WorldWideScience

Sample records for c-type allatostatin-like peptide

  1. C-type natriuretic peptide and its precursor

    DEFF Research Database (Denmark)

    Lippert, Solvej; Iversen, Peter; Brasso, Klaus

    2015-01-01

    AIM: Seminal plasma offer a more organ-specific matrix for markers in prostatic disease. We hypothesized that C-type natriuretic peptide (CNP) expression may constitute such a new target. METHODS: Patients with benign prostatic hyperplasia, clinically localized and metastatic prostate cancer were...

  2. C-type natriuretic peptide in prostate cancer

    DEFF Research Database (Denmark)

    Nielsen, Soeren Junge; Iversen, Peter; Rehfeld, Jens F.

    2009-01-01

    C-type natriuretic peptide (CNP) is expressed in the male reproductive organs in pigs. To examine whether the human prostate also expresses the CNP gene, we measured CNP and N-terminal proCNP in prostate cancer tissue extracts and performed immunohistochemical biopsy staining. Additionally, pro......CNP-derived peptides were quantitated in plasma from patients with prostate cancer. Blood was collected from healthy controls and patients before surgery for localized prostate cancer. Tissue extracts were prepared from tissue biopsies obtained from radical prostatectomy surgery. N-terminal proCNP, proCNP (1...... demonstrated the presence of the peptides in prostatic epithelial cells. The N-terminal proCNP concentrations in plasma were marginally lower in patients with localized prostate cancer compared with control subjects [13.8 pmol/l (11.0-17.2) vs. 15.1 pmol/l (10.4-23.2), p=0.002] but not enough to justify...

  3. Endothelial C-type natriuretic peptide maintains vascular homeostasis.

    Science.gov (United States)

    Moyes, Amie J; Khambata, Rayomand S; Villar, Inmaculada; Bubb, Kristen J; Baliga, Reshma S; Lumsden, Natalie G; Xiao, Fang; Gane, Paul J; Rebstock, Anne-Sophie; Worthington, Roberta J; Simone, Michela I; Mota, Filipa; Rivilla, Fernando; Vallejo, Susana; Peiró, Concepción; Sánchez Ferrer, Carlos F; Djordjevic, Snezana; Caulfield, Mark J; MacAllister, Raymond J; Selwood, David L; Ahluwalia, Amrita; Hobbs, Adrian J

    2014-09-01

    The endothelium plays a fundamental role in maintaining vascular homeostasis by releasing factors that regulate local blood flow, systemic blood pressure, and the reactivity of leukocytes and platelets. Accordingly, endothelial dysfunction underpins many cardiovascular diseases, including hypertension, myocardial infarction, and stroke. Herein, we evaluated mice with endothelial-specific deletion of Nppc, which encodes C-type natriuretic peptide (CNP), and determined that this mediator is essential for multiple aspects of vascular regulation. Specifically, disruption of CNP leads to endothelial dysfunction, hypertension, atherogenesis, and aneurysm. Moreover, we identified natriuretic peptide receptor-C (NPR-C) as the cognate receptor that primarily underlies CNP-dependent vasoprotective functions and developed small-molecule NPR-C agonists to target this pathway. Administration of NPR-C agonists promotes a vasorelaxation of isolated resistance arteries and a reduction in blood pressure in wild-type animals that is diminished in mice lacking NPR-C. This work provides a mechanistic explanation for genome-wide association studies that have linked the NPR-C (Npr3) locus with hypertension by demonstrating the importance of CNP/NPR-C signaling in preserving vascular homoeostasis. Furthermore, these results suggest that the CNP/NPR-C pathway has potential as a disease-modifying therapeutic target for cardiovascular disorders.

  4. C-type natriuretic peptide in prostate cancer

    DEFF Research Database (Denmark)

    Nielsen, Soeren Junge; Iversen, Peter; Rehfeld, Jens F.

    2009-01-01

    C-type natriuretic peptide (CNP) is expressed in the male reproductive organs in pigs. To examine whether the human prostate also expresses the CNP gene, we measured CNP and N-terminal proCNP in prostate cancer tissue extracts and performed immunohistochemical biopsy staining. Additionally, pro......CNP-derived peptides were quantitated in plasma from patients with prostate cancer. Blood was collected from healthy controls and patients before surgery for localized prostate cancer. Tissue extracts were prepared from tissue biopsies obtained from radical prostatectomy surgery. N-terminal proCNP, proCNP (1......-50) and CNP were measured in plasma and tissue extracts. Biopsies were stained for CNP-22 and N-terminal proCNP. Tissue extracts from human prostate cancer contained mostly N-terminal proCNP [median 5.3 pmol/g tissue (range 1.0-12.9)] and less CNP [0.14 pmol/g tissue (0.01-1.34)]. Immunohistochemistry...

  5. Endothelial C-type natriuretic peptide maintains vascular homeostasis

    Science.gov (United States)

    Moyes, Amie J.; Khambata, Rayomand S.; Villar, Inmaculada; Bubb, Kristen J.; Baliga, Reshma S.; Lumsden, Natalie G.; Xiao, Fang; Gane, Paul J.; Rebstock, Anne-Sophie; Worthington, Roberta J.; Simone, Michela I.; Mota, Filipa; Rivilla, Fernando; Vallejo, Susana; Peiró, Concepción; Sánchez Ferrer, Carlos F.; Djordjevic, Snezana; Caulfield, Mark J.; MacAllister, Raymond J.; Selwood, David L.; Ahluwalia, Amrita; Hobbs, Adrian J.

    2014-01-01

    The endothelium plays a fundamental role in maintaining vascular homeostasis by releasing factors that regulate local blood flow, systemic blood pressure, and the reactivity of leukocytes and platelets. Accordingly, endothelial dysfunction underpins many cardiovascular diseases, including hypertension, myocardial infarction, and stroke. Herein, we evaluated mice with endothelial-specific deletion of Nppc, which encodes C-type natriuretic peptide (CNP), and determined that this mediator is essential for multiple aspects of vascular regulation. Specifically, disruption of CNP leads to endothelial dysfunction, hypertension, atherogenesis, and aneurysm. Moreover, we identified natriuretic peptide receptor–C (NPR-C) as the cognate receptor that primarily underlies CNP-dependent vasoprotective functions and developed small-molecule NPR-C agonists to target this pathway. Administration of NPR-C agonists promotes a vasorelaxation of isolated resistance arteries and a reduction in blood pressure in wild-type animals that is diminished in mice lacking NPR-C. This work provides a mechanistic explanation for genome-wide association studies that have linked the NPR-C (Npr3) locus with hypertension by demonstrating the importance of CNP/NPR-C signaling in preserving vascular homoeostasis. Furthermore, these results suggest that the CNP/NPR-C pathway has potential as a disease-modifying therapeutic target for cardiovascular disorders. PMID:25105365

  6. C-Type Natriuretic Peptide Analog as Therapy for Achondroplasia.

    Science.gov (United States)

    Legeai-Mallet, Laurence

    2016-01-01

    Fibroblast growth factor receptor 3 (FGFR3) is an important regulator of bone formation. Gain-of-function mutations in the FGFR3 gene result in chondrodysplasias which include achondroplasia (ACH), the most common form of dwarfism, in which skull, appendicular and axial skeletons are affected. The skeletal phenotype of patients with ACH showed defective proliferation and differentiation of the chondrocytes in the growth plate cartilage. Both endochondral and membranous ossification processes are disrupted during development. At cellular level, Fgfr3 mutations induce increased phosphorylation of the tyrosine kinase receptor FGFR3, which correlate with an enhanced activation of its downstream signaling pathways. Potential therapeutic strategies have emerged for ACH. Several preclinical studies have been conducted such as the C-type natriuretic peptide (CNP) analog (BMN111), intermittent parathyroid hormone injections, soluble FGFR3 therapy, and meclozine and statin treatments. Among the putative targets to antagonize FGFR3 signaling, CNP (or BMN111) is one of the most promising strategies. BMN111 acts as a key regulator of longitudinal bone growth by downregulating the mitogen-activated protein kinase pathway, which is activated as a result of a FGFR3 gain-of-function mutation. Preclinical studies showed that BMN111 treatment led to a large improvement in skeletal parameters in Fgfr3Y367C/+ mice mimicking ACH. In 2014, a clinical trial (phase 2) of BMN111 in pediatric patients with ACH has started. This first clinical trial marks the first big step towards real treatment for these patients. © 2016 S. Karger AG, Basel.

  7. Role of allatostatin-like factors from the brain of Tenebrio molitor females.

    Science.gov (United States)

    Wasielewski, O; Skonieczna, M; Kodrík, D

    2009-08-01

    The effect of brain extract from females of freshly emerged Tenebrio molitor on ovary, oocyte development, total protein content of hemolymph, and ovary was studied in 4-day-old adult mealworm females. Injections of extracts of 2-brain equivalents into intact (unligatured) Tenebrio females did not affect ovarian and oocyte development. Injections of ligated females, however, with 2-brain equivalents on day 1 and 2 after adult emergence strongly inhibited ovarian growth and oocyte development. At day 4, ligated and injected females did not develop their ovaries and pre-vitellogenic oocytes were not found. The changes in ovarian development correlated with an increase in the concentration of soluble proteins in the hemolymph as compared with the saline-injected controls. Additionally, a strong reduction of total protein content in ovarian tissue was observed. Reverse phase HPLC separation of a methanolic brain extract of T. molitor females showed that fraction 5 has a similar retention time to synthetic cockroach allatostatin. Fraction 5 was eluted at 12.88 min, which was closest to the internal standard Dippu-AST I, which eluted at 12.77 min. An ELISA of fraction 5 from the methanolic brain extract using antibodies against allatostatins Grybi-AST A1 and Grybi-AST B1 from cricket Gryllus bimaculatus showed that fraction 5 cross-reacted with Grybi-AST A1 antibodies. The cross-reactivity was similar to the synthetic allatostatin from D. punctata, which was used as a positive control. These observations demonstrate a possible role for allatostatin-like brain factor(s) in regulating the reproductive cycle of Tenebrio molitor.

  8. Processing-independent analysis for pro-C-type natriuretic peptide

    DEFF Research Database (Denmark)

    Lippert, Solvej Kølvraa; Rehfeld, Jens F.; Gøtze, Jens Peter

    2010-01-01

    C-type natriuretic peptide (CNP) is expressed in several human tissues. We designed a specific processing-independent assay for proCNP-derived products and quantitated the concentrations in human seminal plasma from normal and vasectomized men. Antibodies were raised against the N-terminus of human...

  9. Processing-independent analysis for pro-C-type natriuretic peptide

    DEFF Research Database (Denmark)

    Lippert, Solvej Kølvraa; Rehfeld, Jens F.; Gøtze, Jens Peter

    2010-01-01

    C-type natriuretic peptide (CNP) is expressed in several human tissues. We designed a specific processing-independent assay for proCNP-derived products and quantitated the concentrations in human seminal plasma from normal and vasectomized men. Antibodies were raised against the N-terminus of human......-933 pmol/L, age 18-25 years); gel chromatography suggested the presence of several molecular forms. Parameters associated to male fertility, proCNP concentrations in blood plasma and time of abstinence did not correlate to the seminal proCNP concentrations. Measurement in vasectomized men disclosed seminal...

  10. Cardiac C-type natriuretic peptide gene expression and plasma concentrations in neonatal piglets

    DEFF Research Database (Denmark)

    Holst Hansen, Lasse; Smith, Julie; Goetze, Jens P

    2014-01-01

    BACKGROUND: C-type natriuretic peptide (CNP) is a member of the natriuretic peptide family. Cardiac ANP and BNP expressions are firmly established, whereas CNP expression in the mammalian heart remains controversial. In the present report, we used a porcine model of the neonatal period with high...... expressions of cardiac ANP and BNP in order to elucidate the cardiac CNP expression profile. METHODS: Plasma and cardiac tissue were obtained from newborn piglets during the first 72 h of life. The chamber-specific CNP mRNA contents were quantified by real-time PCR analysis. The proCNP concentrations...... in the newborn piglets (n=44) were exceedingly low compared to proANP concentrations (5.3 pmol/L (3.2-8.6) vs. 3438 pmol/L (2790-5418), pANP (130 pmol/g (101-159)) and atrial proANP...

  11. Role of C-type natriuretic peptide in the function of normal human sperm

    Directory of Open Access Journals (Sweden)

    Hui Xia

    2016-01-01

    Full Text Available C-type natriuretic peptide (CNP is a newly discovered type of local regulatory factor that mediates its biological effects through the specific, membrane-bound natriuretic peptide receptor-B (NPR-B. Recent studies have established that CNP is closely related to male reproductive function. The aims of this study were to determine the distribution of CNP/NPR-B in human ejaculated spermatozoa through different methods (such as immunolocalization, real time polymerase chain reaction and Western Blot, and then to evaluate the influence of CNP on sperm function i n vitro, such as motility and acrosome reaction. Human semen samples were collected from consenting donors who met the criteria of the World Health Organization for normozoospermia. Our results show that the specific receptor NPR-B of CNP is localized in the acrosomal region of the head and the membrane of the front-end tail of the sperm, and there is no signal of CNP in human sperm. Compared with the control, CNP can induce a significant dose-dependent increase in spermatozoa motility and acrosome reaction. In summary, CNP/NPR-B can affect sperm motility and acrosome reaction, thus regulating the reproductive function of males. CNP may be a new key factor in regulating sperm function.

  12. B and C types natriuretic peptides modify norepinephrine uptake and release in the rat adrenal medulla.

    Science.gov (United States)

    Vatta, M S; Presas, M F; Bianciotti, L G; Rodriguez-Fermepin, M; Ambros, R; Fernandez, B E

    1997-01-01

    We have previously reported that atrial natriuretic factor (ANF) modulates adrenomedullar norepinephrine (NE) metabolism. On this basis, the aim of the present work was to study the effects of B and C types natriuretic peptides (BNP and CNP) on the uptake, intracellular distribution and release of 3H-NE. Experiments were carried out in rat adrenal medulla slices incubated "in vitro." Results showed that 100 nM of both, CNP and BNP, enhanced total and neuronal NE uptake. Both peptides (100 nM) caused a rapid increase in NE uptake during the first minute, which was sustained for 60 min. NE intracellular distribution was only modified by CNP (100 nM), which increased the granular fraction and decreased the cytosolic pool. On the other hand, spontaneous as well as evoked (KCl) NE release, was decreased by BNP and CNP (50 and 100 nM for spontaneous release and 1, 10, 50 and 100 nM for evoked output). The present results suggest that BNP and CNP may regulate catecholamine secretion and modulate adrenomedullary biological actions mediated by catecholamines, such as blood arterial pressure, smooth muscle tone, and metabolic activities.

  13. C-type natriuretic peptide in complicated pregnancy: increased secretion precedes adverse events.

    Science.gov (United States)

    Reid, Rosemary A; Prickett, Timothy C R; Pullar, Barbra E; Darlow, Brian A; Gullam, Joanna E; Espiner, Eric A

    2014-04-01

    C-type natriuretic peptide (CNP), a vasoactive product of the endothelium, is markedly increased during placentation in ovine pregnancy and is further stimulated by nutrient restriction. Whether CNP products change in human pregnancy is unknown. The objective of the study was to compare serial changes in maternal plasma CNP peptides during normal pregnancy with changes in pregnancy complicated by adverse events and relate these to fetal growth and placental CNP content. This was a prospective observational study undertaken in a tertiary care center. We studied changes in maternal plasma aminoterminal proCNP (NTproCNP) and CNP at monthly intervals, fetal growth, and placental and umbilical plasma CNP peptides in 51 women, 28 of whom experienced an adverse event and 23 were uneventful. Age matched healthy nonpregnant women served as a reference range for NTproCNP. Compared with nonpregnant women, maternal plasma NTproCNP in an uneventful pregnancy was significantly reduced from first sampling (16 wk gestation) until 36 weeks. In contrast, in complicated pregnancy, levels did not decline and were significantly higher (P pregnancy from 20 weeks. Highest values occurred in women later developing hypertension and fetal growth disorders. Placental concentration of NTproCNP was unrelated to maternal NTproCNP but strongly correlated with cord plasma levels. Maternal NTproCNP is significantly raised in women who later exhibit a range of obstetric adverse events. Lack of association with placental concentrations suggests that these changes represent an adaptive response within the maternal circulation to a threatened nutrient supply to the fetus.

  14. Dexamethasone increases production of C-type natriuretic peptide in the sheep brain.

    Science.gov (United States)

    Wilson, Michele O; McNeill, Bryony A; Barrell, Graham K; Prickett, Timothy C R; Espiner, Eric A

    2017-10-01

    Although C-type natriuretic peptide (CNP) has high abundance in brain tissues and cerebrospinal fluid (CSF), the source and possible factors regulating its secretion within the central nervous system (CNS) are unknown. Here we report the dynamic effects of a single IV bolus of dexamethasone or saline solution on plasma, CSF, CNS and pituitary tissue content of CNP products in adult sheep, along with changes in CNP gene expression in selected tissues. Both CNP and NTproCNP (the amino-terminal product of proCNP) in plasma and CSF showed dose-responsive increases lasting 12-16 h after dexamethasone, whereas other natriuretic peptides were unaffected. CNS tissue concentrations of CNP and NTproCNP were increased by dexamethasone in all of the 12 regions examined. Abundance was highest in limbic tissues, pons and medulla oblongata. Relative to controls, CNP gene expression (NPPC) was upregulated by dexamethasone in 5 of 7 brain tissues examined. Patterns of responses differed in pituitary tissue. Whereas the abundance of CNP in both lobes of the pituitary gland greatly exceeded that of brain tissues, neither CNP nor NTproCNP concentration was affected by dexamethasone, despite an increase in NPPC expression. This is the first report of enhanced production and secretion of CNP in brain tissues in response to a corticosteroid. Activation of CNP secretion within CNS tissues by dexamethasone, not exhibited by other natriuretic peptides, suggests an important role for CNP in settings of acute stress. Differential findings in pituitary tissues likely relate to altered processing of proCNP storage and secretion. © 2017 Society for Endocrinology.

  15. B and C types natriuretic peptides modulate norepinephrine uptake and release in the rat hypothalamus.

    Science.gov (United States)

    Vatta, M S; Presas, M; Bianciotti, L G; Zarrabeitia, V; Fernández, B E

    1996-09-16

    We previously reported that atrial natriuretic factor (ANF) regulates catecholamine metabolism in the central nervous system. ANF, B and C types natriuretic peptides (BNP and CNP) also play a regulatory role in body fluid homeostasis, cardiovascular activity and hormonal and neuro-hormonal secretions. The aim of the present work was to investigate BNP and CNP effects on the uptake and release of norepinephrine (NE) in rat hypothalamic slices incubated in vitro. Results showed that BNP (100 nM) and CNP (1, 10 and 100 nM) enhanced total and neuronal [3H]NE uptake but did not modify non-neuronal uptake. BNP (100 nM) and CNP (1 nM) caused a rapid increase in NE uptake (1 min), which was sustained for 60 min. BNP (100 nM) did not modify the intracellular distribution of NE; however, 1 nM CNP increased the granular store and decreased the cytosolic pool of NE. BNP (100 nM) and CNP (1, 10 and 100 nM), diminished spontaneous NE release. In addition, BNP (1, 10, 100 nM) and CNP (1, 10 and 100 pM, as well as 1, 10 and 100 nM) reduced NE output induced by 25 mM KCl. These results suggest that BNP and CNP may be involved in the regulation of several central as well as peripheral physiological functions through the modulation of noradrenergic neurotransmission at the presynaptic neuronal level. Present results provide evidence to consider CNP as the brain natriuretic peptide since physiological concentrations of this peptide (pM) diminished NE evoked release.

  16. Dexamethasone stimulates expression of C-type Natriuretic Peptide in chondrocytes

    Directory of Open Access Journals (Sweden)

    Beier Frank

    2006-11-01

    Full Text Available Abstract Background Growth of endochondral bones is regulated through the activity of cartilaginous growth plates. Disruption of the physiological patterns of chondrocyte proliferation and differentiation – such as in endocrine disorders or in many different genetic diseases (e.g. chondrodysplasias – generally results in dwarfism and skeletal defects. For example, glucocorticoid administration in children inhibits endochondral bone growth, but the molecular targets of these hormones in chondrocytes remain largely unknown. In contrast, recent studies have shown that C-type Natriuretic Peptide (CNP is an important anabolic regulator of cartilage growth, and loss-of-function mutations in the human CNP receptor gene cause dwarfism. We asked whether glucocorticoids could exert their activities by interfering with the expression of CNP or its downstream signaling components. Methods Primary mouse chondrocytes in monolayer where incubated with the synthetic glucocorticoid Dexamethasone (DEX for 12 to 72 hours. Cell numbers were determined by counting, and real-time PCR was performed to examine regulation of genes in the CNP signaling pathway by DEX. Results We show that DEX does influence expression of key genes in the CNP pathway. Most importantly, DEX significantly increases RNA expression of the gene encoding CNP itself (Nppc. In addition, DEX stimulates expression of Prkg2 (encoding cGMP-dependent protein kinase II and Npr3 (natriuretic peptide decoy receptor genes. Conversely, DEX was found to down-regulate the expression of the gene encoding its receptor, Nr3c1 (glucocorticoid receptor, as well as the Npr2 gene (encoding the CNP receptor. Conclusion Our data suggest that the growth-suppressive activities of DEX are not due to blockade of CNP signaling. This study reveals a novel, unanticipated relationship between glucocorticoid and CNP signaling and provides the first evidence that CNP expression in chondrocytes is regulated by endocrine

  17. Urinary C-Type Natriuretic Peptide: An Emerging Biomarker for Heart Failure and Renal Remodeling

    Science.gov (United States)

    Zakeri, Rosita; Burnett, John C.; Sangaralingham, S. Jeson

    2015-01-01

    The public health and economic burden of heart failure (HF) is staggering and the need for relevant pathophysiologic and clinical biomarkers to advance the field and improve HF therapy remains high. Renal dysfunction is common among HF patients and is associated with increased HF hospitalization and mortality. It is widely recognized that mechanisms contributing to HF pathogenesis include a complex bidirectional interaction between the kidney and heart, encompassed by the term cardiorenal syndrome (CRS). Among a new wave of urinary biomarkers germane to CRS, C-type natriuretic peptide (CNP) has emerged as an innovative biomarker of renal structural and functional impairment in HF and chronic renal disease states. CNP is a hormone, synthesized in the kidney, and is an important regulator of cell proliferation and organ fibrosis. Hypoxia, cytokines and fibrotic growth factors, which are inherent to both cardiac and renal remodeling processes, are among the recognized stimuli for CNP production and release. In this review we aim to highlight current knowledge regarding the biology and pathophysiologic correlates of urinary CNP, and its potential clinical utility as a diagnostic and prognostic biomarker in HF and renal disease states. PMID:25512164

  18. C-type natriuretic peptide ameliorates pulmonary fibrosis by acting on lung fibroblasts in mice.

    Science.gov (United States)

    Kimura, Toru; Nojiri, Takashi; Hino, Jun; Hosoda, Hiroshi; Miura, Koichi; Shintani, Yasushi; Inoue, Masayoshi; Zenitani, Masahiro; Takabatake, Hiroyuki; Miyazato, Mikiya; Okumura, Meinoshin; Kangawa, Kenji

    2016-02-19

    Pulmonary fibrosis has high rates of mortality and morbidity; however, no effective pharmacological therapy has been established. C-type natriuretic peptide (CNP), a member of the natriuretic peptide family, selectively binds to the transmembrane guanylyl cyclase (GC)-B receptor and exerts anti-inflammatory and anti-fibrotic effects in various organs through vascular endothelial cells and fibroblasts that have a cell-surface GC-B receptor. Given the pathophysiological importance of fibroblast activation in pulmonary fibrosis, we hypothesized that the anti-fibrotic and anti-inflammatory effects of exogenous CNP against bleomycin (BLM)-induced pulmonary fibrosis were exerted in part by the effect of CNP on pulmonary fibroblasts. C57BL/6 mice were divided into two groups, CNP-treated (2.5 μg/kg/min) and vehicle, to evaluate BLM-induced (1 mg/kg) pulmonary fibrosis and inflammation. A periostin-CNP transgenic mouse model exhibiting CNP overexpression in fibroblasts was generated and examined for the anti-inflammatory and anti-fibrotic effects of CNP via fibroblasts in vivo. Additionally, we assessed CNP attenuation of TGF-β-induced differentiation into myofibroblasts by using immortalized human lung fibroblasts stably expressing GC-B receptors. Furthermore, to investigate whether CNP acts on human lung fibroblasts in a clinical setting, we obtained primary-cultured fibroblasts from surgically resected lungs of patients with lung cancer and analyzed levels of GC-B mRNA transcription. CNP reduced mRNA levels of the profibrotic cytokines interleukin (IL)-1β and IL-6, as well as collagen deposition and the fibrotic area in lungs of mice with bleomycin-induced pulmonary fibrosis. Furthermore, similar CNP effects were observed in transgenic mice exhibiting fibroblast-specific CNP overexpression. In cultured-lung fibroblasts, CNP treatment attenuated TGF-β-induced phosphorylation of Smad2 and increased mRNA and protein expression of α-smooth muscle actin and SM22

  19. Discordant expression of pro-B-type and pro-C-type natriuretic peptide in newborn infants of mothers with type 1 diabetes

    DEFF Research Database (Denmark)

    Nybo, M.; Nielsen, Lars Bo; Nielsen, S.J.

    2007-01-01

    Maternal diabetes increases the risk of hypertrophic cardiomyopathy in the fetus. As signaling via the C-type natriuretic peptide (CNP) specific receptor protects against cardiac hypertrophy, we examined whether maternal type 1 diabetes affects the plasma concentrations of proCNP-derived peptides...

  20. C-type natriuretic peptide is closely associated to obesity in Caucasian adolescents.

    Science.gov (United States)

    Del Ry, Silvia; Cabiati, Manuela; Bianchi, Vanessa; Caponi, Laura; Maltinti, Maristella; Caselli, Chiara; Kozakova, Michaela; Palombo, Carlo; Morizzo, Carmela; Marchetti, Sara; Randazzo, Emioli; Clerico, Aldo; Federico, Giovanni

    2016-09-01

    CNP is a natural regulator of adipogenesis playing a role in the development of obesity in childhood. Aim of the study was to evaluate CNP plasma levels in normal-weight (N), overweight (OW) and obese adolescents (O). Eighty two subjects (age:12.8±2.4, years) without cardiac dysfunction were enrolled and CNP plasma levels were measured by RIA. NT-proBNP, MR-proANP, AGEs, reactive hyperemia index (RHI) and standard clinical chemistry parameters were also measured. O and OW adolescents had higher values of BMI and fat mass than N. CNP levels were significantly lower in OW:4.79[3.29-21.15] and O:3.81[1.55-13.4] than in N:13.21[7.6-37.8]; pobesity resulted significantly (p≪0.0001) associated with CNP values (AUC=0.9724). These results suggest that CNP may play a more important role than BNP and ANP related peptides, as risk marker of obesity, in addition to its involvement in adipogenesis and endothelial dysfunction. Copyright © 2016 Elsevier B.V. All rights reserved.

  1. C-type natriuretic peptide inhibits leukocyte recruitment and platelet-leukocyte interactions via suppression of P-selectin expression

    Science.gov (United States)

    Scotland, Ramona S.; Cohen, Marc; Foster, Paul; Lovell, Matthew; Mathur, Anthony; Ahluwalia, Amrita; Hobbs, Adrian J.

    2005-10-01

    The multifaceted process of immune cell recruitment to sites of tissue injury is key to the development of an inflammatory response and involved in the pathogenesis of numerous cardiovascular disorders. We recently identified C-type natriuretic peptide (CNP) as an important endothelium-derived mediator that regulates vascular tone and protects against myocardial ischemia/reperfusion injury. Herein, we investigated whether CNP inhibits leukocyte recruitment and platelet aggregation and thereby exerts a potential antiinflammatory influence on the blood vessel wall. We assessed the effects of CNP on leukocyte-endothelial cell interactions in mouse mesenteric postcapillary venules in vivo in animals with high basal leukocyte activation (endothelial nitric oxide synthase knockout mice, eNOS-/-) or under acute inflammatory conditions (induced by interleukin-1 or histamine). CNP suppressed basal leukocyte rolling in eNOS-/- mice in a rapid, reversible, and concentration-dependent manner. These effects of CNP were mimicked by the selective natriuretic peptide receptor-C agonist cANF4-23. CNP also suppressed leukocyte rolling induced by IL-1 or histamine, inhibited platelet-leukocyte interactions, and prevented thrombin-induced platelet aggregation of human blood. Furthermore, analysis of human umbilical vein endothelial cells, leukocytes, and platelets revealed that CNP selectively attenuates expression of P-selectin. Thus, CNP is a modulator of acute inflammation in the blood vessel wall characterized by leukocyte and platelet activation. These antiinflammatory effects appear to be mediated, at least in part, via suppression of P-selectin expression. These observations suggest that endothelial CNP might maintain an anti-atherogenic influence on the blood vessel wall and represent a target for therapeutic intervention in inflammatory cardiovascular disorders. endothelium | natriuretic peptide receptor type C | atherosclerosis | thrombosis

  2. C-type natriuretic peptide plasma levels are elevated in subjects with achondroplasia, hypochondroplasia, and thanatophoric dysplasia.

    Science.gov (United States)

    Olney, Robert C; Prickett, Timothy C R; Espiner, Eric A; Mackenzie, William G; Duker, Angela L; Ditro, Colleen; Zabel, Bernhard; Hasegawa, Tomonobu; Kitoh, Hiroshi; Aylsworth, Arthur S; Bober, Michael B

    2015-02-01

    C-type natriuretic peptide (CNP) is a crucial regulator of endochondral bone growth. In a previous report of a child with acromesomelic dysplasia, Maroteaux type (AMDM), caused by loss-of-function of the CNP receptor (natriuretic peptide receptor-B [NPR-B]), plasma levels of CNP were elevated. In vitro studies have shown that activation of the MAPK kinase (MEK)/ERK MAPK pathway causes functional inhibition of NPR-B. Achondroplasia, hypochondroplasia, and thanatophoric dysplasia are syndromes of short-limbed dwarfism caused by activating mutations of fibroblast growth factor receptor-3, which result in overactivation of the MEK/ERK MAPK pathway. The purpose of this study was to determine whether these syndromes exhibit evidence of CNP resistance as reflected by increases in plasma CNP and its amino-terminal propeptide (NTproCNP). This was a prospective, observational study. Participants were 63 children and 20 adults with achondroplasia, 6 children with hypochondroplasia, 2 children with thanatophoric dysplasia, and 4 children and 1 adult with AMDM. Plasma levels of CNP and NTproCNP were higher in children with achondroplasia with CNP SD scores (SDSs) of 1.0 (0.3-1.4) (median [interquartile range]) and NTproCNP SDSs of 1.4 (0.4-1.8; P achondroplasia (CNP SDSs of 1.5 [0.7-2.1] and NTproCNP SDSs of 0.5 [0.1-1.0], P < .005). In children with hypochondroplasia, CNP SDSs were 1.3 (0.7-1.5) (P = .08) and NTproCNP SDSs were 1.9 (1.8-2.3) (P < .05). In children with AMDM, CNP SDSs were 1.6 (1.4-3.3) and NTproCNP SDSs were 4.2 (2.7-6.2) (P < .01). In these skeletal dysplasias, elevated plasma levels of proCNP products suggest the presence of tissue resistance to CNP.

  3. Opposed circulating plasma levels of endothelin-1 and C-type natriuretic peptide in children with Plasmodium falciparum malaria

    Directory of Open Access Journals (Sweden)

    Issifou Saadou

    2008-12-01

    Full Text Available Abstract Background Molecular mechanisms involved in the pathogenesis of severe Plasmodium falciparum malaria (SM, are not yet fully understood. Both endothelin-1 (ET-1 and C-type natriuretic peptide (CNP are produced by vascular endothelium and act locally as paracrine regulators of vascular tone, ET-1 being a potent vasoconstrictor and CNP having strong vasorelaxant properties. Methods Plasma levels of ET-1 and N-terminal fragments of CNP (NT-proCNP were studied on admission and after 24 hours of treatment, using enzyme-linked-immunosorbent-assay (ELISA technique, in Gabonese children with severe falciparum malaria (SM, n = 50, with uncomplicated malaria (UM, n = 39 and healthy controls (HC, n = 25. Results Compared to HC, malaria patients had significantly higher plasma levels of ET-1 and significantly lower levels of NT-proCNP (p p p = 0.034, whereas UM was not significantly different to HC. In the SM group we found a trend towards lower ET-1 levels compared to UM (p = 0.085. Conclusion In the present study, an imbalance between the vasoconstricitve and vasorelaxant endothelium-derived substances ET-1 and CNP in the plasma of children with falciparum malaria is demonstrated, presumably in favor of vasoconstrictive and pro-inflammatory effects. These results may indicate involvement of ET-1 and CNP in malaria pathogenesis. Furthermore, results of lower ET-1 and CNP levels in SM may reflect endothelial cell damage.

  4. Plasma C-type natriuretic peptide as a predictor for therapeutic response to metoprolol in children with postural tachycardia syndrome.

    Directory of Open Access Journals (Sweden)

    Jing Lin

    Full Text Available POTS is a global public-health disease, but predictor for therapeutic response to metoprolol in children with POTS is lacking. This study was designed to investigate predictive value of plasma C-type natriuretic peptide (CNP in the therapeutic efficacy of metoprolol on postural tachycardia syndrome (POTS in children. Totally 34 children with POTS and 27 healthy children were included in the study. The head-up test or head-up tilt test was used to check heart rate and blood pressure from supine to upright in subjects. A double antibody (competitive sandwich immunoluminometric assay was used to detect plasma CNP. Metoprolol was used to treat children with POTS. The difference in plasma concentrations of CNP between responders and non-responders was compared. An ROC curve was used to analyze plasma CNP to predict efficacy of metoprolol on POTS in children. Plasma CNP in children with POTS was significantly higher than that of healthy children [(51.9 ± 31.4 vs. (25.1 ± 19.1 pg/ml, P 32.55 pg/ml yielded a sensitivity of 95.8% and specificity of 70% in predicting therapeutic efficacy of metoprolol on POTS children. Plasma CNP might serve as a useful predictor for the therapeutic efficacy of metoprolol on POTS in children.

  5. New elements in the C-type natriuretic peptide signaling pathway inhibiting swine in vitro oocyte meiotic resumption.

    Science.gov (United States)

    Santiquet, Nicolas; Papillon-Dion, Emilie; Djender, Nadjib; Guillemette, Christine; Richard, François J

    2014-07-01

    C-type natriuretic peptide (CNP) and its cognate receptor, natriuretic peptide receptor (NPR) B, have been shown to promote cGMP production in granulosa/cumulus cells. Once transferred to the oocyte through the gap junctions, the cGMP inhibits oocyte meiotic resumption. CNP has been shown to bind another natriuretic receptor, NPR-C. NPR-C is known to interact with and degrade bound CNP, and has been reported to possess signaling functions. Therefore, NPR-C could participate in the control of oocyte maturation during swine in vitro maturation (IVM). Here, we examine the effect of CNP signaling on meiotic resumption, the amount of cGMP and gap junctional communication (GJC) regulation during swine IVM. The results show an inhibitory effect of CNP in inhibiting oocyte meiotic resumption in follicle-stimulating hormone (FSH)-stimulated IVM. We also found that an NPR-C-specific agonist (cANP([4-23])) is likely to play a role in maintaining meiotic arrest during porcine IVM when in the presence of a suboptimal dose of CNP. Moreover, we show that, even if CNP can increase intracellular concentration of cGMP in cumulus-oocyte complexes, cANP((4-23)) had no impact on cGMP concentration, suggesting a potential cGMP-independent signaling pathway related to NPR-C activation. These data support a potential involvement of cANP((4-23)) through NPR-C in inhibiting oocyte meiotic resumption while in the presence of a suboptimal dose of CNP. The regulation of GJC was not altered by CNP, cANP((4-23)), or the combination of CNP and cANP((4-23)), supporting their potential contribution in sending signals to the oocytes. These findings offer promising insights in to new elements of the signaling pathways that may be involved in inhibiting resumption of meiosis during FSH-stimulated swine IVM. © 2014 by the Society for the Study of Reproduction, Inc.

  6. Shear stress induction of C-type natriuretic peptide (CNP) in endothelial cells is independent of NO autocrine signaling.

    Science.gov (United States)

    Zhang, Z; Xiao, Z; Diamond, S L

    1999-01-01

    C-type natriuretic peptide (CNP) is secreted by endothelial cells and has vasodilatory and antiproliferative activity against smooth muscle cells. Using defined laminar shear stress exposures of cultured bovine aortic endothelial cells, we investigated the regulation of CNP gene by PhosphorImaging the ratio of CNP mRNA to glyceraldehyde 3-phosphate dehydrogenase (GAPDH) mRNA. A 6 h exposure to arterial shear stress of 25 dyn/cm2 caused a marked elevation (10.5 +/- 6.2-fold: n=10, pshear stress was 2.6 times more potent than a venous level of shear stress of 4 dyn/cm2 in elevating the CNP/GAPDH mRNA ratio. After 6 h, CNP secretion by shear stressed BAEC was elevated over stationary controls by 3.1-fold (n=5, pBAEC. Shear stress elevated CNP mRNA in the presence of L-NAME (400 microM) indicating that autocrine signaling through shear-induced NO production or guanylate cyclase activation was not involved. Similarly, the tyrosine kinase inhibitor genistein (10 microM), which can also block shear-induced NO production, had no effect on CNP mRNA induction by shear stress in BAEC. The intracellular calcium chelator BAPTA/AM (5 microM) attenuated the shear stress-induced CNP mRNA expression by 71%. Interestingly, dexamethasone (1 microM) potentiated by 2-fold the shear stress enhancement of CNP mRNA. Shear stress was a more potent inducer of CNP than either phorbol myristrate acetate or lipopolysaccharide. Hemodynamic shear stress may be an important physiological regulator of CNP expression with consequent effects on vasodilation and regulation of intimal hyperplasia.

  7. Vascular relaxation induced by C-type natriuretic peptide involves the ca2+/NO-synthase/NO pathway.

    Directory of Open Access Journals (Sweden)

    Fernanda A Andrade

    Full Text Available AIMS: C-type natriuretic peptide (CNP and nitric oxide (NO are endothelium-derived factors that play important roles in the regulation of vascular tone and arterial blood pressure. We hypothesized that NO produced by the endothelial NO-synthase (NOS-3 contributes to the relaxation induced by CNP in isolated rat aorta via activation of endothelial NPR-C receptor. Therefore, the aim of this study was to investigate the putative contribution of NO through NPR-C activation in the CNP induced relaxation in isolated conductance artery. MAIN METHODS: Concentration-effect curves for CNP were constructed in aortic rings isolated from rats. Confocal microscopy was used to analyze the cytosolic calcium mobilization induced by CNP. The phosphorylation of the residue Ser1177 of NOS was analyzed by Western blot and the expression and localization of NPR-C receptors was analyzed by immunohistochemistry. KEY FINDINGS: CNP was less potent in inducing relaxation in denuded endothelium aortic rings than in intact ones. L-NAME attenuated the potency of CNP and similar results were obtained in the presence of hydroxocobalamin, an intracellular NO0 scavenger. CNP did not change the phosphorylation of Ser1177, the activation site of NOS-3, when compared with control. The addition of CNP produced an increase in [Ca2+]c in endothelial cells and a decrease in [Ca2+]c in vascular smooth muscle cells. The NPR-C-receptors are expressed in endothelial and adventitial rat aortas. SIGNIFICANCE: These results suggest that CNP-induced relaxation in intact aorta isolated from rats involves NO production due to [Ca2+]c increase in endothelial cells possibly through NPR-C activation expressed in these cells. The present study provides a breakthrough in the understanding of the close relationship between the vascular actions of nitric oxide and CNP.

