugated ursodeoxycholic acid (TUDCA or 4-phenylbutyrate (PBA, alleviated ER stress and increased insulin secretion in hIAPP-expressing cells. Our results suggest that the overexpression of hIAPP induces a stronger response of ER stress markers. Moreover, endogenous and chemical chaperones are able to ameliorate induced ER stress and increase insulin secretion, suggesting that improving chaperone capacity can play an important role in improving beta-cell function in type 2 diabetes.

  15. Drosophila Melanogaster as a Model System for Studies of Islet Amyloid Polypeptide Aggregation

    Science.gov (United States)

    Schultz, Sebastian Wolfgang; Nilsson, K. Peter R.; Westermark, Gunilla Torstensdotter

    2011-01-01

    Background Recent research supports that aggregation of islet amyloid polypeptide (IAPP) leads to cell death and this makes islet amyloid a plausible cause for the reduction of beta cell mass, demonstrated in patients with type 2 diabetes. IAPP is produced by the beta cells as a prohormone, and proIAPP is processed into IAPP by the prohormone convertases PC1/3 and PC2 in the secretory granules. Little is known about the pathogenesis for islet amyloid and which intracellular mechanisms are involved in amyloidogenesis and induction of cell death. Methodology/Principal Findings We have established expression of human proIAPP (hproIAPP), human IAPP (hIAPP) and the non-amyloidogenic mouse IAPP (mIAPP) in Drosophila melanogaster, and compared survival of flies with the expression driven to different cell populations. Only flies expressing hproIAPP in neurons driven by the Gal4 driver elavC155,Gal4 showed a reduction in lifespan whereas neither expression of hIAPP or mIAPP influenced survival. Both hIAPP and hproIAPP expression caused formation of aggregates in CNS and fat body region, and these aggregates were both stained by the dyes Congo red and pFTAA, both known to detect amyloid. Also, the morphology of the highly organized protein granules that developed in the fat body of the head in hIAPP and hproIAPP expressing flies was characterized, and determined to consist of 15.8 nm thick pentagonal rod-like structures. Conclusions/Significance These findings point to a potential for Drosophila melanogaster to serve as a model system for studies of hproIAPP and hIAPP expression with subsequent aggregation and developed pathology. PMID:21695120

  16. Neuropeptide Y, peptide YY and pancreatic polypeptide in the gut-brain axis.

    Science.gov (United States)

    Holzer, Peter; Reichmann, Florian; Farzi, Aitak

    2012-12-01

    The gut-brain axis refers to the bidirectional communication between the gut and the brain. Four information carriers (vagal and spinal afferent neurons, immune mediators such as cytokines, gut hormones and gut microbiota-derived signalling molecules) transmit information from the gut to the brain, while autonomic neurons and neuroendocrine factors carry outputs from the brain to the gut. The members of the neuropeptide Y (NPY) family of biologically active peptides, NPY, peptide YY (PYY) and pancreatic polypeptide (PP), are expressed by cell systems at distinct levels of the gut-brain axis. PYY and PP are exclusively expressed by endocrine cells of the digestive system, whereas NPY is found at all levels of the gut-brain and brain-gut axis. The major systems expressing NPY comprise enteric neurons, primary afferent neurons, several neuronal pathways throughout the brain and sympathetic neurons. In the digestive tract, NPY and PYY inhibit gastrointestinal motility and electrolyte secretion and in this way modify the input to the brain. PYY is also influenced by the intestinal microbiota, and NPY exerts, via stimulation of Y1 receptors, a proinflammatory action. Furthermore, the NPY system protects against distinct behavioural disturbances caused by peripheral immune challenge, ameliorating the acute sickness response and preventing long-term depression. At the level of the afferent system, NPY inhibits nociceptive input from the periphery to the spinal cord and brainstem. In the brain, NPY and its receptors (Y1, Y2, Y4, Y5) play important roles in regulating food intake, energy homeostasis, anxiety, mood and stress resilience. In addition, PP and PYY signal to the brain to attenuate food intake, anxiety and depression-related behaviour. These findings underscore the important role of the NPY-Y receptor system at several levels of the gut-brain axis in which NPY, PYY and PP operate both as neural and endocrine messengers. Copyright © 2012 Elsevier Ltd. All rights

  17. Neuropeptide Y, peptide YY and pancreatic polypeptide in the gut–brain axis

    Science.gov (United States)

    Holzer, Peter; Reichmann, Florian; Farzi, Aitak

    2012-01-01

    The gut–brain axis refers to the bidirectional communication between the gut and the brain. Four information carriers (vagal and spinal afferent neurons, immune mediators such as cytokines, gut hormones and gut microbiota-derived signalling molecules) transmit information from the gut to the brain, while autonomic neurons and neuroendocrine factors carry outputs from the brain to the gut. The members of the neuropeptide Y (NPY) family of biologically active peptides, NPY, peptide YY (PYY) and pancreatic polypeptide (PP), are expressed by cell systems at distinct levels of the gut–brain axis. PYY and PP are exclusively expressed by endocrine cells of the digestive system, whereas NPY is found at all levels of the gut–brain and brain–gut axis. The major systems expressing NPY comprise enteric neurons, primary afferent neurons, several neuronal pathways throughout the brain and sympathetic neurons. In the digestive tract, NPY and PYY inhibit gastrointestinal motility and electrolyte secretion and in this way modify the input to the brain. PYY is also influenced by the intestinal microbiota, and NPY exerts, via stimulation of Y1 receptors, a proinflammatory action. Furthermore, the NPY system protects against distinct behavioural disturbances caused by peripheral immune challenge, ameliorating the acute sickness response and preventing long-term depression. At the level of the afferent system, NPY inhibits nociceptive input from the periphery to the spinal cord and brainstem. In the brain, NPY and its receptors (Y1, Y2, Y4, Y5) play important roles in regulating food intake, energy homeostasis, anxiety, mood and stress resilience. In addition, PP and PYY signal to the brain to attenuate food intake, anxiety and depression-related behaviour. These findings underscore the important role of the NPY-Y receptor system at several levels of the gut–brain axis in which NPY, PYY and PP operate both as neural and endocrine messengers. PMID:22979996