  8. Structure-Function Analyses of a Staphylococcus epidermidis Autoinducing Peptide Reveals Motifs Critical for AgrC-type Receptor Modulation.

    Science.gov (United States)

    Yang, Tian; Tal-Gan, Yftah; Paharik, Alexandra E; Horswill, Alexander R; Blackwell, Helen E

    2016-07-15

    Staphylococcus epidermidis is frequently implicated in human infections associated with indwelling medical devices due to its ubiquity in the skin flora and formation of robust biofilms. The accessory gene regulator (agr) quorum sensing (QS) system plays a prominent role in the establishment of biofilms and infection by this bacterium. Agr activation is mediated by the binding of a peptide signal (or autoinducing peptide, AIP) to its cognate AgrC receptor. Many questions remain about the role of QS in S. epidermidis infections, as well as in mixed-microbial populations on a host, and chemical modulators of its agr system could provide novel insights into this signaling network. The AIP ligand provides an initial scaffold for the development of such probes; however, the structure-activity relationships (SARs) for activation of S. epidermidis AgrC receptors by AIPs are largely unknown. Herein, we report the first SAR analyses of an S. epidermidis AIP by performing systematic alanine and d-amino acid scans of the S. epidermidis AIP-I. On the basis of these results, we designed and identified potent, pan-group inhibitors of the AgrC receptors in the three S. epidermidis agr groups, as well as a set of AIP-I analogs capable of selective AgrC inhibition in either specific S. epidermidis agr groups or in another common staphylococcal species, S. aureus. In addition, we uncovered a non-native peptide agonist of AgrC-I that can strongly inhibit S. epidermidis biofilm growth. Together, these synthetic analogs represent new and readily accessible probes for investigating the roles of QS in S. epidermidis colonization and infections.

  9. Increased arterial compliance in cirrhosis is related to decreased arterial C-type natriuretic peptide, but not to atrial natriuretic peptide

    DEFF Research Database (Denmark)

    Henriksen, Jens Henrik Sahl; Gülberg, V; Gerbes, A L

    2003-01-01

    BACKGROUND: Increased arterial compliance (COMPart) has recently been described in patients with cirrhosis, particularly in advanced disease. The aim of the present study was to relate COMPart with arterial levels of the circulating natriuretic peptides: atrial natriuretic peptide (ANP) and C...... with cirrhosis showed the well-known hyperdynamic circulation with elevated cardiac output, low arterial blood pressure, and reduced systemic vascular resistance. COMPart in the patients with cirrhosis (1.30 mL/mmHg) was significantly (P

  10. Controlled release of C-type natriuretic peptide by microencapsulation dampens proinflammatory effects induced by IL-1β in cartilage explants.

    Science.gov (United States)

    Peake, Nick J; Pavlov, Anton M; D'Souza, Alveena; Pingguan-Murphy, Belinda; Sukhorukov, Gleb B; Hobbs, Adrian J; Chowdhury, Tina T

    2015-02-09

    C-type natriuretic peptide (CNP) exhibits potent anti-inflammatory effects in chondrocytes that have the potential to repair cartilage damage observed in osteoarthritis (OA). However, treatments for OA have been challenging due to poor targeting and delivery of therapeutics. The present study fabricated polyelectrolyte microcapsules loaded with CNP and examined whether the layer-by-layer (LbL) approach could have protective effects in cartilage explants treated with the pro-inflammatory cytokine, interleukin-1β (IL-1β). SEM showed uniform, 2 to 3 μm spherical microcapsules with morphological characteristic similar to templates loaded with or without CNP. The protein was localized around the external surface of the microcapsules with encapsulation efficiencies >82.9%. CNP release profiles were broadly similar following 9 days of culture. The presence of CNP microcapsules did not significantly affect cell viability (80%) with DNA values that remained stable throughout the culture conditions. Confocal imaging showed clustering of microcapsules in chondrocytes to natriuretic peptide receptor (Npr) 2 and 3. Treatment of cartilage explants with CNP microcapsules led to concentration-dependent inhibition of NO release in response to IL-1β and restoration of matrix synthesis. In summary, we demonstrate controlled delivery of CNP to dampen pro-inflammatory effects induced by IL-1β in cartilage explants. The LbL approach has the potential to promote cartilage repair in vivo.

  11. Heart specific up-regulation of genes for B-type and C-type natriuretic peptide receptors in diabetic mice

    DEFF Research Database (Denmark)

    Christoffersen, Christina; Bartels, E D; Nielsen, L B

    2006-01-01

    Diabetes may cause cardiomyopathy characterized by cardiac fibrosis. Recent studies of genetically modified mice have elucidated a role of the natriuretic peptides (NP), type-A and type-B (ANP and BNP), and their common receptor [natriuretic peptide receptor (NPR), type-A] in development of cardiac...

  12. Discordant expression of pro-B-type and pro-C-type natriuretic peptide in newborn infants of mothers with type 1 diabetes

    DEFF Research Database (Denmark)

    Nybo, Mads; Nielsen, Lars Bo; Nielsen, Søren Junge

    2007-01-01

    CNP concentrations were similar in umbilical cord plasma from pregnant women with and without type 1 diabetes (17 pmol/L vs. 19 pmol/L, P not significant) and did not correlate with the proBNP concentrations in the same samples. However, the molar ratio between the proCNP and the CNP peptide was increased...

  13. P17, an Original Host Defense Peptide from Ant Venom, Promotes Antifungal Activities of Macrophages through the Induction of C-Type Lectin Receptors Dependent on LTB4-Mediated PPARγ Activation

    Directory of Open Access Journals (Sweden)

    Khaddouj Benmoussa

    2017-11-01

    Full Text Available Despite the growing knowledge with regard to the immunomodulatory properties of host defense peptides, their impact on macrophage differentiation and on its associated microbicidal functions is still poorly understood. Here, we demonstrated that the P17, a new cationic antimicrobial peptide from ant venom, induces an alternative phenotype of human monocyte-derived macrophages (h-MDMs. This phenotype is characterized by a C-type lectin receptors (CLRs signature composed of mannose receptor (MR and Dectin-1 expression. Concomitantly, this activation is associated to an inflammatory profile characterized by reactive oxygen species (ROS, interleukin (IL-1β, and TNF-α release. P17-activated h-MDMs exhibit an improved capacity to recognize and to engulf Candida albicans through the overexpression both of MR and Dectin-1. This upregulation requires arachidonic acid (AA mobilization and the activation of peroxisome proliferator-activated receptor gamma (PPARγ nuclear receptor through the leukotriene B4 (LTB4 production. AA/LTB4/PPARγ/Dectin-1-MR signaling pathway is crucial for P17-mediated anti-fungal activity of h-MDMs, as indicated by the fact that the activation of this axis by P17 triggered ROS production and inflammasome-dependent IL-1β release. Moreover, we showed that the increased anti-fungal immune response of h-MDMs by P17 was dependent on intracellular calcium mobilization triggered by the interaction of P17 with pertussis toxin-sensitive G-protein-coupled receptors on h-MDMs. Finally, we also demonstrated that P17-treated mice infected with C. albicans develop less severe gastrointestinal infection related to a higher efficiency of their macrophages to engulf Candida, to produce ROS and IL-1β and to kill the yeasts. Altogether, these results identify P17 as an original activator of the fungicidal response of macrophages that acts upstream PPARγ/CLRs axis and offer new immunomodulatory therapeutic perspectives in the field of

  14. The question of histidine content in c-type cytochromes.

    Science.gov (United States)

    Cusanovich, M A; Meyer, T; Tedro, S M; Kamen, M D

    1971-03-01

    Reports that histidine may not occur in heme peptides derived from c-type cytochromes isolated from chloroplasts of Euglena gracilis and Porphyra sp. have not been substantiated in the present investigation, in which the amino acid composition and a partial sequence were determined for a heme peptide derived from the c-type cytochromes of a strain of Euglena closely related to that used in the previous studies. It is concluded that no evidence exists to challenge the generalization that histidine is always present vicinal to the hemebinding site in c-type cytochromes.

  15. Biosynthesis of cardiac natriuretic peptides

    DEFF Research Database (Denmark)

    Goetze, Jens Peter

    2010-01-01

    peptides has only been elucidated during the last decade. The cellular synthesis including amino acid modifications and proteolytic cleavages has proven considerably more complex than initially perceived. Consequently, the elimination phase of the peptide products in circulation is not yet well...... competent endocrine cells. The structurally related atrial natriuretic peptide will be mentioned where appropriate, whereas C-type natriuretic peptide will not be considered as a cardiac peptide of relevance in mammalian physiology....

  16. Quantum Torus Algebras and B(C)-Type Toda Systems

    Science.gov (United States)

    Wang, Na; Li, Chuanzhong

    2017-12-01

    In this paper, we construct a new even constrained B(C)-type Toda hierarchy and derive its B(C)-type Block-type additional symmetry. Also we generalize the B(C)-type Toda hierarchy to the N-component B(C)-type Toda hierarchy which is proved to have symmetries of a coupled \\bigotimes ^NQT_+ algebra ( N-fold direct product of the positive half of the quantum torus algebra QT).

  17. DC-SIGN, a C-type lectin on dendritic cells that unveils many aspects of dendritic cell biology

    NARCIS (Netherlands)

    Geijtenbeek, Teunis B. H.; Engering, Anneke; van Kooyk, Yvette

    2002-01-01

    Dendritic cells (DC) are present in essentially every tissue where they operate at the interface of innate and acquired immunity by recognizing pathogens and presenting pathogen-derived peptides to T cells. It is becoming clear that not all C-type lectins on DC serve as antigen receptors recognizing

  18. Biosynthesis of cardiac natriuretic peptides

    DEFF Research Database (Denmark)

    Goetze, Jens Peter

    2010-01-01

    Cardiac-derived peptide hormones were identified more than 25 years ago. An astonishing amount of clinical studies have established cardiac natriuretic peptides and their molecular precursors as useful markers of heart disease. In contrast to the clinical applications, the biogenesis of cardiac....... An inefficient post-translational prohormone maturation will also affect the biology of the cardiac natriuretic peptide system. This review aims at summarizing the myocardial synthesis of natriuretic peptides focusing on B-type natriuretic peptide, where new data has disclosed cardiac myocytes as highly...... competent endocrine cells. The structurally related atrial natriuretic peptide will be mentioned where appropriate, whereas C-type natriuretic peptide will not be considered as a cardiac peptide of relevance in mammalian physiology....

  19. A novel C-type lectin identified by EST analysis in tissue migratory larvae of Ascaris suum.

    Science.gov (United States)

    Yoshida, Ayako; Nagayasu, Eiji; Horii, Yoichiro; Maruyama, Haruhiko

    2012-04-01

    C-type lectins (CTLs) are a group of proteins which bind to carbohydrate epitopes in the presence of Ca(2+), which have been described in a wide range of species. In this study, a cDNA sequence coding a putative CTL has been identified from the cDNA library constructed from the pig round worm Ascaris suum lung L3 (LL3) larvae, which was designated as A. suum C-type lectin-1 (As-CTL-1). The 510 nucleotide open reading frame of As-CTL-1 cDNA encoded the predicted 169 amino acid protein including a putative signal peptide of 23 residues and C-type lectin/C-type lectin-like domain (CLECT) at residue 26 to 167. As-CTL-1 was most similar to Toxocara canis C-type lectin-1 and 4 (Tc-CTL-1 and 4), and highly homologous to namatode CTLs and mammalian CTLs as well, such as human C-type lectin domain family 4 member G (CLECG4). In addition, As-CTL-1 was strongly expressed in tissue migrating LL3 and the L4 larvae, which were developmental larvae stages within the mammalian host. These results suggest that A. suum larvae might utilize As-CTL-1 to avoid pathogen recognition mechanisms in mammalian hosts due to it is similarity to host immune cell receptors.

  20. Tetranectin, a trimeric plasminogen-binding C-type lectin

    DEFF Research Database (Denmark)

    Holtet, T L; Graversen, Jonas Heilskov; Clemmensen, I

    1997-01-01

    Tetranectin, a plasminogen-binding protein belonging to the family of C-type lectins, was expressed in E. coli and converted to its native form by in vitro refolding and proteolytic processing. Recombinant tetranectin-as well as natural tetranectin from human plasma-was shown by chemical cross......-linking analysis and SDS-PAGE to be a homo-trimer in solution as are other known members of the collectin family of C-type lectins. Biochemical evidence is presented showing that an N-terminal domain encoded within exons 1 and 2 of the tetranectin gene is necessary and sufficient to govern subunit trimerization....

  1. Signalling through C-type lectin receptors: shaping immune responses

    NARCIS (Netherlands)

    Geijtenbeek, Teunis B. H.; Gringhuis, Sonja I.

    2009-01-01

    C-type lectin receptors (CLRs) expressed by dendritic cells are crucial for tailoring immune responses to pathogens. Following pathogen binding, CLRs trigger distinct signalling pathways that induce the expression of specific cytokines which determine T cell polarization fates. Some CLRs can induce

  2. C-type lectin receptors orchestrate antifungal immunity

    NARCIS (Netherlands)

    Wevers, Brigitte A.; Geijtenbeek, Teunis B. H.; Gringhuis, Sonja I.

    2013-01-01

    Fungal infections are an emerging threat for human health. A coordinated host immune response is fundamental for successful elimination of an invading fungal microbe. A panel of C-type lectin receptors expressed on antigen-presenting dendritic cells enable innate recognition of fungal cell wall

  3. [C-type scaphoid fracture in a elite power lifting].

    Science.gov (United States)

    Heckmann, A; Lahoda, L U; Alkandari, Q; Vogt, P M; Knobloch, K

    2008-06-01

    Power lifting injuries most often involve shoulder injuries with an injury rate of 0.57 to 0.71/1000 hours of power lifting. Wrist injuries are less common in power lifters with 0.05/1000 hours exposure vs. 0.23/1000 h in elite weight lifting men. Often, two contributing factors causing wrist injuries are encountered: a) loss of balance causing the barbell to drift back behind the head of the power lifter, which hyperextends the wrist and b) the maximal weight. We report on an elite power lifting athlete preparing for the World Masters Bench press championships suffering two months of persisting pain during bench press exercise and rest in the snuff-box area following a loss of balance of the bar-bell during bench press with 280 kg load. Following prolonged presentation 2 months after the initial injury with training in the meantime, CT-scan was performed revealing a C-type scaphoid fracture. Surgery was performed as Herbert screw fixation and bone grafting according to the technique of Matti-Russe, followed by an immobilisation of twelve weeks with a plaster. We recommended ending the athletes' power lifting career, however he further exercised with the plaster with consecutive re-operation 3months later and 2nd Matti-Russe and Herbert screw re-do. One year later he became national champion with 240 kg bench pressing. Given the limited scaphoid blood supply and the high complication rate especially among C-type scaphoid fractures, a surgical procedure with bone grafting, Herbert screw fixation and sufficient plaster immobilisation is advocated in scaphoid fractures in elite athletes.

  4. Production, purification, and capsid stability of rhinovirus C types.

    Science.gov (United States)

    Griggs, Theodor F; Bochkov, Yury A; Nakagome, Kazuyuki; Palmenberg, Ann C; Gern, James E

    2015-06-01

    The rhinovirus C (RV-C) were discovered in 2006 and these agents are an important cause of respiratory morbidity. Little is known about their biology. RV-C15 (C15) can be produced by transfection of recombinant viral RNA into cells and subsequent purification over a 30% sucrose cushion, even though yields and infectivity of other RV-C genotypes with this protocol are low. The goal of this study was to determine whether poor RV-C yields were due to capsid instability, and moreover, to develop a robust protocol suitable for the purification of many RV-C types. Capsid stability assays indicated that virions of RV-C41 (refractory to purification) have similar tolerance for osmotic and temperature stress as RV-A16 (purified readily), although C41 is more sensitive to low pH. Modification to the purification protocol by removing detergent increased the yield of RV-C. Addition of nonfat dry milk to the sucrose cushion increased the virus yield but sacrificed purity of the viral suspension. Analysis of virus distribution following centrifugation indicated that the majority of detectable viral RNA (vRNA) was found in pellets refractory to resuspension. Reduction of the centrifugal force with commiserate increase in spin-time improved the recovery of RV-C for both C41 and C2. Transfection of primary lung fibroblasts (WisL cells) followed by the modified purification protocol further improved yields of infectious C41 and C2. Described herein is a higher yield purification protocol suitable for RV-C types refractory to the standard purification procedure. The findings suggest that aggregation-adhesion problems rather than capsid instability influence RV-C yield during purification. Copyright © 2015 Elsevier B.V. All rights reserved.

  5. Molecular Cloning and Characterization of a New C-type Lysozyme Gene from Yak Mammary Tissue

    Directory of Open Access Journals (Sweden)

    Ming Feng Jiang

    2015-12-01

    Full Text Available Milk lysozyme is the ubiquitous enzyme in milk of mammals. In this study, the cDNA sequence of a new chicken-type (c-type milk lysozyme gene (YML, was cloned from yak mammary gland tissue. A 444 bp open reading frames, which encodes 148 amino acids (16.54 kDa with a signal peptide of 18 amino acids, was sequenced. Further analysis indicated that the nucleic acid and amino acid sequences identities between yak and cow milk lysozyme were 89.04% and 80.41%, respectively. Recombinant yak milk lysozyme (rYML was produced by Escherichia coli BL21 and Pichia pastoris X33. The highest lysozyme activity was detected for heterologous protein rYML5 (M = 1,864.24 U/mg, SD = 25.75 which was expressed in P. pastoris with expression vector pPICZαA and it clearly inhibited growth of Staphylococcus aureus. Result of the YML gene expression using quantitative polymerase chain reaction showed that the YML gene was up-regulated to maximum at 30 day postpartum, that is, comparatively high YML can be found in initial milk production. The phylogenetic tree indicated that the amino acid sequence was similar to cow kidney lysozyme, which implied that the YML may have diverged from a different ancestor gene such as cow mammary glands. In our study, we suggest that YML be a new c-type lysozyme expressed in yak mammary glands that plays a role as host immunity.

  6. C-type Lectin Receptors for Tumor Eradication: Future Directions

    Energy Technology Data Exchange (ETDEWEB)

    Streng-Ouwehand, Ingeborg; Unger, Wendy W. J.; Kooyk, Yvette van, E-mail: y.vankooyk@vumc.nl [Department of Molecular Cell Biology and Immunology, VU University Medical Center, P.O. Box 7057, 1007 MB Amsterdam (Netherlands)

    2011-08-08

    Dendritic cells are key regulators in directing immune responses and therefore are under extensive research for the induction of anti-tumor responses. DCs express a large array of receptors by which they scan their surroundings for recognition and uptake of pathogens. One of the receptor-families is the C-type lectins (CLR), which bind carbohydrate structures and internalize antigens upon recognition. Intracellular routing of antigen through CLR enhances loading and presentation of antigen through MHC class I and II, inducing antigen-specific CD4{sup +} and CD8{sup +} T-cell proliferation and skewing T-helper cells. These characteristics make CLRs very interesting targets for DC-based immunotherapy. Profound research has been done on targeting specific tumor antigens to CLR using either antibodies or the natural ligands such as glycan structures. In this review we will focus on the current data showing the potency of CLR-targeting and discuss improvements that can be achieved to enhance anti-tumor activity in the near future.

  7. Targeting C-type Lectin Receptors for Cancer Immunity

    Directory of Open Access Journals (Sweden)

    Huimin eYan

    2015-08-01

    Full Text Available C-type lectin receptors (CLRs are a large family of soluble and trans-membrane pattern recognition receptors that are widely and primarily expressed on myeloid cells. CLRs are important for cell-cell communication and host defense against pathogens through the recognition of specific carbohydrate structures. Similar to a family of Toll-like receptors (TLRs, CLRs signaling are involved in the various steps for initiation of innate immune responses and promote secretion of soluble factors such as cytokines and interferons, Moreover, CLRs contribute to endocytosis and antigen-presentation, thereby fine-tune adaptive immune responses. In addition, there may also be a direct activation of acquired immunity. On the other hand, glycans, such as mannose structures, Lewis-type antigens or GalNAc are components of tumor antigens and ligate CLRs, leading to immunoregulation. Therefore agonists or antagonists of CLRs signaling are potential therapeutic reagents for cancer immunotherapy. We aim to overview the current knowledge of CLRs signaling and the application of their ligands on tumor-associating immune response.

  8. Isolation and characterization of two novel C-type lectins from the oriental river prawn, Macrobrachium nipponense.

    Science.gov (United States)

    Xiu, Yunji; Hou, Libo; Liu, Xiaoqian; Wang, Yinghui; Gu, Wei; Meng, Qingguo; Wang, Wen

    2015-10-01

    C-type lectins are a family of calcium-dependent carbohydrate-binding proteins which are believed to play important roles in the innate immunity of invertebrates. This study identified two novel C-type lectins, designated as MnCTLDcp2 and MnCTLDcp3, from the oriental river prawn Macrobrachium nipponense. The full-length cDNA of MnCTLDcp2 was of 1582 bp with an open reading frame (ORF) of 972 bp encoding a polypeptide of 323 amino acids. The complete nucleotide sequence of MnCTLDcp3 cDNA was 583 bp, containing a 555 bp ORF encoding a putative protein of 184 deduced amino acids. The deduced MnCTLDcp2 and MnCTLDcp3 proteins both contained a single C-type lectin-like domain (CTLD). Besides, MnCTLDcp2 contains a signal peptide and an low-density lipoprotein receptor class A (LDLa) domain. Reverse transcription PCR showed that MnCTLDcp2 was expressed in the heart, gill, nerve hepatopancreas and intestine; MnCTLDcp3 was expressed in the hepatopancreas, heart, nerve, gill and muscle. Their expression in the heart tissue was regulated following challenge with bacteria. The microbial agglutination assay showed that both MnCTLDcp2 and MnCTLDcp3 could agglutinated bacteria in the presence of calcium. All these results suggested that MnCTLDcp2 and MnCTLDcp3 functioned as pattern recognition receptors in the immune system of M. nipponense. Copyright © 2015 Elsevier Ltd. All rights reserved.

  9. Bioactive Peptides

    Directory of Open Access Journals (Sweden)

    Eric Banan-Mwine Daliri

    2017-04-01

    Full Text Available The increased consumer awareness of the health promoting effects of functional foods and nutraceuticals is the driving force of the functional food and nutraceutical market. Bioactive peptides are known for their high tissue affinity, specificity and efficiency in promoting health. For this reason, the search for food-derived bioactive peptides has increased exponentially. Over the years, many potential bioactive peptides from food have been documented; yet, obstacles such as the need to establish optimal conditions for industrial scale production and the absence of well-designed clinical trials to provide robust evidence for proving health claims continue to exist. Other important factors such as the possibility of allergenicity, cytotoxicity and the stability of the peptides during gastrointestinal digestion would need to be addressed. This review discusses our current knowledge on the health effects of food-derived bioactive peptides, their processing methods and challenges in their development.

  10. Bioactive Peptides.

    Science.gov (United States)

    Daliri, Eric Banan-Mwine; Oh, Deog H; Lee, Byong H

    2017-04-26

    The increased consumer awareness of the health promoting effects of functional foods and nutraceuticals is the driving force of the functional food and nutraceutical market. Bioactive peptides are known for their high tissue affinity, specificity and efficiency in promoting health. For this reason, the search for food-derived bioactive peptides has increased exponentially. Over the years, many potential bioactive peptides from food have been documented; yet, obstacles such as the need to establish optimal conditions for industrial scale production and the absence of well-designed clinical trials to provide robust evidence for proving health claims continue to exist. Other important factors such as the possibility of allergenicity, cytotoxicity and the stability of the peptides during gastrointestinal digestion would need to be addressed. This review discusses our current knowledge on the health effects of food-derived bioactive peptides, their processing methods and challenges in their development.

  11. Macrophage galactose-type C-type lectin receptor for DC targeting of antitumor glycopeptide vaccines

    DEFF Research Database (Denmark)

    Nuti, M; Zizzari, I; Napoletano, C

    2011-01-01

    e13528 Background: Dendritic cells (DCs) are the most potent antigen presenting cells and are employed in cancer vaccination. Several receptors are being studied in order to identif strategies to increase DCs activating capacity. The C-type lectin macrophage galactose type C-type lectin (MGL...

  12. C-type lectins do not act as functional receptors for filovirus entry into cells

    Energy Technology Data Exchange (ETDEWEB)

    Matsuno, Keita; Nakayama, Eri; Noyori, Osamu [Department of Global Epidemiology, Hokkaido University Research Center for Zoonosis Control, Sapporo (Japan); Marzi, Andrea; Ebihara, Hideki [Laboratory of Virology, Division of Intramural Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rocky Mountain Laboratories, Hamilton, MT (United States); Irimura, Tatsuro [Graduate School of Pharmaceutical Science, University of Tokyo, Tokyo (Japan); Feldmann, Heinz [Laboratory of Virology, Division of Intramural Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rocky Mountain Laboratories, Hamilton, MT (United States); Takada, Ayato, E-mail: atakada@czc.hokudai.ac.jp [Department of Global Epidemiology, Hokkaido University Research Center for Zoonosis Control, Sapporo (Japan)

    2010-12-03

    Research highlights: {yields} Filovirus glycoprotein (GP) having a deficient receptor binding region were generated. {yields} Mutant GPs mediated virus entry less efficiently than wild-type GP. {yields} Mutant GPs bound to C-type lectins but not mediated entire steps of cellular entry. {yields} C-type lectins do not independently mediate filovirus entry into cells. {yields} Other molecule(s) are required for C-type lectin-mediated entry of filoviruses. -- Abstract: Cellular C-type lectins have been reported to facilitate filovirus infection by binding to glycans on filovirus glycoprotein (GP). However, it is not clearly known whether interaction between C-type lectins and GP mediates all the steps of virus entry (i.e., attachment, internalization, and membrane fusion). In this study, we generated vesicular stomatitis viruses pseudotyped with mutant GPs that have impaired structures of the putative receptor binding regions and thus reduced ability to infect the monkey kidney cells that are routinely used for virus propagation. We found that infectivities of viruses with the mutant GPs dropped in C-type lectin-expressing cells, parallel with those in the monkey kidney cells, whereas binding activities of these GPs to the C-type lectins were not correlated with the reduced infectivities. These results suggest that C-type lectin-mediated entry of filoviruses requires other cellular molecule(s) that may be involved in virion internalization or membrane fusion.

  13. Differential regulation of C-type lectin expression on tolerogenic dendritic cell subsets

    NARCIS (Netherlands)

    van Vliet, Sandra J.; van Liempt, Ellis; Geijtenbeek, Teunis B. H.; van Kooyk, Yvette

    2006-01-01

    Antigen presenting cells (APC) express high levels of C-type lectins, which play a major role in cellular interactions as well as pathogen recognition and antigen presentation. The C-type lectin macrophage galactose-type lectin (MGL), expressed by dendritic cells (DC) and macrophages, mediates

  14. A scallop C-type lectin from Argopecten irradians (AiCTL5) with activities of lipopolysaccharide binding and Gram-negative bacteria agglutination.

    Science.gov (United States)

    Mu, Changkao; Song, Xiaoyan; Zhao, Jianmin; Wang, Lingling; Qiu, Limei; Zhang, Huan; Zhou, Zhi; Wang, Mengqiang; Song, Linsheng; Wang, Chunlin

    2012-05-01

    C-type lectins are a family of calcium-dependent carbohydrate-binding proteins. In the present study, a C-type lectin (designated as AiCTL5) was identified and characterized from Argopecten irradians. The full-length cDNA of AiCTL5 was of 673 bp, containing a 5' untranslated region (UTR) of 24 bp, a 3' UTR of 130 bp with a poly (A) tail, and an open reading frame (ORF) of 519 bp encoding a polypeptide of 172 amino acids with a putative signal peptide of 17 amino acids. A C-type lectin-like domain (CRD) containing 6 conserved cysteines and a putative glycosylation sites were identified in the deduced amino acid sequence of AiCTL5. AiCTL5 shared 11%-27.5% identity with the previous reported C-type lectin from A. irradians. The cDNA fragment encoding the mature peptide of AiCTL5 was recombined into pET-21a (+) with a C-terminal hexa-histidine tag fused in-frame, and expressed in Escherichia coli Origami (DE3). The recombinant AiCTL5 (rAiCTL5) agglutinated Gram-negative E. coli TOP10F' and Listonella anguillarum, but did not agglutinate Gram-positive bacteria Bacillus thuringiensis and Micrococcus luteus, and the agglutination could be inhibited by EDTA, indicating that AiCTL5 was a Ca(2+)-dependent lectin. rAiCTL5 exhibited a significantly strong activity to bind LPS from E. coli, which conformed to the agglutinating activity toward Gram-negative bacteria. Moreover, rAiCTL5 also agglutinated rabbit erythrocytes. These results indicated that AiCTL5 could function as a pattern recognition receptor to protect bay scallop from Gram-negative bacterial infection, and also provide evidence to understand the structural and functional diverse of lectin. Copyright © 2012 Elsevier Ltd. All rights reserved.

  15. Peptide YY.

    Science.gov (United States)

    Chandarana, Keval; Batterham, Rachel

    2008-02-01

    This review discusses recent studies examining the effects of peptide YY on energy homeostasis, highlights the emerging hedonic effects of peptide YY and evaluates the therapeutic potential of the peptide YY system. A role for exogenous PYY3-36 as an anorectic agent in obese humans and rodents has been established and weight loss effects demonstrated in obese rodents. New lines of evidence support a role for endogenous peptide YY in regulating energy homeostasis. The NPY-Y2 receptor mediates the anorectic actions of PYY3-36 with rodent studies implicating the hypothalamus, vagus and brainstem as key target sites. Functional imaging in humans has confirmed that PYY3-36 activates brainstem and hypothalamic regions. The greatest effects, however, were observed within the orbitofrontal cortex, a brain region involved in reward processing. Further evidence for a hedonic role for PYY3-36 is supported by rodent studies showing that PYY3-36 decreases the motivation to seek high-fat food. Rodent studies using selective Y2 agonists and strategies combining PYY3-36/Y2 agonists with other anorectic agents have revealed increased anorectic and weight-reducing effects. Peptide YY plays a role in the integrative regulation of metabolism. The emerging hedonic effects of peptide YY together with the weight-reducing effects observed in obese rodents suggest that targeting the peptide YY system may offer a therapeutic strategy for obesity.

  16. Urinary osteocalcin and serum pro-C-type natriuretic peptide predict linear catch-up growth in infants

    DEFF Research Database (Denmark)

    Kilpeläinen, Leena; Ivaska, Kaisa K; Kuiri-Hänninen, Tanja

    2012-01-01

    Preterm (PT) infants are at risk of growth failure despite advanced early care and nutrition. In addition to poor weight gain, slow postnatal linear growth also is associated with adverse neurological outcome. Markers distinguishing infants at risk for impaired catch-up growth are needed. The aim......-MidOC levels, but not U-α-CTX-I and U-β-CTX-I levels, correlated positively with prospective growth velocity from M3 to M14 (ρ = 0.460, p

  17. Increased renal production of C-type natriuretic peptide (CNP) in patients with cirrhosis and functional renal failure

    DEFF Research Database (Denmark)

    Gülberg, V; Møller, S; Henriksen, Jens Henrik Sahl

    2000-01-01

    homeostasis. Therefore, the aim of the present study was to investigate the possible role of CNP in renal function disturbances in patients with cirrhosis of the liver. METHODS: Peripheral venous and urinary concentrations of CNP were determined in samples from 11 healthy controls, 20 cirrhotic patients...... with normal renal function (creatinine clearance 117 (8) ml/min), and 20 cirrhotic patients with impaired renal function (creatinine clearance 35 (4) ml/min). In a second protocol, arterial and renal venous plasma concentrations of CNP were determined in 37 patients with cirrhosis of the liver to estimate...... renal extraction ratios of CNP. A sensitive and specific radioimmunoassay was applied after solid phase extraction of samples. RESULTS: Plasma CNP was lower in cirrhotic patients with normal and impaired renal function than in controls (3.0 (0.4) and 2.7 (0.2) v. 4.2 (0.4) pg/ml, respectively; p

  18. N-terminal pro-C-type natriuretic peptide in serum associated with bone destruction in patients with multiple myeloma

    DEFF Research Database (Denmark)

    Mylin, Anne K; Goetze, Jens P; Heickendorff, Lene

    2015-01-01

    evaluated at specific time-points. RESULTS: N-terminal proCNP concentrations increased with age. High N-terminal proCNP concentrations were associated with high-risk disease and renal impairment. Renal function explained 22% of the variation. N-terminal proCNP concentrations correlated with serum bone ALP...... and serum PINP, but lacked association with bone resorption markers, radiographic bone disease and skeletal-related events. CONCLUSION: Serum N-terminal proCNP are associated with bone formation activity in patients with multiple myeloma, but should be interpreted with caution in patients with renal...

  19. Expression of guanylyl cyclase B in the human corpus cavernosum penis and the possible involvement of its ligand C-type natriuretic polypeptide in the induction of penile erection.

    Science.gov (United States)

    Küthe, Andrea; Reinecke, Manfred; Uckert, Stefan; Becker, Armin; David, Ivana; Heitland, Aleksandra; Stief, Christian G; Forssmann, Wolf-Georg; Mägert, Hans-Jürgen

    2003-05-01

    The induction of penile erection depends on the depletion of free intracellular Ca2+ from the cytosol into the sarcoplasmic reticulum of smooth muscle cells of the corpus cavernosum. This process is regulated by a complex system of signal transduction pathways. In this context guanylyl and adenylyl cyclases as well as cyclic nucleotide monophosphate degrading phosphodiesterases have essential roles and represent important target molecules for the development of drugs for erectile dysfunction. Sildenafil, which is an inhibitor of phosphodiesterase 5, is frequently used for this application but, unfortunately, it has undesirable side effects. Therefore, we investigated the suitability of membrane bound guanylyl cyclases as alternative target proteins. We determined mRNA transcripts specific for guanylyl cyclase B, a receptor of the peptide hormone C-type natriuretic polypeptide, in human corpus cavernosum. We performed immunohistochemistry to evaluate the presence of guanylyl cyclase B in corpus cavernosum and helical artery smooth muscle cells. We further investigated whether C-type natriuretic polypeptide increases intracellular cyclic guanosine monophosphate and performed organ bath studies using corpus cavernosum muscle strips and C-type natriuretic polypeptide at concentrations of 1 to 1 microM. mRNA transcripts were detected encoding for guanylyl cyclase-B, a receptor of the peptide hormone C-type natriuretic polypeptide, in human corpus cavernosum. This finding was verified at the protein level by immunohistochemistry that demonstrated guanylyl cyclase B in corpus cavernosum and helical artery smooth muscle cells. We further noted that C-type natriuretic polypeptide increased intracellular cyclic guanosine monophosphate. In organ bath studies with corpus cavernosum muscle strips C-type natriuretic polypeptide at concentrations of 1 to 1 microM. led to smooth muscle relaxation from 5% to 40%. The results indicate a role for C-type natriuretic polypeptide and

  20. Impacts of Shewanella oneidensis c-type cytochromes on aerobic and anaerobic respiration.

    Science.gov (United States)

    Gao, Haichun; Barua, Soumitra; Liang, Yili; Wu, Lin; Dong, Yangyang; Reed, Samantha; Chen, Jingrong; Culley, Dave; Kennedy, David; Yang, Yunfeng; He, Zhili; Nealson, Kenneth H; Fredrickson, James K; Tiedje, James M; Romine, Margaret; Zhou, Jizhong

    2010-07-01

    Shewanella are renowned for their ability to utilize a wide range of electron acceptors (EA) for respiration, which has been partially accredited to the presence of a large number of the c-type cytochromes. To investigate the involvement of c-type cytochrome proteins in aerobic and anaerobic respiration of Shewanella oneidensis Mr -1, 36 in-frame deletion mutants, among possible 41 predicted, c-type cytochrome genes were obtained. The potential involvement of each individual c-type cytochrome in the reduction of a variety of EAs was assessed individually as well as in competition experiments. While results on the well-studied c-type cytochromes CymA(SO4591) and MtrC(SO1778) were consistent with previous findings, collective observations were very interesting: the responses of S. oneidensis Mr -1 to low and highly toxic metals appeared to be significantly different; CcoO, CcoP and PetC, proteins involved in aerobic respiration in various organisms, played critical roles in both aerobic and anaerobic respiration with highly toxic metals as EA. In addition, these studies also suggested that an uncharacterized c-type cytochrome (SO4047) may be important to both aerobiosis and anaerobiosis. © 2010 The Authors. Journal compilation © 2010 Society for Applied Microbiology and Blackwell Publishing Ltd.

  1. Molecular and mass spectral identification of the broadly conserved decapod crustacean neuropeptide pQIRYHQCYFNPISCF: the first PISCF-allatostatin (Manduca sexta- or C-type allatostatin) from a non-insect

    OpenAIRE

    Stemmler, Elizabeth A.; Bruns, Emily A.; Cashman, Christopher R.; Dickinson, Patsy S.; Andrew E Christie

    2009-01-01

    The PISCF-allatostatins (Manduca sexta- or C-type allatostatins) are a family of pentadecapeptides characterized by a pyroglutamine blocked N-terminus, an unamidated –PISCF C-terminus, and a disulfide bridge between two internal Cys residues. Several isoforms of PISCF-AST are known, all from holometabolous insects. Using a combination of transcriptomics and mass spectrometry, we have identified the first PISCF-type peptides from a non-insect species. In silico analysis of crustacean ESTs iden...

  2. New insights into the role of natriuretic peptides in the regulation of apoptosis in cardiovascular system.

    Science.gov (United States)

    Gao, Pan; Huang, Lan

    2009-05-01

    Natriuretic peptides NPs are a family of structurally similar but genetically distinct peptides with paracrine and autocrine functions of regulating blood volume, blood pressure, ventricular hypertrophy, pulmonary hypertension, fat metabolism, and long bone growth. There are 3 main natriuretic peptides: atria natriuretic peptides ANP, brain natriuretic peptides BNP and C-type natriuretic peptides CNP. As investigations of the in vivo activities of natriuretic peptides were expanded, evidence suggested that natriuretic peptides might function as regulators of cell proliferation and/or death in a variety of tissues and cell types. Natriuretic peptides are much more frequently observed in cardiovascular system, the present discussion is focus on cell death in cardiovascular system, especially vascular endothelial cells ECs, vascular smooth muscle cells VSMCs, cardiac myocyte.

  3. Antimicrobial properties of avian eggshell-specific C-type lectin-like proteins.

    Science.gov (United States)

    Wellman-Labadie, Olivier; Lakshminarayanan, Rajamani; Hincke, Maxwell T

    2008-03-05

    C-type lectin-like proteins are major components of the calcified eggshell of multiple avian species. In this study, two representative avian C-type lectin-like proteins, ovocleidin-17 and ansocalcin, were purified from decalcified chicken and goose eggshell protein extracts and investigated for carbohydrate binding activity as well as antimicrobial activity. Purified ovocleidin-17 and ansocalcin were found to bind bacterial polysaccharides, and were bactericidal against Bacillus subtilis, Staphylococcus aureus and Pseudomona aeruginosa. Bactericidal activity was found to be enhanced in the presence of calcium but was not dependent on its presence. The results suggest that avian C-type lectin-like proteins may play an important antimicrobial role in defence of the avian embryo.

  4. DMPD: C-type lectin receptors in antifungal immunity. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available nds Microbiol. 2008 Jan;16(1):27-32. Epub 2007 Dec 21. (.png) (.svg) (.html) (.csml) Show C-type lectin rece... 2007 Dec 21. Pathway - PNG File (.png) SVG File (.svg) HTML File (.html) CSML File (.csml) Open .csml file

  5. Structure of the C-type lectin carbohydrate recognition domain of human tetranectin

    DEFF Research Database (Denmark)

    Kastrup, J S; Nielsen, B B; Rasmussen, H

    1998-01-01

    Tetranectin (TN) is a C-type lectin involved in fibrinolysis, being the only endogenous ligand known to bind specifically to the kringle 4 domain of plasminogen. TN was originally isolated from plasma, but shows a wide tissue distribution. Furthermore, TN has been found in the extracellular matrix...

  6. Dusting the sugar fingerprint: C-type lectin signaling in adaptive immunity

    NARCIS (Netherlands)

    den Dunnen, Jeroen; Gringhuis, Sonja I.; Geijtenbeek, Teunis B. H.

    2010-01-01

    Pathogen recognition by dendritic cells (DCs) is central to the induction of adaptive immunity. Pattern recognition receptors (PRRs) on DCs interact with pathogens, leading to signaling events that dictate adaptive immune responses. It is becoming clear that C-type lectins are important PRRs that

  7. Transmission-blocking antibodies against mosquito C-type lectins for dengue prevention.

    Directory of Open Access Journals (Sweden)

    Yang Liu

    2014-02-01

    Full Text Available C-type lectins are a family of proteins with carbohydrate-binding activity. Several C-type lectins in mammals or arthropods are employed as receptors or attachment factors to facilitate flavivirus invasion. We previously identified a C-type lectin in Aedes aegypti, designated as mosquito galactose specific C-type lectin-1 (mosGCTL-1, facilitating the attachment of West Nile virus (WNV on the cell membrane. Here, we first identified that 9 A. aegypti mosGCTL genes were key susceptibility factors facilitating DENV-2 infection, of which mosGCTL-3 exhibited the most significant effect. We found that mosGCTL-3 was induced in mosquito tissues with DENV-2 infection, and that the protein interacted with DENV-2 surface envelop (E protein and virions in vitro and in vivo. In addition, the other identified mosGCTLs interacted with the DENV-2 E protein, indicating that DENV may employ multiple mosGCTLs as ligands to promote the infection of vectors. The vectorial susceptibility factors that facilitate pathogen invasion may potentially be explored as a target to disrupt the acquisition of microbes from the vertebrate host. Indeed, membrane blood feeding of antisera against mosGCTLs dramatically reduced mosquito infective ratio. Hence, the immunization against mosGCTLs is a feasible approach for preventing dengue infection. Our study provides a future avenue for developing a transmission-blocking vaccine that interrupts the life cycle of dengue virus and reduces disease burden.

  8. C-type lectin receptors in the control of T helper cell differentiation

    NARCIS (Netherlands)

    Geijtenbeek, Teunis B. H.; Gringhuis, Sonja I.

    2016-01-01

    Pathogen recognition by C-type lectin receptors (CLRs) expressed by dendritic cells is important not only for antigen presentation, but also for the induction of appropriate adaptive immune responses via T helper (TH) cell differentiation. CLRs act either by themselves or in cooperation with other

  9. Modulation of the immune system by ligands of the C-type lectin DC-SIGN

    NARCIS (Netherlands)

    Gijzen, K.

    2007-01-01

    DC-SIGN is a C-type lectin specifically expressed on dendritic cells that recognize high-mannose and fucose glycans. This carbohydrate specificity of DC-SIGN enables recognition of a large array of ligands which include both pathogen-derived as well as endogenous glycoconjugates. Because of the wide

  10. Innate signaling by the C-type lectin DC-SIGN dictates immune responses

    NARCIS (Netherlands)

    Dunnen, den J.; Gringhuis, S.I.; Geijtenbeek, T.B.H.

    2009-01-01

    Effective immune responses depend on the recognition of pathogens by dendritic cells (DCs) through pattern recognition receptors (PRRs). These receptors induce specific signaling pathways that lead to the induction of immune responses against the pathogens. It is becoming evident that C-type lectins

  11. C-type lectin interactions with Schistosoma mansoni SEA : Molecular basis and function

    NARCIS (Netherlands)

    Liempt, van P.A.G.

    2007-01-01

    Outline of this thesis The studies described in this thesis have been performed to gain more insight in the recognition of Schistosoma mansoni glycans by C-type lectins and the consequences for dendritic cell mediated immune responses. As a first approach to understand the molecular interactions

  12. Carbohydrate signaling by C-type lectin DC-SIGN affects NF-kappaB activity

    NARCIS (Netherlands)

    Gringhuis, Sonja I.; Geijtenbeek, Teunis B. H.

    2010-01-01

    Pathogen recognition is central to the induction of adaptive immunity. Dendritic cells (DCs) express different pattern recognition receptors (PRRs), such as Toll-like receptors and C-type lectins, that sense invading pathogens. Pathogens trigger a specific set of PRRs, leading to activation of

  13. Dual function of C-type lectin-like receptors in the immune system.

    NARCIS (Netherlands)

    Cambi, A.; Figdor, C.G.

    2003-01-01

    Carbohydrate-binding C-type lectin and lectin-like receptors play an important role in the immune system. The large family can be subdivided into subtypes according to their structural similarities and functional differences. The selectins are of major importance in mediating cell adhesion and

  14. Human peptide transporters

    DEFF Research Database (Denmark)

    Nielsen, Carsten Uhd; Brodin, Birger; Jørgensen, Flemming Steen

    2002-01-01

    Peptide transporters are epithelial solute carriers. Their functional role has been characterised in the small intestine and proximal tubules, where they are involved in absorption of dietary peptides and peptide reabsorption, respectively. Currently, two peptide transporters, PepT1 and PepT2...... to peptide transporters, as well as their role in drug delivery and in potential future drug design and targeted tissue delivery of peptides and peptidomimetics....

  15. Occurrence and transmission efficiencies of Borrelia burgdorferi ospC types in avian and mammalian wildlife.

    Science.gov (United States)

    Vuong, Holly B; Canham, Charles D; Fonseca, Dina M; Brisson, Dustin; Morin, Peter J; Smouse, Peter E; Ostfeld, Richard S

    2014-10-01

    Borrelia burgdorferi s.s., the bacterium that causes Lyme disease in North America, circulates among a suite of vertebrate hosts and their tick vector. The bacterium can be differentiated at the outer surface protein C (ospC) locus into 25 genotypes. Wildlife hosts can be infected with a suite of ospC types but knowledge on the transmission efficiencies of these naturally infected hosts to ticks is still lacking. To evaluate the occupancy and detection of ospC types in wildlife hosts, we adapted a likelihood-based species patch occupancy model to test for the occurrence probabilities (ψ - "occupancy") and transmission efficiencies (ε - "detection") of each ospC type. We detected differences in ospC occurrence and transmission efficiencies from the null models with HIS (human invasive strains) types A and K having the highest occurrence estimates, but both HIS and non-HIS types having high transmission efficiencies. We also examined ospC frequency patterns with respect to strains known to be invasive in humans across the host species and phylogenetic groups. We found that shrews and to a lesser extent, birds, were important host groups supporting relatively greater frequencies of HIS to non-HIS types. This novel method of simultaneously assessing occurrence and transmission of ospC types provides a powerful tool in assessing disease risk at the genotypic level in naturally infected wildlife hosts and offers the opportunity to examine disease risk at the community level. Copyright © 2013 Elsevier B.V. All rights reserved.

  16. Optimal C-type Filter for Harmonics Mitigation and Resonance Damping in Industrial Distribution Systems

    OpenAIRE

    Abdel Aleem, SHE; Zobaa, AF

    2016-01-01

    Single-tuned passive filters offer reasonable mitigation for harmonic distortion at a specific harmonic frequency with a high filtering percentage, but resonance hazards exist. Traditional damped filters offer high-pass filtering for the high-frequency range, but suffer from extra ohmic losses. C-type filters may operate in a manner similar to the tuned filters with low damping losses and marginal resonance damping capabilities. Also, they can be designed as damped filters with increased reso...

  17. Modification of C-type inactivating Shaker potassium channels by chloramine-T.

    Science.gov (United States)

    Schlief, T; Schönherr, R; Heinemann, S H

    1996-02-01

    Shaker potassium channels undergo a slow C-type inactivation which can be hastened dramatically by single-point mutations in or near the pore region. We found that the oxidizing agent chloramine-T (Chl-T) causes an irreversible loss of current for those mutants which show C-type inactivation. For several mutants at position T449, which show a wide spectrum of inactivation time constants, the time constant of current rundown induced by Chl-T correlated with the speed of inactivation. Rundown was accelerated when the channels were in the inactivated state but rundown also occurred when channels were not opened or inactivated. Apparently, only those channels which can undergo C-type inactivation are accessible to Chl-T. In order to gain information about the target amino-acid residue for the action of Chl-T and the structural rearrangements occurring during C-type inactivation, several mutant channel proteins were compared with respect to their response to Chl-T. Since Chl-T can oxidize cysteine and methionine residues, we mutated the possible targets in and close to the pore region, namely C462 to A, and M440 and M448 to I. While the residues M440 and C462 were not important for channel rundown, mutation of M448 to I made the channels more resistant to Chl-T by about one order of magnitude. While inactivation was accelerated upon application of Chl-T in most mutants, mutation of M448 to I abolished this effect on the time course of inactivation, indicating that M448 is one of the target residues for Chl-T.

  18. Prenatal diagnosis of methymalonic aciduria and homocystinuria cblC type using DNA analysis

    Directory of Open Access Journals (Sweden)

    Antonietta Zappu

    2015-12-01

    Full Text Available Methylmalonic aciduria (MMA and homocystinuria, cblC type is the most frequent inborn error of vitamin B12. CblC patients present with a heterogeneous clinical picture.To date, the early prenatal diagnosis of MMA and homocystinuria, cblC type is performed by determination of methylmalonic acid and total homocysteine (Hcy in amniotic fluid supernatant. In this paper we report a case of prenatal diagnosis, using genetic analysis, of MMA and homocystinuria, cblC type in an at risk couple. Direct sequencing analysis of the amplified products of chorionic villi biopsy extracted DNA showed normal sequence in the fetal DNA. Mutation analysis of the MMACHC gene is more cost-effective and less time-consuming than the biochemical approach. Early prenatal treatment may have an impact on the long-term complications associated with cblC disease. Future studies with the aim of determining the long-term benefits of daily parenteral OHCbl started soon after conception in at risk mothers should be considered. In this context early prenatal diagnosis could determine whether therapy needs to be continued.

  19. Antimicrobial peptides in action

    NARCIS (Netherlands)

    Leontiadou, Hari; Mark, Alan E.; Marrink, Siewert J.

    2006-01-01

    Molecular dynamics simulations of the magainin MG-H2 peptide interacting with a model phospholipid membrane have been used to investigate the mechanism by which antimicrobial peptides act. Multiple copies of the peptide were randomly placed in solution close to the membrane. The peptide readily

  20. DIFFERENT ORIGINS OR DIFFERENT EVOLUTIONS? DECODING THE SPECTRAL DIVERSITY AMONG C-TYPE ASTEROIDS

    Energy Technology Data Exchange (ETDEWEB)

    Vernazza, P.; Marsset, M.; Groussin, O.; Lamy, P.; Jorda, L.; Mousis, O.; Delsanti, A. [Aix Marseille Univ, CNRS, LAM, Laboratoire d’Astrophysique de Marseille, Marseille (France); Castillo-Rogez, J. [Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA 91109 (United States); Beck, P. [UJF-Grenoble 1, CNRS-INSU, Institut de Planétologie et d’Astrophysique de Grenoble (IPAG), UMR 5274, Grenoble F-38041 (France); Emery, J. [Department of Earth and Planetary Sciences and Planetary Geosciences Institute, University of Tennessee, Knoxville, TN 37996-1410 (United States); Brunetto, R.; Djouadi, Z.; Dionnet, Z. [Institut d’Astrophysique Spatiale, CNRS, UMR-8617, Université Paris-Sud, bâtiment 121, F-91405 Orsay Cedex (France); Delbo, M.; Carry, B. [Laboratoire Lagrange, UNS-CNRS, Observatoire de la Cote d’Azur, Boulevard de l’Observatoire-CS 34229, F-06304 Nice Cedex 4 (France); Marchis, F. [Carl Sagan Center at the SETI Institute, Mountain View, CA 94043 (United States); Zanda, B. [IMCCE, Observatoire de Paris, 77 avenue Denfert-Rochereau, F-75014 Paris Cedex (France); Borondics, F., E-mail: pierre.vernazza@lam.fr [SMIS Beamline, Soleil Synchrotron, BP48, L’Orme des Merisiers, F-91192 Gif sur Yvette Cedex (France)

    2017-02-01

    Anhydrous pyroxene-rich interplanetary dust particles (IDPs) have been proposed as surface analogs for about two-thirds of all C-complex asteroids. However, this suggestion appears to be inconsistent with the presence of hydrated silicates on the surfaces of some of these asteroids, including Ceres. Here, we report the presence of enstatite (pyroxene) on the surface of two C-type asteroids (Ceres and Eugenia) based on their spectral properties in the mid-infrared range. The presence of this component is particularly unexpected in the case of Ceres, because most thermal evolution models predict a surface consisting of hydrated compounds only. The most plausible scenario is that Ceres’ surface has been partially contaminated by exogenous enstatite-rich material, possibly coming from the Beagle asteroid family. This scenario questions a similar origin for Ceres and the remaining C-types, and it possibly supports recent results obtained by the Dawn mission (NASA) that Ceres may have formed in the very outer solar system. Concerning the smaller D  ∼ 200 km C-types such as Eugenia, both their derived surface composition (enstatite and amorphous silicates) and low density (<1.5 g cm{sup −3}) suggest that these bodies accreted from the same building blocks, namely chondritic porous, pyroxene-rich IDPs and volatiles (mostly water ice), and that a significant volume fraction of these bodies has remained unaffected by hydrothermal activity likely implying a late accretion. In addition, their current heliocentric distance may best explain the presence or absence of water ice at their surfaces. Finally, we raise the possibility that CI chondrites, Tagish-Lake-like material, or hydrated IDPs may be representative samples of the cores of these bodies.

  1. A C-Type Lectin from Bothrops jararacussu Venom Disrupts Staphylococcal Biofilms

    Science.gov (United States)

    Klein, Raphael Contelli; Fabres-Klein, Mary Hellen; de Oliveira, Leandro Licursi; Feio, Renato Neves; Malouin, François; Ribon, Andréa de Oliveira Barros

    2015-01-01

    Bovine mastitis is a major threat to animal health and the dairy industry. Staphylococcus aureus is a contagious pathogen that is usually associated with persistent intramammary infections, and biofilm formation is a relevant aspect of the outcome of these infections. Several biological activities have been described for snake venoms, which led us to screen secretions of Bothrops jararacussu for antibiofilm activity against S. aureus NRS155. Crude venom was fractionated by size-exclusion chromatography, and the fractions were tested against S. aureus. Biofilm growth, but not bacterial growth, was affected by several fractions. Two fractions (15 and 16) showed the best activities and were also assayed against S. epidermidis NRS101. Fraction 15 was identified by TripleTOF mass spectrometry as a galactose-binding C-type lectin with a molecular weight of 15 kDa. The lectin was purified from the crude venom by D-galactose affinity chromatography, and only one peak was observed. This pure lectin was able to inhibit 75% and 80% of S. aureus and S. epidermidis biofilms, respectively, without affecting bacterial cell viability. The lectin also exhibited a dose-dependent inhibitory effect on both bacterial biofilms. The antibiofilm activity was confirmed using scanning electron microscopy. A pre-formed S. epidermidis biofilm was significantly disrupted by the C-type lectin in a time-dependent manner. Additionally, the lectin demonstrated the ability to inhibit biofilm formation by several mastitis pathogens, including different field strains of S. aureus, S. hyicus, S. chromogenes, Streptococcus agalactiae, and Escherichia coli. These findings reveal a new activity for C-type lectins. Studies are underway to evaluate the biological activity of these lectins in a mouse mastitis model. PMID:25811661

  2. [Surgical treatment for Tile C type pelvis fracture through posterior approach].

    Science.gov (United States)

    Chen, Zhi-wei; Yang, Le-zhong; Liu, Chun-lei

    2011-02-01

    To study the clinical results of surgical treatment for Tile C type pelvis fractures with internal fixation by posterior approach. From January 2005 to June 2009, 12 patients with Tile C type pelvis fracture were treated by open reduction through posterior approach. There were 8 males and 4 females, with an average age of 39.5 years ranging from 25 to 58 years. The time from injury to operation was ranged from 7 to 10 days with an average of 9.5 days. All the patients were given X-ray, 3-D CT examinations before operation. The fracture were classified by Tile classification: Type C1 in 5 cases, Type C2 in 2 cases, Type C1 and Type C2 in 4 cases, Type C3 in 1 case. All the posterior rings were fixed by re-establishing steel board without anterior ring fixation after stabilization of body condition. All the patients were treated with skin traction for 3 weeks after operation. All 12 patients were followed up for 6 months to 24 months with an average of 12.6 months. All the incisions healed well, and the fractures got union. No pelvic malunion, low back pain or leg length discrepancy was found. According to Majeed criteria for the evaluation of therapeutic effect, 10 patients were excellent, and 2 were good. In the management of the Tile C type pelvis fractures, a stable pelvis can be reconstructed by fixing posterior ring simply through the posterior approach, so that further sequelae can be reduced.

  3. Targeting of macrophage galactose-type C-type lectin (MGL) induces DC signaling and activation

    DEFF Research Database (Denmark)

    Napoletano, Chiara; Zizzari, Ilaria G; Rughetti, Aurelia

    2012-01-01

    Dendritic cells (DCs) sense the microenvironment through several types of receptors recognizing pathogen-associated molecular patterns. In particular, C-type lectins, expressed by distinct subsets of DCs, recognize and internalize specific carbohydrate antigen in a Ca(2+) -dependent manner....... Targeting of these receptors is becoming an efficient strategy of delivering antigens in DC-based anticancer immunotherapy. Here we investigated the role of the macrophage galactose type C-lectin receptor (MGL), expressed by immature DCs (iDCs), as a molecular target for a-N-acetylgalactosamine (Gal...

  4. Regulation of C-Type Lectin Receptor-Mediated Antifungal Immunity

    Directory of Open Access Journals (Sweden)

    Juan Tang

    2018-02-01

    Full Text Available Of all the pathogen recognition receptor families, C-type lectin receptor (CLR-induced intracellular signal cascades are indispensable for the initiation and regulation of antifungal immunity. Ongoing experiments over the last decade have elicited diverse CLR functions and novel regulatory mechanisms of CLR-mediated-signaling pathways. In this review, we highlight novel insights in antifungal innate and adaptive-protective immunity mediated by CLRs and discuss the potential therapeutic strategies against fungal infection based on targeting the mediators in the host immune system.

  5. Artefacts induced on c-type haem proteins by electrode surfaces

    OpenAIRE

    Sousa, Patrícia M. Paes de; Pauleta, Sofia R.; Gonçalves, M. Lurdes Simões; Pettigrew, Graham W.; Moura, Isabel; Moura, José J. G.; Santos, Margarida M. Correia dos

    2011-01-01

    J Biol Inorg Chem (2011) 16:209–215 DOI 10.1007/s00775-010-0717-z In this work it is demonstrated that the characterization of c-type haem containing proteins by electrochemical techniques needs to be cautiously performed when using pyrolytic graphite electrodes. An altered form of the cytochromes, which has a redox potential 300 mV lower than that of the native state and displays peroxidatic activity, can be induced by interaction with the pyrolytic graphite electrode. Proper control e...

  6. Crystalline and structural properties of acid-modified lotus rhizome C-type starch.

    Science.gov (United States)

    Cai, Jinwen; Cai, Canhui; Man, Jianmin; Yang, Yang; Zhang, Fengmin; Wei, Cunxu

    2014-02-15

    The crystalline and structural properties of acid-modified C-type starch from lotus rhizomes were investigated using a combination of techniques. The degradation of granule during hydrolysis began from the end distant from the hilum and then propagated into the center of granule, accompanied by loss of birefringence. The crystallinity changed from C-type to A-type via CA-type during hydrolysis. At the early stage of hydrolysis, the amylose content substantially reduced, the peak and conclusion gelatinization temperatures increased, and the enthalpy decreased. During hydrolysis, the double helix content gradually increased and the amorphous component decreased, the lamellar peak intensity firstly increased and then decreased accompanied by hydrolysis of amorphous and crystalline regions. This study elucidated that B-type allomorph was mainly arranged in the distal region of eccentric hilum, A-type allomorph was mainly located in the periphery of hilum end, and the center of granule was a mixed distribution of A- and B-type allomorphs. Copyright © 2013 Elsevier Ltd. All rights reserved.

  7. Molecular cloning and analysis of a C-type lectin from silkworm Bombyx mori.

    Science.gov (United States)

    Shahzad, Toufeeq; Zhan, Ming-Yue; Yang, Pei-Jin; Yu, Xiao-Qiang; Rao, Xiang-Jun

    2017-07-01

    C-type lectins (CTLs) play a variety of roles in plants and animals. They are involved in animal development, pathogen recognition, and the activation of immune responses. CTLs carry one or more non-catalytic carbohydrate-recognition domains (CRDs) to bind specific carbohydrates reversibly. Here, we report the molecular cloning and functional analysis of a single-CRD CTL, named C-type lectin-S2 (BmCTL-S2) from the domesticated silkmoth Bombyx mori (Lepidoptera: Bombycidae). The ORF of CTL-S2 is 666 bp, which encodes a putative protein of 221 amino acids. BmCTL-S2 is expressed in a variety of immune-related tissues, including hemocytes and fat body among others. BmCTL-S2 mRNA level in the midgut and the fat body was significantly increased by bacterial challenges. The recombinant protein (rBmCTL-S2) bound different bacterial cell wall components and bacterial cells. rBmCTL-S2 also inhibited the growth of Bacillus subtilis and Staphylococcus aureus. Taken together, we infer that BmCTL-S2 is a pattern-recognition receptor with antibacterial activities. © 2017 Wiley Periodicals, Inc.

  8. A novel C-type lectin is involved in the innate immunity of Macrobrachium nipponense.

    Science.gov (United States)

    Xiu, Yunji; Wang, Yinghui; Bi, Jingxiu; Liu, Yuhan; Ning, Mingxiao; Liu, Hui; Li, Shuang; Gu, Wei; Wang, Wen; Meng, Qingguo

    2016-03-01

    C-type lectins (CTLs) play important roles in invertebrate innate immunity by recognizing and eliminating pathogens. In the present study, a low-density lipoprotein receptor class A (LDLa) domain-containing CTL was identified from the oriental river prawn Macrobrachium nipponense, designated as MnCTLDcp1. The full-length cDNA of MnCTLDcp1 was composed of 1462 bp, with a 999-bp ORF encoding a 332-aa protein. An LDLa and a single C-type lectin-like domain (CTLD) were found. The mRNA transcripts of MnCTLDcp1 was expressed the highest in heart. After the prawns were challenged by Aeromonas hydrophila and Staphylococcus aureus, the expression level of MnCTLDcp1 in heart and hemocytes were all significantly up-regulated. Sugar binding assay revealed that the MnCTLDcp1 could bind to the glycoconjugates of bacteria surface, such as LPS, PGN and they can compete with bacterial as competitors. The recombinant MnCTLDcp1 agglutinates Gram-positive (S. aureus and Bacillus subtilis) and Gram-negative bacteria (A. hydrophila, Vibrio parahaemolyticus, Escherichia coli and Pseudomonas aeruginosa) in the presence of calcium and also could bind to these bacteria. These results clearly suggested that MnCTLDcp1 functions as a pattern-recognition receptor involved in the innate immunity of M. nipponense. Copyright © 2016 Elsevier Ltd. All rights reserved.

  9. C-type lectin binds to β-integrin to promote hemocytic phagocytosis in an invertebrate.

    Science.gov (United States)

    Wang, Xian-Wei; Zhao, Xiao-Fan; Wang, Jin-Xing

    2014-01-24

    Phagocytosis is a conserved cellular response among metazoans. Opsonins are some molecules that label targets to increase their susceptibility to phagocytosis. Opsonins are usually captured by receptors on the surface of phagocytes. Our previous study found the C-type lectin FcLec4 from Chinese white shrimp Fenneropenaeus chinensis might function as an opsonin to facilitate bacterial clearance. In the present study we purified the native FcLec4 protein and confirmed its opsonic activity in the near relation, kuruma shrimp Marsupenaeus japonicus. The possible receptor of FcLec4 was identified as β-integrin by panning a T7 phage display library of shrimp hemocytes and then confirmed by co-immunoprecipitation assay. We further proved that the interaction between FcLec4 and β-integrin did not rely on the carbohydrate recognition domain but on the N terminus of FcLec4. In addition, inhibition of FcLec4 expression using RNAi delayed bacterial clearance, and β-integrin knockdown suppressed the opsonic activity of FcLec4. This study is the first to show the direct interaction between an opsonin and its receptor in crustaceans. Our study provides new insights into invertebrate phagocytosis and the functions of C-type lectins.

  10. Human Antimicrobial Peptides and Proteins

    Directory of Open Access Journals (Sweden)

    Guangshun Wang

    2014-05-01

    Full Text Available As the key components of innate immunity, human host defense antimicrobial peptides and proteins (AMPs play a critical role in warding off invading microbial pathogens. In addition, AMPs can possess other biological functions such as apoptosis, wound healing, and immune modulation. This article provides an overview on the identification, activity, 3D structure, and mechanism of action of human AMPs selected from the antimicrobial peptide database. Over 100 such peptides have been identified from a variety of tissues and epithelial surfaces, including skin, eyes, ears, mouths, gut, immune, nervous and urinary systems. These peptides vary from 10 to 150 amino acids with a net charge between −3 and +20 and a hydrophobic content below 60%. The sequence diversity enables human AMPs to adopt various 3D structures and to attack pathogens by different mechanisms. While α-defensin HD-6 can self-assemble on the bacterial surface into nanonets to entangle bacteria, both HNP-1 and β-defensin hBD-3 are able to block cell wall biosynthesis by binding to lipid II. Lysozyme is well-characterized to cleave bacterial cell wall polysaccharides but can also kill bacteria by a non-catalytic mechanism. The two hydrophobic domains in the long amphipathic α-helix of human cathelicidin LL-37 lays the basis for binding and disrupting the curved anionic bacterial membrane surfaces by forming pores or via the carpet model. Furthermore, dermcidin may serve as ion channel by forming a long helix-bundle structure. In addition, the C-type lectin RegIIIα can initially recognize bacterial peptidoglycans followed by pore formation in the membrane. Finally, histatin 5 and GAPDH(2-32 can enter microbial cells to exert their effects. It appears that granulysin enters cells and kills intracellular pathogens with the aid of pore-forming perforin. This arsenal of human defense proteins not only keeps us healthy but also inspires the development of a new generation of personalized

  11. Importance of c-Type cytochromes for U(VI reduction by Geobacter sulfurreducens

    Directory of Open Access Journals (Sweden)

    Leang Ching

    2007-03-01

    Full Text Available Abstract Background In order to study the mechanism of U(VI reduction, the effect of deleting c-type cytochrome genes on the capacity of Geobacter sulfurreducens to reduce U(VI with acetate serving as the electron donor was investigated. Results The ability of several c-type cytochrome deficient mutants to reduce U(VI was lower than that of the wild type strain. Elimination of two confirmed outer membrane cytochromes and two putative outer membrane cytochromes significantly decreased (ca. 50–60% the ability of G. sulfurreducens to reduce U(VI. Involvement in U(VI reduction did not appear to be a general property of outer membrane cytochromes, as elimination of two other confirmed outer membrane cytochromes, OmcB and OmcC, had very little impact on U(VI reduction. Among the periplasmic cytochromes, only MacA, proposed to transfer electrons from the inner membrane to the periplasm, appeared to play a significant role in U(VI reduction. A subpopulation of both wild type and U(VI reduction-impaired cells, 24–30%, accumulated amorphous uranium in the periplasm. Comparison of uranium-accumulating cells demonstrated a similar amount of periplasmic uranium accumulation in U(VI reduction-impaired and wild type G. sulfurreducens. Assessment of the ability of the various suspensions to reduce Fe(III revealed no correlation between the impact of cytochrome deletion on U(VI reduction and reduction of Fe(III hydroxide and chelated Fe(III. Conclusion This study indicates that c-type cytochromes are involved in U(VI reduction by Geobacter sulfurreducens. The data provide new evidence for extracellular uranium reduction by G. sulfurreducens but do not rule out the possibility of periplasmic uranium reduction. Occurrence of U(VI reduction at the cell surface is supported by the significant impact of elimination of outer membrane cytochromes on U(VI reduction and the lack of correlation between periplasmic uranium accumulation and the capacity for uranium

  12. Dendroaspis natriuretic peptide in hepatic cirrhosis.

    Science.gov (United States)

    Fábrega, E; Crespo, J; Rivero, M; Casafont, F; Castro, B; García-Unzueta, M T; Amado, J A; Pons-Romero, F

    2001-09-01

    Dendroaspis natriuretic peptide (DNP) is a novel peptide that is structurally similar to atrial, brain, and C-type natriuretic peptides. Many natriuretic peptides are increased in hepatic cirrhosis, but the role of DNP in cirrhosis is unknown at present. The aim of the study was to investigate plasma levels of dendroaspis natriuretic-like immunoreactivity in cirrhosis. We measured plasma concentrations of DNP by radioimmunoassay methods in 12 cirrhotic patients without ascites and 44 cirrhotic patients with ascites, and compared these values with 20 age-matched healthy subjects. Renal function, plasma cGMP concentration, plasma renin activity, and plasma endothelin concentration were measured in each patient. Patients without ascites had circulating levels of DNP similar to those of healthy subjects. By contrast, patients with ascites had increased circulating DNP levels compared to both patients without ascites and healthy subjects. In addition, circulating levels of DNP increased in relation to the severity of cirrhosis. Significant positive correlations were also found between DNP levels, endothelin concentrations, and plasma renin activity. The results of this study indicate that plasma DNP is increased in cirrhotic patients with ascites.

  13. The C-type lectin like fold in natural killer cell receptors

    Czech Academy of Sciences Publication Activity Database

    Dohnálek, Jan; Skálová, Tereza; Kolenko, Petr; Kotýnková, Kristýna; Hašek, Jindřich; Man, Petr; Hanč, Pavel; Vaněk, Ondřej; Rozbeský, Daniel; Bezouška, Karel

    2012-01-01

    Roč. 19, č. 1 (2012), s. 14 ISSN 1211-5894. [Discussions in Structural Molecular Biology /10./. 22.03.2012-24.03.2012, Nové Hrady] R&D Projects: GA AV ČR KJB101120805; GA ČR GA303/09/0477; GA ČR GD305/09/H008; GA ČR GA305/07/1073; GA ČR GAP302/11/0855; GA ČR(CZ) GAP207/10/1040 EU Projects: European Commission(XE) 31220 - SPINE2-COMPLEXES Institutional research plan: CEZ:AV0Z40500505; CEZ:AV0Z50200510 Institutional support: RVO:61389013 ; RVO:61388971 Keywords : NK receptor * structure * C-type lectin like Subject RIV: EE - Microbiology, Virology; EB - Genetics ; Molecular Biology (MBU-M)

  14. The role of C-type lectin receptors in immune homeostasis.

    Science.gov (United States)

    Yan, Huimin; Ohno, Naohito; Tsuji, Noriko M

    2013-07-01

    C-type lectin receptors (CLRs) are important pathogen pattern recognition molecules that recognize carbohydrate structures. Upon ligand binding, CLRs induce a variety of cellular responses, such as respiratory burst, production of cytokines and chemokines, and consequently shaping the adaptive immune responses. Recent frontier studies have demonstrated that CLRs play a significant role in development of anti-inflammatory immune responses and maintenance of host immune-homeostasis. In this review we describe the major CLRs involved in production of IL-10 by immune-related cells and functional maturation of regulatory T cells. In addition, we discuss the potential role of CLRs signaling in regulating intestinal immune-homeostasis and inflammation. Further understanding of the precise role for these receptors on immunoregulatory cells will provide unexpected opportunities for developing new therapies for inflammatory diseases. Copyright © 2013 Elsevier B.V. All rights reserved.

  15. Rewiring monocyte glucose metabolism via C-type lectin signaling protects against disseminated candidiasis.

    Science.gov (United States)

    Domínguez-Andrés, Jorge; Arts, Rob J W; Ter Horst, Rob; Gresnigt, Mark S; Smeekens, Sanne P; Ratter, Jacqueline M; Lachmandas, Ekta; Boutens, Lily; van de Veerdonk, Frank L; Joosten, Leo A B; Notebaart, Richard A; Ardavín, Carlos; Netea, Mihai G

    2017-09-01

    Monocytes are innate immune cells that play a pivotal role in antifungal immunity, but little is known regarding the cellular metabolic events that regulate their function during infection. Using complementary transcriptomic and immunological studies in human primary monocytes, we show that activation of monocytes by Candida albicans yeast and hyphae was accompanied by metabolic rewiring induced through C-type lectin-signaling pathways. We describe that the innate immune responses against Candida yeast are energy-demanding processes that lead to the mobilization of intracellular metabolite pools and require induction of glucose metabolism, oxidative phosphorylation and glutaminolysis, while responses to hyphae primarily rely on glycolysis. Experimental models of systemic candidiasis models validated a central role for glucose metabolism in anti-Candida immunity, as the impairment of glycolysis led to increased susceptibility in mice. Collectively, these data highlight the importance of understanding the complex network of metabolic responses triggered during infections, and unveil new potential targets for therapeutic approaches against fungal diseases.

  16. Modeling the differentiation of A- and C-type baroreceptor firing patterns

    DEFF Research Database (Denmark)

    Sturdy, Jacob; Ottesen, Johnny T.; Olufsen, Mette

    2017-01-01

    of their axons and their distinct firing patterns elicited in response to specific pressure stimuli. This study has developed a comprehensive model of the afferent baroreceptor discharge built on physiological knowledge of arterial wall mechanics, firing rate responses to controlled pressure stimuli, and ion...... channel dynamics within the baroreceptor neurons. With this model, we were able to predict firing rates observed in previously published experiments in both A- and C-type neurons. These results were obtained by adjusting model parameters determining the maximal ion-channel conductances. The observed...... basal firing, whereas a tenfold higher mechanosensitive conductance is responsible for the greater firing rate observed in A-type neurons. A better understanding of the difference between the two neuron types can potentially be used to gain more insight into the underlying pathophysiology facilitating...

  17. Myeloid C-Type Lectin Receptors in Viral Recognition and Antiviral Immunity.

    Science.gov (United States)

    Monteiro, João T; Lepenies, Bernd

    2017-03-22

    Recognition of viral glycans by pattern recognition receptors (PRRs) in innate immunity contributes to antiviral immune responses. C-type lectin receptors (CLRs) are PRRs capable of sensing glycans present in viral pathogens to activate antiviral immune responses such as phagocytosis, antigen processing and presentation, and subsequent T cell activation. The ability of CLRs to elicit and shape adaptive immunity plays a critical role in the inhibition of viral spread within the host. However, certain viruses exploit CLRs for viral entry into host cells to avoid immune recognition. To block CLR interactions with viral glycoproteins, antiviral strategies may involve the use of multivalent glycan carrier systems. In this review, we describe the role of CLRs in antiviral immunity and we highlight their dual function in viral clearance and exploitation by viral pathogens.

  18. Quantitative Expression of C-Type Lectin Receptors in Humans and Mice

    Directory of Open Access Journals (Sweden)

    Hans-Joachim Anders

    2012-08-01

    Full Text Available C-type lectin receptors and their adaptor molecules are involved in the recognition of glycosylated self-antigens and pathogens. However, little is known about the species- and organ-specific expression profiles of these molecules. We therefore determined the mRNA expression levels of Dectin-1, MR1, MR2, DC-SIGN, Syk, Card-9, Bcl-10, Malt-1, Src, Dec-205, Galectin-1, Tim-3, Trem-1, and DAP-12 in 11 solid organs of human and mice. Mouse organs revealed lower mRNA levels of most molecules compared to spleen. However, Dec-205 and Galectin-1 in thymus, Src in brain, MR2, Card-9, Bcl-10, Src, and Dec-205 in small intestine, MR2, Bcl-10, Src, Galectin-1 in kidney, and Src and Galectin-1 in muscle were at least 2-fold higher expressed compared to spleen. Human lung, liver and heart expressed higher mRNA levels of most genes compared to spleen. Dectin-1, MR1, Syk and Trem-1 mRNA were strongly up-regulated upon ischemia-reperfusion injury in murine kidney. Tim3, DAP-12, Card-9, DC-SIGN and MR2 were further up-regulated during renal fibrosis. Murine kidney showed higher DAP-12, Syk, Card-9 and Dectin-1 mRNA expression during the progression of lupus nephritis. Thus, the organ-, and species-specific expression of C-type lectin receptors is different between mice and humans which must be considered in the interpretation of related studies.

  19. A C-type lectin (MrLec) with high expression in intestine is involved in innate immune response of Macrobrachium rosenbergii.

    Science.gov (United States)

    Feng, Jinling; Huang, Xin; Jin, Min; Zhang, Yi; Li, Tingting; Hui, Kaimin; Ren, Qian

    2016-12-01

    C-type lectins (CTLs) are pattern-recognition proteins that play an important role in innate immunity of vertebrates and invertebrates. In this study, a lectin cDNA named MrLec was cloned and characterized from giant freshwater prawns (Macrobrachiun rosenbergii). The full-length cDNA of MrLec was 1431 bp, which contained an open reading frame of 1041 bp that encoded a protein with 346 amino acids. MrLec was found to contain a typical signal peptide of 18 amino acids and a single carbohydrate-recognition domain with 121 amino acids. The phylogenetic analysis showed that MrLec was grouped with vertebrates and had 57% identity with C-type lectin 3 from Marsupenaeus japonicas. Tissue expression analysis showed that MrLec was ubiquitously distributed at a high level in the intestine, with lower expression levels in the hemocytes, heart, hepatopancreas, gill and stomach. Vibrio parahaemolyticus infection induced the upregulation of MrLec in the gills and intestine. For the white spot syndrome virus (WSSV) challenge, MrLec in gills was upregulated at 24, 36 and 48 h. In intestine, MrLec also went up at 36 and 48 h WSSV challenge. Recombinant MrLec can agglutinate (Ca2+-dependent) and bind both Gram-negative and Gram-positive bacteria. rMrLec could attach to lipopolysaccharide and peptidoglycan in a dose-dependent manner. These results indicated possible MrLec involvement in the immune response of giant freshwater prawns. Copyright © 2016 Elsevier Ltd. All rights reserved.