  18. Human Islet Amyloid Polypeptide Fibril Binding to Catalase: A Transmission Electron Microscopy and Microplate Study

    Directory of Open Access Journals (Sweden)

    Nathaniel G. N. Milton

    2010-01-01

    Full Text Available The diabetes-associated human islet amyloid polypeptide (IAPP is a 37-amino-acid peptide that forms fibrils in vitro and in vivo. Human IAPP fibrils are toxic in a similar manner to Alzheimer's amyloid-β (Aβ and prion protein (PrP fibrils. Previous studies have shown that catalase binds to Aβ fibrils and appears to recognize a region containing the Gly-Ala-Ile-Ile sequence that is similar to the Gly-Ala-Ile-Leu sequence found in human IAPP residues 24-27. This study presents a transmission electron microscopy (TEM—based analysis of fibril formation and the binding of human erythrocyte catalase to IAPP fibrils. The results show that human IAPP 1-37, 8-37, and 20-29 peptides form fibrils with diverse and polymorphic structures. All three forms of IAPP bound catalase, and complexes of IAPP 1-37 or 8-37 with catalase were identified by immunoassay. The binding of biotinylated IAPP to catalase was high affinity with a KD of 0.77nM, and could be inhibited by either human or rat IAPP 1-37 and 8-37 forms. Fibrils formed by the PrP 118-135 peptide with a Gly-Ala-Val-Val sequence also bound catalase. These results suggest that catalase recognizes a Gly-Ala-Ile-Leu—like sequence in amyloid fibril-forming peptides. For IAPP 1-37 and 8-37, the catalase binding was primarily directed towards fibrillar rather than ribbon-like structures, suggesting differences in the accessibility of the human IAPP 24-27 Gly-Ala-Ile-Leu region. This suggests that catalase may be able to discriminate between different structural forms of IAPP fibrils. The ability of catalase to bind IAPP, Aβ, and PrP fibrils demonstrates the presence of similar accessible structural motifs that may be targets for antiamyloid therapeutic development.

  19. The multi-epitope polypeptide approach in HIV-1 vaccine development.

    Science.gov (United States)

    Cano, C A

    1999-11-01

    The application of a preventive HIV vaccine is the only hope for most developing countries to halt the AIDS pandemic. A project aimed to develop a preventive AIDS vaccine is being carried out since 1992 by three Cuban research institutions: Centro de Ingeniería Genética y Biotecnologia de La Habana, Instituto de Medicina Tropical 'Pedro Kouri' and Laboratorio de Investigaciones de SIDA de La Habana. The project includes two main strategies: (a) generation of recombinant multi-epitope polypeptides (MEPs) bearing several copies of the V3 loop from different HIV-1 isolates; and (b) development of immunogens capable of inducing a cytotoxic T cell response (CTL) specific for human immunodeficiency virus type 1 (HIV-1) antigens. This article summarizes the work in the first of these strategies. Based on the sequence of the V3 loop of HIV-1 we constructed a series of MEPs and evaluated their immunogenicity in mice, rabbits and macaques. The MEP TAB9, containing six V3 epitopes from isolates LR10, JY1, RF, MN, BRVA and IIIB, was selected together with the oil adjuvant Montanide ISA720 (SEPPIC, France) to perform a Phase I clinical trial in HIV seronegative Cuban volunteers. The trial was double blinded, randomized, and fulfilled all ethical and regulatory requirements. All TAB9 vaccinated volunteers developed a strong immune response and neutralizing antibodies were observed in the 50% of the subjects. However the second and third inoculations of the vaccine were not well tolerated because transient severe local reactions appeared in some individuals. A new formulation of TAB9 is currently in pre-clinical studies and is expected to enter clinical trials in 1999.

  20. Comprehensive behavioral analysis of pituitary adenylate cyclase-activating polypeptide (PACAP knockout mice

    Directory of Open Access Journals (Sweden)

    Satoko eHattori

    2012-10-01

    Full Text Available Pituitary adenylate cyclase-activating polypeptide (PACAP is a neuropeptide acting as a neurotransmitter, neuromodulator, or neurotrophic factor. PACAP is widely expressed throughout the brain and exerts its functions through the PACAP-specific receptor (PAC1. Recent studies reveal that genetic variants of the PACAP and PAC1 genes are associated with mental disorders, and several behavioral abnormalities of PACAP knockout (KO mice are reported. However, an insufficient number of backcrosses was made using PACAP KO mice on the C57BL/6J background due to their postnatal mortality. To elucidate the effects of PACAP on neuropsychiatric function, the PACAP gene was knocked out in F1 hybrid mice (C57BL/6J x 129SvEv for appropriate control of the genetic background. The PACAP KO mice were then subjected to a behavioral test battery. PACAP deficiency had no significant effects on neurological screen. As shown previously, the mice exhibited significantly increased locomotor activity in a novel environment and abnormal anxiety-like behavior, while no obvious differences between genotypes were shown in home cage activity. In contrast to previous reports, the PACAP KO mice showed normal prepulse inhibition and slightly decreased depression-like behavior. Previous study demonstrates that the social interaction in a resident-intruder test was decreased in PACAP KO mice. On the other hand, we showed that PACAP KO mice exhibited increased social interaction in Crawley’s three-chamber social approach test, although PACAP KO had no significant impact on social interaction in a home cage. PACAP KO mice also exhibited mild performance deficit in working memory in an eight-arm radial maze and the T-maze, while they did not show any significant abnormalities in the left-right discrimination task in the T-maze. These results suggest that PACAP has an important role in the regulation of locomotor activity, social behavior, anxiety-like behavior and, potentially