  20. Brain natriutetic peptide test

    Science.gov (United States)

    ... medlineplus.gov/ency/article/007509.htm Brain natriuretic peptide test To use the sharing features on this page, please enable JavaScript. Brain natriuretic peptide (BNP) test is a blood test that measures ...

  1. Vasoactive intestinal peptide test

    Science.gov (United States)

    ... medlineplus.gov/ency/article/003508.htm Vasoactive intestinal peptide test To use the sharing features on this page, please enable JavaScript. Vasoactive intestinal peptide (VIP) is a test that measures the amount ...

  2. TRH-like peptides.

    Science.gov (United States)

    Bílek, R; Bičíková, M; Šafařík, L

    2011-01-01

    TRH-like peptides are characterized by substitution of basic amino acid histidine (related to authentic TRH) with neutral or acidic amino acid, like glutamic acid, phenylalanine, glutamine, tyrosine, leucin, valin, aspartic acid and asparagine. The presence of extrahypothalamic TRH-like peptides was reported in peripheral tissues including gastrointestinal tract, placenta, neural tissues, male reproductive system and certain endocrine tissues. Work deals with the biological function of TRH-like peptides in different parts of organisms where various mechanisms may serve for realisation of biological function of TRH-like peptides as negative feedback to the pituitary exerted by the TRH-like peptides, the role of pEEPam such as fertilization-promoting peptide, the mechanism influencing the proliferative ability of prostatic tissues, the neuroprotective and antidepressant function of TRH-like peptides in brain and the regulation of thyroid status by TRH-like peptides.

  3. PeptideAtlas

    Data.gov (United States)

    U.S. Department of Health & Human Services — PeptideAtlas is a multi-organism, publicly accessible compendium of peptides identified in a large set of tandem mass spectrometry proteomics experiments. Mass...

  4. An activating mutation in the kinase homology domain of the natriuretic peptide receptor-2 causes extremely tall stature without skeletal deformities

    NARCIS (Netherlands)

    S.E. Hannema (Sabine); H.A. van Duyvenvoorde (Hermine); P. Thomas (Premsler); R.-B. Yang (Ruey-Bing); T.D. Mueller (Thomas); I.J. Gassner (Ingrid); H. Oberwinkler (Heike); F. Roelfsema (Ferdinand); G.W.E. Santen (Gijs); T. Prickett (Timothy); S.G. Kant (Sarina); A. Verkerk; A.G. Uitterlinden (André); E. Espiner (Eric); C.A. Ruivenkamp (Claudia); W. Oostdijk (Wilma); A.M. Pereira (Alberto); M. Losekoot (Monique); M. Kuhn (Michael); J.M. Wit (Jan)

    2013-01-01

    textabstractBackground: C-type natriuretic peptide (CNP)/natriuretic peptide receptor 2 (NPR2) signaling is essential for long bone growth. Enhanced CNP production caused by chromosomal translocations results in tall stature, a Marfanoid phenotype, and skeletal abnormalities.Asimilar phenotype was

  5. Peptide Nucleic Acids

    DEFF Research Database (Denmark)

    2003-01-01

    A novel class of compounds, known as peptide nucleic acids, bind complementary ssDNA and RNA strands more strongly than a corresponding DNA. The peptide nucleic acids generally comprise ligands such as naturally occurring DNA bases attached to a peptide backbone through a suitable linker....

  6. Peptide Nucleic Acids (PNA)

    DEFF Research Database (Denmark)

    2002-01-01

    A novel class of compounds, known as peptide nucleic acids, bind complementary ssDNA and RNA strands more strongly than a corresponding DNA. The peptide nucleic acids generally comprise ligands such as naturally occurring DNA bases attached to a peptide backbone through a suitable linker....

  7. Peptide Nucleic Acids

    DEFF Research Database (Denmark)

    1998-01-01

    A novel class of compounds, known as peptide nucleic acids, bind complementary ssDNA and RNA strands more strongly than a corresponding DNA. The peptide nucleic acids generally comprise ligands such as naturally occurring DNA bases attached to a peptide backbone through a suitable linker....

  8. PH dependent adhesive peptides

    Science.gov (United States)

    Tomich, John; Iwamoto, Takeo; Shen, Xinchun; Sun, Xiuzhi Susan

    2010-06-29

    A novel peptide adhesive motif is described that requires no receptor or cross-links to achieve maximal adhesive strength. Several peptides with different degrees of adhesive strength have been designed and synthesized using solid phase chemistries. All peptides contain a common hydrophobic core sequence flanked by positively or negatively charged amino acids sequences.

  9. Antimicrobial Peptides in 2014

    Directory of Open Access Journals (Sweden)

    Guangshun Wang

    2015-03-01

    Full Text Available This article highlights new members, novel mechanisms of action, new functions, and interesting applications of antimicrobial peptides reported in 2014. As of December 2014, over 100 new peptides were registered into the Antimicrobial Peptide Database, increasing the total number of entries to 2493. Unique antimicrobial peptides have been identified from marine bacteria, fungi, and plants. Environmental conditions clearly influence peptide activity or function. Human α-defensin HD-6 is only antimicrobial under reduced conditions. The pH-dependent oligomerization of human cathelicidin LL-37 is linked to double-stranded RNA delivery to endosomes, where the acidic pH triggers the dissociation of the peptide aggregate to release its cargo. Proline-rich peptides, previously known to bind to heat shock proteins, are shown to inhibit protein synthesis. A model antimicrobial peptide is demonstrated to have multiple hits on bacteria, including surface protein delocalization. While cell surface modification to decrease cationic peptide binding is a recognized resistance mechanism for pathogenic bacteria, it is also used as a survival strategy for commensal bacteria. The year 2014 also witnessed continued efforts in exploiting potential applications of antimicrobial peptides. We highlight 3D structure-based design of peptide antimicrobials and vaccines, surface coating, delivery systems, and microbial detection devices involving antimicrobial peptides. The 2014 results also support that combination therapy is preferred over monotherapy in treating biofilms.

  10. Peptide Nucleic Acid Synthons

    DEFF Research Database (Denmark)

    2004-01-01

    A novel class of compounds, known as peptide nucleic acids, bind complementary ssDNA and RNA strands more strongly than a corresponding DNA. The peptide nucleic acids generally comprise ligands such as naturally occurring DNA bases attached to a peptide backbone through a suitable linker....

  11. C-Peptide Test

    Science.gov (United States)

    ... Weisenberger, J. (2013 March) Why Does a C-Peptide Test Matter? Diabetes Forecast [On-line information]. Available online at http:// ... Updated). What is c-peptide? What do c-peptide levels mean? Misc.health.diabetes, diabetes FAQ [On-line information from newsgroup]. Available ...

  12. Monocyte galactose/N-acetylgalactosamine-specific C-type lectin receptor stimulant immunotherapy of an experimental glioma. Part II: combination with external radiation improves survival

    Directory of Open Access Journals (Sweden)

    Kushchayev SV

    2012-09-01

    Full Text Available Sergiy V Kushchayev,1 Tejas Sankar,1 Laura L Eggink,5,6 Yevgeniya S Kushchayeva,5 Philip C Wiener,1,5 J Kenneth Hoober,5,6 Jennifer Eschbacher,3 Ruolan Liu,2 Fu-Dong Shi,2 Mohammed G Abdelwahab,4 Adrienne C Scheck,4 Mark C Preul11Neurosurgery Research Laboratory, 2Neuroimmunology Laboratory, 3Department of Pathology, 4Neurooncology Research, Barrow Neurological Institute, St Joseph's Hospital and Medical Center, Phoenix, 5School of Life Sciences, Arizona State University, Tempe, 6Susavion Biosciences, Inc, Tempe, AZ, USABackground: A peptide mimetic of a ligand for the galactose/N-acetylgalactosamine-specific C-type lectin receptors (GCLR exhibited monocyte-stimulating activity, but did not extend survival when applied alone against a syngeneic murine malignant glioma. In this study, the combined effect of GCLRP with radiation was investigated.Methods: C57BL/6 mice underwent stereotactic intracranial implantation of GL261 glioma cells. Animals were grouped based on randomized tumor size by magnetic resonance imaging on day seven. One group that received cranial radiation (4 Gy on days seven and nine only were compared with animals treated with radiation and GCLRP (4 Gy on days seven and nine combined with subcutaneous injection of 1 nmol/g on alternative days beginning on day seven. Magnetic resonance imaging was used to assess tumor growth and correlated with survival rate. Blood and brain tissues were analyzed with regard to tumor and contralateral hemisphere using fluorescence-activated cell sorting analysis, histology, and enzyme-linked immunosorbent assay.Results: GCLRP activated peripheral monocytes and was associated with increased blood precursors of dendritic cells. Mean survival increased (P < 0.001 and tumor size was smaller (P < 0.02 in the GCLRP + radiation group compared to the radiation-only group. Accumulation of dendritic cells in both the tumoral hemisphere (P < 0.005 and contralateral tumor-free hemisphere (P< 0.01 was

  13. Macrophage Inducible C-Type Lectin As a Multifunctional Player in Immunity

    Directory of Open Access Journals (Sweden)

    Emmanuel C. Patin

    2017-07-01

    Full Text Available The macrophage-inducible C-type lectin (Mincle is an innate immune receptor on myeloid cells sensing diverse entities including pathogens and damaged cells. Mincle was first described as a receptor for the mycobacterial cell wall glycolipid, trehalose-6,6′-dimycolate, or cord factor, and the mammalian necrotic cell-derived alarmin histone deacetylase complex unit Sin3-associated protein 130. Upon engagement by its ligands, Mincle induces secretion of innate cytokines and other immune mediators modulating inflammation and immunity. Since its discovery more than 25 years ago, the understanding of Mincle’s immune function has made significant advances in recent years. In addition to mediating immune responses to infectious agents, Mincle has been linked to promote tumor progression, autoimmunity, and sterile inflammation; however, further studies are required to completely unravel the complex role of Mincle in these distinct host responses. In this review, we discuss recent findings on Mincle’s biology with an emphasis on its diverse functions in immunity.

  14. The Macrophage Galactose-Type C-Type Lectin (MGL Modulates Regulatory T Cell Functions.

    Directory of Open Access Journals (Sweden)

    Ilaria Grazia Zizzari

    Full Text Available Regulatory T cells (Tregs are physiologically designed to prevent autoimmune disease and maintain self-tolerance. In tumour microenvironments, their presence is related to a poor prognosis, and they influence the therapeutic outcome due to their capacity to suppress the immune response by cell-cell contact and to release immunosuppressive cytokines. In this study, we demonstrate that Treg immunosuppressive activity can be modulated by the cross-linking between the CD45RA expressed by Tregs and the C-type lectin MGL. This specific interaction strongly decreases the immunosuppressive activity of Tregs, restoring the proliferative capacity of co-cultured T lymphocytes. This effect can be attributed to changes in CD45RA and TCR signalling through the inhibition of Lck and inactivation of Zap-70, an increase in the Foxp3 methylation status and, ultimately, the reduced production of suppressive cytokines. These results indicate a role of MGL as an immunomodulator within the tumour microenvironment interfering with Treg functions, suggesting its possible use in the design of anticancer vaccines.

  15. Assessment of C-Type Darrieus Wind Turbine Under Low Wind Speed Condition

    Science.gov (United States)

    Misaran, M. S.; Rahman, Md. M.; Muzammil, W. K.; Ismail, M. A.

    2017-07-01

    Harvesting wind energy in in a low wind speed region is deem un-economical if not daunting task. Study shows that a minimum cut in speed of 3.5 m/s is required to extract a meaningful wind energy for electricity while a mean speed of 6 m/s is preferred. However, in Malaysia the mean speed is at 2 m/s with certain potential areas having 3 m/s mean speed. Thus, this work aims to develop a wind turbine that able to operate at lower cut-in speed and produce meaningful power for electricity generation. A C-type Darrieus blade is selected as it shows good potential to operate in arbitrary wind speed condition. The wind turbine is designed and fabricated in UMS labs while the performance of the wind turbine is evaluated in a simulated wind condition. Test result shows that the wind turbine started to rotate at 1 m/s compared to a NACA 0012 Darrieus turbine that started to rotate at 3 m/s. The performance of the turbine shows that it have good potential to be used in an intermittent arbitrary wind speed condition as well as low mean wind speed condition.

  16. Rewiring monocyte glucose metabolism via C-type lectin signaling protects against disseminated candidiasis.

    Directory of Open Access Journals (Sweden)

    Jorge Domínguez-Andrés

    2017-09-01

    Full Text Available Monocytes are innate immune cells that play a pivotal role in antifungal immunity, but little is known regarding the cellular metabolic events that regulate their function during infection. Using complementary transcriptomic and immunological studies in human primary monocytes, we show that activation of monocytes by Candida albicans yeast and hyphae was accompanied by metabolic rewiring induced through C-type lectin-signaling pathways. We describe that the innate immune responses against Candida yeast are energy-demanding processes that lead to the mobilization of intracellular metabolite pools and require induction of glucose metabolism, oxidative phosphorylation and glutaminolysis, while responses to hyphae primarily rely on glycolysis. Experimental models of systemic candidiasis models validated a central role for glucose metabolism in anti-Candida immunity, as the impairment of glycolysis led to increased susceptibility in mice. Collectively, these data highlight the importance of understanding the complex network of metabolic responses triggered during infections, and unveil new potential targets for therapeutic approaches against fungal diseases.

  17. Orthogonal plating of Vancouver B1 and C-type periprosthetic femur fracture nonunions.

    Science.gov (United States)

    Birch, Christopher E; Blankstein, Michael; Chlebeck, Jesse D; Bartlett Rd, Craig S

    2017-11-21

    Periprosthetic femoral shaft fractures are a significant complication after total hip arthroplasty (THA). Plate osteosynthesis has been the mainstay of treatment around well-fixed stems. Nonunions are a rare and challenging complication of this fixation method. We report the outcomes of a novel orthogonal plating surgical technique for Vancouver B1 and C-type periprosthetic fractures that previously failed open reduction internal fixation (ORIF). A retrospective review identified all patients with Vancouver B1/C THA periprosthetic femoral nonunions from 2010 to 2015. Exclusion criteria included open fractures and periprosthetic infections. The technique utilised a mechanobiologic strategy of atraumatic exposure, resection of necrotic tissue, bone grafting with adjuvant bone morphogenetic protein (BMP) and revision open reduction internal fixation with orthogonal plate osteosynthesis. 6 Vancouver B1/C periprosthetic femoral nonunions were treated. 5 patients were female with an average age of 80.3 years (range 72-91 years). The fractures occurred at a mean of 5.8 years (range 1-10 years) from their initial arthroplasty procedure. No patients underwent further revision surgery; there were no perioperative complications. All patients had a minimum of 11 months follow-up (mean 18.6, range 11-36 months). All fractures achieved osseous union, defined as solid bridging callus over at least 2 cortices and pain free, independent ambulation, at an average of 24.4 weeks (range 6.1-39.7 weeks). This is the 1st series describing orthogonal locked compression plating using modern implants for periprosthetic femoral nonunions. This technique should be considered in periprosthetic femur fracture nonunions around a well-fixed stem.

  18. Thermal Infrared Imaging Experiments of C-Type Asteroid 162173 Ryugu on Hayabusa2

    Science.gov (United States)

    Okada, Tatsuaki; Fukuhara, Tetsuya; Tanaka, Satoshi; Taguchi, Makoto; Imamura, Takeshi; Arai, Takehiko; Senshu, Hiroki; Ogawa, Yoshiko; Demura, Hirohide; Kitazato, Kohei; Nakamura, Ryosuke; Kouyama, Toru; Sekiguchi, Tomohiko; Hasegawa, Sunao; Matsunaga, Tsuneo; Wada, Takehiko; Takita, Jun; Sakatani, Naoya; Horikawa, Yamato; Endo, Ken; Helbert, Jörn; Müller, Thomas G.; Hagermann, Axel

    2017-07-01

    The thermal infrared imager TIR onboard Hayabusa2 has been developed to investigate thermo-physical properties of C-type, near-Earth asteroid 162173 Ryugu. TIR is one of the remote science instruments on Hayabusa2 designed to understand the nature of a volatile-rich solar system small body, but it also has significant mission objectives to provide information on surface physical properties and conditions for sampling site selection as well as the assessment of safe landing operations. TIR is based on a two-dimensional uncooled micro-bolometer array inherited from the Longwave Infrared Camera LIR on Akatsuki (Fukuhara et al., 2011). TIR takes images of thermal infrared emission in 8 to 12 μm with a field of view of 16 × 12° and a spatial resolution of 0.05° per pixel. TIR covers the temperature range from 150 to 460 K, including the well calibrated range from 230 to 420 K. Temperature accuracy is within 2 K or better for summed images, and the relative accuracy or noise equivalent temperature difference (NETD) at each of pixels is 0.4 K or lower for the well-calibrated temperature range. TIR takes a couple of images with shutter open and closed, the corresponding dark frame, and provides a true thermal image by dark frame subtraction. Data processing involves summation of multiple images, image processing including the StarPixel compression (Hihara et al., 2014), and transfer to the data recorder in the spacecraft digital electronics (DE). We report the scientific and mission objectives of TIR, the requirements and constraints for the instrument specifications, the designed instrumentation and the pre-flight and in-flight performances of TIR, as well as its observation plan during the Hayabusa2 mission.

  19. c-Type cytochrome-dependent formation of U(IV nanoparticles by Shewanella oneidensis.

    Directory of Open Access Journals (Sweden)

    Matthew J Marshall

    2006-09-01

    Full Text Available Modern approaches for bioremediation of radionuclide contaminated environments are based on the ability of microorganisms to effectively catalyze changes in the oxidation states of metals that in turn influence their solubility. Although microbial metal reduction has been identified as an effective means for immobilizing highly-soluble uranium(VI complexes in situ, the biomolecular mechanisms of U(VI reduction are not well understood. Here, we show that c-type cytochromes of a dissimilatory metal-reducing bacterium, Shewanella oneidensis MR-1, are essential for the reduction of U(VI and formation of extracellular UO(2 nanoparticles. In particular, the outer membrane (OM decaheme cytochrome MtrC (metal reduction, previously implicated in Mn(IV and Fe(III reduction, directly transferred electrons to U(VI. Additionally, deletions of mtrC and/or omcA significantly affected the in vivo U(VI reduction rate relative to wild-type MR-1. Similar to the wild-type, the mutants accumulated UO(2 nanoparticles extracellularly to high densities in association with an extracellular polymeric substance (EPS. In wild-type cells, this UO(2-EPS matrix exhibited glycocalyx-like properties and contained multiple elements of the OM, polysaccharide, and heme-containing proteins. Using a novel combination of methods including synchrotron-based X-ray fluorescence microscopy and high-resolution immune-electron microscopy, we demonstrate a close association of the extracellular UO(2 nanoparticles with MtrC and OmcA (outer membrane cytochrome. This is the first study to our knowledge to directly localize the OM-associated cytochromes with EPS, which contains biogenic UO(2 nanoparticles. In the environment, such association of UO(2 nanoparticles with biopolymers may exert a strong influence on subsequent behavior including susceptibility to oxidation by O(2 or transport in soils and sediments.

  20. MCL and mincle: C-type lectin receptors that sense damaged self and pathogen associated molecular patterns

    Directory of Open Access Journals (Sweden)

    Mark B Richardson

    2014-06-01

    Full Text Available MCL (macrophage C-type lectin and mincle (macrophage inducible C-type lectin comprise part of an extensive repertoire of pattern recognition receptors with the ability to sense damage associated and pathogen associated molecular patterns. In this review we cover the discovery and molecular characterization of these C-type lectin receptors, and highlight recent advances in the understanding of their roles in orchestrating the response of the immune system to bacterial and fungal infection, and damaged self. We also discuss the identification and structure-activity relationships of activating ligands, particularly trehalose dimycolate (TDM and related mycobacterial glycolipids, which have significant potential in the development of TH1/TH17 vaccination strategies.

  1. Topical peptides as cosmeceuticals

    Directory of Open Access Journals (Sweden)

    Varadraj Vasant Pai

    2017-01-01

    Full Text Available Peptides are known to have diverse biological roles, most prominently as signaling/regulatory molecules in a broad variety of physiological processes including defense, immunity, stress, growth, homeostasis and reproduction. These aspects have been used in the field of dermatology and cosmetology to produce short, stable and synthetic peptides for extracellular matrix synthesis, pigmentation, innate immunity and inflammation. The evolution of peptides over the century, which started with the discovery of penicillin, has now extended to their usage as cosmeceuticals in recent years. Cosmeceutical peptides may act as signal modulators of the extracellular matrix component, as structural peptides, carrier peptides and neurotransmitter function modulators. Transdermal delivery of peptides can be made more effective by penetration enhancers, chemical modification or encapsulation of peptides. The advantages of using peptides as cosmeceuticals include their involvement in many physiological functions of the skin, their selectivity, their lack of immunogenicity and absence of premarket regulatory requirements for their use. However, there are disadvantages: clinical evidence for efficacy is often weak, absorption may be poor due to low lipophilicity, high molecular weight and binding to other ingredients, and prices can be quite high.

  2. Antimicrobial Peptides in Reptiles

    Science.gov (United States)

    van Hoek, Monique L.

    2014-01-01

    Reptiles are among the oldest known amniotes and are highly diverse in their morphology and ecological niches. These animals have an evolutionarily ancient innate-immune system that is of great interest to scientists trying to identify new and useful antimicrobial peptides. Significant work in the last decade in the fields of biochemistry, proteomics and genomics has begun to reveal the complexity of reptilian antimicrobial peptides. Here, the current knowledge about antimicrobial peptides in reptiles is reviewed, with specific examples in each of the four orders: Testudines (turtles and tortosises), Sphenodontia (tuataras), Squamata (snakes and lizards), and Crocodilia (crocodilans). Examples are presented of the major classes of antimicrobial peptides expressed by reptiles including defensins, cathelicidins, liver-expressed peptides (hepcidin and LEAP-2), lysozyme, crotamine, and others. Some of these peptides have been identified and tested for their antibacterial or antiviral activity; others are only predicted as possible genes from genomic sequencing. Bioinformatic analysis of the reptile genomes is presented, revealing many predicted candidate antimicrobial peptides genes across this diverse class. The study of how these ancient creatures use antimicrobial peptides within their innate immune systems may reveal new understandings of our mammalian innate immune system and may also provide new and powerful antimicrobial peptides as scaffolds for potential therapeutic development. PMID:24918867

  3. Effect of natriuretic peptides on cerebral artery blood flow in healthy volunteers

    DEFF Research Database (Denmark)

    Guo, Song; Gøtze, Jens Peter; Jeppesen, Jørgen L

    2015-01-01

    ) by transcranial Doppler. In addition, we measured temporal and radial artery diameters, headache response and plasma concentrations of the NPs. In guinea pigs, ANP and BNP but not CNP showed significant dose-dependent relaxation of cerebral arteries. In healthy humans, NP infusion had no effect on mean VMCA......The natriuretic peptides (NPs), atrial natriuretic peptide (ANP), brain natriuretic peptide (BNP) and C-type natriuretic peptide (CNP), have vasoactive functions that concern humans and most animals, but their specific effects on cerebral circulation are poorly understood. We therefore examined...... the responsiveness of cerebral arteries to different doses of the natriuretic peptides in animals and humans. We conducted a dose-response experiment in guinea pigs (in vitro) and a double-blind, three-way cross-over study in healthy volunteers (in vivo). In the animal experiment, we administered cumulative doses...

  4. C-type lectin Mermaid inhibits dendritic cell mediated HIV-1 transmission to CD4+ T cells

    NARCIS (Netherlands)

    Nabatov, Alexey A.; de Jong, Marein A. W. P.; de Witte, Lot; Bulgheresi, Silvia; Geijtenbeek, Teunis B. H.

    2008-01-01

    Dendritic cells (DCs) are important in HIV-1 transmission; DCs capture invading HIV-1 through the interaction of the gp120 oligosaccharides with the C-type lectin DC-SIGN and migrate to the lymphoid tissues where HIV-1 is transmitted to T cells. Thus, the HIV-1 envelope glycoprotein gp120 is an

  5. Chicken lung lectin is a functional C-type lectin and inhibits haemagglutination by influenza A virus.

    NARCIS (Netherlands)

    Hogenkamp, A.|info:eu-repo/dai/nl/243274319; Isohadouten, N.; Reemers, S.S.N.|info:eu-repo/dai/nl/304836508; Romijn, R.A.|info:eu-repo/dai/nl/26228359X; Hemrika, W.|info:eu-repo/dai/nl/121631362; White, M.R.; Tefsen, B.; Vervelde, L.|info:eu-repo/dai/nl/134923391; van Eijk, M.|info:eu-repo/dai/nl/255160216; Veldhuizen, E.J.A.|info:eu-repo/dai/nl/19545264X; Haagsman, H.P.|info:eu-repo/dai/nl/069273278

    2008-01-01

    Many proteins of the calcium-dependent (C-type) lectin family have been shown to play an important role in innate immunity. They can bind to a broad range of carbohydrates, which enables them to interact with ligands present on the surface of micro-organisms.We previously reported the finding of a

  6. C-type lectins on dendritic cells and their interaction with pathogen-derived and endogenous glycoconjugates.

    NARCIS (Netherlands)

    Gijzen, K.; Cambi, A.; Torensma, R.; Figdor, C.G.

    2006-01-01

    Human C-type lectin receptors (CLRs) characteristically bind glycosylated ligands in a Ca(2+)-dependent way via their carbohydrate recognition domain (CRD). Their carbohydrate preference is dependent on the amino acid sequence in the CRD domain and on the ability and flexibility of the CRD domain to

  7. C-type lectin receptors and RIG-I-like receptors: new points on the oncogenomics map

    Directory of Open Access Journals (Sweden)

    Yuzhalin AE

    2012-02-01

    Full Text Available Anton G Kutikhin, Arseniy E YuzhalinDepartment of Epidemiology, Kemerovo State Medical Academy, Kemerovo, Russian FederationAbstract: The group of pattern recognition receptors includes families of Toll-like receptors, NOD-like receptors, C-type lectin receptors, and RIG-I-like receptors. They are key sensors for a number of infectious agents, some of which are oncogenic, and they launch an immune response against them, normally promoting their eradication. Inherited variations in genes encoding these receptors and proteins and their signaling pathways may affect their function, possibly modulating cancer risk and features of cancer progression. There are numerous studies investigating the association of single nucleotide polymorphisms within or near genes encoding Toll-like receptors and NOD-like receptors, cancer risk, and features of cancer progression. However, there is an almost total absence of articles analyzing the correlation between polymorphisms of genes encoding C-type lectin receptors and RIG-I-like receptors and cancer risk or progression. Nevertheless, there is some evidence supporting the hypothesis that inherited C-type lectin receptor and RIG-I-like receptor variants can be associated with increased cancer risk. Certain C-type lectin receptors and RIG-I-like receptors recognize pathogen-associated molecular patterns of potentially oncogenic infectious agents, and certain polymorphisms of genes encoding C-type lectin receptors and RIG-I-like receptors may have functional consequences at the molecular level that can lead to association of such single nucleotide polymorphisms with risk or progression of some diseases that may modulate cancer risk, so these gene polymorphisms may affect cancer risk indirectly. Polymorphisms of genes encoding C-type lectin receptors and RIG-I-like receptors thereby may be correlated with a risk of lung, oral, esophageal, gastric, colorectal, and liver cancer, as well as nasopharyngeal carcinoma

  8. PNA Peptide chimerae

    DEFF Research Database (Denmark)

    Koch, T.; Næsby, M.; Wittung, P.

    1995-01-01

    Radioactive labelling of PNA has been performed try linking a peptide segment to the PNA which is substrate for protein kinase A. The enzymatic phosphorylation proceeds in almost quantitative yields.......Radioactive labelling of PNA has been performed try linking a peptide segment to the PNA which is substrate for protein kinase A. The enzymatic phosphorylation proceeds in almost quantitative yields....

  9. GROUPS IN PEPTIDE SYNTHESIS

    African Journals Online (AJOL)

    In order to improve the synthesis of peptides with asparagine and glutamine residues, various carboxamide ... protecting groups in solid-phase peptide synthesis (SPPS). This method eliminates all .... to the filtrate, the solution was washed with three 9 mL portions of 5% aqueous citric acid, three 12 mL portions of 5% ...

  10. Multidimensional Design of Anticancer Peptides

    OpenAIRE

    Lin YC; Lim YF; Russo E.; Schneider P; Bolliger L; Edenharter A; Altmann KH; Halin C; Hiss JA; Schneider G

    2015-01-01

    The computer assisted design and optimization of peptides with selective cancer cell killing activity was achieved through merging the features of anticancer peptides cell penetrating peptides and tumor homing peptides. Machine learning classifiers identified candidate peptides that possess the predicted properties. Starting from a template amino acid sequence peptide cytotoxicity against a range of cancer cell lines was systematically optimized while minimizing the effects on primary human e...

  11. Acylation of Therapeutic Peptides

    DEFF Research Database (Denmark)

    Trier, Sofie; Henriksen, Jonas Rosager; Jensen, Simon Bjerregaard

    Oral administration of therapeutic peptides could benefit millions of chronically ill people worldwide, through easier and less stigmatized therapy, and likely improve the long-term effects of currently widespread disease mismanagement. However, oral peptide delivery is a formidable task due......, but it is not widely studied in an oral context. As acylation furthermore increases interactions with the lipid membranes of mammalian cells, it offers several potential benefits for oral delivery of therapeutic peptides, and we hypothesize that tailoring the acylation may be used to optimize intestinal translocation...... to the harsh and selective gastrointestinal system, and development has lacked far behind injection therapy. Peptide acylation is a powerful tool to alter the pharmacokinetics, biophysical properties and chemical stability of injectable peptide drugs, primarily used to prolong blood circulation...

  12. Descriptors for antimicrobial peptides

    DEFF Research Database (Denmark)

    Jenssen, Håvard

    2011-01-01

    Introduction: A frightening increase in the number of isolated multidrug resistant bacterial strains linked to the decline in novel antimicrobial drugs entering the market is a great cause for concern. Cationic antimicrobial peptides (AMPs) have lately been introduced as a potential new class...... of antimicrobial drugs, and computational methods utilizing molecular descriptors can significantly accelerate the development of new peptide drug candidates. Areas covered: This paper gives a broad overview of peptide and amino-acid scale descriptors available for AMP modeling and highlights which...... examples of different peptide QSAR studies, this review highlights some of the missing links and illuminates some of the questions that would be interesting to challenge in a more systematic fashion. Expert opinion: Computer-aided peptide QSAR using molecular descriptors may provide the necessary edge...

  13. mosGCTL-7, a C-Type Lectin Protein, Mediates Japanese Encephalitis Virus Infection in Mosquitoes.

    Science.gov (United States)

    Liu, Ke; Qian, Yingjuan; Jung, Yong-Sam; Zhou, Bin; Cao, Ruibing; Shen, Ting; Shao, Donghua; Wei, Jianchao; Ma, Zhiyong; Chen, Puyan; Zhu, Huaimin; Qiu, Yafeng

    2017-05-15

    Japanese encephalitis virus (JEV) is an arthropod-borne flavivirus prevalent in Asia and the Western Pacific and is the leading cause of viral encephalitis. JEV is maintained in a transmission cycle between mosquitoes and vertebrate hosts, but the molecular mechanisms by which the mosquito vector participates in transmission are unclear. We investigated the expression of all C-type lectins during JEV infection in Aedes aegypti The C-type lectin mosquito galactose-specific C-type lectin 7 (mosGCTL-7) (VectorBase accession no. AAEL002524) was significantly upregulated by JEV infection and facilitated infection in vivo and in vitro mosGCTL-7 bound to the N-glycan at N154 on the JEV envelope protein. This recognition of viral N-glycan by mosGCTL-7 is required for JEV infection, and we found that this interaction was Ca(2+) dependent. After mosGCTL-7 bound to the glycan, mosPTP-1 bound to mosGCTL-7, promoting JEV entry. The viral burden in vivo and in vitro was significantly decreased by mosPTP-1 double-stranded RNA (dsRNA) treatment, and infection was abolished by anti-mosGCTL-7 antibodies. Our results indicate that the mosGCTL-7/mosPTP-1 pathway plays a key role in JEV infection in mosquitoes. An improved understanding of the mechanisms underlying flavivirus infection in mosquitoes will provide further opportunities for developing new strategies to control viral dissemination in nature.IMPORTANCE Japanese encephalitis virus is a mosquito-borne flavivirus and is the primary cause of viral encephalitis in the Asia-Pacific region. Twenty-four countries in the WHO Southeast Asia and Western Pacific regions have endemic JEV transmission, which exposes >3 billion people to the risks of infection, although JEV primarily affects children. C-type lectins are host factors that play a role in flavivirus infection in humans, swine, and other mammals. In this study, we investigated C-type lectin functions in JEV-infected Aedes aegypti and Culex pipiens pallens mosquitoes and

  14. Molecular characterization, expression and antimicrobial activities of two c-type lysozymes from manila clam Venerupis philippinarum.

    Science.gov (United States)

    Yang, Dinglong; Wang, Qing; Cao, Ruiwen; Chen, Lizhu; Liu, Yongliang; Cong, Ming; Wu, Huifeng; Li, Fei; Ji, Chenglong; Zhao, Jianmin

    2017-08-01

    Lysozymes play an important role in the innate immune responses with which mollusks respond to bacterial invasion through its lytic activity. In the present study, two c-type lysozymes (designed as VpCLYZ-1 and VpCLYZ-2, respectively) were identified and characterized from the manila clam Venerupis philippinarum. The full-length cDNA of VpCLYZ-1 and VpCLYZ-2 was of 629 and 736 bp, encoding a polypeptide of 156 and153 amino acid residues, respectively. The deduced amino acid sequences of VpCLYZs showed high similarity to other known invertebrate c-type lysozymes. Multiple alignments and phylogenetic relationship strongly suggested that VpCLYZ-1 and VpCLYZ-2 belonged to the c-type lysozyme family. Both VpCLYZ-1 and VpCLYZ-2 transcripts were constitutively expressed in a wide range of tissues with different levels. The VpCLYZ-1 transcript was dominantly expressed in hepatopancreas and hemocytes, while VpCLYZ-2 transcript was mainly expressed in the tissues of hepatopancreas and gills. Both the mRNA expression of VpCLYZ-1 and VpCLYZ-2 was significantly up-regulated at 12 h post Vibrio anguillarum challenge. The recombinant VpCLYZ-1 and VpCLYZ-2 (designed as rVpCLYZ-1 and rVpCLYZ-2) exhibited lytic activity against all tested bacteria, and rVpCLYZ-1 showed higher activities than rVpCLYZ-2 in killing Micrococcus luteus and V. anguillarum. Overall, our results suggested that VpCLYZ-1 and VpCLYZ-2 belonged to the c-type lysozyme family, and played important roles in the immune responses of manila clam, especially in the elimination of pathogens. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. Molecular Characterization and Biological Effects of a C-Type Lectin-Like Receptor in Large Yellow Croaker (Larimichthys crocea

    Directory of Open Access Journals (Sweden)

    Jingqun Ao

    2015-12-01

    Full Text Available The C-type lectin-like receptors (CTLRs play important roles in innate immunity as one type of pattern recognition receptors. Here, we cloned and characterized a C-type lectin-like receptor (LycCTLR from large yellow croaker Larimichthys crocea. The full-length cDNA of LycCTLR is 880 nucleotides long, encoding a protein of 215 amino acids. The deduced LycCTLR contains a C-terminal C-type lectin-like domain (CTLD, an N-terminal cytoplasmic tail, and a transmembrane region. The CTLD of LycCTLR possesses six highly conserved cysteine residues (C1–C6, a conserved WI/MGL motif, and two sugar binding motifs, EPD (Glu-Pro-Asp and WYD (Trp-Tyr-Asp. Ca2+ binding site 1 and 2 were also found in the CTLD. The LycCTLR gene consists of five exons and four introns, showing the same genomic organization as tilapia (Oreochromis niloticus and guppy (Poecilia retitculata CTLRs. LycCTLR was constitutively expressed in various tissues tested, and its transcripts significantly increased in the head kidney and spleen after stimulation with inactivated trivalent bacterial vaccine. Recombinant LycCTLR (rLycCTLR protein produced in Escherichia coli BL21 exhibited not only the hemagglutinating activity and a preference for galactose, but also the agglutinating activity against two food-borne pathogenic bacteria E. coli and Bacillus cereus in a Ca2+-dependent manner. These results indicate that LycCTLR is a potential galactose-binding C-type lectin that may play a role in the antibacterial immunity in fish.

  16. An EPD/WSD motifs containing C-type lectin from Argopectens irradians recognizes and binds microbes with broad spectrum.

    Science.gov (United States)

    Huang, Mengmeng; Zhang, Huan; Jiang, Shuai; Wang, Lingling; Liu, Rui; Yi, Qilin; Song, Linsheng

    2015-03-01

    C-type lectins are a superfamily of Ca(2+)-dependent carbohydrate-recognition proteins consisting of at least one carbohydrate-recognition domain (CRD), which play significant roles in nonself-recognition and clearance of invaders. The immune function of a C-type lectin (AiCTL-7) with EPD/WSD motifs from Argopectens irradians was investigated in the present study. The recombinant protein of AiCTL-7 (rAiCTL-7) could bind LPS, PGN, mannan, yeast glucan and poly I:C in vitro, and displayed a broader microbes binding spectrum towards Gram-positive bacteria Staphylococcus aureus, Gram-negative bacteria Escherichia coli, Vibrio anguillarum, as well as fungi Pichia pastoris and Yarrowia lipolytica. Moreover, it could also inhibit the growth of E. coli and significantly (P EPD/WSD motifs containing lectin AiCTL-7 could serve as PRR with wider recognition spectrum, and function both as collectin and selectin participating in the immunity against invaders in scallops. It could be inferred that the diversity and complexity of motifs in Ca(2+) binding site 2 in CRDs endowed C-type lectins with comprehensive recognition spectrum and multiple immune functions against complex living environment. Copyright © 2015 Elsevier Ltd. All rights reserved.

  17. Insulin C-peptide

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/003701.htm Insulin C-peptide test To use the sharing features ... a product that is created when the hormone insulin is produced and released into the body. The ...