  1. Directed evolution of DNA polymerase, RNA polymerase and reverse transcriptase activity in a single polypeptide.

    Science.gov (United States)

    Ong, Jennifer L; Loakes, David; Jaroslawski, Szymon; Too, Kathleen; Holliger, Philipp

    2006-08-18

    DNA polymerases enable key technologies in modern biology but for many applications, native polymerases are limited by their stringent substrate recognition. Here we describe short-patch compartmentalized self-replication (spCSR), a novel strategy to expand the substrate spectrum of polymerases in a targeted way. spCSR is based on the previously described CSR, but unlike CSR only a short region (a "patch") of the gene under investigation is diversified and replicated. This allows the selection of polymerases under conditions where catalytic activity and processivity are compromised to the extent that full self-replication is inefficient. We targeted two specific motifs involved in substrate recognition in the active site of DNA polymerase I from Thermus aquaticus (Taq) and selected for incorporation of both ribonucleotide- (NTP) and deoxyribonucleotide-triphosphates (dNTPs) using spCSR. This allowed the isolation of multiple variants of Taq with apparent dual substrate specificity. They were able to synthesize RNA, while still retaining essentially wild-type (wt) DNA polymerase activity as judged by PCR. One such mutant (AA40: E602V, A608V, I614M, E615G) was able to incorporate both NTPs and dNTPs with the same catalytic efficiency as the wt enzyme incorporates dNTPs. AA40 allowed the generation of mixed RNA-DNA amplification products in PCR demonstrating DNA polymerase, RNA polymerase as well as reverse transcriptase activity within the same polypeptide. Furthermore, AA40 displayed an expanded substrate spectrum towards other 2'-substituted nucleotides and was able to synthesize nucleic acid polymers in which each base bore a different 2'-substituent. Our results suggest that spCSR will be a powerful strategy for the generation of polymerases with altered substrate specificity for applications in nano- and biotechnology and in the enzymatic synthesis of antisense and RNAi probes.

  2. The Influence of Active Transport Systems on Morphine -6-Glucuronide Transport in MDCKII and MDCK-PGP Cells

    Directory of Open Access Journals (Sweden)

    SO. Mashayekhi

    2011-12-01

    Full Text Available Background and the purpose of the study: Morphine-6-glucuronide (M6G is a potent metabolite of morphine which has high penetration into the brain despite its high polarity, which could be the result of an active transport system involved in M6G transport through blood brain barrier. Examples of such transporters are p-glycoprotein (PGP, probenecid-sensitive transport mechanism, multidrug resistance related protein 1-3, the organic anion transporter family, and the organic anion transporter polypeptide family. The aim of present study was to elucidate the mechanisms involved in transporting morphine's potent metabolite, M6G.Methods: M6G permeability via two cell lines; MDCKII and MDCK-PGP, was compared with that of sucrose. M6G transport was examined in different concentrations and in the presence of inhibitors of different transport systems such as cyclosporine, digoxin and probenecid. M6G concentration was measured using ELISA assay. The method was sensitive, reliable and reproducible.Results: The results confirmed that M6G could cross a layer of MDCK II or MDR-PGP cells more than sucrose could. It was also observed that M6G is a PGP transporter substrate. Its permeability was increased by the use of a PGP expressed cell line, and also in the presence of a strong PGP inhibitor. Digoxin related transporters such as Oatp2 may also involved in transport of M6G. M6G seemed to be a glucose transporter 1 substrate, but was not a substrate to probenecid sensitive transporters.Major conclusion: It is concluded that different transporters are responsible for M6G transports via different membrane, which could have effects on its pharmacokinetics or pharmacodynamics.

  3. Drug Transporter Expression and Activity in Human Hepatoma HuH-7 Cells

    Directory of Open Access Journals (Sweden)

    Elodie Jouan

    2016-12-01

    Full Text Available Human hepatoma cells may represent a valuable alternative to the use of human hepatocytes for studying hepatic drug transporters, which is now a regulatory issue during drug development. In the present work, we have characterized hepatic drug transporter expression, activity and regulation in human hepatoma HuH-7 cells, in order to determine the potential relevance of these cells for drug transport assays. HuH-7 cells displayed notable multidrug resistance-associated protein (MRP activity, presumed to reflect expression of various hepatic MRPs, including MRP2. By contrast, they failed to display functional activities of the uptake transporters sodium taurocholate co-transporting polypeptide (NTCP, organic anion-transporting polypeptides (OATPs and organic cation transporter 1 (OCT1, and of the canalicular transporters P-glycoprotein and breast cancer resistance protein (BCRP. Concomitantly, mRNA expressions of various sinusoidal and canalicular hepatic drug transporters were not detected (NTCP, OATP1B1, organic anion transporter 2 (OAT2, OCT1 and bile salt export pump or were found to be lower (OATP1B3, OATP2B1, multidrug and toxin extrusion protein 1, BCRP and MRP3 in hepatoma HuH-7 cells than those found in human hepatocytes, whereas other transporters such as OAT7, MRP4 and MRP5 were up-regulated. HuH-7 cells additionally exhibited farnesoid X receptor (FXR- and nuclear factor erythroid 2-related factor 2 (Nrf2-related up-regulation of some transporters. Such data indicate that HuH-7 cells, although expressing rather poorly some main hepatic drug transporters, may be useful for investigating interactions of drugs with MRPs, notably MRP2, and for studying FXR- or Nrf2-mediated gene regulation.

  4. A pH- and temperature-responsive bioresorbable injectable hydrogel based on polypeptide block copolymers for the sustained delivery of proteins in vivo.