  18. Tumor penetrating peptides

    Directory of Open Access Journals (Sweden)

    Tambet eTeesalu

    2013-08-01

    Full Text Available Tumor-homing peptides can be used to deliver drugs into tumors. Phage library screening in live mice has recently identified homing peptides that specifically recognize the endothelium of tumor vessels, extravasate, and penetrate deep into the extravascular tumor tissue. The prototypic peptide of this class, iRGD (CRGDKGPDC, contains the integrin-binding RGD motif. RGD mediates tumor homing through binding to αv integrins, which are selectively expressed on various cells in tumors, including tumor endothelial cells. The tumor-penetrating properties of iRGD are mediated by a second sequence motif, R/KXXR/K. This C-end Rule (or CendR motif is active only when the second basic residue is exposed at the C-terminus of the peptide. Proteolytic processing of iRGD in tumors activates the cryptic CendR motif, which then binds to neuropilin-1 activating an endocytic bulk transport pathway through tumor tissue. Phage screening has also yielded tumor-penetrating peptides that function like iRGD in activating the CendR pathway, but bind to a different primary receptor. Moreover, novel tumor-homing peptides can be constructed from tumor-homing motifs, CendR elements and protease cleavage sites. Pathologies other than tumors can be targeted with tissue-penetrating peptides, and the primary receptor can also be a vascular zip code of a normal tissue. The CendR technology provides a solution to a major problem in tumor therapy, poor penetration of drugs into tumors. The tumor-penetrating peptides are capable of taking a payload deep into tumor tissue in mice, and they also penetrate into human tumors ex vivo. Targeting with these peptides specifically increases the accumulation in tumors of a variety of drugs and contrast agents, such as doxorubicin, antibodies and nanoparticle-based compounds. Remarkably the drug to be targeted does not have to be coupled to the peptide; the bulk transport system activated by the peptide sweeps along any compound that is

  19. Innovative Therapeutics: Designer Natriuretic Peptides.

    Science.gov (United States)

    Meems, Laura M G; Burnett, John C

    2016-12-01

    Endogenous natriuretic peptides serve as potent activators of particulate guanylyl cyclase receptors and the second messenger cGMP. Natriuretic peptides are essential in maintenance of volume homeostasis, and can be of myocardial, renal and endothelial origin. Advances in peptide engineering have permitted the ability to pursue highly innovative drug discovery strategies. This has resulted in designer natriuretic peptides that go beyond native peptides in efficacy, specificity, and resistance to enzymatic degradation. Together with recent improvements in peptide delivery systems, which have improved bioavailability, further advances in this field have been made. Therefore, designer natriuretic peptides with pleotropic actions together with strategies of chronic delivery have provided an unparalleled opportunity for the treatment of cardiovascular disease. In this review, we report the conceptual framework of peptide engineering of the natriuretic peptides that resulted in designer peptides for cardiovascular disease. We specifically provide an update on those currently in clinical trials for heart failure and hypertension, which include Cenderitide, ANX042 and ZD100.

  20. Peptide Nucleic Acids

    DEFF Research Database (Denmark)

    2004-01-01

    A novel class of compounds known as peptide nucleic acids, bind complementary DNA and RNA strands, and generally do so more strongly than the corresponding DNA or RNA strands while exhibiting increased sequence specificity and solubility. The peptide nucleic acids comprise ligands selected from a...... a group consisting of naturally-occurring nucleobases and non-naturally-occurring nucleobases, including 2,6-diaminopurine, attached to a polyamide backbone, and contain alkyl amine side chains....

  1. Natriuretic Peptides, Diagnostic and Prognostic Biomarkers

    NARCIS (Netherlands)

    J.H.W. Rutten (Joost)

    2010-01-01

    textabstractIn humans, the natriuretic peptide family consists of three different types of peptides: atrial natriuretic peptide (synonym: atrial natriuretic factor), B-type natriuretic peptide (synonym: brain natriuretic peptide) and C-natriuretic peptide.1 Atrial natriuretic peptide (ANP) was

  2. Natriuretic Peptides, Diagnostic and Prognostic Biomarkers

    OpenAIRE

    Rutten, Joost

    2010-01-01

    textabstractIn humans, the natriuretic peptide family consists of three different types of peptides: atrial natriuretic peptide (synonym: atrial natriuretic factor), B-type natriuretic peptide (synonym: brain natriuretic peptide) and C-natriuretic peptide.1 Atrial natriuretic peptide (ANP) was the fi rst natriuretic peptide to be discovered and in humans ANP is predominantly formed in the cardiomyocytes of the atria.2 B-type natriuretic peptide (BNP) was fi rst discovered in porcine brain hen...

  3. Granin-derived peptides.

    Science.gov (United States)

    Troger, Josef; Theurl, Markus; Kirchmair, Rudolf; Pasqua, Teresa; Tota, Bruno; Angelone, Tommaso; Cerra, Maria C; Nowosielski, Yvonne; Mätzler, Raphaela; Troger, Jasmin; Gayen, Jaur R; Trudeau, Vance; Corti, Angelo; Helle, Karen B

    2017-07-01

    The granin family comprises altogether 7 different proteins originating from the diffuse neuroendocrine system and elements of the central and peripheral nervous systems. The family is dominated by three uniquely acidic members, namely chromogranin A (CgA), chromogranin B (CgB) and secretogranin II (SgII). Since the late 1980s it has become evident that these proteins are proteolytically processed, intragranularly and/or extracellularly into a range of biologically active peptides; a number of them with regulatory properties of physiological and/or pathophysiological significance. The aim of this comprehensive overview is to provide an up-to-date insight into the distribution and properties of the well established granin-derived peptides and their putative roles in homeostatic regulations. Hence, focus is directed to peptides derived from the three main granins, e.g. to the chromogranin A derived vasostatins, betagranins, pancreastatin and catestatins, the chromogranin B-derived secretolytin and the secretogranin II-derived secretoneurin (SN). In addition, the distribution and properties of the chromogranin A-derived peptides prochromacin, chromofungin, WE14, parastatin, GE-25 and serpinins, the CgB-peptide PE-11 and the SgII-peptides EM66 and manserin will also be commented on. Finally, the opposing effects of the CgA-derived vasostatin-I and catestatin and the SgII-derived peptide SN on the integrity of the vasculature, myocardial contractility, angiogenesis in wound healing, inflammatory conditions and tumors will be discussed. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. Peptide Optical waveguides.

    Science.gov (United States)

    Handelman, Amir; Apter, Boris; Shostak, Tamar; Rosenman, Gil

    2017-02-01

    Small-scale optical devices, designed and fabricated onto one dielectric substrate, create integrated optical chip like their microelectronic analogues. These photonic circuits, based on diverse physical phenomena such as light-matter interaction, propagation of electromagnetic waves in a thin dielectric material, nonlinear and electro-optical effects, allow transmission, distribution, modulation, and processing of optical signals in optical communication systems, chemical and biological sensors, and more. The key component of these optical circuits providing both optical processing and photonic interconnections is light waveguides. Optical confinement and transmitting of the optical waves inside the waveguide material are possible due to the higher refractive index of the waveguides in comparison with their surroundings. In this work, we propose a novel field of bionanophotonics based on a new concept of optical waveguiding in synthetic elongated peptide nanostructures composed of ordered peptide dipole biomolecules. New technology of controllable deposition of peptide optical waveguiding structures by nanofountain pen technique is developed. Experimental studies of refractive index, optical transparency, and linear and nonlinear waveguiding in out-of-plane and in-plane diphenylalanine peptide nanotubes have been conducted. Optical waveguiding phenomena in peptide structures are simulated by the finite difference time domain method. The advantages of this new class of bio-optical waveguides are high refractive index contrast, wide spectral range of optical transparency, large optical nonlinearity, and electro-optical effect, making them promising for new applications in integrated multifunctional photonic circuits. Copyright © 2016 European Peptide Society and John Wiley & Sons, Ltd. Copyright © 2016 European Peptide Society and John Wiley & Sons, Ltd.

  5. Diversity-oriented peptide stapling

    DEFF Research Database (Denmark)

    Tran, Thu Phuong; Larsen, Christian Ørnbøl; Røndbjerg, Tobias

    2017-01-01

    The introduction of macrocyclic constraints in peptides (peptide stapling) is an important tool within peptide medicinal chemistry for stabilising and pre-organising peptides in a desired conformation. In recent years, the copper-catalysed azide-alkyne cycloaddition (CuAAC) has emerged...... as a powerful method for peptide stapling. However, to date CuAAC stapling has not provided a simple method for obtaining peptides that are easily diversified further. In the present study, we report a new diversity-oriented peptide stapling (DOPS) methodology based on CuAAC chemistry. Stapling of peptides...... incorporating two azide-modified amino acids with 1,3,5-triethynylbenzene efficiently provides (i, i+7)- and (i, i+9)-stapled peptides with a single free alkyne positioned on the staple, that can be further conjugated or dimerised. A unique feature of the present method is that it provides easy access...

  6. Recognition of DHN-melanin by a C-type lectin receptor is required for immunity to Aspergillus.

    Science.gov (United States)

    Stappers, Mark H T; Clark, Alexandra E; Aimanianda, Vishukumar; Bidula, Stefan; Reid, Delyth M; Asamaphan, Patawee; Hardison, Sarah E; Dambuza, Ivy M; Valsecchi, Isabel; Kerscher, Bernhard; Plato, Anthony; Wallace, Carol A; Yuecel, Raif; Hebecker, Betty; da Glória Teixeira Sousa, Maria; Cunha, Cristina; Liu, Yan; Feizi, Ten; Brakhage, Axel A; Kwon-Chung, Kyung J; Gow, Neil A R; Zanda, Matteo; Piras, Monica; Zanato, Chiara; Jaeger, Martin; Netea, Mihai G; van de Veerdonk, Frank L; Lacerda, João F; Campos, António; Carvalho, Agostinho; Willment, Janet A; Latgé, Jean-Paul; Brown, Gordon D

    2018-02-28

    Resistance to infection is critically dependent on the ability of pattern recognition receptors to recognize microbial invasion and induce protective immune responses. One such family of receptors are the C-type lectins, which are central to antifungal immunity. These receptors activate key effector mechanisms upon recognition of conserved fungal cell-wall carbohydrates. However, several other immunologically active fungal ligands have been described; these include melanin, for which the mechanism of recognition is hitherto undefined. Here we identify a C-type lectin receptor, melanin-sensing C-type lectin receptor (MelLec), that has an essential role in antifungal immunity through recognition of the naphthalene-diol unit of 1,8-dihydroxynaphthalene (DHN)-melanin. MelLec recognizes melanin in conidial spores of Aspergillus fumigatus as well as in other DHN-melanized fungi. MelLec is ubiquitously expressed by CD31 + endothelial cells in mice, and is also expressed by a sub-population of these cells that co-express epithelial cell adhesion molecule and are detected only in the lung and the liver. In mouse models, MelLec was required for protection against disseminated infection with A. fumigatus. In humans, MelLec is also expressed by myeloid cells, and we identified a single nucleotide polymorphism of this receptor that negatively affected myeloid inflammatory responses and significantly increased the susceptibility of stem-cell transplant recipients to disseminated Aspergillus infections. MelLec therefore recognizes an immunologically active component commonly found on fungi and has an essential role in protective antifungal immunity in both mice and humans.

  7. Association of a hepatopancreas-specific C-type lectin with the antibacterial response of Eriocheir sinensis.

    Directory of Open Access Journals (Sweden)

    Xing-Kun Jin

    Full Text Available Pattern recognition receptors (PPRs are part of the initial step of a host defense against pathogens in detecting pathogen-associated molecular patterns. However, determinants of the specificity of this recognition by innate immune molecules of invertebrates remain largely unknown. In this study, we investigated the potential involvement of an invertebrate PRR C-type lectin in the antimicrobial response of the crustacean Eriocheir sinensis. Based on the initial expressed sequence tags (EST of a hepatopancreatic cDNA library, the full-length EsLecF cDNA was cloned and determined to contain a 477-bp open reading frame encoding a putative 158-amino-acid protein. A comparison with other reported invertebrate and vertebrate C-type lectin superfamily sequences revealed the presence of a common carbohydrate recognition domain (CRD. EsLecF transcripts in E. sinensis were mainly detected in the hepatopancreas and were inducible by a lipopolysaccharide (LPS injection. The recombinant EsLecF (rEsLecF protein produced via a prokaryotic expression system and affinity chromatography was found to have a wide spectrum of binding activities towards various microorganisms, and its microbial-binding activity was calcium-independent. Moreover, the binding of rEsLecF induced the aggregation of microbial pathogens. Results of the microorganism growth inhibitory assay and antibacterial assay revealed capabilities of rEsLecF in suppressing microorganism growth and directly killing bacteria, respectively. Furthermore, rEsLecF could enhance cellular encapsulation in vitro. Collectively, the findings presented here demonstrated the successful isolation of a novel C-type lectin in a crustacean and highlighted its critical role in the innate immunity of an invertebrate.

  8. Antimicrobial Peptides from Plants

    Directory of Open Access Journals (Sweden)

    James P. Tam

    2015-11-01

    Full Text Available Plant antimicrobial peptides (AMPs have evolved differently from AMPs from other life forms. They are generally rich in cysteine residues which form multiple disulfides. In turn, the disulfides cross-braced plant AMPs as cystine-rich peptides to confer them with extraordinary high chemical, thermal and proteolytic stability. The cystine-rich or commonly known as cysteine-rich peptides (CRPs of plant AMPs are classified into families based on their sequence similarity, cysteine motifs that determine their distinctive disulfide bond patterns and tertiary structure fold. Cystine-rich plant AMP families include thionins, defensins, hevein-like peptides, knottin-type peptides (linear and cyclic, lipid transfer proteins, α-hairpinin and snakins family. In addition, there are AMPs which are rich in other amino acids. The ability of plant AMPs to organize into specific families with conserved structural folds that enable sequence variation of non-Cys residues encased in the same scaffold within a particular family to play multiple functions. Furthermore, the ability of plant AMPs to tolerate hypervariable sequences using a conserved scaffold provides diversity to recognize different targets by varying the sequence of the non-cysteine residues. These properties bode well for developing plant AMPs as potential therapeutics and for protection of crops through transgenic methods. This review provides an overview of the major families of plant AMPs, including their structures, functions, and putative mechanisms.

  9. Peptide Integrated Optics.

    Science.gov (United States)

    Handelman, Amir; Lapshina, Nadezda; Apter, Boris; Rosenman, Gil

    2018-02-01

    Bio-nanophotonics is a wide field in which advanced optical materials, biomedicine, fundamental optics, and nanotechnology are combined and result in the development of biomedical optical chips. Silk fibers or synthetic bioabsorbable polymers are the main light-guiding components. In this work, an advanced concept of integrated bio-optics is proposed, which is based on bioinspired peptide optical materials exhibiting wide optical transparency, nonlinear and electrooptical properties, and effective passive and active waveguiding. Developed new technology combining bottom-up controlled deposition of peptide planar wafers of a large area and top-down focus ion beam lithography provides direct fabrication of peptide optical integrated circuits. Finding a deep modification of peptide optical properties by reconformation of biological secondary structure from native phase to β-sheet architecture is followed by the appearance of visible fluorescence and unexpected transition from a native passive optical waveguiding to an active one. Original biocompatibility, switchable regimes of waveguiding, and multifunctional nonlinear optical properties make these new peptide planar optical materials attractive for application in emerging technology of lab-on-biochips, combining biomedical photonic and electronic circuits toward medical diagnosis, light-activated therapy, and health monitoring. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Fast response in-line gas sensor using C-type fiber and Ge-doped ring defect photonic crystal fiber.

    Science.gov (United States)

    Kassani, Sahar Hosseinzadeh; Park, Jiyoung; Jung, Yongmin; Kobelke, Jens; Oh, Kyunghwan

    2013-06-17

    An in-line chemical gas sensor was proposed and experimentally demonstrated using a new C-type fiber and a Ge-doped ring defect photonic crystal fiber (PCF). The C-type fiber segment served as a compact gas inlet/outlet directly spliced to PCF, which overcame previous limitations in packaging and dynamic responses. C-type fiber was prepared by optimizing drawing process for a silica tube with an open slot. Splicing conditions for SMF/C-type fiber and PCF/C-type fiber were experimentally established to provide an all-fiber sensor unit. To enhance the sensitivity and light coupling efficiency we used a special PCF with Ge-doped ring defect to further enhance the sensitivity and gas flow rate. Sensing capability of the proposed sensor was investigated experimentally by detecting acetylene absorption lines.

  11. Biomimetic peptide nanosensors.

    Science.gov (United States)

    Cui, Yue; Kim, Sang N; Naik, Rajesh R; McAlpine, Michael C

    2012-05-15

    The development of a miniaturized sensing platform tailored for sensitive and selective detection of a variety of biochemical analytes could offer transformative fundamental and technological opportunities. Due to their high surface-to-volume ratios, nanoscale materials are extremely sensitive sensors. Likewise, peptides represent robust substrates for selective recognition due to the potential for broad chemical diversity within their relatively compact size. Here we explore the possibilities of linking peptides to nanosensors for the selective detection of biochemical targets. Such systems raise a number of interesting fundamental challenges: What are the peptide sequences, and how can rational design be used to derive selective binders? What nanomaterials should be used, and what are some strategies for assembling hybrid nanosensors? What role does molecular modeling play in elucidating response mechanisms? What is the resulting performance of these sensors, in terms of sensitivity, selectivity, and response time? What are some potential applications? This Account will highlight our early attempts to address these research challenges. Specifically, we use natural peptide sequences or sequences identified from phage display as capture elements. The sensors are based on a variety of nanomaterials including nanowires, graphene, and carbon nanotubes. We couple peptides to the nanomaterial surfaces via traditional surface functionalization methods or self-assembly. Molecular modeling provides detailed insights into the hybrid nanostructure, as well as the sensor detection mechanisms. The peptide nanosensors can distinguish chemically camouflaged mixtures of vapors and detect chemical warfare agents with sensitivities as low as parts-per-billion levels. Finally, we anticipate future uses of this technology in biomedicine: for example, devices based on these sensors could detect disease from the molecular components in human breath. Overall, these results provide a

  12. Scavenger Receptor C-Type Lectin Binds to the Leukocyte Cell Surface Glycan Lewis By a Novel Mechanism

    Energy Technology Data Exchange (ETDEWEB)

    Feinberg, H.; Taylor, M.E.; Weis, W.I.; /Stanford U., Med. School /Imperial Coll., London

    2007-07-10

    The scavenger receptor C-type lectin (SRCL) is unique in the family of class A scavenger receptors, because in addition to binding sites for oxidized lipoproteins it also contains a C-type carbohydrate-recognition domain (CRD) that interacts with specific glycans. Both human and mouse SRCL are highly specific for the Lewis(x) trisaccharide, which is commonly found on the surfaces of leukocytes and some tumor cells. Structural analysis of the CRD of mouse SRCL in complex with Lewis(x) and mutagenesis show the basis for this specificity. The interaction between mouse SRCL and Lewis(x) is analogous to the way that selectins and DC-SIGN bind to related fucosylated glycans, but the mechanism of the interaction is novel, because it is based on a primary galactose-binding site similar to the binding site in the asialoglycoprotein receptor. Crystals of the human receptor lacking bound calcium ions reveal an alternative conformation in which a glycan ligand would be released during receptor-mediated endocytosis.

  13. Function of a novel C-type lectin with two CRD domains from Macrobrachium rosenbergii in innate immunity.

    Science.gov (United States)

    Huang, Xin; Huang, Ying; Shi, Yan-Ru; Ren, Qian; Wang, Wen

    2015-03-01

    C-type lectins play crucial roles in innate immunity. In the present study, a novel C-type lectin gene, designated as MrCTL, was identified from Macrobrachium rosenbergii. MrCTL contains 2 carbohydrate-recognition domains (CRDs), namely MrCRD1 and MrCRD2. The MrCRD1 contains a QEP motif and MrCRD2 contains a motif of EPD. MrCTL was mainly expressed in the hepatopancreas. The expression level of MrCTL in hepatopancreas was significantly upregulated after a challenge with Vibrio parahaemolyticus or White spot syndrome virus (WSSV). The recombinant MrCTL, MrCRD1 and MrCRD2 have an ability to agglutinate both Gram-negative (V. parahaemolyticus) and Gram-positive bacteria (Staphylococcus aureus) in a calcium dependent manner. The recombinant MrCTL, MrCRD1 and MrCRD2 bind directly to all tested microorganisms. All these results suggested that MrCTL may have important roles in immune defense against invading pathogens in prawns. Copyright © 2014 Elsevier Ltd. All rights reserved.

  14. Immunotherapy with Allergen Peptides

    Directory of Open Access Journals (Sweden)

    Larché Mark

    2007-06-01

    Full Text Available Specific allergen immunotherapy (SIT is disease-modifying and efficacious. However, the use of whole allergen preparations is associated with frequent allergic adverse events during treatment. Many novel approaches are being designed to reduce the allergenicity of immunotherapy preparations whilst maintaining immunogenicity. One approach is the use of short synthetic peptides which representing dominant T cell epitopes of the allergen. Short peptides exhibit markedly reduced capacity to cross link IgE and activate mast cells and basophils, due to lack of tertiary structure. Murine pre-clinical studies have established the feasibility of this approach and clinical studies are currently in progress in both allergic and autoimmune diseases.

  15. Therapeutic HIV Peptide Vaccine

    DEFF Research Database (Denmark)

    Fomsgaard, Anders

    2015-01-01

    Therapeutic vaccines aim to control chronic HIV infection and eliminate the need for lifelong antiretroviral therapy (ART). Therapeutic HIV vaccine is being pursued as part of a functional cure for HIV/AIDS. We have outlined a basic protocol for inducing new T cell immunity during chronic HIV-1...... infection directed to subdominant conserved HIV-1 epitopes restricted to frequent HLA supertypes. The rationale for selecting HIV peptides and adjuvants are provided. Peptide subunit vaccines are regarded as safe due to the simplicity, quality, purity, and low toxicity. The caveat is reduced immunogenicity...

  16. GROUPS IN PEPTIDE SYNTHESIS

    African Journals Online (AJOL)

    carboxamide protecting group in peptide synthesis. RESULTS AND DISCUSSION l-Tetralinylamines used as precursors to prepare the carboxamide derivatives of asparagine and glutamine are shown in Table 1: Table 1. Summary of l-tetralinyl amines. Amines Aromatic ring NHZ. X Y Z Z. 1 H H H. 2 OCH; H H. 3 H OCH ...

  17. Natriuretic peptides and cerebral hemodynamics

    DEFF Research Database (Denmark)

    Guo, Song; Barringer, Filippa; Zois, Nora Elisabeth

    2014-01-01

    Natriuretic peptides have emerged as important diagnostic and prognostic tools for cardiovascular disease. Plasma measurement of the bioactive peptides as well as precursor-derived fragments is a sensitive tool in assessing heart failure. In heart failure, the peptides are used as treatment...

  18. NCAM Mimetic Peptides: An Update

    DEFF Research Database (Denmark)

    Berezin, Vladimir; Bock, Elisabeth

    2008-01-01

    of combinatorial peptide libraries. The C3 and NBP10 peptides target the first Ig module whereas the ENFIN2 and ENFIN11 peptides target fibronectin type III (FN3) modules of NCAM. A number of NCAM mimetics can induce neurite outgrowth and exhibit neuroprotective and synaptic plasticity modulating properties...

  19. 'optimization' of animal peptide toxins

    African Journals Online (AJOL)

    McRoy

    peptides of ca. 4 to 70 amino acid residues, with a number of potential therapeutic applications.[1]. Because of the intrinsic structural complexities of these peptides (different types of fold and 1-5 disulfide bridges), this size range implicates that only a fraction of them (< 50-mer peptides) can routinely be produced by ...

  20. Peptide vectors for gene delivery: from single peptides to multifunctional peptide nanocarriers.

    Science.gov (United States)

    Raad, Markus de; Teunissen, Erik A; Mastrobattista, Enrico

    2014-07-01

    The therapeutic use of nucleic acids relies on the availability of sophisticated delivery systems for targeted and intracellular delivery of these molecules. Such a gene delivery should possess essential characteristics to overcome several extracellular and intracellular barriers. Peptides offer an attractive platform for nonviral gene delivery, as several functional peptide classes exist capable of overcoming these barriers. However, none of these functional peptide classes contain all the essential characteristics required to overcome all of the barriers associated with successful gene delivery. Combining functional peptides into multifunctional peptide vectors will be pivotal for improving peptide-based gene delivery systems. By using combinatorial strategies and high-throughput screening, the identification of multifunctional peptide vectors will accelerate the optimization of peptide-based gene delivery systems.

  1. [Biosynthesis of opioid peptides].

    Science.gov (United States)

    Rossier, J

    1988-01-01

    The endogenous opioid peptides all contain the enkephalin sequence Tyr-Gly-Gly-Phe-Met and Tyr-Gly-Gly-Phe-Leu at their aminoterminus. Three distinct families of these peptides (endorphins, enkephalins and dynorphins) are present in different neuronal pathways within the central nervous system. Molecular genetics have shown that these three families of opioid peptides are derived from three distinct precursors. Pro-opiomelanocortin gives rise to the endorphins, as well as adrenocorticotropic hormone (ACTH) and the melanotropic hormones (MSH's). [Met] enkephalin, [Leu] enkephalin and the related heptapeptide [Met] enkephalin-Arg6-Phe7 and octapeptide [Met] enkephalin-Arg6-Gly7-Leu8 are derived from proenkephalin. The third family is derived from prodynorphin and includes dynorphin A, dynorphin B (also known as rimorphin) and alpha- and beta-neo-endorphin. The structure of the genes coding for these precursors are similar, suggesting the possibility of one common ancestral gene. The most common scheme for enzymatic maturation of precursors proposes the action of a trypsin-like endopeptidase followed by a carboxypeptidase B-like exopeptidase. However, we have provided evidence that this combination of trypsin-like and carboxypeptidase B-like enzymes may not be the only mechanism for liberating enkephalin from low molecular weight enkephalin-containing peptides. Indeed, endo-oligopeptidase A, an enzyme, known to hydrolyze the Phe5-Ser6 bond of bradykinin and the Arg8-Arg9 bond of neurotensin, has been shown to produce, by a single cleavage, [Leu] enkephalin or [Met] enkephalin from small enkephalin-containing peptides, (Camargo et al., 1987, J. Neurochem. 48, 1258-1263).(ABSTRACT TRUNCATED AT 250 WORDS)

  2. Antagonistic peptide technology for functional dissection of CLE peptides revisited.

    Science.gov (United States)

    Czyzewicz, Nathan; Wildhagen, Mari; Cattaneo, Pietro; Stahl, Yvonne; Pinto, Karine Gustavo; Aalen, Reidunn B; Butenko, Melinka A; Simon, Rüdiger; Hardtke, Christian S; De Smet, Ive

    2015-08-01

    In the Arabidopsis thaliana genome, over 1000 putative genes encoding small, presumably secreted, signalling peptides can be recognized. However, a major obstacle in identifying the function of genes encoding small signalling peptides is the limited number of available loss-of-function mutants. To overcome this, a promising new tool, antagonistic peptide technology, was recently developed. Here, this antagonistic peptide technology was tested on selected CLE peptides and the related IDA peptide and its usefulness in the context of studies of peptide function discussed. Based on the analyses, it was concluded that the antagonistic peptide approach is not the ultimate means to overcome redundancy or lack of loss-of-function lines. However, information collected using antagonistic peptide approaches (in the broad sense) can be very useful, but these approaches do not work in all cases and require a deep insight on the interaction between the ligand and its receptor to be successful. This, as well as peptide ligand structure considerations, should be taken into account before ordering a wide range of synthetic peptide variants and/or generating transgenic plants. © The Author 2015. Published by Oxford University Press on behalf of the Society for Experimental Biology.

  3. High Bacterial Agglutination Activity in a Single-CRD C-Type Lectin from Spodoptera exigua (Lepidoptera: Noctuidae).

    Science.gov (United States)

    Gasmi, Leila; Ferré, Juan; Herrero, Salvador

    2017-03-01

    Lectins are carbohydrate-interacting proteins that play a pivotal role in multiple physiological and developmental aspects of all organisms. They can specifically interact with different bacterial and viral pathogens through carbohydrate-recognition domains (CRD). In addition, lectins are also of biotechnological interest because of their potential use as biosensors for capturing and identifying bacterial species. In this work, three C-type lectins from the Lepidoptera Spodoptera exigua were produced as recombinant proteins and their bacterial agglutination properties were characterized. The lowest protein concentration producing bacterial agglutination against a panel of different Gram+ and Gram- as well as their carbohydrate binding specificities was determined for the three lectins. One of these lectins, BLL2, was able to agglutinate cells from a broad range of bacterial species at an extremely low concentration, becoming a very interesting protein to be used as a biosensor or for other biotechnological applications involving bacterial capture.

  4. Identification of a Macrobrachium nipponense C-type lectin with a close evolutionary relationship to vertebrate lectins.

    Science.gov (United States)

    Huang, Xin; Li, Tingting; Jin, Min; Yin, Shaowu; Wang, Wen; Ren, Qian

    2017-07-01

    C-type lectins (CTLs) are involved in the innate immune defense of vertebrates and invertebrates against invading pathogens. This study cloned and characterized a novel C-type lectin (MnCTL) of the oriental river prawn, Macrobrachium nipponense. The cloned MnCTL cDNA encompasses an open reading frame of 774 nucleotides and encodes polypeptides of 257 residues. The deduced MnCTL protein contains a single carbohydrate recognition domain (CRD) with an EPN (Glu-Pro-Asn) motif in calcium-binding site 2. Phylogenetic analysis indicated that MnCTL has a closer evolutionary relationship with vertebrate lectins than with invertebrate lectins. Tissue expression analysis showed that high levels of MnCTL are ubiquitously distributed in the gills and stomach of M. nipponense. Quantitative real-time RT-PCR (qRT-PCR) analysis showed that MnCTL expression was up-regulated by bacteria or white spot syndrome virus (WSSV) challenge. Knock-down of the MnCTL gene in WSSV-challenged prawns significantly decreased MnALF1 and MnALF2 transcript levels. The recombinant MnCRD (rMnCRD) agglutinated both Gram-positive (Staphylococcus aureus) and Gram-negative bacteria (Vibrio parahaemolyticus) in the presence of calcium. Furthermore, rMnCRD could bind to all the tested bacteria with different activities. The sugar-binding assay showed that rMnCRD was able to bind lipopolysaccharide and peptidoglycan in a concentration-dependent manner. In addition, rMnCRD could accelerate bacterial clearance. On the contrary, MnCTL silencing by dsRNA interference could weaken the bacterial clearance ability. All these findings implicated MnCTL were involved in the antiviral and antibacterial innate immunity of M. nipponense. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. Differential contribution of sodium channel subtypes to action potential generation in unmyelinated human C-type nerve fibers.

    Science.gov (United States)

    Lang, Philip M; Hilmer, Verena B; Grafe, Peter

    2007-09-01

    Multiple voltage-dependent sodium channels (Na(v)) contribute to action potentials and excitability of primary nociceptive neurons. The aim of the current study was to characterize subtypes of Na(v) that contribute to action potential generation in peripheral unmyelinated human C-type nerve fibers. Registration of C-fiber compound action potentials and determination of membrane threshold was performed by a computerized threshold tracking program. Nerve fibers were stimulated with a 1-ms current pulse either alone or after a small ramp current lasting 300 ms. Compound C-fiber action potentials elicited by supramaximal 1-ms current pulses were rather resistant to application of tetrodotoxin (30-90 nM). However, the same concentrations of tetrodotoxin strongly reduced the peak height and elevated membrane threshold of action potentials evoked at the end of a 300-ms current ramp. A similar effect was observed during application of lidocaine and mexiletine (50 microM each). These data indicate that more than one type of Na(v) contributes to the generation of action potentials in unmyelinated human C-type nerve fibers. The peak height of an action potential produced by a short electrical impulse is dependent on the activation of tetrodotoxin-resistant ion channels. In contrast, membrane threshold and action potential peak height at the end of a slow membrane depolarization are regulated by a subtype of Na(v) with high sensitivity to low concentrations of tetrodotoxin, lidocaine, and mexiletine. The electrophysiologic and pharmacologic characteristics may indicate the functional activity of the Na(v) 1.7 subtype of voltage-dependent sodium channels.

  6. Radiolabelled peptides for oncological diagnosis

    Energy Technology Data Exchange (ETDEWEB)

    Laverman, Peter; Boerman, Otto C.; Oyen, Wim J.G. [Radboud University Nijmegen Medical Centre, Department of Nuclear Medicine, Nijmegen (Netherlands); Sosabowski, Jane K. [Queen Mary University of London, Centre for Molecular Oncology, Barts Cancer Institute, London (United Kingdom)

    2012-02-15

    Radiolabelled receptor-binding peptides targeting receptors (over)expressed on tumour cells are widely under investigation for tumour diagnosis and therapy. The concept of using radiolabelled receptor-binding peptides to target receptor-expressing tissues in vivo has stimulated a large body of research in nuclear medicine. The {sup 111}In-labelled somatostatin analogue octreotide (OctreoScan trademark) is the most successful radiopeptide for tumour imaging, and was the first to be approved for diagnostic use. Based on the success of these studies, other receptor-targeting peptides such as cholecystokinin/gastrin analogues, glucagon-like peptide-1, bombesin (BN), chemokine receptor CXCR4 targeting peptides, and RGD peptides are currently under development or undergoing clinical trials. In this review, we discuss some of these peptides and their analogues, with regard to their potential for radionuclide imaging of tumours. (orig.)

  7. Multidimensional Design of Anticancer Peptides.

    Science.gov (United States)

    Lin, Yen-Chu; Lim, Yi Fan; Russo, Erica; Schneider, Petra; Bolliger, Lea; Edenharter, Adriana; Altmann, Karl-Heinz; Halin, Cornelia; Hiss, Jan A; Schneider, Gisbert

    2015-08-24

    The computer-assisted design and optimization of peptides with selective cancer cell killing activity was achieved through merging the features of anticancer peptides, cell-penetrating peptides, and tumor-homing peptides. Machine-learning classifiers identified candidate peptides that possess the predicted properties. Starting from a template amino acid sequence, peptide cytotoxicity against a range of cancer cell lines was systematically optimized while minimizing the effects on primary human endothelial cells. The computer-generated sequences featured improved cancer-cell penetration, induced cancer-cell apoptosis, and were enabled a decrease in the cytotoxic concentration of co-administered chemotherapeutic agents in vitro. This study demonstrates the potential of multidimensional machine-learning methods for rapidly obtaining peptides with the desired cellular activities. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Antimicrobial Peptides (AMPs

    Directory of Open Access Journals (Sweden)

    Mehrzad Sadredinamin

    2016-04-01

    Full Text Available Antimicrobial peptides (AMPs are extensive group of molecules that produced by variety tissues of invertebrate, plants, and animal species which play an important role in their immunity response. AMPs have different classifications such as; biosynthetic machines, biological sources, biological functions, molecular properties, covalent bonding patterns, three dimensional structures, and molecular targets.These molecules have multidimensional properties including antimicrobial activity, antiviral activity, antifungal activity, anti-parasite activity, biofilm control, antitumor activity, mitogens activity and linking innate to adaptive immunity that making them promising agents for therapeutic drugs. In spite of this advantage of AMPs, their clinical developments have some limitation for commercial development. But some of AMPs are under clinical trials for the therapeutic purpose such as diabetic foot ulcers, different bacterial infections and tissue damage. In this review, we emphasized on the source, structure, multidimensional properties, limitation and therapeutic applications of various antimicrobial peptides.

  9. Antimicrobial peptides in annelids

    OpenAIRE

    Tasiemski, A.

    2008-01-01

    Gene encoded antimicrobial peptides (AMPs) are widely distributed among living organisms including plants, invertebrates and vertebrates. They constitute important effectors of the innate immune response by exerting multiple roles as mediators of inflammation with impact on epithelial and inflammatory cells influencing diverse processes such as cytokine release, cell proliferation, angiogenesis, wound healing, chemotaxis and immune induction. In invertebrates, most of the data describe the ch...

  10. Monocyte galactose/N-acetylgalactosamine-specific C-type lectin receptor stimulant immunotherapy of an experimental glioma. Part 1: stimulatory effects on blood monocytes and monocyte-derived cells of the brain

    Directory of Open Access Journals (Sweden)

    Kushchayev SV

    2012-09-01

    Full Text Available Sergiy V Kushchayev,1 Tejas Sankar,1 Laura L Eggink,4,5 Yevgeniya S Kushchayeva,5 Philip C Wiener,1,5 J Kenneth Hoober,5,6 Jennifer Eschbacher,3 Ruolan Liu,2 Fu-Dong Shi,2 Mohammed G Abdelwahab,4 Adrienne C Scheck,4 Mark C Preul11Neurosurgery Research Laboratory, 2Neuroimmunology Laboratory, 3Department of Pathology, 4Neurooncology Research, Barrow Neurological Institute, St Joseph's Hospital and Medical Center, Phoenix, 5School of Life Sciences, Arizona State University, Tempe, 6Susavion Biosciences, Inc, Tempe, AZ, USAObjectives: Immunotherapy with immunostimulants is an attractive therapy against gliomas. C-type lectin receptors specific for galactose/N-acetylgalactosamine (GCLR regulate cellular differentiation, recognition, and trafficking of monocyte-derived cells. A peptide mimetic of GCLR ligands (GCLRP was used to activate blood monocytes and populations of myeloid-derived cells against a murine glioblastoma.Methods: The ability of GCLRP to stimulate phagocytosis by human microglia and monocyte-derived cells of the brain (MDCB isolated from a human glioblastoma was initially assessed in vitro. Induction of activation markers on blood monocytes was assayed by flow cytometry after administration of GCLRP to naive mice. C57BL/6 mice underwent stereotactic intracranial implantation of GL261 glioma cells and were randomized for tumor size by magnetic resonance imaging, which was also used to assess increase in tumor size. Brain tumor tissues were analyzed using flow cytometry, histology, and enzyme-linked immunosorbent assay with respect to tumor, peritumoral area, and contralateral hemisphere regions.Results: GCLRP exhibited strong stimulatory effect on MDCBs and blood monocytes in vitro and in vivo. GCLRP was associated with an increased percentage of precursors of dendritic cells in the blood (P = 0.003, which differentiated into patrolling macrophages in tumoral (P = 0.001 and peritumoral areas (P = 0.04, rather than into dendritic cells

  11. Venom of parasitoid, Pteromalus puparum, suppresses host, Pieris rapae, immune promotion by decreasing host C-type lectin gene expression.

    Directory of Open Access Journals (Sweden)

    Qi Fang

    Full Text Available Insect hosts have evolved immunity against invasion by parasitoids, and in co-evolutionary response parasitoids have also developed strategies to overcome host immune systems. The mechanisms through which parasitoid venoms disrupt the promotion of host immunity are still unclear. We report here a new mechanism evolved by parasitoid Pteromalus puparum, whose venom inhibited the promotion of immunity in its host Pieris rapae (cabbage white butterfly.A full-length cDNA encoding a C-type lectin (Pr-CTL was isolated from P. rapae. Quantitative PCR and immunoblotting showed that injection of bacterial and inert beads induced expression of Pr-CTL, with peaks of mRNA and Pr-CTL protein levels at 4 and 8 h post beads challenge, respectively. In contrast, parasitoid venom suppressed Pr-CTL expression when co-injected with beads, in a time and dose-dependent manner. Immunolocalization and immunoblotting results showed that Pr-CTL was first detectable in vesicles present in cytoplasm of granulocytes in host hemolymph, and was then secreted from cells into circulatory fluid. Finally, the secreted Pr-CTL bound to cellular membranes of both granulocytes and plasmatocytes. Injection of double-stranded RNA specific for target gene decreased expression of Pr-CTL, and a few other host immune-related genes. Suppression of Pr-CTL expression also down-regulated antimicrobial and phenoloxidase activities, and reducing phagocytotic and encapsulation rates in host. The inhibitory effect of parasitoid venom on host encapsulation is consistent with its effect in suppressing Pr-CTL expression. Binding assay results showed that recombinant Pr-CTL directly attached to the surface of P. puparum egges. We infer that Pr-CTL may serve as an immune signalling co-effector, first binding to parasitoid eggs, regulating expression of a set of immune-related genes and promoting host immunity.P. puparum venom inhibits promotion of host immune responses by silencing expression of host C-type

  12. CNP signal peptide (CNPsp in patients with cardiovascular disease

    Directory of Open Access Journals (Sweden)

    Jacqui eLee

    2015-06-01

    Full Text Available We have previously reported that signal peptide fragments of C-type natriuretic peptide (CNP are present in the human circulation. Here, we provide the first preliminary assessment of the potential utility of CNP signal peptide (CNPsp measurement in acute cardiovascular disease. Utilising our specific and sensitive immunoassay, we assessed the potential of CNPsp measurement to assist in the identification of acute coronary syndromes in 494 patients presenting consecutively with chest pain. The diagnostic and prognostic potential of CNPsp was assessed in conjunction with a contemporary clinical troponin I assay, an investigational highly sensitive troponin T assay and NT-proBNP measurement. Utility was assessed via receiver operator curve characteristic analysis.CNPsp did not identify patients with myocardial infarction (MI or those with unstable angina, nor did it assist the diagnostic ability of clinical or investigational troponin measurement. CNPsp levels were significantly elevated in patients presenting with atrial fibrillation (P<0.05 and were significantly lower in those with a history of previous MI (P<0.05. CNPsp could identify those at risk of mortality within 1 year (P<0.05 and also could identify those at risk of death or re-infarction within 1 year (P<0.01. This is the first exploratory report describing the potential of CNPsp measurement in acute cardiovascular disease. Whilst CNPsp does not have utility in acute diagnosis, it may have potential in assisting risk prognosis with respect to mortality and re-infarction.

  13. Peptide-enhanced oral delivery of therapeutic peptides and proteins

    DEFF Research Database (Denmark)

    Kristensen, Mie; Foged, Camilla; Berthelsen, Jens

    2013-01-01

    Systemic therapy upon oral delivery of biologics, such as peptide and protein drugs is limited due to their large molecular size, their low enzymatic stability and their inability to cross the intestinal epithelium. Ways to overcome the epithelial barrier include the use of peptide-based excipients...... throughout the gastrointestinal (GI) tract, chemical stability is an inherent challenge when employing amino acid-based excipients for oral delivery, and multiple approaches have been investigated to improve this. The exact mechanisms of transepithelial translocation are discussed, and it is believed...... for oral delivery of peptide and protein drugs highlighting recent studies and the most promising compounds from these classes of peptide excipients....

  14. Conservation of the C-type lectin fold for massive sequence variation in a Treponema diversity-generating retroelement

    Energy Technology Data Exchange (ETDEWEB)

    Le Coq, Johanne; Ghosh, Partho (UCSD)

    2012-06-19

    Anticipatory ligand binding through massive protein sequence variation is rare in biological systems, having been observed only in the vertebrate adaptive immune response and in a phage diversity-generating retroelement (DGR). Earlier work has demonstrated that the prototypical DGR variable protein, major tropism determinant (Mtd), meets the demands of anticipatory ligand binding by novel means through the C-type lectin (CLec) fold. However, because of the low sequence identity among DGR variable proteins, it has remained unclear whether the CLec fold is a general solution for DGRs. We have addressed this problem by determining the structure of a second DGR variable protein, TvpA, from the pathogenic oral spirochete Treponema denticola. Despite its weak sequence identity to Mtd ({approx}16%), TvpA was found to also have a CLec fold, with predicted variable residues exposed in a ligand-binding site. However, this site in TvpA was markedly more variable than the one in Mtd, reflecting the unprecedented approximate 10{sup 20} potential variability of TvpA. In addition, similarity between TvpA and Mtd with formylglycine-generating enzymes was detected. These results provide strong evidence for the conservation of the formylglycine-generating enzyme-type CLec fold among DGRs as a means of accommodating massive sequence variation.

  15. The Structure of the Poxvirus A33 Protein Reveals a Dimer of Unique C-Type Lectin-Like Domains

    Energy Technology Data Exchange (ETDEWEB)

    Su, Hua-Poo; Singh, Kavita; Gittis, Apostolos G.; Garboczi, David N. (NIH)

    2010-11-03

    The current vaccine against smallpox is an infectious form of vaccinia virus that has significant side effects. Alternative vaccine approaches using recombinant viral proteins are being developed. A target of subunit vaccine strategies is the poxvirus protein A33, a conserved protein in the Chordopoxvirinae subfamily of Poxviridae that is expressed on the outer viral envelope. Here we have determined the structure of the A33 ectodomain of vaccinia virus. The structure revealed C-type lectin-like domains (CTLDs) that occur as dimers in A33 crystals with five different crystal lattices. Comparison of the A33 dimer models shows that the A33 monomers have a degree of flexibility in position within the dimer. Structural comparisons show that the A33 monomer is a close match to the Link module class of CTLDs but that the A33 dimer is most similar to the natural killer (NK)-cell receptor class of CTLDs. Structural data on Link modules and NK-cell receptor-ligand complexes suggest a surface of A33 that could interact with viral or host ligands. The dimer interface is well conserved in all known A33 sequences, indicating an important role for the A33 dimer. The structure indicates how previously described A33 mutations disrupt protein folding and locates the positions of N-linked glycosylations and the epitope of a protective antibody.

  16. Mechanistic insights into the role of C-type lectin receptor/CARD9 signaling in human antifungal immunity

    Directory of Open Access Journals (Sweden)

    Rebecca A. Drummond

    2016-04-01

    Full Text Available Human CARD9 deficiency is an autosomal recessive primary immunodeficiency disorder caused by biallelic mutations in the gene CARD9, which encodes a signaling protein that is found downstream of many C-type lectin receptors (CLRs. CLRs encompass a large family of innate recognition receptors, expressed predominantly by myeloid and epithelial cells, which bind fungal carbohydrates and initiate antifungal immune responses. Accordingly, human CARD9 deficiency is associated with the spontaneous development of persistent and severe fungal infections that primarily localize to the skin and subcutaneous tissue, mucosal surfaces and/or central nervous system (CNS. In the last few years, more than 15 missense and nonsense CARD9 mutations have been reported which associate with the development of a wide spectrum of fungal infections caused by a variety of fungal organisms. The mechanisms by which CARD9 provides organ-specific protection against these fungal infections are now emerging. In this review, we summarize recent immunological and clinical advances that have provided significant mechanistic insights into the pathogenesis of human CARD9 deficiency. We also discuss how genetic mutations in CARD9-coupled receptors (Dectin-1, Dectin-2 and CARD9-binding partners (MALT1, BCL10 affect human antifungal immunity relative to CARD9 deficiency, and we highlight major understudied research questions which merit future investigation.

  17. Hemolytic C-type lectin CEL-III from sea cucumber expressed in transgenic mosquitoes impairs malaria parasite development.

    Directory of Open Access Journals (Sweden)

    Shigeto Yoshida

    2007-12-01

    Full Text Available The midgut environment of anopheline mosquitoes plays an important role in the development of the malaria parasite. Using genetic manipulation of anopheline mosquitoes to change the environment in the mosquito midgut may inhibit development of the malaria parasite, thus blocking malaria transmission. Here we generate transgenic Anopheles stephensi mosquitoes that express the C-type lectin CEL-III from the sea cucumber, Cucumaria echinata, in a midgut-specific manner. CEL-III has strong and rapid hemolytic activity toward human and rat erythrocytes in the presence of serum. Importantly, CEL-III binds to ookinetes, leading to strong inhibition of ookinete formation in vitro with an IC(50 of 15 nM. Thus, CEL-III exhibits not only hemolytic activity but also cytotoxicity toward ookinetes. In these transgenic mosquitoes, sporogonic development of Plasmodium berghei is severely impaired. Moderate, but significant inhibition was found against Plasmodium falciparum. To our knowledge, this is the first demonstration of stably engineered anophelines that affect the Plasmodium transmission dynamics of human malaria. Although our laboratory-based research does not have immediate applications to block natural malaria transmission, these findings have significant implications for the generation of refractory mosquitoes to all species of human Plasmodium and elucidation of mosquito-parasite interactions.

  18. C-type Lectin Mincle Recognizes Glucosyl-diacylglycerol of Streptococcus pneumoniae and Plays a Protective Role in Pneumococcal Pneumonia.

    Science.gov (United States)

    Behler-Janbeck, Friederike; Takano, Tomotsugu; Maus, Regina; Stolper, Jennifer; Jonigk, Danny; Tort Tarrés, Meritxell; Fuehner, Thomas; Prasse, Antje; Welte, Tobias; Timmer, Mattie S M; Stocker, Bridget L; Nakanishi, Yoichi; Miyamoto, Tomofumi; Yamasaki, Sho; Maus, Ulrich A

    2016-12-01

    Among various innate immune receptor families, the role of C-type lectin receptors (CLRs) in lung protective immunity against Streptococcus pneumoniae (S. pneumoniae) is not fully defined. We here show that Mincle gene expression was induced in alveolar macrophages and neutrophils in bronchoalveolar lavage fluids of mice and patients with pneumococcal pneumonia. Moreover, S. pneumoniae directly triggered Mincle reporter cell activation in vitro via its glycolipid glucosyl-diacylglycerol (Glc-DAG), which was identified as the ligand recognized by Mincle. Purified Glc-DAG triggered Mincle reporter cell activation and stimulated inflammatory cytokine release by human alveolar macrophages and alveolar macrophages from WT but not Mincle KO mice. Mincle deficiency led to increased bacterial loads and decreased survival together with strongly dysregulated cytokine responses in mice challenged with focal pneumonia inducing S. pneumoniae, all of which was normalized in Mincle KO mice reconstituted with a WT hematopoietic system. In conclusion, the Mincle-Glc-DAG axis is a hitherto unrecognized element of lung protective immunity against focal pneumonia induced by S. pneumoniae.

  19. C-type Lectin Mincle Recognizes Glucosyl-diacylglycerol of Streptococcus pneumoniae and Plays a Protective Role in Pneumococcal Pneumonia.

    Directory of Open Access Journals (Sweden)

    Friederike Behler-Janbeck

    2016-12-01

    Full Text Available Among various innate immune receptor families, the role of C-type lectin receptors (CLRs in lung protective immunity against Streptococcus pneumoniae (S. pneumoniae is not fully defined. We here show that Mincle gene expression was induced in alveolar macrophages and neutrophils in bronchoalveolar lavage fluids of mice and patients with pneumococcal pneumonia. Moreover, S. pneumoniae directly triggered Mincle reporter cell activation in vitro via its glycolipid glucosyl-diacylglycerol (Glc-DAG, which was identified as the ligand recognized by Mincle. Purified Glc-DAG triggered Mincle reporter cell activation and stimulated inflammatory cytokine release by human alveolar macrophages and alveolar macrophages from WT but not Mincle KO mice. Mincle deficiency led to increased bacterial loads and decreased survival together with strongly dysregulated cytokine responses in mice challenged with focal pneumonia inducing S. pneumoniae, all of which was normalized in Mincle KO mice reconstituted with a WT hematopoietic system. In conclusion, the Mincle-Glc-DAG axis is a hitherto unrecognized element of lung protective immunity against focal pneumonia induced by S. pneumoniae.

  20. Solid-phase peptide synthesis

    DEFF Research Database (Denmark)

    Jensen, Knud Jørgen

    2013-01-01

    This chapter provides an introduction to and overview of peptide chemistry with a focus on solid-phase peptide synthesis. The background, the most common reagents, and some mechanisms are presented. This chapter also points to the different chapters and puts them into perspective.......This chapter provides an introduction to and overview of peptide chemistry with a focus on solid-phase peptide synthesis. The background, the most common reagents, and some mechanisms are presented. This chapter also points to the different chapters and puts them into perspective....

  1. Biodiscovery of aluminum binding peptides

    Science.gov (United States)

    Adams, Bryn L.; Sarkes, Deborah A.; Finch, Amethist S.; Hurley, Margaret M.; Stratis-Cullum, Dimitra

    2013-05-01

    Cell surface peptide display systems are large and diverse libraries of peptides (7-15 amino acids) which are presented by a display scaffold hosted by a phage (virus), bacteria, or yeast cell. This allows the selfsustaining peptide libraries to be rapidly screened for high affinity binders to a given target of interest, and those binders quickly identified. Peptide display systems have traditionally been utilized in conjunction with organic-based targets, such as protein toxins or carbon nanotubes. However, this technology has been expanded for use with inorganic targets, such as metals, for biofabrication, hybrid material assembly and corrosion prevention. While most current peptide display systems employ viruses to host the display scaffold, we have recently shown that a bacterial host, Escherichia coli, displaying peptides in the ubiquitous, membrane protein scaffold eCPX can also provide specific peptide binders to an organic target. We have, for the first time, extended the use of this bacterial peptide display system for the biodiscovery of aluminum binding 15mer peptides. We will present the process of biopanning with macroscopic inorganic targets, binder enrichment, and binder isolation and discovery.

  2. Antitumor Peptides from Marine Organisms

    Directory of Open Access Journals (Sweden)

    Mi Sun

    2011-10-01

    Full Text Available The biodiversity of the marine environment and the associated chemical diversity constitute a practically unlimited resource of new antitumor agents in the field of the development of marine bioactive substances. In this review, the progress on studies of antitumor peptides from marine sources is provided. The biological properties and mechanisms of action of different marine peptides are described; information about their molecular diversity is also presented. Novel peptides that induce apoptosis signal pathway, affect the tubulin-microtubule equilibrium and inhibit angiogenesis are presented in association with their pharmacological properties. It is intended to provide useful information for further research in the fields of marine antitumor peptides.

  3. Improving Peptide Applications Using Nanotechnology.

    Science.gov (United States)

    Narayanaswamy, Radhika; Wang, Tao; Torchilin, Vladimir P

    2016-01-01

    Peptides are being successfully used in various fields including therapy and drug delivery. With advancement in nanotechnology and targeted delivery carrier systems, suitable modification of peptides has enabled achievement of many desirable goals over-riding some of the major disadvantages associated with the delivery of peptides in vivo. Conjugation or physical encapsulation of peptides to various nanocarriers, such as liposomes, micelles and solid-lipid nanoparticles, has improved their in vivo performance multi-fold. The amenability of peptides to modification in chemistry and functionalization with suitable nanocarriers are very relevant aspects in their use and have led to the use of 'smart' nanoparticles with suitable linker chemistries that favor peptide targeting or release at the desired sites, minimizing off-target effects. This review focuses on how nanotechnology has been used to improve the number of peptide applications. The paper also focuses on the chemistry behind peptide conjugation to nanocarriers, the commonly employed linker chemistries and the several improvements that have already been achieved in the areas of peptide use with the help of nanotechnology.

  4. Peptides and Food Intake

    Science.gov (United States)

    Sobrino Crespo, Carmen; Perianes Cachero, Aránzazu; Puebla Jiménez, Lilian; Barrios, Vicente; Arilla Ferreiro, Eduardo

    2014-01-01

    The mechanisms for controlling food intake involve mainly an interplay between gut, brain, and adipose tissue (AT), among the major organs. Parasympathetic, sympathetic, and other systems are required for communication between the brain satiety center, gut, and AT. These neuronal circuits include a variety of peptides and hormones, being ghrelin the only orexigenic molecule known, whereas the plethora of other factors are inhibitors of appetite, suggesting its physiological relevance in the regulation of food intake and energy homeostasis. Nutrients generated by food digestion have been proposed to activate G-protein-coupled receptors on the luminal side of enteroendocrine cells, e.g., the L-cells. This stimulates the release of gut hormones into the circulation such as glucagon-like peptide-1 (GLP-1), oxyntomodulin, pancreatic polypeptides, peptide tyrosine tyrosine, and cholecystokinin, which inhibit appetite. Ghrelin is a peptide secreted from the stomach and, in contrast to other gut hormones, plasma levels decrease after a meal and potently stimulate food intake. Other circulating factors such as insulin and leptin relay information regarding long-term energy stores. Both hormones circulate at proportional levels to body fat content, enter the CNS proportionally to their plasma levels, and reduce food intake. Circulating hormones can influence the activity of the arcuate nucleus (ARC) neurons of the hypothalamus, after passing across the median eminence. Circulating factors such as gut hormones may also influence the nucleus of the tractus solitarius (NTS) through the adjacent circumventricular organ. On the other hand, gastrointestinal vagal afferents converge in the NTS of the brainstem. Neural projections from the NTS, in turn, carry signals to the hypothalamus. The ARC acts as an integrative center, with two major subpopulations of neurons influencing appetite, one of them coexpressing neuropeptide Y and agouti-related protein (AgRP) that increases food

  5. Anticancer peptides from bacteria

    Directory of Open Access Journals (Sweden)

    Tomasz M. Karpiński

    2013-08-01

    Full Text Available Cancer is a leading cause of death in the world. The rapid development of medicine and pharmacology allows to create new and effective anticancer drugs. Among modern anticancer drugs are bacterial proteins. Until now has been shown anticancer activity among others azurin and exotoxin A from Pseudomonas aeruginosa, Pep27anal2 from Streptococcus pneumoniae, diphtheria toxin from Corynebacterium diphtheriae, and recently discovered Entap from Enterococcus sp. The study presents the current data regarding the properties, action and anticancer activity of listed peptides.

  6. Peptide Vaccines for Cancer

    Directory of Open Access Journals (Sweden)

    Kono K

    2013-10-01

    Full Text Available Background: In general, the preferable characteristic of the target molecules for development of cancer vaccines are high immunogenicity, very common expression in cancer cells, specific expression in cancer cells and essential molecules for cell survival (to avoid loss of expression. We previously reported that three novel HLA-A24-restricted immunodominant peptides, which were derived from three different oncoantigens, TTK, LY6K, and IMP-3,were promising targets for cancer vaccination for esophageal squamous cell carcinoma (ESCCpatients. Then, we had performed a phase I clinical trial using three HLA-A24-binding peptides and the results had been shown to be promising for ESCC. Therefore, we further performed a multicenter, non-randomized phase II clinical trial. Patients and Methods: Sixty ESCC patients were enrolled to evaluate OS, PFS, immunological response employing ELISPOT and pentamer assays. Each of the three peptides was administered with IFA weekly. All patients received the vaccination without knowing an HLA-A type, and the HLA types were key-opened at the analysis point. Hence, the endpoints were set to evaluate differences between HLA-A*2402-positive (24(+ and -negative (24(- groups. Results: The OS in the 24 (+ group (n=35 tended to be better than that in the 24(- group (n=25 (MST 4.6 vs. 2.6 month, respectively, p = 0.121, although the difference was not statistically significant. However, the PFS in the 24(+ group was significantly better than that in the 24(- group (p = 0.032. In the 24(+ group, ELISPOT assay indicated that the LY6K-, TTK-, and IMP3-specific CTL responses were observed after the vaccination in 63%, 45%, and 60% of the 24(+ group, respectively. The patients having LY6K-, TTK-, and IMP3-specific CTL responses revealed the better OS than those not having CTL induction, respectively. The patients showing the CTL induction for multiple peptides have better clinical responses. Conclusion: The immune response induced

  7. Thermal Inertia Determination of C-type Asteroid Ryugu from in-situ Surface Brightness Temperature Measurements

    Science.gov (United States)

    Hamm, Maximilian; Grott, Matthias; Knollenberg, Jörg; Kührt, Ekkehard; Pelivan, Ivanka

    2016-10-01

    The Japanese Hayabusa-2 mission is a sample-return mission currently on its way to the C-type asteroid Ryugu. Hayabusa-2 carries the small lander MASCOT (Mobile Asteroid Surface Scout), whose scientific payload includes the infrared radiometer MARA. The primary science goal of MARA is to determine Ryugu's surface brightness temperatures at the landing site for a full asteroid rotation, which will be measured using a long-pass filter, an 8 to 12 µm bandpass, as well as four narrow bandpasses centered at wavelengths between 5 and 15 µm. From these measurements, surface thermal inertia will be derived, but because MARA performs single pixel measurements, heterogeneity in the field of view cannot be resolved. Yet, the surface will likely exhibit different surface textures, and thermal inertia in the field of view could vary from 600 (small rocks) to 50 Jm-2s-0.5K-1 (fine regolith grains). Sub-pixel heterogeneity is a common problem when interpreting radiometer data, since the associated ambiguities cannot be resolved without additional information on surface texture. For MARA, this information will be provided by the MASCOT camera, and in the present paper we have investigated to what extent different thermal inertias can be retrieved from MARA data. To test the applied approach, we generated synthetic MARA data using a thermal model of Ryugu, assuming different thermal inertias for sections of the field of view. We find that sub-pixel heterogeneity systematically deforms the diurnal temperature curve so that it is not possible to fit the data using a single thermal inertia value. However, including the area fractions of the different surface sections enables us to reconstruct the different thermal inertias to within 10% assuming appropriate measurement noise. The presented approach will increase robustness of the Ryugu thermal inertia determination and results will serve as a ground truth for the global measurements performed by the thermal infrared mapper (TIR) on

  8. Drosophila QVR/SSS modulates the activation and C-type inactivation kinetics of Shaker K(+) channels.

    Science.gov (United States)

    Dean, Terry; Xu, Rong; Joiner, William; Sehgal, Amita; Hoshi, Toshinori

    2011-08-03

    The quiver/sleepless (qvr/sss) gene encodes a small, glycosylphosphatidylinositol-anchored protein that plays a critical role in the regulation of sleep in Drosophila. Loss-of-function mutations in qvr/sss severely suppress sleep and effect multiple changes in in situ Shaker K(+) currents, including decreased magnitude, slower time-to-peak, and cumulative inactivation. Recently, we demonstrated that SLEEPLESS (SSS) protein modulates Shaker channel activity, possibly through a direct interaction at the plasma membrane. We show here that SSS accelerates the activation of heterologously expressed Shaker channels with no effect on deactivation or fast N-type inactivation. Furthermore, this SSS-induced acceleration is sensitive to the pharmacological disruption of lipid rafts and sufficiently accounts for the slower time-to-peak of in situ Shaker currents seen in qvr/sss mutants. We also find that SSS decreases the rate of C-type inactivation of heterologously expressed Shaker channels, providing a potential mechanism for the cumulative inactivation phenotype induced by qvr/sss loss-of-function mutations. Kinetic modeling based on the in vitro results suggests that the SSS-dependent regulation of channel kinetics accounts for nearly 40% of the decrease in Shaker current magnitude in flies lacking SSS. Sleep duration in qvr/sss-null mutants is restored to normal by a qvr/sss transgene that fully rescues the Shaker kinetic phenotypes but only partially rescues the decrease in current magnitude. Together, these results suggest that the role of SSS in the regulation of sleep in Drosophila correlates more strongly with the effects of SSS on Shaker kinetics than current magnitude.

  9. QTL involved in the partial restoration of male fertility of C-type cytoplasmic male sterility in maize.

    Science.gov (United States)

    Kohls, Susanne; Stamp, Peter; Knaak, Carsten; Messmer, Rainer

    2011-07-01

    Partial restoration of male fertility limits the use of C-type cytoplasmic male sterility (C-CMS) for the production of hybrid seeds in maize. Nevertheless, the genetic basis of the trait is still unknown. Therefore, the aim to this study was to identify genomic regions that govern partial restoration by means of a QTL analysis carried out in an F(2) population (n = 180). This population was derived from the Corn Belt inbred lines B37C and K55. F(2)BC(1) progenies were phenotyped at three locations in Switzerland. Male fertility was rated according to the quality and number of anthers as well as the anthesis-silking interval. A weak effect of environment on the expression of partial restoration was reflected by high heritabilities of all fertility-related traits. Partial restoration was inherited like an oligogenic trait. Three major QTL regions were found consistently across environments in the chromosomal bins 2.09, 3.06 and 7.03. Therefore, a marker-assisted counter-selection of partial restoration is promising. Minor QTL regions were found on chromosomes 3, 4, 5, 6 and 8. A combination of partial restorer alleles at different QTL can lead to full restoration of fertility. The maternal parent was clearly involved in the partial restoration, because the restorer alleles at QTL in bins 2.09, 6.04 and 7.03 originated from B37. The three major QTL regions collocated with other restorer genes of maize, a phenomenon, which seems to be typical for restorer genes. Therefore, a study of the clusters of restorer genes in maize could lead to a better understanding of their evolution and function. In this respect, the long arm of chromosome 2 is particularly interesting, because it harbors restorer genes for the three major CMS systems (C, T and S) of maize.

  10. Surface multiheme c-type cytochromes from Thermincola potens: Implications for dissimilatory metal reduction by Gram-positive bacteria

    Science.gov (United States)

    Carlson, H. K.; Iavarone, A. T.; Gorur, A.; Yeo, B. S.; Tran, R.; Melnyk, R. A.; Mathies, R. A.; Auer, M.; Coates, J. D.

    2011-12-01

    Almost nothing is known about the mechanisms of dissimilatory metal reduction by Gram-positive bacteria, although they have been shown to be the dominant species in some environments. Thermincola potens strain JR was isolated from the anode of a microbial fuel cell inoculated with anaerobic digester sludge and operated at 55 °C. Preliminary characterization revealed that T. potens coupled acetate oxidation to the reduction of hydrous ferric oxides (HFO) or the humic substances analog, anthraquinone-2,6-disulfonate (AQDS). The genome of T. potens was recently sequenced, and the abundance of multiheme c-type cytochromes (MHCs) is unusual for a Gram-positive bacterium. We present evidence from trypsin shaving LC-MS/MS experiments and surface-enhanced Raman spectroscopy (SERS) that indicates the expression of a number of MHCs during T. potens growth on either HFO or AQDS and that several MHCs are localized to the cell wall or cell surface of T. potens. Furthermore, one of the MHCs can be extracted from cells with low pH or denaturants suggesting a loose association with the cell wall or cell surface. Electron microscopy does not reveal an S-layer, and the precipitation of silver metal on the cell surface is inhibited by cyanide, supporting the involvement of surface-localized redox-active heme proteins in dissimilatory metal reduction. These results are the first direct evidence for cell-wall associated cytochromes and MHC involvement in conducting electrons across the cell envelope of a Gram-positive bacterium.

  11. Detection and identification of heme c-modified peptides by histidine affinity chromatography, high-performance liquid chromatography-mass spectrometry, and database searching.

    Science.gov (United States)

    Merkley, Eric D; Anderson, Brian J; Park, Jea; Belchik, Sara M; Shi, Liang; Monroe, Matthew E; Smith, Richard D; Lipton, Mary S

    2012-12-07

    Multiheme c-type cytochromes (proteins with covalently attached heme c moieties) play important roles in extracellular metal respiration in dissimilatory metal-reducing bacteria. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) characterization of c-type cytochromes is hindered by the presence of multiple heme groups, since the heme c modified peptides are typically not observed or, if observed, not identified. Using a recently reported histidine affinity chromatography (HAC) procedure, we enriched heme c tryptic peptides from purified bovine heart cytochrome c, two bacterial decaheme cytochromes, and subjected these samples to LC-MS/MS analysis. Enriched bovine cytochrome c samples yielded 3- to 6-fold more confident peptide-spectrum matches to heme c containing peptides than unenriched digests. In unenriched digests of the decaheme cytochrome MtoA from Sideroxydans lithotrophicus ES-1, heme c peptides for 4 of the 10 expected sites were observed by LC-MS/MS; following HAC fractionation, peptides covering 9 out of 10 sites were obtained. Heme c peptide spiked into E. coli lysates at mass ratios as low as 1×10(-4) was detected with good signal-to-noise after HAC and LC-MS/MS analysis. In addition to HAC, we have developed a proteomics database search strategy that takes into account the unique physicochemical properties of heme c peptides. The results suggest that accounting for the double thioether link between heme c and peptide, and the use of the labile heme fragment as a reporter ion, can improve database searching results. The combination of affinity chromatography and heme-specific informatics yielded increases in the number of peptide-spectrum matches of 20-100-fold for bovine cytochrome c.

  12. Natriuretic peptides in cardiometabolic regulation and disease

    DEFF Research Database (Denmark)

    Zois, Nora E; Bartels, Emil D; Hunter, Ingrid

    2014-01-01

    these conditions can coexist and potentially lead to heart failure, a syndrome associated with a functional natriuretic peptide deficiency despite high circulating concentrations of immunoreactive peptides. Therefore, dysregulation of the natriuretic peptide system, a 'natriuretic handicap', might be an important...

  13. Chemical Synthesis of Antimicrobial Peptides.

    Science.gov (United States)

    Münzker, Lena; Oddo, Alberto; Hansen, Paul R

    2017-01-01

    Solid-phase peptide synthesis (SPPS) is the method of choice for chemical synthesis of peptides. In this nonspecialist review, we describe commonly used resins, linkers, protecting groups, and coupling reagents in 9-fluorenylmethyloxycarbonyl (Fmoc) SPPS. Finally, a detailed protocol for manual Fmoc SPPS is presented.

  14. Urinary Peptides in Rett Syndrome.

    Science.gov (United States)

    Solaas, K. M.; Skjeldal, O.; Gardner, M. L. G.; Kase, B. F.; Reichelt, K. L.

    2002-01-01

    A study found a significantly higher level of peptides in the urine of 53 girls with Rett syndrome compared with controls. The elevation was similar to that in 35 girls with infantile autism. Levels of peptides were lower in girls with classic Rett syndrome than those with congenital Rett syndrome. (Contains references.) (Author/CR)

  15. Peptides: A new class of anticancer drugs

    OpenAIRE

    Ryszard Smolarczyk; Tomasz Cichoń; Stanisław Szala

    2009-01-01

    Peptides are a novel class of anticancer agents embracing two distinct categories: natural antibacterial peptides, which are preferentially bound by cancer cells, and chemically synthesized peptides, which bind specifically to precise molecular targets located on the surface of tumor cells. Antibacterial peptides bind to both cell and mitochondrial membranes. Some of these peptides attach to the cell membrane, resulting in its disorganization. Other antibacterial peptides penetrate cancer cel...

  16. Peptide-LNA oligonucleotide conjugates

    DEFF Research Database (Denmark)

    Astakhova, I Kira; Hansen, Lykke Haastrup; Vester, Birte

    2013-01-01

    Although peptide-oligonucleotide conjugates (POCs) are well-known for nucleic acids delivery and therapy, reports on internal attachment of peptides to oligonucleotides are limited in number. To develop a convenient route for preparation of internally labeled POCs with improved biomedical...... properties, peptides were introduced into oligonucleotides via a 2'-alkyne-2'-amino-LNA scaffold. Derivatives of methionine- and leucine-enkephalins were chosen as model peptides of mixed amino acid content, which were singly and doubly incorporated into LNA/DNA strands using highly efficient copper......(i)-catalyzed azide-alkyne cycloaddition (CuAAC) "click" chemistry. DNA/RNA target binding affinity and selectivity of the resulting POCs were improved in comparison to LNA/DNA mixmers and unmodified DNA controls. This clearly demonstrates that internal attachment of peptides to oligonucleotides can significantly...

  17. The Equine PeptideAtlas

    DEFF Research Database (Denmark)

    Bundgaard, Louise; Jacobsen, Stine; Sorensen, Mette A.

    2014-01-01

    Progress in MS-based methods for veterinary research and diagnostics is lagging behind compared to the human research, and proteome data of domestic animals is still not well represented in open source data repositories. This is particularly true for the equine species. Here we present a first...... Equine PeptideAtlas encompassing high-resolution tandem MS analyses of 51 samples representing a selection of equine tissues and body fluids from healthy and diseased animals. The raw data were processed through the Trans-Proteomic Pipeline to yield high quality identification of proteins and peptides....... The current release comprises 24 131 distinct peptides representing 2636 canonical proteins observed at false discovery rates of 0.2% at the peptide level and 1.4% at the protein level. Data from the Equine PeptideAtlas are available for experimental planning, validation of new datasets, and as a proteomic...

  18. Maize Bioactive Peptides against Cancer

    Science.gov (United States)

    Díaz-Gómez, Jorge L.; Castorena-Torres, Fabiola; Preciado-Ortiz, Ricardo E.; García-Lara, Silverio

    2017-06-01

    Cancer is one of the main chronic degenerative diseases worldwide. In recent years, consumption of whole-grain cereals and their derived food products has been associated with reduction risks of various types of cancer. Cereals main biomolecules includes proteins, peptides, and amino acids present in different quantities within the grain. The nutraceutical properties associated with peptides exerts biological functions that promote health and prevent this disease. In this review, we report the current status and advances on maize peptides regarding bioactive properties that have been reported such as antioxidant, antihypertensive, hepatoprotective, and anti-tumour activities. We also highlighted its biological potential through which maize bioactive peptides exert anti-cancer activity. Finally, we analyse and emphasize the possible areas of application for maize peptides.

  19. Cathepsin-Mediated Cleavage of Peptides from Peptide Amphiphiles Leads to Enhanced Intracellular Peptide Accumulation.

    Science.gov (United States)

    Acar, Handan; Samaeekia, Ravand; Schnorenberg, Mathew R; Sasmal, Dibyendu K; Huang, Jun; Tirrell, Matthew V; LaBelle, James L

    2017-09-20

    Peptides synthesized in the likeness of their native interaction domain(s) are natural choices to target protein-protein interactions (PPIs) due to their fidelity of orthostatic contact points between binding partners. Despite therapeutic promise, intracellular delivery of biofunctional peptides at concentrations necessary for efficacy remains a formidable challenge. Peptide amphiphiles (PAs) provide a facile method of intracellular delivery and stabilization of bioactive peptides. PAs consisting of biofunctional peptide headgroups linked to hydrophobic alkyl lipid-like tails prevent peptide hydrolysis and proteolysis in circulation, and PA monomers are internalized via endocytosis. However, endocytotic sequestration and steric hindrance from the lipid tail are two major mechanisms that limit PA efficacy to target intracellular PPIs. To address these problems, we have constructed a PA platform consisting of cathepsin-B cleavable PAs in which a selective p53-based inhibitory peptide is cleaved from its lipid tail within endosomes, allowing for intracellular peptide accumulation and extracellular recycling of the lipid moiety. We monitor for cleavage and follow individual PA components in real time using a Förster resonance energy transfer (FRET)-based tracking system. Using this platform, we provide a better understanding and quantification of cellular internalization, trafficking, and endosomal cleavage of PAs and of the ultimate fates of each component.

  20. Purification and use of E. coli peptide deformylase for peptide deprotection in chemoenzymatic peptide synthesis

    NARCIS (Netherlands)

    Di Toma, Claudia; Sonke, Theo; Quaedflieg, Peter J.; Janssen, Dick B.

    Peptide deformylases (PDFs) catalyze the removal of the formyl group from the N-terminal methionine residue in nascent polypeptide chains in prokaryotes. Its deformylation activity makes PDF an attractive candidate for the biocatalytic deprotection of formylated peptides that are used in

  1. Cathepsin-Mediated Cleavage of Peptides from Peptide Amphiphiles Leads to Enhanced Intracellular Peptide Accumulation

    Energy Technology Data Exchange (ETDEWEB)

    Acar, Handan [Institute; Department; Samaeekia, Ravand [Institute; Department; Schnorenberg, Mathew R. [Institute; Department; Medical; Sasmal, Dibyendu K. [Institute; Huang, Jun [Institute; Tirrell, Matthew V. [Institute; Institute; LaBelle, James L. [Department

    2017-08-24

    Peptides synthesized in the likeness of their native interaction domain(s) are natural choices to target protein protein interactions (PPIs) due to their fidelity of orthostatic contact points between binding partners. Despite therapeutic promise, intracellular delivery of biofunctional peptides at concentrations necessary for efficacy remains a formidable challenge. Peptide amphiphiles (PAs) provide a facile method of intracellular delivery and stabilization of bioactive peptides. PAs consisting of biofunctional peptide headgroups linked to hydrophobic alkyl lipid-like tails prevent peptide hydrolysis and proteolysis in circulation, and PA monomers are internalized via endocytosis. However, endocytotic sequestration and steric hindrance from the lipid tail are two major mechanisms that limit PA efficacy to target intracellular PPIs. To address these problems, we have constructed a PA platform consisting of cathepsin-B cleavable PAs in which a selective p53-based inhibitory peptide is cleaved from its lipid tail within endosomes, allowing for intracellular peptide accumulation and extracellular recycling of the lipid moiety. We monitor for cleavage and follow individual PA components in real time using a resonance energy transfer (FRET)-based tracking system. Using this platform, components in real time using a Forster we provide a better understanding and quantification of cellular internalization, trafficking, and endosomal cleavage of PAs and of the ultimate fates of each component.

  2. B-type natriuretic peptide and acute heart failure: Fluid homeostasis, biomarker and therapeutics.

    Science.gov (United States)

    Torres-Courchoud, I; Chen, H H

    2016-10-01

    Natriuretic peptides are a family of peptides with similar structures, but are genetically distinct with diverse actions in cardiovascular, renal and fluid homeostasis. The family consists of an atrial natriuretic peptide (ANP) and a brain natriuretic peptide (BNP) of myocardial cell origin, a C-type natriuretic peptide (CNP) of endothelial origin, and a urodilatin (Uro) which is processed from a prohormone ANP in the kidney. Nesiritide, a human recombinant BNP, was approved by the Federal Drug Administration (FDA) for the management of acute heart failure (AHF) in 2001. Human recombinant ANP (Carperitide) was approved for the same clinical indication in Japan in 1995, and human recombinant Urodilatin (Ularitide) is currently undergoing phase III clinical trial (TRUE AHF). This review will provide an update on important issues regarding the role of BNP in fluid hemostasis as a biomarker and therapeutics in AHF. Copyright © 2016 Elsevier España, S.L.U. and Sociedad Española de Medicina Interna (SEMI). All rights reserved.

  3. The plasminogen binding site of the C-type lectin tetranectin is located in the carbohydrate recognition domain, and binding is sensitive to both calcium and lysine

    DEFF Research Database (Denmark)

    Graversen, Jonas Heilskov; Lorentsen, R H; Jacobsen, C

    1998-01-01

    Tetranectin, a homotrimeric protein belonging to the family of C-type lectins and structurally highly related to corresponding regions of the mannose-binding proteins, is known specifically to bind the plasminogen kringle 4 protein domain, an interaction sensitive to lysine. Surface plasmon...

  4. Structure of the plasminogen kringle 4 binding calcium-free form of the C-type lectin-like domain of tetranectin

    DEFF Research Database (Denmark)

    Nielbo, Steen; Thomsen, Jens K; Graversen, Jonas Heilskov

    2004-01-01

    Tetranectin is a homotrimeric protein containing a C-type lectin-like domain. This domain (TN3) can bind calcium, but in the absence of calcium, the domain binds a number of kringle-type protein ligands. Two of the calcium-coordinating residues are also critical for binding plasminogen kringle 4 (K...

  5. Specific glycan elements determine differential binding of individual egg glycoproteins of the human parasite Schistosoma mansoni by host C-type lectin receptors

    NARCIS (Netherlands)

    Meevissen, M.H.J.; Driessen, N.N.; Smits, H.H.; Versteegh, R.; van Vliet, S.J.; van Kooijk, Y.; Schramm, G.; Deelder, A.M.; de Haas, H.; Yazdanbakhsh, M.; Hokke, C.H.

    2012-01-01

    During infection with the blood fluke Schistosoma mansoni, glycan motifs present on glycoproteins of the parasite's eggs mediate immunomodulatory effects on the host. The recognition of these glycan motifs is primarily mediated by C-type lectin receptors on dendritic cells and other cells of the

  6. The dendritic cell-specific C-type lectin DC-SIGN is a receptor for Schistosoma mansoni egg antigens and recognizes the glycan antigen Lewis x.

    NARCIS (Netherlands)

    Die, van I.M.; Vliet, van SJ; Nyame, AK; Cummings, RD; Bank, CM; Appelmelk, B.J.; Geijtenbeek, T.B.H.; Kooijk, van Y.