    Science.gov (United States)

    Turabee, Md Hasan; Thambi, Thavasyappan; Duong, Huu Thuy Trang; Jeong, Ji Hoon; Lee, Doo Sung

    2018-02-27

    Sustained delivery of protein therapeutics is limited owing to the fragile nature of proteins. Despite its great potential, delivery of proteins without any loss of bioactivity remains a challenge in the use of protein therapeutics in the clinic. To surmount this shortcoming, we report a pH- and temperature-responsive in situ-forming injectable hydrogel based on comb-type polypeptide block copolymers for the controlled delivery of proteins. Polypeptide block copolymers, composed of hydrophilic polyethylene glycol (PEG), temperature-responsive poly(γ-benzyl-l-glutamate) (PBLG), and pH-responsive oligo(sulfamethazine) (OSM), exhibit pH- and temperature-induced sol-to-gel transition behavior in aqueous solutions. Polypeptide block copolymers were synthesized by combining N-carboxyanhydride-based ring-opening polymerization and post-functionalization of the chain-end using N-hydroxy succinimide ester activated OSM. The physical properties of polypeptide-based hydrogels were tuned by varying the composition of temperature- and pH-responsive PBLG and OSM in block copolymers. Polypeptide block copolymers were non-toxic to human embryonic kidney cells at high concentrations (2000 μg mL -1 ). Subcutaneous administration of polypeptide block copolymer sols formed viscoelastic gel instantly at the back of Sprague-Dawley (SD) rats. The in vivo gels exhibited sustained degradation and were found to be bioresorbable in 6 weeks without any noticeable inflammation at the injection site. Anionic characteristics of hydrogels allow efficient loading of a cationic model protein, lysozyme, through electrostatic interaction. Lysozyme-loaded polypeptide block copolymer sols readily formed a viscoelastic gel in vivo and sustained lysozyme release for at least a week. Overall, the results demonstrate an elegant approach to control the release of certain charged proteins and open a myriad of therapeutic possibilities in protein therapeutics.

  5. Primary biliary acids inhibit hepatitis D virus (HDV entry into human hepatoma cells expressing the sodium-taurocholate cotransporting polypeptide (NTCP.

    Directory of Open Access Journals (Sweden)

    Isabel Veloso Alves Pereira

    Full Text Available The sodium-taurocholate cotransporting polypeptide (NTCP is both a key bile acid (BA transporter mediating uptake of BA into hepatocytes and an essential receptor for hepatitis B virus (HBV and hepatitis D virus (HDV. In this study we aimed to characterize to what extent and through what mechanism BA affect HDV cell entry.HuH-7 cells stably expressing NTCP (HuH-7/NTCP and primary human hepatocytes (PHH were infected with in vitro generated HDV particles. Infectivity in the absence or presence of compounds was assessed using immunofluorescence staining for HDV antigen, standard 50% tissue culture infectious dose (TCID50 assays and quantitative PCR.Addition of primary conjugated and unconjugated BA resulted in a dose dependent reduction in the number of infected cells while secondary, tertiary and synthetic BA had a lesser effect. This effect was observed both in HuH-7/NTCP and in PHH. Other replication cycle steps such as replication and particle assembly and release were unaffected. Moreover, inhibitory BA competed with a fragment from the large HBV envelope protein for binding to NTCP-expressing cells. Conversely, the sodium/BA-cotransporter function of NTCP seemed not to be required for HDV infection since infection was similar in the presence or absence of a sodium gradient across the plasma membrane. When chenodeoxycolic acid (15 mg per kg body weight was administered to three chronically HDV infected individuals over a period of up to 16 days there was no change in serum HDV RNA.Primary BA inhibit NTCP-mediated HDV entry into hepatocytes suggesting that modulation of the BA pool may affect HDV infection of hepatocytes.

  6. Sediment Transport

    DEFF Research Database (Denmark)

    Liu, Zhou

    Flow and sediment transport are important in relation to several engineering topics, e.g. erosion around structures, backfilling of dredged channels and nearshore morphological change. The purpose of the present book is to describe both the basic hydrodynamics and the basic sediment transport...... mechanics. Chapter 1 deals with fundamentals in fluid mechanics with emphasis on bed shear stress by currents, while chapter 3 discusses wave boundary layer theory. They are both written with a view to sediment transport. Sediment transport in rivers, cross-shore and longshore are dealt with in chapters 2...

  7. Ocean transportation

    National Research Council Canada - National Science Library

    Frankel, Ernst G; Marcus, Henry S

    1973-01-01

    .... This analysis starts with a review of ocean transportation demand and supply including projections of ship capacity demand and world shipbuilding capacity under various economic and political assumptions...

  8. INTERACTION BETWEEN DIFFERENT MOLECULAR FORMS OF IMMUNOGLOBULIN A AND RECOMBINANT DERIVATIVES POLYPEPTIDES OF BAC RECEPTOR PROTEINS FROM GROUP B STREPTOCOCCI

    Directory of Open Access Journals (Sweden)

    A. S. Korzhueva

    2008-01-01

    Full Text Available Abstract. The article concerns interactions between immunoglobulin A and recombinant P6, P7, P8 polypeptides, designed on the basis of externally localized Bac protein of the Group B streptococci, possessing IgA-binding activity.There is a current demand for immunochemical reagents that are strictly specific for IgA, in order to develop antigenic standards for detection of IgA levels in biological fluids, as well as for affinity purification of IgA and its fragments.To analyze an opportunity of the abovementioned application ways for these proteins, a special study was performed to assay an interaction capability of recombinant P6, P7, P8 polypeptides binding to Fc regions of different IgA forms (serum IgA, secretory IgA, subclasses of serum IgA – IgA1, IgA2. Selectivity of ligand binding was specially confirmed.It was found out that, among three presented polypeptides, the structure of recombinant P6 derivative proved to be optimal for IgA-binding ability of Bac protein.Structural features of IgA-binding fragments of Bac protein, i.e., binding site position on the IgA molecule (proximity to epitopes for three monoclonal antibodies, variability of the site structure, as well as resistance of binding site for P6, P7, P8 in IgA molecule against partial disulfide bonds reduction. (Med. Immunol., vol. 10, N 4-5, pp 327-336.

  9. Do natural proteins differ from random sequences polypeptides? Natural vs. random proteins classification using an evolutionary neural network.

    Directory of Open Access Journals (Sweden)

    Davide De Lucrezia

    Full Text Available Are extant proteins the exquisite result of natural selection or are they random sequences slightly edited by evolution? This question has puzzled biochemists for long time and several groups have addressed this issue comparing natural protein sequences to completely random ones coming to contradicting conclusions. Previous works in literature focused on the analysis of primary structure in an attempt to identify possible signature of evolutionary editing. Conversely, in this work we compare a set of 762 natural proteins with an average length of 70 amino acids and an equal number of completely random ones of comparable length on the basis of their structural features. We use an ad hoc Evolutionary Neural Network Algorithm (ENNA in order to assess whether and to what extent natural proteins are edited from random polypeptides employing 11 different structure-related variables (i.e. net charge, volume, surface area, coil, alpha helix, beta sheet, percentage of coil, percentage of alpha helix, percentage of beta sheet, percentage of secondary structure and surface hydrophobicity. The ENNA algorithm is capable to correctly distinguish natural proteins from random ones with an accuracy of 94.36%. Furthermore, we study the structural features of 32 random polypeptides misclassified as natural ones to unveil any structural similarity to natural proteins. Results show that random proteins misclassified by the ENNA algorithm exhibit a significant fold similarity to portions or subdomains of extant proteins at atomic resolution. Altogether, our results suggest that natural proteins are significantly edited from random polypeptides and evolutionary editing can be readily detected analyzing structural features. Furthermore, we also show that the ENNA, employing simple structural descriptors, can predict whether a protein chain is natural or random.

  10. Enamel formation in vitro in mouse molar explants exposed to amelogenin polypeptides ATMP and LRAP on enamel development.

    Science.gov (United States)

    Ravindranath, Rajeswari M H; Devarajan, Asokan; Bringas, Pablo

    2007-12-01

    The enamel matrix contains amelogenin, leucine-rich amelogenin-polypeptide (LRAP), resulting from alternative splicing of the primary amelogenin-RNA transcript and tyrosine-rich amelogenin-polypeptide (TRAP), a proteolytic product of amelogenin. Presence of amelogenin-trityrosyl-motif peptide (ATMP) distinguishes TRAP from LRAP. The roles of these polypeptides in the formation of enamel remain to be elucidated. The mouse in vitro molar tooth-organ developed from bud stage (E16) was exposed to LRAP, ATMP, and mutated ATMP (T-ATMP, third proline replaced by threonine). The histology and morphometry of the explants on day-12 in culture was examined using Mallory's stain. Guanidine-HCl soluble protein concentrations of explants were compared. The enamel width and protein solubility indicate that the explant on day-12 is comparable to postnatal molar on day-3 in vivo. The enamel of both untreated explants as well as that in vivo is fuchinophilic (acid fuchsin, AF+). ATMP reduced the ameloblast-height, accumulated AF+ spherules at the apical end of ameloblasts, and disrupted enamel-dentin bonding. T-ATMP abrogated deposition of AF+ material on the aniline blue positive (AB+) enamel matrix. LRAP reduced ameloblast-height, increased the enamel-width without disruption (at 17.25 nmol) and increased the density of AF+ dentinal tubules. AF+ substance from the tubules is released onto the surface of the dentin. The Guanidine-HCl-soluble protein is elevated in ATMP-treated explants but decreased in LRAP-treated explants. Exogenous ATMP, T-ATMP and LRAP have divergent effects on developing enamel. Exogenous ATMP, but not LRAP, abrogates enamel-dentin bonding at 17.25 nmol. LRAP may play a role in the differentiation of ameloblasts, growth of enamel and formation of dentinal tubules.

  11. Design and synthesis of elastin-like polypeptides for an ideal nerve conduit in peripheral nerve regeneration

    Energy Technology Data Exchange (ETDEWEB)

    Hsueh, Yu-Sheng [Institute of Biomedical Engineering, College of Engineering, National Taiwan University, Taipei 100, Taiwan (China); Institute of Biomedical Engineering, College of Medicine, National Taiwan University, Taipei 100, Taiwan (China); Savitha, S. [Institute of Biomedical Engineering, College of Engineering, National Taiwan University, Taipei 100, Taiwan (China); Department of Biotechnology, Sree Sastha Institute of Engineering and Technology, Chennai (India); Institute of Biomedical Engineering, College of Medicine, National Taiwan University, Taipei 100, Taiwan (China); Sadhasivam, S. [Division of Biomedical Engineering and Nanomedicine Research, National Health Research Institutes, Miaoli 350, Taiwan (China); Lin, Feng-Huei, E-mail: double@ntu.edu.tw [Institute of Biomedical Engineering, College of Engineering, National Taiwan University, Taipei 100, Taiwan (China); Division of Biomedical Engineering and Nanomedicine Research, National Health Research Institutes, Miaoli 350, Taiwan (China); Institute of Biomedical Engineering, College of Medicine, National Taiwan University, Taipei 100, Taiwan (China); Shieh, Ming-Jium [Institute of Biomedical Engineering, College of Engineering, National Taiwan University, Taipei 100, Taiwan (China); College of Medicine, National Taiwan University Hospital, Taipei 100, Taiwan (China); Institute of Biomedical Engineering, College of Medicine, National Taiwan University, Taipei 100, Taiwan (China)