    2003-01-01

    Schistosoma mansoni soluble egg antigens (SEAs) are crucially involved in modulating the host immune response to infection by S. mansoni. We report that human dendritic cells bind SEAs through the C-type lectin dendritic cell-specific ICAM-3-grabbing nonintegrin (DC-SIGN). Monoclonal antibodies

  7. The dendritic cell-specific C-type lectin DC-SIGN is a receptor for Schistosoma mansoni egg antigens and recognizes the glycan antigen Lewis x

    NARCIS (Netherlands)

    van Die, Irma; van Vliet, Sandra J.; Nyame, A. Kwame; Cummings, Richard D.; Bank, Christine M. C.; Appelmelk, Ben; Geijtenbeek, Teunis B. H.; van Kooyk, Yvette

    2003-01-01

    Schistosoma mansoni soluble egg antigens (SEAs) are crucially involved in modulating the host immune response to infection by S. mansoni. We report that human dendritic cells bind SEAs through the C-type lectin dendritic cell-specific ICAM-3-grabbing nonintegrin (DC-SIGN). Monoclonal antibodies

  8. Radiopharmaceutical development of radiolabelled peptides

    Energy Technology Data Exchange (ETDEWEB)

    Fani, Melpomeni; Maecke, Helmut R. [University Hospital Freiburg, Department of Nuclear Medicine, Freiburg (Germany)

    2012-02-15

    Receptor targeting with radiolabelled peptides has become very important in nuclear medicine and oncology in the past few years. The overexpression of many peptide receptors in numerous cancers, compared to their relatively low density in physiological organs, represents the molecular basis for in vivo imaging and targeted radionuclide therapy with radiolabelled peptide-based probes. The prototypes are analogs of somatostatin which are routinely used in the clinic. More recent developments include somatostatin analogs with a broader receptor subtype profile or with antagonistic properties. Many other peptide families such as bombesin, cholecystokinin/gastrin, glucagon-like peptide-1 (GLP-1)/exendin, arginine-glycine-aspartic acid (RGD) etc. have been explored during the last few years and quite a number of potential radiolabelled probes have been derived from them. On the other hand, a variety of strategies and optimized protocols for efficient labelling of peptides with clinically relevant radionuclides such as {sup 99m}Tc, M{sup 3+} radiometals ({sup 111}In, {sup 86/90}Y, {sup 177}Lu, {sup 67/68}Ga), {sup 64/67}Cu, {sup 18}F or radioisotopes of iodine have been developed. The labelling approaches include direct labelling, the use of bifunctional chelators or prosthetic groups. The choice of the labelling approach is driven by the nature and the chemical properties of the radionuclide. Additionally, chemical strategies, including modification of the amino acid sequence and introduction of linkers/spacers with different characteristics, have been explored for the improvement of the overall performance of the radiopeptides, e.g. metabolic stability and pharmacokinetics. Herein, we discuss the development of peptides as radiopharmaceuticals starting from the choice of the labelling method and the conditions to the design and optimization of the peptide probe, as well as some recent developments, focusing on a selected list of peptide families, including somatostatin

  9. Tryptathionine bridges in peptide synthesis.

    Science.gov (United States)

    May, Jonathan P; Perrin, David M

    2007-01-01

    The tryptathionine linkage is a crosslink formed between tryptophan and cysteine. This feature is characteristic of the bicyclic peptides: the phallotoxins and the amatoxins. These peptides both bind to protein folds of their respective targets (F-actin and RNA pol II, respectively) with extremely high affinities. Studies on these peptides have shown that the tryptathionine crosslink is essential for this binding affinity. Tryptathionines have been investigated for many years and several syntheses exist for their formation. In this review, we report on the various methodologies employed in tryptathionine synthesis, and discuss some of the advantages and disadvantages associated with each of them. Copyright (c) 2007 Wiley Periodicals, Inc.

  10. Next generation natriuretic peptide measurement

    DEFF Research Database (Denmark)

    Hunter, Ingrid; Goetze, Jens P

    2012-01-01

    Plasma measurement of natriuretic peptides is a "must" for clinical laboratories. For the next generation measurement, the unraveling of the molecular complexity of the peptides points toward a more qualitative assessment, as the posttranslational processing also changes with disease. Changes...... in the molecular heterogeneity could in itself contain valuable information of clinical status, and the time seems right for industry and dedicated researchers in the field to get together and discuss the next generation natriuretic peptide measurement. In such an environment, new strategies can be developed...

  11. Granule structure and distribution of allomorphs in C-type high-amylose rice starch granule modified by antisense RNA inhibition of starch branching enzyme.

    Science.gov (United States)

    Wei, Cunxu; Qin, Fengling; Zhou, Weidong; Yu, Huaguang; Xu, Bin; Chen, Chong; Zhu, Lijia; Wang, Youping; Gu, Minghong; Liu, Qiaoquan

    2010-11-24

    C-type starch, which is a combination of both A-type and B-type crystal starch, is usually found in legumes and rhizomes. We have developed a high-amylose transgenic line of rice (TRS) by antisense RNA inhibition of starch branching enzymes. The starch in the endosperm of this TRS was identified as typical C-type crystalline starch, but its fine granular structure and allomorph distribution remained unclear. In this study, we conducted morphological and spectroscopic studies on this TRS starch during acid hydrolysis to determine the distribution of A- and B-type allomorphs. The morphology of starch granules after various durations of acid hydrolysis was compared by optical microscopy, scanning electron microscopy, and transmission electron microscopy. The results showed that amorphous regions were located at the center part of TRS starch subgranules. During acid hydrolysis, starch was degraded from the interior of the subgranule to the outer surface, while the peripheral part of the subgranules and the surrounding band of the starch granule were highly resistant to acid hydrolysis. The spectroscopic changes detected by X-ray powder diffraction, 13C cross-polarization magic-angle spinning NMR, and attenuated total reflectance Fourier transform infrared showed that the A-type allomorph was hydrolyzed more rapidly than the B-type, and that the X-ray diffraction profile gradually changed from a native C-type to a CB-type with increasing hydrolysis time. Our results showed that, in TRS starch, the A-type allomorph was located around the amorphous region, and was surrounded by the B-type allomorph located in the peripheral region of the subgranules and the surrounding band of the starch granule. Thus, the positions of A- and B-type allomorphs in the TRS C-type starch granule differ markedly from those in C-type legume and rhizome starch.

  12. Targeting the Eph System with Peptides and Peptide Conjugates.

    Science.gov (United States)

    Riedl, Stefan J; Pasquale, Elena B

    2015-01-01

    Eph receptor tyrosine kinases and ephrin ligands constitute an important cell communication system that controls development, tissue homeostasis and many pathological processes. Various Eph receptors/ephrins are present in essentially all cell types and their expression is often dysregulated by injury and disease. Thus, the 14 Eph receptors are attracting increasing attention as a major class of potential drug targets. In particular, agents that bind to the extracellular ephrin-binding pocket of these receptors show promise for medical applications. This pocket comprises a broad and shallow groove surrounded by several flexible loops, which makes peptides particularly suitable to target it with high affinity and selectivity. Accordingly, a number of peptides that bind to Eph receptors with micromolar affinity have been identified using phage display and other approaches. These peptides are generally antagonists that inhibit ephrin binding and Eph receptor/ ephrin signaling, but some are agonists mimicking ephrin-induced Eph receptor activation. Importantly, some of the peptides are exquisitely selective for single Eph receptors. Most identified peptides are linear, but recently the considerable advantages of cyclic scaffolds have been recognized, particularly in light of potential optimization towards drug leads. To date, peptide improvements have yielded derivatives with low nanomolar Eph receptor binding affinity, high resistance to plasma proteases and/or long in vivo half-life, exemplifying the merits of peptides for Eph receptor targeting. Besides their modulation of Eph receptor/ephrin function, peptides can also serve to deliver conjugated imaging and therapeutic agents or various types of nanoparticles to tumors and other diseased tissues presenting target Eph receptors.

  13. Novel peptides with tyrosinase inhibitory activity

    NARCIS (Netherlands)

    Schurink, M.; Berkel, van W.J.H.; Wichers, H.J.; Boeriu, C.G.

    2007-01-01

    Tyrosinase inhibition by peptides may find its application in food, cosmetics or medicine. In order to identify novel tyrosinase inhibitory peptides, protein-based peptide libraries made by SPOT synthesis were used to screen for peptides that show direct interaction with tyrosinase. One of the

  14. Fmoc Solid-Phase Peptide Synthesis.

    Science.gov (United States)

    Hansen, Paul R; Oddo, Alberto

    2015-01-01

    Synthetic peptides are important as drugs and in research. Currently, the method of choice for producing these compounds is solid-phase peptide synthesis. In this nonspecialist review, we describe the scope and limitations of Fmoc solid-phase peptide synthesis. Furthermore, we provide a detailed protocol for Fmoc peptide synthesis.

  15. The Pig PeptideAtlas

    DEFF Research Database (Denmark)

    Hesselager, Marianne O.; Codrea, Marius C.; Sun, Zhi

    2016-01-01

    underrepresented in existing repositories. We here present a significantly improved build of the Pig PeptideAtlas, which includes pig proteome data from 25 tissues and three body fluid types mapped to 7139 canonical proteins. The content of the Pig PeptideAtlas reflects actively ongoing research within...... the veterinary proteomics domain, and this article demonstrates how the expression of isoform-unique peptides can be observed across distinct tissues and body fluids. The Pig PeptideAtlas is a unique resource for use in animal proteome research, particularly biomarker discovery and for preliminary design of SRM...... assays, which are equally important for progress in research that supports farm animal production and veterinary health, as for developing pig models with relevance to human health research....

  16. Structural Characterization of Peptide Antibodies

    DEFF Research Database (Denmark)

    Chailyan, Anna; Marcatili, Paolo

    2015-01-01

    can be modified to obtain desired properties or conformation, tagged for purification, isotopically labeled for protein quantitation or conjugated to immunogens for antibody production. The antibodies that bind to these peptides represent an invaluable tool for biological research and discovery...

  17. Therapeutical Potential of Venom Peptides

    Directory of Open Access Journals (Sweden)

    İlker Kelle

    2006-01-01

    Full Text Available The term of pharmazooticals is known as a few amount of drugs derived from natural sources such as plants, venomous species of snakes, spiders, scorpions, frogs, lizards and cone snails. Peptide components of venoms are directed against wide variety of pharmacological targets such as ion channels and receptors. At the beginning, a number of these peptides have been used in experimental studies for defining the physiological, biochemical and immunological activities of organisms like mammalians. In recent studies, it has been shown that venom peptides can be valuable in treatment of acute and chronic pain, autoimmune and cardiovascular diseases, neurological disorders and chronic inflammatory and tumoral processes. Therefore particularly in clinical approaches, these peptide molecules or their synthetic analogues are considered as alternative agents that can be used instead of classical drugs for many clinical disorders due to their potent activity besides very few side effects.

  18. Hemolytic Activity of Antimicrobial Peptides.

    Science.gov (United States)

    Oddo, Alberto; Hansen, Paul R

    2017-01-01

    For antimicrobial peptides to be interesting for systemic applications, they must show low toxicity against erythrocytes. In this chapter, we describe a protocol for measuring the ability of AMPs to lyse human red blood cells, using melittin as positive control.

  19. Moonlighting peptides with emerging function.

    Directory of Open Access Journals (Sweden)

    Jonathan G Rodríguez Plaza

    Full Text Available Hunter-killer peptides combine two activities in a single polypeptide that work in an independent fashion like many other multi-functional, multi-domain proteins. We hypothesize that emergent functions may result from the combination of two or more activities in a single protein domain and that could be a mechanism selected in nature to form moonlighting proteins. We designed moonlighting peptides using the two mechanisms proposed to be involved in the evolution of such molecules (i.e., to mutate non-functional residues and the use of natively unfolded peptides. We observed that our moonlighting peptides exhibited two activities that together rendered a new function that induces cell death in yeast. Thus, we propose that moonlighting in proteins promotes emergent properties providing a further level of complexity in living organisms so far unappreciated.

  20. Biomedical Applications of Organometal-Peptide Conjugates

    Science.gov (United States)

    Metzler-Nolte, Nils

    Peptides are well suited as targeting vectors for the directed delivery of metal-based drugs or probes for biomedical investigations. This chapter describes synthetic strategies for the preparation of conjugates of medically interesting peptides with covalently bound metal complexes. Peptides that were used include neuropeptides (enkephalin, neuropeptide Y, neurotensin), uptake peptides (TAT and poly-Arg), and intracellular localization sequences. To these peptides, a whole variety of transition metal complexes has been attached in recent years by solid-phase peptide synthesis (SPPS) techniques. The metal complex can be attached to the peptide on the resin as part of the SPPS scheme. Alternatively, the metal complex may be attached to the peptide as a postsynthetic modification. Advantages as well as disadvantages for either strategy are discussed. Biomedical applications include radiopharmaceutical applications, anticancer and antibacterial activity, metal-peptide conjugates as targeted CO-releasing molecules, and metal-peptide conjugates in biosensor applications.

  1. Production and characterization of peptide antibodies

    DEFF Research Database (Denmark)

    Trier, Nicole Hartwig; Hansen, P. R.; Houen, G.

    2012-01-01

    Proteins are effective immunogens for generation of antibodies. However, occasionally the native protein is known but not available for antibody production. In such cases synthetic peptides derived from the native protein are good alternatives for antibody production. These peptide antibodies...... are powerful tools in experimental biology and are easily produced to any peptide of choice. A widely used approach for production of peptide antibodies is to immunize animals with a synthetic peptide coupled to a carrier protein. Very important is the selection of the synthetic peptide, where factors......, including solid-phase peptide-carrier conjugation and peptide-carrier conjugation in solution. Upon immunization, adjuvants such as Al(OH)(3) are added together with the immunogenic peptide-carrier conjugate, which usually leads to high-titred antisera. Following immunization and peptide antibody...

  2. The greening of peptide synthesis

    OpenAIRE

    Lawrenson, Stefan B.; Arav, Roy; North, Michael

    2017-01-01

    The synthesis of peptides by amide bond formation between suitably protected amino acids is a fundamental part of the drug discovery process. However, the required coupling and deprotection reactions are routinely carried out in dichloromethane and DMF, both of which have serious toxicity concerns and generate waste solvent which constitutes the vast majority of the waste generated during peptide synthesis. In this work, propylene carbonate has been shown to be a green polar aprotic solvent w...

  3. Material Binding Peptides for Nanotechnology

    Directory of Open Access Journals (Sweden)

    Urartu Ozgur Safak Seker

    2011-02-01

    Full Text Available Remarkable progress has been made to date in the discovery of material binding peptides and their utilization in nanotechnology, which has brought new challenges and opportunities. Nowadays phage display is a versatile tool, important for the selection of ligands for proteins and peptides. This combinatorial approach has also been adapted over the past decade to select material-specific peptides. Screening and selection of such phage displayed material binding peptides has attracted great interest, in particular because of their use in nanotechnology. Phage display selected peptides are either synthesized independently or expressed on phage coat protein. Selected phage particles are subsequently utilized in the synthesis of nanoparticles, in the assembly of nanostructures on inorganic surfaces, and oriented protein immobilization as fusion partners of proteins. In this paper, we present an overview on the research conducted on this area. In this review we not only focus on the selection process, but also on molecular binding characterization and utilization of peptides as molecular linkers, molecular assemblers and material synthesizers.

  4. Matrix-assisted peptide synthesis on nanoparticles.

    Science.gov (United States)

    Khandadash, Raz; Machtey, Victoria; Weiss, Aryeh; Byk, Gerardo

    2014-09-01

    We report a new method for multistep peptide synthesis on polymeric nanoparticles of differing sizes. Polymeric nanoparticles were functionalized via their temporary embedment into a magnetic inorganic matrix that allows multistep peptide synthesis. The matrix is removed at the end of the process for obtaining nanoparticles functionalized with peptides. The matrix-assisted synthesis on nanoparticles was proved by generating various biologically relevant peptides. Copyright © 2014 European Peptide Society and John Wiley & Sons, Ltd.

  5. Vascular effects and electrolyte homeostasis of the natriuretic peptide isolated from Crotalus oreganus abyssus (North American Grand Canyon rattlesnake) venom.

    Science.gov (United States)

    Da Silva, S L; Dias-Junior, C A; Baldasso, P A; Damico, D C S; Carvalho, B M A; Garanto, A; Acosta, G; Oliveira, E; Albericio, F; Soares, A M; Marangoni, S; Resende, R R

    2012-08-01

    Crotalus oreganus abyssus is a rattlesnake that is usually found in the Grand Canyon, United States of America. Knowledge regarding the composition of C. o. abyssus venom is scarce. New natriuretic peptides (NPs) have been isolated and characterized from the venoms of members of the Crotalinae family. The NP family comprises three members, ANP (atrial natriuretic peptide), BNP (b-type natriuretic peptide) and CNP (c-type natriuretic peptide), and has an important role in blood pressure regulation and electrolyte homeostasis. The aim of the present study was to characterize a novel natriuretic-like peptide (Coa_NP2), isolated from C. o. abyssus venom. The Coa_NP2 presents an average molecular mass of 3419.88Da (theoretical average molecular mass 3418.94Da, monoisotopic molecular mass 3416.66Da and theoretical PI 7.78) and its amino acid sequence presents the loop region that is characteristic of natriuretic peptides. The peptide has 32 amino acids and its complete sequence is SYGISSGCFGLKLDRIGTMSGLGCWRLLQDSP. Coa_NP2 is a natriuretic peptide of the ANP/BNP-like family, since the carboxyterminal region of CNP has its own NP domain. We demonstrate, herein, that Coa_NP2 produces a dose-dependent decrease in mean arterial pressure in rats, followed by significant increases in concentrations of markers of nitric oxide formation measured in the plasma and vasorelaxation in a thoracic aortic ring bath. The structural and biological aspects confirm Coa_NP2 as a new natriuretic peptide, isolated from snake venom. Copyright © 2012 Elsevier Inc. All rights reserved.

  6. Identification of peptide-cross-linked trisdisaccharide peptide trimers in murein of Escherichia coli.

    OpenAIRE

    Gmeiner, J

    1980-01-01

    Purified murein from Escherichia coli K-12 was degraded into disaccharide peptide fragments by endo-N-acetylmuramidase from Chalaropsis. About 5% of the total murein fragments were recovered as peptide-cross-linked trisdisaccharide peptide trimers.

  7. Versatile Peptide C-Terminal Functionalization via a Computationally Engineered Peptide Amidase

    NARCIS (Netherlands)

    Wu, Bian; Wijma, Hein J.; Song, Lu; Rozeboom, Henriette J.; Poloni, Claudia; Tian, Yue; Arif, Muhammad I.; Nuijens, Timo; Quaedflieg, Peter J. L. M.; Szymanski, Wiktor; Feringa, Ben L.; Janssen, Dick B.

    The properties of synthetic peptides, including potency, stability, and bioavailability, are strongly influenced by modification of the peptide chain termini. Unfortunately, generally applicable methods for selective and mild C-terminal peptide functionalization are lacking. In this work, we

  8. A rapid and clean synthetic approach to cyclic peptides via micro-flow peptide chain elongation and photochemical cyclization: synthesis of a cyclic RGD peptide.

    Science.gov (United States)

    Mifune, Yuto; Nakamura, Hiroyuki; Fuse, Shinichiro

    2016-11-29

    A cyclic RGD peptide was efficiently synthesized based on micro-flow, triphosgene-mediated peptide chain elongation and micro-flow photochemical macrolactamization. Our approach enabled a rapid (amidation for peptide chain elongation peptide.

  9. The Mycobacterium tuberculosis cell-surface glycoprotein apa as a potential adhesin to colonize target cells via the innate immune system pulmonary C-type lectin surfactant protein A.

    Science.gov (United States)

    Ragas, Aude; Roussel, Lucie; Puzo, Germain; Rivière, Michel

    2007-02-23

    Tuberculosis is still a major health problem, and understanding the mechanism by which Mycobacterium tuberculosis (Mtb) invades and colonizes its host target cells remains an important issue for the control of infection. The innate immune system C-type lectins (C-TLs), including the human pulmonary surfactant protein A (PSP-A), have been recently identified as determinant players in the early recognition of the invading pathogen and in mounting the host defense response. Although the antigenic lipoglycan mannosylated lipoarabinomannan is currently considered to be the major C-TL target on the mycobacterial surface, the recognition by some C-TLs of the only mycobacterial species composing the "Mtb complex" indicates that mannosylated lipoarabinomannan cannot account alone for this specificity. Thus, we searched for the mycobacterial molecules targeted by human PSP-A, focusing our attention on the Mtb surface glycoproteins. We developed an original functional proteomic approach based on a lectin blot assay using crude human bronchoalveolar lavage fluid as a source of physiological PSP-A. Combined with selective cell-surface protein extraction and mass spectrometry peptide mapping, this strategy allowed us to identify the Apa (alanine- and proline-rich antigenic) glycoprotein as new potential target for PSP-A. This result was supported by direct binding of PSP-A to purified Apa. Moreover, EDTA addition or deglycosylation of purified Apa samples completely abolished the interaction, demonstrating that the interaction is calcium- and mannose-dependent, as expected. Finally, we provide convincing evidence that Apa, formerly considered as mainly secreted, is associated with the cell wall for a sufficiently long time to aid in the attachment of PSP-A. Because, to date, Apa seems to be restricted to the Mtb complex strains, we propose that it may account for the selective recognition of those strains by PSP-A and other immune system C-TLs containing homologous functional

  10. Peptides and Food Intake

    Directory of Open Access Journals (Sweden)

    Carmen Sobrino Crespo

    2014-04-01

    Full Text Available Nutrients created by the digestion of food are proposed to active G protein coupled receptors on the luminal side of enteroendocrine cells e.g. the L-cell. This stimulates the release of gut hormones. Hormones released from the gut and adipose tissue play an important rol in the regulation of food intake and energy expenditure (1.Many circulating signals, including gut hormones, can influence the activity of the arcuate nucleus (ARC neurons directly, after passing across the median eminence. The ARC is adjacent to the median eminence, a circumventricular organ with fenestrated capillaries and hence an incomplete blood-brain barrier (2. The ARC of the hypothalamus is believed to play a crucial role in the regulation of food intake and energy homeostasis. The ARC contains two populations of neurons with opposing effect on food intake (3. Medially located orexigenic neurons (i.e those stimulating appetite express neuropeptide Y (NPY and agouti-related protein (AgRP (4-5. Anorexigenic neurons (i.e. those inhibiting appetite in the lateral ARC express alpha-melanocyte stimulating hormone (α-MSH derived from pro-opiomelanocortin (POMC and cocaine and amphetamine-regulated transcript (CART (6. The balance between activities of these neuronal circuits is critical to body weight regulation.In contrast, other peripheral signals influence the hypothalamus indirectly via afferent neuronal pathway and brainstem circuits. In this context gastrointestinal’s vagal afferents are activated by mechanoreceptors and chemoreceptors, and converge in the nucleus of the tractus solitaries (NTS of the brainstem. Neuronal projections from the NTS, in turn, carry signals to the hypotalamus (1, 7. Gut hormones also alter the activity of the ascending vagal pathway from the gut to the brainstem. In the cases of ghrelin and Peptide tyrosine tyrosine (PYY, there are evidences for both to have a direct action on the arcuate nucleus and an action via the vagus nerve a

  11. Automated solid-phase peptide synthesis to obtain therapeutic peptides

    Directory of Open Access Journals (Sweden)

    Veronika Mäde

    2014-05-01

    Full Text Available The great versatility and the inherent high affinities of peptides for their respective targets have led to tremendous progress for therapeutic applications in the last years. In order to increase the drugability of these frequently unstable and rapidly cleared molecules, chemical modifications are of great interest. Automated solid-phase peptide synthesis (SPPS offers a suitable technology to produce chemically engineered peptides. This review concentrates on the application of SPPS by Fmoc/t-Bu protecting-group strategy, which is most commonly used. Critical issues and suggestions for the synthesis are covered. The development of automated methods from conventional to essentially improved microwave-assisted instruments is discussed. In order to improve pharmacokinetic properties of peptides, lipidation and PEGylation are described as covalent conjugation methods, which can be applied by a combination of automated and manual synthesis approaches. The synthesis and application of SPPS is described for neuropeptide Y receptor analogs as an example for bioactive hormones. The applied strategies represent innovative and potent methods for the development of novel peptide drug candidates that can be manufactured with optimized automated synthesis technologies.

  12. A missense mutation in the aggrecan C-type lectin domain disrupts extracellular matrix interactions and causes dominant familial osteochondritis dissecans

    DEFF Research Database (Denmark)

    Stattin, Eva-Lena; Wiklund, Fredrik; Lindblom, Karin

    2010-01-01

    aggrecan (ACAN) as a prime candidate gene for the disorder. Sequence analysis of ACAN revealed heterozygosity for a missense mutation (c.6907G > A) in affected individuals, resulting in a p.V2303M amino acid substitution in the aggrecan G3 domain C-type lectin, which mediates interactions with other...... is produced and present in the tissue. Our results provide a molecular mechanism for the etiology of familial osteochondritis dissecans and show the importance of the aggrecan C-type lectin interactions for cartilage function in vivo....... proteins in the cartilage extracellular matrix. Binding studies with recombinant mutated and wild-type G3 proteins showed loss of fibulin-1, fibulin-2, and tenascin-R interactions for the V2303M protein. Mass spectrometric analyses of aggrecan purified from patient cartilage verified that V2303M aggrecan...

  13. Recent advances in solid-phase peptide synthesis and preparation of antibodies to synthetic peptides.

    Science.gov (United States)

    Plaue, S; Muller, S; Briand, J P; Van Regenmortel, M H

    1990-07-01

    Peptides prepared by the solid-phase peptide synthesis (SPPS) approach are used increasingly in biological research, for instance to elicit anti-peptide antibodies that will recognize the intact, cognate protein. Recent advances in SPPS are reviewed, including the use of new coupling reagents, new methods for evaluating peptide purity and new techniques of automated and multiple peptide synthesis. Methods for enhancing peptide immunogenicity are discussed such as the use of adjuvants and liposomes, and of synthetic branched polypeptides as carriers.

  14. Lech, M., et al., Quantitative Expression of C-Type Lectin Receptors in Humans and Mice. Int. J. Mol. Sci. 2012, 13, 10113-10131.

    Directory of Open Access Journals (Sweden)

    Hans-Joachim Anders

    2012-12-01

    Full Text Available The authors wish to add this correction on their paper published in IJMS [1]. Galectin-1 was misclassified as a C-type lectin. Galectin-1 belongs to the family of the S-type lectins, i.e., the galectins. These errors have been amended in an amended version of the manuscript, which is available from the International Journal of Molecular Sciences website. The authors and publisher apologize for the inconvenience. [...

  15. The presence of multiple c-type cytochromes at the surface of the methanotrophic bacterium Methylococcus capsulatus (Bath) is regulated by copper.

    Science.gov (United States)

    Karlsen, O A; Lillehaug, J R; Jensen, H B

    2008-10-01

    Identification of surface proteins is essential to understand bacterial communication with its environment. Analysis of the surface-associated proteins of Methylococcus capsulatus (Bath) revealed a highly dynamic structure responding closely to the availability of copper in the medium in the range from approximately 0 to 10 microM. Several c-type cytochromes, including three novel multihaem proteins, are present at the cellular surface, a feature that is otherwise a peculiarity of dissimilatory metal-reducing bacteria. At low copper concentrations, the cytochrome c(553o) and the cytochrome c(553o) family protein, encoded by the MCA0421 and MCA0423 genes, respectively, are major constituents of the surfaceome and show a fine-tuned copper-dependent regulation of expression. Two novel members of the cytochrome c(553o) family were identified: MCA0338 was abundant between 5 and 10 microM copper, while MCA2259 was detected only in the surface fraction obtained from approximately 0 microM copper cultures. The presence at the bacterial surface of several c-type cytochromes, generally involved in energy transduction, indicates strongly that redox processes take place at the bacterial surface. Due to the unique role of copper in the biology of M. capsulatus (Bath), it appears that c-type cytochromes have essential functions in copper homeostasis allowing the cells to adapt to varying copper exposure.

  16. Perspectives and Peptides of the Next Generation

    Science.gov (United States)

    Brogden, Kim A.

    Shortly after their discovery, antimicrobial peptides from prokaryotes and eukaryotes were recognized as the next potential generation of pharmaceuticals to treat antibiotic-resistant bacterial infections and septic shock, to preserve food, or to sanitize surfaces. Initial research focused on identifying the spectrum of antimicrobial agents, determining the range of antimicrobial activities against bacterial, fungal, and viral pathogens, and assessing the antimicrobial activity of synthetic peptides versus their natural counterparts. Subsequent research then focused on the mechanisms of antimicrobial peptide activity in model membrane systems not only to identify the mechanisms of antimicrobial peptide activity in microorganisms but also to discern differences in cytotoxicity for prokaryotic and eukaryotic cells. Recent, contemporary work now focuses on current and future efforts to construct hybrid peptides, peptide congeners, stabilized peptides, peptide conjugates, and immobilized peptides for unique and specific applications to control the growth of microorganisms in vitro and in vivo.

  17. [Peptides: a new class of anticancer drugs].

    Science.gov (United States)

    Smolarczyk, Ryszard; Cichoń, Tomasz; Szala, Stanisław

    2009-07-22

    Peptides are a novel class of anticancer agents embracing two distinct categories: natural antibacterial peptides, which are preferentially bound by cancer cells, and chemically synthesized peptides, which bind specifically to precise molecular targets located on the surface of tumor cells. Antibacterial peptides bind to both cell and mitochondrial membranes. Some of these peptides attach to the cell membrane, resulting in its disorganization. Other antibacterial peptides penetrate cancer cells without causing cell membrane damage, but they disrupt mitochondrial membranes. Thanks to phage and aptamer libraries, it has become possible to obtain synthetic peptides blocking or activating some target proteins found in cancer cells as well as in cells forming the tumor environment. These synthetic peptides can feature anti-angiogenic properties, block enzymes indispensable for sustained tumor growth, and reduce tumor ability to metastasize. In this review the properties of peptides belonging to both categories are discussed and attempts of their application for therapeutic purposes are outlined.

  18. Peptides: A new class of anticancer drugs

    Directory of Open Access Journals (Sweden)

    Ryszard Smolarczyk

    2009-07-01

    Full Text Available Peptides are a novel class of anticancer agents embracing two distinct categories: natural antibacterial peptides, which are preferentially bound by cancer cells, and chemically synthesized peptides, which bind specifically to precise molecular targets located on the surface of tumor cells. Antibacterial peptides bind to both cell and mitochondrial membranes. Some of these peptides attach to the cell membrane, resulting in its disorganization. Other antibacterial peptides penetrate cancer cells without causing cell membrane damage, but they disrupt mitochondrial membranes. Thanks to phage and aptamer libraries, it has become possible to obtain synthetic peptides blocking or activating some target proteins found in cancer cells as well as in cells forming the tumor environment. These synthetic peptides can feature anti-angiogenic properties, block enzymes indispensable for sustained tumor growth, and reduce tumor ability to metastasize. In this review the properties of peptides belonging to both categories are discussed and attempts of their application for therapeutic purposes are outlined.

  19. Peptide Selection for Targeted Protein Quantitation.

    Science.gov (United States)

    Chiva, Cristina; Sabidó, Eduard

    2017-03-03

    Targeted proteomics methods in their different flavors rely on the use of a few peptides as proxies for protein quantitation, which need to be specified either prior to or after data acquisition. However, in contrast with discovery methods that use all identified peptides for a given protein to estimate its abundance, targeted proteomics methods are limited in the number of peptides that are used for protein quantitation. Because only a few peptides per protein are acquired or extracted in targeted experiments, the selection of peptides that are used for targeted protein quantitation becomes crucial. Several rules have been proposed to guide peptide selection for targeted proteomics studies, which have generally been based on the amino acidic composition of the peptide sequences. However, the compliance of these rules does not imply that not-conformed peptides are not reproducibly generated nor do they guarantee that the selected peptides correctly represent the behavior of the protein abundance under different conditions.

  20. Peptide pool immunization and CD8+ T cell reactivity

    DEFF Research Database (Denmark)

    Rasmussen, Susanne B; Harndahl, Mikkel N; Buus, Anette Stryhn

    2013-01-01

    peptides induced normal peptide immunity i.e. the specific T cell reactivity in the Elispot culture was strictly dependent on exposure to the immunizing peptide ex vivo. However, immunization with two of the peptides, a VSV- and a Mycobacterium-derived peptide, resulted in IFNγ spot formation without...... peptide in the Elispot culture. Immunization with a mixture of the VSV-peptide and a "normal" peptide also resulted in IFNγ spot formation without addition of peptide to the assay culture. Peptide-tetramer staining of CD8(+) T cells from mice immunized with a mixture of VSV-peptide and "normal" peptide...

  1. Atomic coordination reflects peptide immunogenicity

    Directory of Open Access Journals (Sweden)

    Georgios S.E. Antipas

    2016-01-01

    Full Text Available We demonstrated that the immunological identity of variant peptides may be accurately predicted on the basis of atomic coordination of both unprotonated and protonated tertiary structures, provided that the structure of the native peptide (index is known. The metric which was discovered to account for this discrimination is the coordination difference between the variant and the index; we also showed that increasing coordination difference in respect to the index was correlated to a correspondingly weakening immunological outcome of the variant. Additionally, we established that this metric quickly seizes to operate beyond the peptide scale, e.g. over a coordination shell inclusive of atoms up to a distance of 7 Å away from the peptide or over the entire pMHC-TCR complex. Analysis of molecular orbital interactions over a range of formal charges further revealed that the N-terminus of the agonists was always able to sustain a stable ammonium (NH3+ group which was consistently absent in antagonists. We deem that the presence of NH3+ constitutes a secondary observable with a biological consequence, signifying a change in T cell activation. While our analysis of protonated structures relied on the quantum chemical relaxation of the H species, the results were consistent over a wide range of peptide charge and spin polarization conditions.

  2. Delivery systems for antimicrobial peptides

    DEFF Research Database (Denmark)

    Nordström, Randi; Malmsten, Martin

    2017-01-01

    are likely to play a key role in the development of potent and safe AMP-based therapeutics, e.g., through reducing chemical or biological degradation of AMPs either in the formulation or after administration, by reducing adverse side-effects, by controlling AMP release rate, by promoting biofilm penetration......Due to rapidly increasing resistance development against conventional antibiotics, finding novel approaches for the treatment of infections has emerged as a key health issue. Antimicrobial peptides (AMPs) have attracted interest in this context, and there is by now a considerable literature...... on the identification such peptides, as well as on their optimization to reach potent antimicrobial and anti-inflammatory effects at simultaneously low toxicity against human cells. In comparison, delivery systems for antimicrobial peptides have attracted considerably less interest. However, such delivery systems...

  3. Antimicrobial Peptides from Marine Proteobacteria

    Directory of Open Access Journals (Sweden)

    Yannick Fleury

    2013-09-01

    Full Text Available After years of inadequate use and the emergence of multidrug resistant (MDR strains, the efficiency of “classical” antibiotics has decreased significantly. New drugs to fight MDR strains are urgently needed. Bacteria hold much promise as a source of unusual bioactive metabolites. However, the potential of marine bacteria, except for Actinomycetes and Cyanobacteria, has been largely underexplored. In the past two decades, the structures of several antimicrobial compounds have been elucidated in marine Proteobacteria. Of these compounds, polyketides (PKs, synthesised by condensation of malonyl-coenzyme A and/or acetyl-coenzyme A, and non-ribosomal peptides (NRPs, obtained through the linkage of (unusual amino acids, have recently generated particular interest. NRPs are good examples of naturally modified peptides. Here, we review and compile the data on the antimicrobial peptides isolated from marine Proteobacteria, especially NRPs.

  4. Dietary bioactive peptides: Human studies.

    Science.gov (United States)

    Bouglé, Dominique; Bouhallab, Saïd

    2017-01-22

    Current opinion strongly links nutrition and health. Among nutrients, proteins, and peptides which are encrypted in their sequences and released during digestion could play a key role in improving health. These peptides have been claimed to be active on a wide spectrum of biological functions or diseases, including blood pressure and metabolic risk factors (coagulation, obesity, lipoprotein metabolism, and peroxidation), gut and neurological functions, immunity, cancer, dental health, and mineral metabolism. A majority of studies involved dairy peptides, but the properties of vegetal, animal, and sea products were also assessed. However, these allegations are mainly based on in vitro and experimental studies which are seldom confirmed in humans. This review focused on molecules which were tested in humans, and on the mechanisms explaining discrepancies between experimental and human studies.

  5. Neoglycolipidation for modulating peptide properties

    DEFF Research Database (Denmark)

    van Witteloostuijn, Søren Blok

    regulation of appetite, food intake, and glucose homeostasis, and many of these peptides display a signicant potential for treatment of obesity and/or type 2 diabetes. This Ph.D. thesis describes three novel approaches for utilizing gut peptides as the starting point for developing obesity and diabetes drugs....... In addition, neoglycolipidation led to selfassembly and formation of well-dened oligomers as well as non-covalent binding to human serum albumin. In lean mice, acute treatment of lean mice with the neoglycolipidated GLP-1 analogs provided a marked improvement of glucose homeostasis and a potent inhibition......The alarming increase in the prevalence of obesity and associated comorbidities such as type 2 diabetes emphasizes the urgent need for new drugs with both anorectic and antidiabetic eects. Several peptide hormones secreted from the gastrointestinal tract play an important role in the physiological...

  6. A self-replicating peptide

    Science.gov (United States)

    Lee, David H.; Granja, Juan R.; Martinez, Jose A.; Severin, Kay; Ghadiri, M. Reza

    1996-08-01

    THE production of amino acids and their condensation to polypeptides under plausibly prebiotic conditions have long been known1,2. But despite the central importance of molecular self-replication in the origin of life, the feasibility of peptide self-replication has not been established experimentally3-6. Here we report an example of a self-replicating peptide. We show that a 32-residue α-helical peptide based on the leucine-zipper domain of the yeast transcription factor GCN4 can act autocatalytically in templating its own synthesis by accelerating the thioester-promoted amide-bond condensation of 15- and 17-residue fragments in neutral, dilute aqueous solutions. The self-replication process displays parabolic growth pattern with the initial rates of product formation correlating with the square-root of initial template concentration.

  7. The Pig PeptideAtlas

    DEFF Research Database (Denmark)

    Hesselager, Marianne Overgaard; Codrea, Marius; Sun, Zhi

    2016-01-01

    Biological research of Sus scrofa, the domestic pig, is of immediate relevance for food production sciences, and for developing pig as a model organism for human biomedical research. Publicly available data repositories play a fundamental role for all biological sciences, and protein data...... repositories are in particular essential for the successful development of new proteomic methods. Cumulative proteome data repositories, including the PeptideAtlas, provide the means for targeted proteomics, system-wide observations, and cross-species observational studies, but pigs have so far been...... underrepresented in existing repositories. We here present a significantly improved build of the Pig PeptideAtlas, which includes pig proteome data from 25 tissues and three body fluid types mapped to 7139 canonical proteins. The content of the Pig PeptideAtlas reflects actively ongoing research within...

  8. Novel Formulations for Antimicrobial Peptides

    Directory of Open Access Journals (Sweden)

    Ana Maria Carmona-Ribeiro

    2014-10-01

    Full Text Available Peptides in general hold much promise as a major ingredient in novel supramolecular assemblies. They may become essential in vaccine design, antimicrobial chemotherapy, cancer immunotherapy, food preservation, organs transplants, design of novel materials for dentistry, formulations against diabetes and other important strategical applications. This review discusses how novel formulations may improve the therapeutic index of antimicrobial peptides by protecting their activity and improving their bioavailability. The diversity of novel formulations using lipids, liposomes, nanoparticles, polymers, micelles, etc., within the limits of nanotechnology may also provide novel applications going beyond antimicrobial chemotherapy.