    2014-05-01

    The study involves design and synthesis of three different elastin like polypeptide (ELP) gene monomers namely ELP1, ELP2 and ELP3 that encode for ELP proteins. The formed ELPs were assessed as an ideal nerve conduit for peripheral nerve regeneration. ELP1 was constructed with a small elongated pentapeptide carrying VPGVG sequence to mimic the natural polypeptide ELP. The ELP2 was designed by the incorporation of 4-penta peptide chains to improve the biocompatibility and mechanical strength. Thus, the third position in unique VPGVG was replaced with alanine to VPAVG and in a similar way modified to VPGKG, VPGEG and VPGIG with the substitution of lysine, glutamic acid and isoleucine. In ELP3, fibronectin C5 domain endowed with REDV sequence was introduced to improve the cell attachment. The ELP1, ELP2 and ELP3 proteins expressed by Escherichia coli were purified by inverse transition cycling (ITC). The purified ELPs were confirmed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and western blotting. The Schwann cell (SC) morphology and cell adhesion were assessed by fabrication of ELP membrane cross-linked with glutaraledhyde. The Schwann cell proliferation was measured by WST-1 assay. Immunofluorostaining of Schwann cells was accomplished with SC specific phenotypic marker, S100. - Highlights: • Design and synthesis of three gene monomers of elastin like polypeptides (ELP1, 2 and 3) were reported. • Molecular weight of ITC purified ELP1, ELP2 and ELP3 was in the range of 37–38 kDa. • Schwann cell adhesion was found to be prominent in ELP3 and could be used as nerve conduit for peripheral nerve regeneration.

  12. Design and synthesis of elastin-like polypeptides for an ideal nerve conduit in peripheral nerve regeneration

    International Nuclear Information System (INIS)

    Hsueh, Yu-Sheng; Savitha, S.; Sadhasivam, S.; Lin, Feng-Huei; Shieh, Ming-Jium

    2014-01-01

    The study involves design and synthesis of three different elastin like polypeptide (ELP) gene monomers namely ELP1, ELP2 and ELP3 that encode for ELP proteins. The formed ELPs were assessed as an ideal nerve conduit for peripheral nerve regeneration. ELP1 was constructed with a small elongated pentapeptide carrying VPGVG sequence to mimic the natural polypeptide ELP. The ELP2 was designed by the incorporation of 4-penta peptide chains to improve the biocompatibility and mechanical strength. Thus, the third position in unique VPGVG was replaced with alanine to VPAVG and in a similar way modified to VPGKG, VPGEG and VPGIG with the substitution of lysine, glutamic acid and isoleucine. In ELP3, fibronectin C5 domain endowed with REDV sequence was introduced to improve the cell attachment. The ELP1, ELP2 and ELP3 proteins expressed by Escherichia coli were purified by inverse transition cycling (ITC). The purified ELPs were confirmed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and western blotting. The Schwann cell (SC) morphology and cell adhesion were assessed by fabrication of ELP membrane cross-linked with glutaraledhyde. The Schwann cell proliferation was measured by WST-1 assay. Immunofluorostaining of Schwann cells was accomplished with SC specific phenotypic marker, S100. - Highlights: • Design and synthesis of three gene monomers of elastin like polypeptides (ELP1, 2 and 3) were reported. • Molecular weight of ITC purified ELP1, ELP2 and ELP3 was in the range of 37–38 kDa. • Schwann cell adhesion was found to be prominent in ELP3 and could be used as nerve conduit for peripheral nerve regeneration

  13. Iodine and tritium labelling of curarizing and cardiotoxic agents. Study of the conformation of toxic polypeptides extracted from snake venom

    International Nuclear Information System (INIS)

    Menez, Andre.

    1977-01-01

    A short review of present-day knowledge on the action mechanism of toxic snake venom polypeptides is followed by a study of the radioactive labelling of some toxic compounds. Those dealt with more especially are Naja nigricollis α toxin and Laticauda semifasciata b erabutoxin, then (+) tubocurarin, a non-peptidic curarizing alkaloid, and two cardiotoxic polypeptides: cytotoxin II and cardiotoxin γ extracted from the venom of Naja naja and Naja nigricollis respectively. The labelling principle is based on the specific fixation of one or more iodine atoms then tritium substitution of the halogen by catalytic hydrogenolysis. As predicted from titration of the aromatic groups the halogenation process, obtained by addition of iodine monochloride, takes place sometimes on the phenolic nuclei and sometimes on the imidazole nuclei, the position of which targets within each sequence has been identified. From results of the study of reactivity towards iodine combined with those of basic titration, the accessibility of several aromatic nuclei has also been defined. Each iodinated polypeptide is then hydrogenolysed in the presence of tritium gas giving a specific activity between 4 and 27 Ci/mmole according to the compound treated. In all cases the biological potential and physical properties of the radioactive material obtained by the above titration process remained intact. An example of the bonding kinetics of short toxins with the partially purified choligenic receptor is given in the special case of tritiated b erabutoxin. The affinity of this toxin for its receptor target is strong, though slightly less so than that of tritiated Naja nigricollis α toxin [fr

  14. Molluscan mega-hemocyanin: an ancient oxygen carrier tuned by a ~550 kDa polypeptide

    Directory of Open Access Journals (Sweden)

    Harasewych Myroslaw G

    2010-05-01

    Full Text Available Abstract Background The allosteric respiratory protein hemocyanin occurs in gastropods as tubular di-, tri- and multimers of a 35 × 18 nm, ring-like decamer with a collar complex at one opening. The decamer comprises five subunit dimers. The subunit, a 400 kDa polypeptide, is a concatenation of eight paralogous functional units. Their exact topology within the quaternary structure has recently been solved by 3D electron microscopy, providing a molecular model of an entire didecamer (two conjoined decamers. Here we study keyhole limpet hemocyanin (KLH2 tridecamers to unravel the exact association mode of the third decamer. Moreover, we introduce and describe a more complex type of hemocyanin tridecamer discovered in fresh/brackish-water cerithioid snails (Leptoxis, Melanoides, Terebralia. Results The "typical" KLH2 tridecamer is partially hollow, whereas the cerithioid tridecamer is almost completely filled with material; it was therefore termed "mega-hemocyanin". In both types, the staggering angle between adjoining decamers is 36°. The cerithioid tridecamer comprises two typical decamers based on the canonical 400 kDa subunit, flanking a central "mega-decamer" composed of ten unique ~550 kDa subunits. The additional ~150 kDa per subunit substantially enlarge the internal collar complex. Preliminary oxygen binding measurements indicate a moderate hemocyanin oxygen affinity in Leptoxis (p50 ~9 mmHg, and a very high affinity in Melanoides (~3 mmHg and Terebralia (~2 mmHg. Species-specific and individual variation in the proportions of the two subunit types was also observed, leading to differences in the oligomeric states found in the hemolymph. Conclusions In cerithioid hemocyanin tridecamers ("mega-hemocyanin" the collar complex of the central decamer is substantially enlarged and modified. The preliminary O2 binding curves indicate that there are species-specific functional differences in the cerithioid mega-hemocyanins which might reflect

  15. Identification of a major polypeptide component of the sea urchin fertilization envelope.

    Science.gov (United States)

    Vater, C A; Jackson, R C

    1989-03-01

    A monoclonal antibody (MAb No. 25-16), raised against purified cortical secretory vesicles (CVs) from the eggs of Strongylocentrotus purpuratus, has been used to identify a previously uncharacterized CV-derived polypeptide component of the sea urchin fertilization envelope (FE). MAb No. 25-16, an IgG1, bound to a group of proteins with Mr approximately 200,000 on immunoblots of CVs. This same group of proteins also was detected in fertilization product and in soft FEs prepared from early embryos, indicating that the antigen is released at fertilization by CV exocytosis and becomes incorporated into the FE. The multiple components recognized by MAb No. 25-16 apparently did not result from proteolysis during sample preparation or differential N-linked glycosylation. No simplification of the SDS-gel or immunoblot patterns was observed when samples of fertilization product or cell surface complex were prepared in the presence of a cocktail of protease inhibitors; nor was a change in mobility of any of the antigen forms detected following treatment with endoglycosidase F. Upon partial denaturation and reduction of the protein by incubation at room temperature in the presence of SDS and dithiothreitol, the antigen was shown to undergo a decrease in relative mobility on SDS-PAGE. Complete reduction and denaturation, by boiling in dithiothreitol-containing SDS sample buffer or by an on-blot reduction technique, resulted in loss of the epitope. The protein component recognized by MAb No. 25-16 underwent a striking increase in mobility on SDS-PAGE after chelation of calcium ions with EGTA. Immunogold labeling on thin sections of unfertilized eggs revealed that the antigen is located in the spiral lamellar cores of all CVs. In fertilized eggs, fixed 5 min after insemination, the antigen was detected in the FE. Based on these biochemical and immunological data, we suggest that the antigen recognized by MAb No. 25-16 is released exocytotically from the CVs into the

  16. Role of pancreatic polypeptide as a market of transplanted insulin-producing fetal pig cells.

    Science.gov (United States)

    Tuch, B E; Tabiin, M T; Casamento, F M; Yao, M; Georges, P; Amaratunga, A; Pinto, A N

    2001-01-01

    Transplantation of insulin-producing fetal pancreatic tissue into diabetic recipients has been shown to normalize blood glucose levels after several months. This time period is required for the growth and maturation of the fetal tissue so insulin levels cannot be used as a marker of graft function while the beta-cell is immature. Therefore, we have examined the use of another pancreatic endocrine hormone, pancreatic polypeptide (PP), to monitor graft function. The cell that produces this hormone has been shown to be the first mature endocrine cell in the fetal pancreas. Fetal pig pancreatic tissue, both in the form of 1 mm3 explants and islet-like cell clusters (ICCs), was transplanted into immunodeficient SCID mice and the levels of PP and insulin were measured in plasma and in the graft for up to 12 weeks. PP was detected in the untransplanted explants (0.58 pmol/mg) and ICCs (0.06 pmol/ICC) and the PP to insulin ratio was 2.7% and 5.8%, respectively. PP (but not porcine C-peptide, a marker of insulin secretion) was detectable in the plasma of SCID mice from 4 days to 3 weeks after transplantation, but not thereafter. The highest values were obtained at 4 days to 1 week. In the grafted tissue PP and insulin were present at all time points and the ratio of PP to insulin was 59%, 87%, 75%, 56%, 7%, 8%, and 7% at 4 days, 1, 2, 3, 6, 9, and 12 weeks, respectively. The decline in PP levels 3 weeks after transplantation was associated with beta-cell development in the graft. PP was also secreted by fetal pig pancreatic explants transplanted into diabetic NOD/SCID mice, with plasma levels measurable in the first week after the tissue was grafted. In immunocompetent BALB/c mice transplanted with the tissue, PP was detectable in plasma for 2 days after transplantation but not at 4 days, when cellular rejection commenced, or thereafter. We conclude that plasma PP levels can be used as a marker of the viability of fetal porcine pancreatic tissue in the first 3 weeks after

  17. Dynamic simulations of polypeptide templates to promote Ca-carbonate nuclei

    Science.gov (United States)

    Becker, U.; Biswas, S.; Wang, J.

    2008-12-01

    Over the years, there have been a number of attempts to form synthetic organic templates that mimic dynamic processes at the interface between organic matter and mineral surfaces. One approach has been to isolate the templating matrix from mineralized tissues and examine the growth of calcium salts in the presence of this matrix. Other experiments have focused on synthetic (bio-)organic templates, such as polymers, macromolecular complexes, phospholipid vesicles, pleated polyamino acids entrapped in gelatin self-assembled monolayers on gold substrates, and Langmuir films. In the case of Langmuir monolayers, the amphiphilic molecules can be designed in such a way that they act as artificial two-dimensional nuclei for the promotion of crystal nucleation. Such films have been used as templates to direct the crystal nucleation and growth of calcium carbonate. For example, Buijnsters et al. (2001)1 used Langmuir films of amide-containing phospholipids in the presence of calcium ions to form well-defined two-dimensional domains at the air-water interface. This is the starting point of our molecular dynamics simulations. After deriving a pure-core potential set for fast molecular dynamics simulations, we have created different two-dimensional networks of amide-containing phospho¬lipids that serve as templates for Ca carbonate seed formation. We can vary the distance and structural arrangement of the functional groups to control adsorption and seed formation. The molecular dynamics runs in these calculations contain water with different concentrations of Ca2+ and CO32- ions. We have chosen a slightly different approach for polypeptide chains as template formers. Hybrids of two and three-dimensional networks of these chains with varying connectivities (chemically and structurally) were used to simulate interfaces for early seed formation. Charged (mostly negatively) functional groups on the networks allow polar carbonate surfaces to be exposed at the interface whereas in

  18. A Study on the Clinical Significance of Serum Tissue Polypeptide Antigen Levels in Patients with Malignancy

    International Nuclear Information System (INIS)

    Park, Sung Ki; Moon, Dae Hyuk; Lee, Myung Chul; Cho, Bo Youn; Kim, Byoung Kook; Kim, Noe Kyeong; Koh, Chang Soon; Lee, Mun Ho

    1984-01-01

    To evaluate the clinical significance of serum tissue polypeptide antigen (TPA) levels in patients with malignancy, serum TPA levels were measured by radioimmunoassay in 49 normal controls, 9 patients of postoperative colon cancer without recurrence and 68 patients with various untreated malignancy, who visited Seoul National University Hospital from February, 1983 to September, 1983. The results were as follows; 1) Serum TPA levels in 49 normal controls were in the range of 22-135 U/L (74 ± 28 U/L, mean ± S.D.). There was no sex or age difference. Normal upper limit of serum TPA was defined as 130 U/L (mean+2 S.D.). 2) Serum TPA levels in 68 patients with various untreated malignancy (stomach cancer 33 cases, colon cancer 11 cases, lung cancer 10 cases, primary liver. cancer 9 cases and metastatic cancer of unknown primary site 5 cases) were in the range of 10-800 U/L (189 ± 170 U/L, mean ± S.D.) and significantly elevated, compared with those of normal controls (p<0.005). 3) The sensitivities of serum TPA in various untreated malignancy were 39% in stomach cancer, 55% in colon cancer, 50% in lung cancer, 67% in primary liver cancer and 80% in metastatic cancer of unknown primary site respectively. 4) The sensitivities of serum TEA related to resectability in stomach and colon cancer were 32% in resectable stomach cancer, 50% in unresectable stomach cancer, 29% in resectable colon cancer and 100% in unresectable colon cancer respectively. 5) The mean value of serum TPA levels in 9 patients of postoperative colon cancer without recurrence was 70 ± 39 U/L and significantly decreased, compared with that of untreated colon cancer, 180 ± 150 U/L (p<0.05). 6) In patients with stomach or colon cancer, there was no significant correlation between serum TPA and serum CEA levels, but simultaneous measurement of serum TPA and serum CEA levels increased sensitivities. From above results, we concluded that serum TPA level is a useful indicator reflecting tumor activity

  19. HIV-neutralizing activity of cationic polypeptides in cervicovaginal secretions of women in HIV-serodiscordant relationships.

    Directory of Open Access Journals (Sweden)

    Pauline Levinson

    Full Text Available HIV exposed seronegative (HESN women represent the population most in need of a prophylactic antiviral strategy. Mucosal cationic polypeptides can potentially be regulated for this purpose and we here aimed to determine their endogenous expression and HIV neutralizing activity in genital secretions of women at risk of HIV infection.Cervicovaginal secretions (CVS of Kenyan women in HIV-serodiscordant relationships (HESN, n = 164; HIV seropositive, n = 60 and low-risk controls (n = 72 were assessed for the cationic polypeptides HNP1-3, LL-37 and SLPI by ELISA and for HIV neutralizing activity by a PBMC-based assay using an HIV primary isolate. Median levels of HNP1-3 and LL-37 in CVS were similar across study groups. Neither HSV-2 serostatus, nor presence of bacterial vaginosis, correlated with levels of HNP1-3 or LL-37 in the HESN women. However, an association with their partner's viral load was observed. High viral load (>10,000 HIV RNA copies/ml plasma correlated with higher levels of HNP1-3 and LL-37 (p = 0.04 and 0.03, respectively. SLPI was most abundant in the low-risk group and did not correlate with male partner's viral load in the HESN women. HIV neutralizing activity was found in CVS of all study groups. In experimental studies, selective depletion of cationic polypeptides from CVS rendered the remaining CVS fraction non-neutralizing, whereas the cationic polypeptide fraction retained the activity. Furthermore, recombinant HNP1-3 and LL-37 could induce neutralizing activity when added to CVS lacking intrinsic activity.These findings show that CVS from HESN, low-risk, and HIV seropositive women contain HIV neutralizing activity. Although several innate immune proteins, including HNP1-3 and LL-37, contribute to this activity these molecules can also have inflammatory properties. This balance is influenced by hormonal and environmental factors and in the present HIV serodiscordant couple cohort study we show that a partner

  20. Probing isoform-specific functions of polypeptide GalNAc-transferases using zinc finger nuclease glycoengineered SimpleCells

    DEFF Research Database (Denmark)

    Schjoldager, Katrine Ter-Borch Gram; Vakhrushev, Sergey Y; Kong, Yun

    2012-01-01

    function, and validates the use of GALNT gene targeting with SimpleCells for broad discovery of disease-causing deficiencies in O-glycosylation. The presented glycoengineering strategy opens the way for proteome-wide discovery of functions of GalNAc-T isoforms and their role in congenital diseases......Our knowledge of the O-glycoproteome [N-acetylgalactosamine (GalNAc) type] is highly limited. The O-glycoproteome is differentially regulated in cells by dynamic expression of a subset of 20 polypeptide GalNAc-transferases (GalNAc-Ts), and methods to identify important functions of individual Gal...