  9. Novel Formulations for Antimicrobial Peptides

    Science.gov (United States)

    Carmona-Ribeiro, Ana Maria; Carrasco, Letícia Dias de Melo

    2014-01-01

    Peptides in general hold much promise as a major ingredient in novel supramolecular assemblies. They may become essential in vaccine design, antimicrobial chemotherapy, cancer immunotherapy, food preservation, organs transplants, design of novel materials for dentistry, formulations against diabetes and other important strategical applications. This review discusses how novel formulations may improve the therapeutic index of antimicrobial peptides by protecting their activity and improving their bioavailability. The diversity of novel formulations using lipids, liposomes, nanoparticles, polymers, micelles, etc., within the limits of nanotechnology may also provide novel applications going beyond antimicrobial chemotherapy. PMID:25302615

  10. Antimicrobial peptides: old molecules with new ideas

    National Research Council Canada - National Science Library

    Nakatsuji, Teruaki; Gallo, Richard L

    2012-01-01

    .... So far, more than 1,200 types of peptides with antimicrobial activity have been isolated from various cells and tissues, and it appears that all living organisms use these antimicrobial peptides (AMPs...

  11. Histidine-Containing Peptide Nucleic Acids

    DEFF Research Database (Denmark)

    2000-01-01

    Peptide nucleic acids containing histidine moieties are provided. These compounds have applications including diagnostics, research and potential therapeutics.......Peptide nucleic acids containing histidine moieties are provided. These compounds have applications including diagnostics, research and potential therapeutics....

  12. Tulane/Xavier Vaccine Peptide Program

    Science.gov (United States)

    2014-09-01

    identified a candidate anti -viral therapeutic peptide, designated Flufirvitide-3. We found that Flufirvitide-3 is a potent inhibitor of infections by...dispersed in an aqueous solution containing the flufirvitide peptide using Tween 80 and propylene glycol co- surfactants. This emulsion preparation is...concentration of peptide at the oil/water interface on the emulsion droplet surface will also improve the effectiveness of Flufirvitide-3 peptide as

  13. 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.

  14. Development and use of engineered peptide deformylase in chemoenzymatic peptide synthesis

    NARCIS (Netherlands)

    Di Toma, Claudia

    2012-01-01

    Deze thesis beschrijft het onderzoek naar potentieel van het gebruik van het peptide deformylase (PDF) in chemo enzymatische peptide synthese. PDF is geschikt voor selective N terminale deformylatie van bepaalde N-formyl-peptides zonder gelijktijdige hydrolyse van de peptide binding. Door de

  15. A novel C-type lectin in the black tiger shrimp Penaeus monodon functions as a pattern recognition receptor by binding and causing bacterial agglutination.

    Science.gov (United States)

    Wongpanya, Ratree; Sengprasert, Panjana; Amparyup, Piti; Tassanakajon, Anchalee

    2017-01-01

    C-type lectins are pattern recognition proteins that play important roles in innate immunity in invertebrates by mediating the recognition of pathogens. In this study, a novel C-type lectin gene, PmCLec, was cloned and characterized from the black tiger shrimp Penaeus monodon. The open reading frame of PmCLec is 657 bp in length. It encodes a predicted protein of 218 amino acids with a calculated molecular mass and an isoelectric point of 24086 Da and 4.67, respectively. Sequence analysis of PmCLec showed similarity to members of the C-type lectin gene superfamily. The deduced protein contains a single carbohydrate recognition domain (CRD) and four conserved cysteine residues (Cys58, Cys126, Cys141, Cys149) that are involved in the formation of disulfide bridges. PmCLec transcripts are expressed in various tiger shrimp tissues, with the highest expression in the lymphoid organ. RNAi-mediated silencing of PmCLec resulted in higher cumulative mortality of knockdown shrimp after Vibrio harveyi infection compared to the control groups. Recombinant PmCLec was successfully expressed in the E. coli system. In the presence of Ca2+, purified rPmCLec protein binds and agglutinates Gram-positive bacteria (Staphylococcus aureus, S. hemolyticus), but only slightly binds and agglutinates E. coli and could not bind to the Gram-negative bacteria Bacillus megaterium and Vibrio harveyi. These results suggest that PmCLec functions as a pattern recognition receptor that is implicated in shrimp innate immunity. Copyright © 2016 Elsevier Ltd. All rights reserved.

  16. Ophioluxin, a convulxin-like C-type lectin from Ophiophagus hannah (King cobra) is a powerful platelet activator via glycoprotein VI.

    Science.gov (United States)

    Du, Xiao-Yan; Clemetson, Jeannine M; Navdaev, Alexei; Magnenat, Edith M; Wells, Timothy N C; Clemetson, Kenneth J

    2002-09-20

    Ophioluxin, a potent platelet agonist, was purified from the venom of Ophiophagus hannah (King cobra). Under nonreducing conditions it has a mass of 85 kDa, similar to convulxin, and on reduction gives two subunits with masses of 16 and 17 kDa, slightly larger than those of convulxin. The N-terminal sequences of both subunits are very similar to those of convulxin and other C-type lectins. Ophioluxin induces a pattern of tyrosine-phosphorylated proteins in platelets like that caused by convulxin, when using appropriate concentrations based on aggregation response, because it is about 2-4 times more powerful as agonist than the latter. Ophioluxin and convulxin induce [Ca(2+)](i) elevation both in platelets and in Dami megakaryocytic cells, and each of these C-type lectins desensitizes responses to the other. Convulxin agglutinates fixed platelets at 2 microg/ml, whereas ophioluxin does not, even at 80 microg/ml. Ophioluxin resembles convulxin more than echicetin or alboaggregin B because polyclonal anti-ophioluxin antibodies recognize both ophioluxin and convulxin, but not echicetin, and platelets adhere to and spread on ophioluxin- or convulxin-precoated surfaces in the same way that is clearly different from their behavior on an alboaggregin B surface. Immobilized ophioluxin was used to isolate the glycoprotein VI-Fcgamma complex from resting platelets, which also contained Fyn, Lyn, Syk, LAT, and SLP76. Ophioluxin is the first multiheterodimeric, convulxin-like snake C-type lectin, as well as the first platelet agonist, to be described from the Elapidae snake family.

  17. Structure of asymmetrical peptide dendrimers

    NARCIS (Netherlands)

    Okrugin, B.M.; Neelov, I.M.; Leermakers, F.A.M.; Borisov, Oleg V.

    2017-01-01

    Structural properties of asymmetric peptide dendrimers up to the 11th generation are studied on the basis of the self-consistent field Scheutjens-Fleer numerical approach. It is demonstrated that large scale properties such as, e.g., the gyration radius, are relatively weakly affected by the

  18. Peptide-functionalized polyphenylene dendrimers

    NARCIS (Netherlands)

    Herrmann, Andreas; Mihov, Gueorgui; Vandermeulen, Guido W.M.; Klok, Harm-Anton; Müllen, Klaus

    2003-01-01

    This contribution describes the synthesis of polyphenylene dendrimers that are functionalized with up to 16 lysine residues or substituted with short peptide sequences composed of 5 lysine or glutamic acid repeats and a C- or N-terminal cysteine residue. Polyphenylene dendrimers were prepared via a

  19. Synthetic Procedures for Peptide Nucleic Acids

    DEFF Research Database (Denmark)

    2004-01-01

    A novel class of compounds, known as peptide nucleic acids, bind complementary ssDNA and RNA strands more strongly than a corresponding DNA. The peptide nucleic acids generally comprise ligands such as naturally occurring DNA bases attached to a peptide backbone through a suitable linker....

  20. Double-Stranded Peptide Nucleic Acids

    DEFF Research Database (Denmark)

    2001-01-01

    A novel class of compounds, known as peptide nucleic acids, form double-stranded structures with one another and with ssDNA. The peptide nucleic acids generally comprise ligands such as naturally occurring DNA bases attached to a peptide backbone through a suitable linker....

  1. Identification of multifunctional peptides from human milk.

    Science.gov (United States)

    Mandal, Santi M; Bharti, Rashmi; Porto, William F; Gauri, Samiran S; Mandal, Mahitosh; Franco, Octavio L; Ghosh, Ananta K

    2014-06-01

    Pharmaceutical industries have renewed interest in screening multifunctional bioactive peptides as a marketable product in health care applications. In this context, several animal and plant peptides with potential bioactivity have been reported. Milk proteins and peptides have received much attention as a source of health-enhancing components to be incorporated into nutraceuticals and functional foods. By using this source, 24 peptides have been fractionated and purified from human milk using RP-HPLC. Multifunctional roles including antimicrobial, antioxidant and growth stimulating activity have been evaluated in all 24 fractions. Nevertheless, only four fractions show multiple combined activities among them. Using a proteomic approach, two of these four peptides have been identified as lactoferrin derived peptide and kappa casein short chain peptide. Lactoferrin derived peptide (f8) is arginine-rich and kappa casein derived (f12) peptide is proline-rich. Both peptides (f8 and f12) showed antimicrobial activities against both Gram-positive and Gram-negative bacteria. Fraction 8 (f8) exhibits growth stimulating activity in 3T3 cell line and f12 shows higher free radical scavenging activity in comparison to other fractions. Finally, both peptides were in silico evaluated and some insights into their mechanism of action were provided. Thus, results indicate that these identified peptides have multiple biological activities which are valuable for the quick development of the neonate and may be considered as potential biotechnological products for nutraceutical industry. Copyright © 2014 Elsevier Inc. All rights reserved.

  2. Characterization of Synthetic Peptides by Mass Spectrometry

    DEFF Research Database (Denmark)

    Prabhala, Bala K; Mirza, Osman; Højrup, Peter

    2015-01-01

    Mass spectrometry (MS) is well suited for analysis of the identity and purity of synthetic peptides. The sequence of a synthetic peptide is most often known, so the analysis is mainly used to confirm the identity and purity of the peptide. Here, simple procedures are described for MALDI...

  3. Peptides and metallic nanoparticles for biomedical applications.

    NARCIS (Netherlands)

    Kogan, M.J.; Olmedo, I.; Hosta, L.; Guerrero, A.R.; Cruz Ricondo, L.J.; Albericio, F.

    2007-01-01

    In this review, we describe the contribution of peptides to the biomedical applications of metallic nanoparticles. We also discuss strategies for the preparation of peptide-nanoparticle conjugates and the synthesis of the peptides and metallic nanoparticles. An overview of the techniques used for

  4. Protein-Protein Interaction between Surfactant Protein D and DC-SIGN via C-Type Lectin Domain Can Suppress HIV-1 Transfer.

    Science.gov (United States)

    Dodagatta-Marri, Eswari; Mitchell, Daniel A; Pandit, Hrishikesh; Sonawani, Archana; Murugaiah, Valarmathy; Idicula-Thomas, Susan; Nal, Béatrice; Al-Mozaini, Maha M; Kaur, Anuvinder; Madan, Taruna; Kishore, Uday

    2017-01-01

    Surfactant protein D (SP-D) is a soluble C-type lectin, belonging to the collectin (collagen-containing calcium-dependent lectin) family, which acts as an innate immune pattern recognition molecule in the lungs at other mucosal surfaces. Immune regulation and surfactant homeostasis are salient functions of SP-D. SP-D can bind to a range of viral, bacterial, and fungal pathogens and trigger clearance mechanisms. SP-D binds to gp120, the envelope protein expressed on HIV-1, through its C-type lectin or carbohydrate recognition domain. This is of importance since SP-D is secreted by human mucosal epithelial cells and is present in the female reproductive tract, including vagina. Another C-type lectin, dendritic cell (DC)-specific intercellular adhesion molecule-3-grabbing non-integrin (DC-SIGN), present on the surface of the DCs, also binds to HIV-1 gp120 and facilitates viral transfer to the lymphoid tissues. DCs are also present at the site of HIV-1 entry, embedded in vaginal or rectal mucosa. In the present study, we report a direct protein-protein interaction between recombinant forms of SP-D (rfhSP-D) and DC-SIGN via their C-type lectin domains. Both SP-D and DC-SIGN competed for binding to immobilized HIV-1 gp120. Pre-incubation of human embryonic kidney cells expressing surface DC-SIGN with rfhSP-D significantly inhibited the HIV-1 transfer to activated peripheral blood mononuclear cells. In silico analysis revealed that SP-D and gp120 may occupy same sites on DC-SIGN, which may explain the reduced transfer of HIV-1. In summary, we demonstrate, for the first time, that DC-SIGN is a novel binding partner of SP-D, and this interaction can modulate HIV-1 capture and transfer to CD4+ T cells. In addition, the present study also reveals a novel and distinct mechanism of host defense by SP-D against HIV-1.

  5. Recombinant Expression, In Vitro Refolding and Characterizing Disulfide Bonds of a Mouse Inhibitory C-Type Lectin-Like Receptor Nkrp1b

    Czech Academy of Sciences Publication Activity Database

    Hernychová, Lucie; Mrázek, Hynek; Ivanova, Ljubina; Kukačka, Zdeněk; Chmelík, Josef; Novák, Petr

    2015-01-01

    Roč. 64, č. 2015 (2015), s. 85-93 ISSN 0862-8408 R&D Projects: GA MŠk(CZ) EE2.3.30.0003; GA MŠk(CZ) ED1.1.00/02.0109; GA MŠk LO1509 Grant - others:OPPC(XE) CZ.2.16/3.1.00/24023 Institutional support: RVO:61388971 Keywords : NK cell * C-type lectin -like receptor (CTLR) * Nkrp1 Subject RIV: CE - Biochemistry Impact factor: 1.643, year: 2015

  6. cGMP-activating peptides do not regulate electrogenic electrolyte transport in principal cells of rat CCD.

    Science.gov (United States)

    Schlatter, E; Cermak, R; Forssmann, W G; Hirsch, J R; Kleta, R; Kuhn, M; Sun, D; Schafer, J A

    1996-12-01

    K+ channels in the basolateral membrane of rat cortical collecting duct (CCD) are regulated by a cGMP-dependent protein kinase (J. Hirsch and E. Schlatter. Pfluegers Arch. 429: 338-344, 1995). Conflicting data exist on the effects of cGMP-activating agonists on Na+ transport in these cells. Thus we tested members of the family of peptides that increase intracellular cGMP [cardiodilatin/atrial natriuretic peptide (CDD/ANP), brain natriuretic peptide, C-type natriuretic peptide, urodilatin, guanylin, and uroguanylin], as well as bradykinin +/- CDD/ANP on membrane voltages (Vm) of principal cells of isolated rat CCD using the slow whole cell patch-clamp technique (E. Schlatter, U. Fröbe, and R. Greger. Pfluegers Arch. 421: 381-387, 1992). None of the agonists tested changed Vm significantly. There was also no effect of dibutyryl guanosine 3',5'-cyclic monophosphate (DBcGMP) on AVP-dependent lumen-to-bath Na+ flux, transepithelial voltage, or osmotic water permeability in isolated perfused rat CCD. Finally, CDD/ANP increased intracellular cGMP only in glomeruli but not in CCD. Thus the findings provide no evidence for control of electrogenic electrolyte transport by these natriuretic peptides in principal cells of rat CCD, and the agonist that physiologically regulates the cGMP-dependent K+ channels remains to be identified.

  7. Insect Peptides - Perspectives in Human Diseases Treatment.

    Science.gov (United States)

    Chowanski, Szymon; Adamski, Zbigniew; Lubawy, Jan; Marciniak, Pawel; Pacholska-Bogalska, Joanna; Slocinska, Malgorzata; Spochacz, Marta; Szymczak, Monika; Urbanski, Arkadiusz; Walkowiak-Nowicka, Karolina; Rosinski, Grzegorz

    2017-01-01

    Insects are the largest and the most widely distributed group of animals in the world. Their diversity is a source of incredible variety of different mechanisms of life processes regulation. There are many agents that regulate immunology, reproduction, growth and development or metabolism. Hence, it seems that insects may be a source of numerous substances useful in human diseases treatment. Especially important in the regulation of insect physiology are peptides, like neuropeptides, peptide hormones or antimicrobial peptides. There are two main aspects where they can be helpful, 1) Peptides isolated from insects may become potential drugs in therapy of different diseases, 2) A lot of insect peptide hormones show structural or functional homology to mammalian peptide hormones and the comparative studies may give a new look on human disorders. In our review we focused on three group of insect derived peptides: 1) immune-active peptides, 2) peptide hormones and 3) peptides present in venoms. In our review we try to show the considerable potential of insect peptides in searching for new solutions for mammalian diseases treatment. We summarise the knowledge about properties of insect peptides against different virulent agents, anti-inflammatory or anti-nociceptive properties as well as compare insect and mammalian/vertebrate peptide endocrine system to indicate usefulness of knowledge about insect peptide hormones in drug design. The field of possible using of insect delivered peptide to therapy of various human diseases is still not sufficiently explored. Undoubtedly, more attention should be paid to insects due to searching new drugs. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  8. Peptides: Production, bioactivity, functionality, and applications

    DEFF Research Database (Denmark)

    Hajfathalian, Mona; Ghelichi, Sakhi; García Moreno, Pedro Jesús

    2017-01-01

    Production of peptides with various effects from proteins of different sources continues to receive academic attention. Researchers of different disciplines are putting increasing efforts to produce bioactive and functional peptides from different sources such as plants, animals, and food industry...... by-products. The aim of this review is to introduce production methods of hydrolysates and peptides and provide a comprehensive overview of their bioactivity in terms of their effects on immune, cardiovascular, nervous, and gastrointestinal systems. Moreover, functional and antioxidant properties...... of hydrolysates and isolated peptides are reviewed. Finally, industrial and commercial applications of bioactive peptides including their use in nutrition and production of pharmaceuticals and nutraceuticals are discussed....

  9. Interpreting peptide mass spectra by VEMS

    DEFF Research Database (Denmark)

    Mathiesen, Rune; Lundsgaard, M.; Welinder, Karen G.

    2003-01-01

    of peptide MS/MS spectra imported in text file format. Peaks are annotated, the monoisotopic peaks retained, and the b-and y-ion series identified in an interactive manner. The called peptide sequence is searched against a local protein database for sequence identity and peptide mass. The report compares...... the calculated and the experimental mass spectrum of the called peptide. The program package includes four accessory programs. VEMStrans creates protein databases in FASTA format from EST or cDNA sequence files. VEMSdata creates a virtual peptide database from FASTA files. VEMSdist displays the distribution...

  10. Developments in peptide and amide synthesis.

    Science.gov (United States)

    Albericio, Fernando

    2004-06-01

    The solid-phase methodology is key for an effective synthesis of peptides, from a milligram scale for research to a multi-kilo scale for drug production. Indeed, small peptides containing up to 20-30 amino acids are most readily synthesized by a solid-phase strategy. Larger peptides (up to 60 amino acids) should be synthesized by a convergent approach (i.e. synthesis of protected constituent peptides in solid-phase and combination of these units in solution). Larger peptides and proteins are prepared by chemical ligation, where unprotected segments have been prepared in solid-phase.

  11. A C-type lectin isolated from the skin of Japanese bullhead shark (Heterodontus japonicus) binds a remarkably broad range of sugars and induces blood coagulation.

    Science.gov (United States)

    Tsutsui, Shigeyuki; Dotsuta, Yuma; Ono, Ayaka; Suzuki, Masanari; Tateno, Hiroaki; Hirabayashi, Jun; Nakamura, Osamu

    2015-05-01

    The aim of this study was to determine the physiological role of skin lectins of the Japanese bullhead shark (Heterodontus japonicus). A skin extract was subjected to affinity chromatography using seven different sugars as ligands. Molecular mass and N-terminal amino acid sequence analyses indicated elution of the same protein by each of the seven respective cognate ligands from sugar affinity columns. The predicted amino acid sequence encoded by the cDNA of this protein [designated as H. japonicus C-type-lectin (HjCL)] identified it as a novel fish subgroup VII C-type lectin evolutionarily related to snake venom lectins. HjCL was predicted to bind to mannose because of the presence of a Glu-Pro-Asn (EPN) motif; however, haemagglutination inhibition assays and glycoconjugate microarray analysis demonstrated its binding to numerous structurally diverse sugars. Competitive sugar-binding assays using affinity chromatography indicated that HjCL bound multiple sugars via a common carbohydrate-recognition domain. The mRNA encoding HjCL was specifically detected in the skin, and immunohistochemical analysis detected its expression in uncharacterized large cells in the epidermis. HjCL agglutinated the bacterial pathogen Edwardsiella tarda and promoted immediate clotting of shark blood, indicating that HjCL is involved in host defence on the skin surface especially when the shark is injured and bleeds. © The Authors 2014. Published by Oxford University Press on behalf of the Japanese Biochemical Society. All rights reserved.

  12. Oxidation of c-Type Cytochromes by the Membrane-Bound Cytochrome Oxidase (Cytochrome aa(3)) of Blue-Green Algae.

    Science.gov (United States)

    Kienzl, P F; Peschek, G A

    1982-03-01

    Respiratory particles containing an aa(3)-type cytochrome oxidase were prepared from Anacystis nidulans, Synechocystis 6714, Synechococcus lividus, Anabaena variabilis, Nostoc sp. strain MAC, Nostoc muscorum, and Mastigocladus laminosus. Oxidation of c-type cytochromes by membrane preparations of the different blue-green algae was observed using purified cytochromes from horse heart, Candida krusei, tuna, Saccharomyces oviformis, Rhodospirillum rubrum, Rhodospirillum molischianum, Rhodopseudomonas palustris, Rhodocyclus purpureus, Paracoccus denitrificans, Anacystis nidulans, Anabaena variabilis, Euglena gracilis, and Scenedesmus obliquus. Rapid oxidations were consistently observed with the mitochondrial c-type cytochromes (horse heart cytochrome c reacts most rapidly) and with cytochromes c(2) from Rhodopseudomonas palustris and Rhodocyclus purpureus; in contrast, the cytochrome c(2) from Rhodospirillum rubrum and the plastidic cytochromes from E. gracilis and Scendesmus obliquus were inactive with all membrane preparations. All reactions were inhibited by low concentrations of KCN, NaN(3), and CO, and they were activated by Tween 80, thus indicating participation of the terminal oxidase. The results are discussed in view of the spectral similarities between the terminal oxidase of blue-green algae and the mitochondrial aa(3)-type cytochrome oxidase of plants and other eukaryotes.

  13. Evolution of the C-Type Lectin-Like Receptor Genes of the DECTIN-1 Cluster in the NK Gene Complex

    Directory of Open Access Journals (Sweden)

    Susanne Sattler

    2012-01-01

    Full Text Available Pattern recognition receptors are crucial in initiating and shaping innate and adaptive immune responses and often belong to families of structurally and evolutionarily related proteins. The human C-type lectin-like receptors encoded in the DECTIN-1 cluster within the NK gene complex contain prominent receptors with pattern recognition function, such as DECTIN-1 and LOX-1. All members of this cluster share significant homology and are considered to have arisen from subsequent gene duplications. Recent developments in sequencing and the availability of comprehensive sequence data comprising many species showed that the receptors of the DECTIN-1 cluster are not only homologous to each other but also highly conserved between species. Even in Caenorhabditis elegans, genes displaying homology to the mammalian C-type lectin-like receptors have been detected. In this paper, we conduct a comprehensive phylogenetic survey and give an up-to-date overview of the currently available data on the evolutionary emergence of the DECTIN-1 cluster genes.

  14. Conformation and location of amorphous and semi-crystalline regions in C-type starch granules revealed by SEM, NMR and XRD.

    Science.gov (United States)

    Wang, Shujun; Yu, Jinglin; Yu, Jiugao

    2008-09-01

    The conformations and locations of amorphous and semi-crystalline regions in C-type starch granules from Chinese yam were evaluated by a combination of morphology and spectroscopy studies during acid hydrolysis. Scanning electron micrographs showed that amorphous or less crystalline areas were essentially located in the centre part of C-type starch granules, whereas the semi-crystalline and amorphous growth rings were found mainly in the outer part of the granules. (13)C cross-polarization magic angle spinning NMR ((13)C CP/MAS NMR) showed that amorphous regions were hydrolyzed faster than the crystalline ones. In addition, B-type polymorphs were shown to be hydrolyzed more rapidly than A-types. Powder X-ray diffraction (XRD) also revealed that the B-polymorph was hydrolyzed more rapidly than the A-type. XRD showed that the amorphous or less crystalline areas were mainly located in the core of starch granules, while the amorphous growth rings are distributed toward the outside of the granules and alternatively arranged with semi-crystalline growth rings. The amorphous or less crystalline areas predominantly consisted of the B-polymorph whereas the outer semi-crystalline and amorphous growth rings were mostly composed of the A-polymorph. Copyright © 2008 Elsevier Ltd. All rights reserved.

  15. Pathogen recognition of a novel C-type lectin from Marsupenaeus japonicus reveals the divergent sugar-binding specificity of QAP motif.

    Science.gov (United States)

    Alenton, Rod Russel R; Koiwai, Keiichiro; Miyaguchi, Kohei; Kondo, Hidehiro; Hirono, Ikuo

    2017-04-04

    C-type lectins (CTLs) are calcium-dependent carbohydrate-binding proteins known to assist the innate immune system as pattern recognition receptors (PRRs). The binding specificity of CTLs lies in the motif of their carbohydrate recognition domain (CRD), the tripeptide motifs EPN and QPD bind to mannose and galactose, respectively. However, variants of these motifs were discovered including a QAP sequence reported in shrimp believed to have the same carbohydrate specificity as QPD. Here, we characterized a novel C-type lectin (MjGCTL) possessing a CRD with a QAP motif. The recombinant MjGCTL has a calcium-dependent agglutinating capability against both Gram-negative and Gram-positive bacteria, and its sugar specificity did not involve either mannose or galactose. In an encapsulation assay, agarose beads coated with rMjGCTL were immediately encapsulated from 0 h followed by melanization at 4 h post-incubation with hemocytes. These results confirm that MjGCTL functions as a classical CTL. The structure of QAP motif and carbohydrate-specificity of rMjGCTL was found to be different to both EPN and QPD, suggesting that QAP is a new motif. Furthermore, MjGCTL acts as a PRR binding to hemocytes to activate their adherent state and initiate encapsulation.

  16. Towards the MHC-peptide combinatorics.

    Science.gov (United States)

    Kangueane, P; Sakharkar, M K; Kolatkar, P R; Ren, E C

    2001-05-01

    The exponentially increased sequence information on major histocompatibility complex (MHC) alleles points to the existence of a high degree of polymorphism within them. To understand the functional consequences of MHC alleles, 36 nonredundant MHC-peptide complexes in the protein data bank (PDB) were examined. Induced fit molecular recognition patterns such as those in MHC-peptide complexes are governed by numerous rules. The 36 complexes were clustered into 19 subgroups based on allele specificity and peptide length. The subgroups were further analyzed for identifying common features in MHC-peptide binding pattern. The four major observations made during the investigation were: (1) the positional preference of peptide residues defined by percentage burial upon complex formation is shown for all the 19 subgroups and the burial profiles within entries in a given subgroup are found to be similar; (2) in class I specific 8- and 9-mer peptides, the fourth residue is consistently solvent exposed, however this observation is not consistent in class I specific 10-mer peptides; (3) an anchor-shift in positional preference is observed towards the C terminal as the peptide length increases in class II specific peptides; and (4) peptide backbone atoms are proportionately dominant at the MHC-peptide interface.

  17. Taylor Dispersion Analysis as a promising tool for assessment of peptide-peptide interactions

    DEFF Research Database (Denmark)

    Høgstedt, Ulrich B; Schwach, Grégoire; van de Weert, Marco

    2016-01-01

    . In this work, we show that protein-protein and peptide-peptide interactions can advantageously be investigated by measurement of the diffusion coefficient using Taylor Dispersion Analysis. Through comparison to Dynamic Light Scattering it was shown that Taylor Dispersion Analysis is well suited...... for the characterization of protein-protein interactions of solutions of α-lactalbumin and human serum albumin. The peptide-peptide interactions of three selected peptides were then investigated in a concentration range spanning from 0.5mg/ml up to 80mg/ml using Taylor Dispersion Analysis. The peptide-peptide interactions...... determination indicated that multibody interactions significantly affect the PPIs at concentration levels above 25mg/ml for the two charged peptides. Relative viscosity measurements, performed using the capillary based setup applied for Taylor Dispersion Analysis, showed that the viscosity of the peptide...

  18. Convulxin, a C-type lectin-like protein, inhibits HCASMCs functions via WAD-motif/integrin-αv interaction and NF-κB-independent gene suppression of GRO and IL-8

    Energy Technology Data Exchange (ETDEWEB)

    Shih, Chun-Ho; Chiang, Tin-Bin [Chang Gung University of Science and Technology, Guishan Dist., Taoyuan City, Taiwan (China); Wang, Wen-Jeng, E-mail: wjwang@mail.cgust.edu.tw [Chang Gung University of Science and Technology, Guishan Dist., Taoyuan City, Taiwan (China); Department of Neurological Surgery, Chang Gung Memorial Hospital, Guishan Dist., Taoyuan City, Taiwan (China)

    2017-03-15

    Convulxin (CVX), a C-type lectin-like protein (CLPs), is a potent platelet aggregation inducer. To evaluate its potential applications in angiogenic diseases, the multimeric CVX were further explored on its mode of actions toward human coronary artery smooth muscle cells (HCASMCs). The N-terminus of β-chain of CVX (CVX-β) contains a putative disintegrin-like domain with a conserved motif upon the sequence comparison with other CLPs. Importantly, native CVX had no cytotoxic activity as examined by electrophoretic pattern. A Trp-Ala–Asp (WAD)-containing octapeptide, MTWADAEK, was thereafter synthesized and analyzed in functional assays. In the case of specific integrin antagonists as positive controls, the anti-angiogenic effects of CVX on HCASMCs were investigated by series of functional analyses. CVX showed to exhibit multiple inhibitory activities toward HCASMCs proliferation, adhesion and invasion with a dose- and integrin αvβ3-dependent fashion. However, the WAD-octapeptide exerting a minor potency could also work as an active peptidomimetic. In addition, flow cytometric analysis demonstrated both the intact CVX and synthetic peptide can specifically interact with integrin-αv on HCASMCs and CVX was shown to have a down-regulatory effect on the gene expression of CXC-chemokines, such as growth-related oncogene and interleukin-8. According to nuclear factor-κB (NF-κB) p65 translocation assay and Western blotting analysis, the NF-κB activation was not involved in the signaling events of CVX-induced gene expression. In conclusion, CVX may act as a disintegrin-like protein via the interactions of WAD-motif in CVX-β with integrin-αv on HCASMCs and it also is a gene suppressor with the ability to diminish the expression of two CXC-chemokines in a NF-κB-independent manner. Indeed, more extensive investigations are needed and might create a new avenue for the development of a novel angiostatic agent. - Highlights: • The tetrameric convulxin (CVX) with WAD

  19. Characterization of Peptide Antibodies by Epitope Mapping Using Resin-Bound and Soluble Peptides.

    Science.gov (United States)

    Trier, Nicole Hartwig

    2015-01-01

    Characterization of peptide antibodies through identification of their target epitopes is of utmost importance. Understanding antibody specificity at the amino acid level provides the key to understand the specific interaction between antibodies and their epitopes and their use as research and diagnostic tools as well as therapeutic agents. This chapter describes a straightforward strategy for mapping of continuous peptide antibody epitopes using resin-bound and soluble peptides. The approach combines three different types of peptide sets for full characterization of peptide antibodies: (1) overlapping peptides, used to locate antigenic regions; (2) truncated peptides, used to identify the minimal peptide length required for antibody binding; and (3) substituted peptides, used to identify the key residues important for antibody binding and to determine the specific contribution of key residues. For initial screening resin-bound peptides are used for epitope estimation, while soluble peptides subsequently are used for fine mapping. The combination of resin-bound peptides and soluble peptides for epitope mapping provides a time-sparing and straightforward approach for characterization of peptide antibodies.

  20. Radio peptide imaging and therapy

    Energy Technology Data Exchange (ETDEWEB)

    Buscombe, Jonh [Royal Free Hospital, London (United Kingdom)

    1997-12-31

    Full text. The concept of the magic bullet retains its attraction to us. If only we could take a drug or radioisotope and inject this intravenously and then will attach to the target cancer. This may allow imaging if labelled with a radio pharmaceutical or possibly even effective therapy. Initially work was started using antibodies of mouse origin. These have shown some utility in targeting tumors but there are problems in that these are essentially non-human proteins, often derived from mice. This leads to the formation of antibodies against that antibody so that repeat administrations lead to reduced efficacy and possibly may carry a risk anaphylaxis for the patient. Two different methods have evolved to deal with this situation. Either make antibodies more human or use smaller fragments, so that they are less likely to cause allergic reactions. The second method is to try and use a synthetic peptide. This will contain a series of amino acids which recognize a certain cell receptor. For example the somatostatin analogue Octreotide is an 8 amino acid peptide which has the same biological actions as natural somatostatin but an increased plasma half life. To this is added a linker a good example being DTPA and then radioisotope for example In-111. There we can have the complex In-111-DTPA-Octreotide which can be used to image somatostatin receptors in vivo. The main advantage over antibodies is that the cost production is less and many different variation of peptides for a particular receptor can be manufactured and assessed to find which is the optimal agent tumour imaging at a fraction of the cost of antibody production. There are two main approaches. Firstly to take a natural peptide hormone such as insulin or VIP and label by a simple method such as iodination with I-123. A group in Vienna have done it and shown good uptake of I-123 Insulin in primary hepatomas and of I-123 VIP in pancreatic cancers. Many natural peptide hormones however have a short plasma half

  1. Peptides and methods against diabetes

    Science.gov (United States)

    Albertini, Richard J.; Falta, Michael T.

    2000-01-01

    This invention relates to methods of preventing or reducing the severity of diabetes. In one embodiment, the method involves administering to the individual a peptide having substantially the sequence of a on-conserved region sequence of a T cell receptor present on the surface of T cells mediating diabetes or a fragment thereof, wherein the peptide or fragment is capable of causing an effect on the immune system to regulate the T cells. In particular, the T cell receptor has the V.beta. regional V.beta.6 or V.beta.14. In another embodiment, the method involves gene therapy. The invention also relates to methods of diagnosing diabetes by determining the presence of diabetes predominant T cell receptors.

  2. Antimicrobial peptides from Capsicum sp.

    African Journals Online (AJOL)

    ajl yemi

    2011-12-30

    Dec 30, 2011 ... alternative: Antimicrobial peptides from Capsicum sp. Moguel-Salazar Fernando, Brito-Argáez Ligia, Díaz-Brito Mayra and Islas-Flores Ignacio*. Unidad de Bioquímica y Biología Molecular de Plantas del Centro de Investigación Científica de Yucatán A.C. Calle 43. No. 130, Colonia Chuburná de Hidalgo, ...

  3. Biodiscovery of Aluminum Binding Peptides

    Science.gov (United States)

    2013-08-01

    conjunction with organic-based targets, such as protein toxins or carbon nanotubes . However, this technology has been expanded for use with inorganic...conjunction with organic-based targets, such as protein toxins or carbon nanotubes . However, this technology has been expanded for use with inorganic targets...8] Rothenstein, D. C., et al., "Isolation of ZnO -binding 12-mer peptides and determination of their binding epitopes by NMR spectroscopy," J. Am

  4. Photosystem Inspired Peptide Hybrid Catalysts

    Science.gov (United States)

    2017-06-07

    peptide-based hybrid material can be a promising new class of proton conductor. Contrary to the conventional viewpoint on CO2 as a major contributor of... materials (Figure 2) Tyrosine is known to be an important sequence that helps electron transfer and hydrogen ion transfer in the natural world. In...13. SUPPLEMENTARY NOTES 14. ABSTRACT Biological systems can inspire to make new hybrid materials defined at the molecular level. We propose a novel

  5. Peptide-targeted polymer cancerostatics

    Czech Academy of Sciences Publication Activity Database

    Böhmová, Eliška; Pola, Robert

    2016-01-01

    Roč. 65, Suppl. 2 (2016), S153-S164 ISSN 0862-8408 R&D Projects: GA MŠk(CZ) LO1507 Institutional support: RVO:61389013 Keywords : HPMA copolymers * tumor targeting * peptides Subject RIV: CD - Macromolecular Chemistry Impact factor: 1.461, year: 2016 http://www.biomed.cas.cz/physiolres/pdf/65%20Suppl%202/65_S153.pdf

  6. Biopharmaceuticals: From peptide to drug

    Science.gov (United States)

    Hannappel, Margarete

    2017-08-01

    Biologics are therapeutic proteins or peptides that are produced by means of biological processes within living organisms and cells. They are highly specific molecules and play a crucial role as therapeutics for the treatment of severe and chronic diseases (e.g. cancer, rheumatoid arthritis, diabetes, autoimmune disorders). The development of new biologics and biologics-based drugs gains more and more importance in the fight against various diseases. A short overview on biotherapeutical drug development is given. Cone snails are a large group of poisonous, predatory sea snails with more than 700 species. They use a very powerful venom which rapidly inactivates and paralyzes their prey. Most bioactive venom components are small peptides (conotoxins, conopeptides) which are precisely directed towards a specific target (e.g. ion channel, receptors). Due to their small size, their precision and speed of action, naturally occurring cone snail venom peptides represent an attractive source for the identification and design of novel biological drug entities. The Jagna cone snail project is an encouraging initiative to map the ecological variety of cone snails around the island of Bohol (Philippines) and to conserve the biological information for potential future application.

  7. Antihypertensive Peptides from Milk Proteins

    Directory of Open Access Journals (Sweden)

    Heikki Vapaatalo

    2010-01-01

    Full Text Available Dietary proteins possess a wide range of nutritional and functional properties. They are used as a source of energy and amino acids, which are needed for growth and development. Many dietary proteins, especially milk proteins, contain physiologically active peptides encrypted in the protein sequence. These peptides may be released during gastrointestinal digestion or food processing and once liberated, cause different physiological functions. Milk-derived bioactive peptides are shown to have antihypertensive, antimicrobial, immunomodulatory, antioxidative and mineral-binding properties. During the fermentation of milk with certain lactobacilli, two interesting tripeptides Ile-Pro-Pro and Val-Pro-Pro are released from casein to the final product. These lactotripeptides have attenuated the development of hypertension in several animal models and lowered blood pressure in clinical studies. They inhibit ACE in vitro at micromolar concentrations, protect endothelial function in vitro and reduce arterial stiffness in humans. Thus, milk as a traditional food product can after certain processing serve as a functional food and carry specific health-promoting effects, providing an option to control blood pressure.

  8. Synthesis of cyclic tryptathionine peptides.

    Science.gov (United States)

    Zanotti, G; Beijer, B; Wieland, T

    1987-09-01

    The helicity of the tryptathionine moiety of the phallotoxins has been recognized by comparison with cyclic tryptathionine tripeptides. In order to investigate the influence of the configuration of the component amino acids on the conformation of the cyclic peptides, six analogue thioether tripeptides containing L- and D-alanine and L- and D-cysteine, respectively, have been synthesized. The CD spectra of the peptides are very similar to each other, showing mirror images of the CD of phalloidin and, therefore, negative helicity. The spectra of the D-cysteine containing compounds differ from the L-cysteine containing compounds by their weakly positive ellipticity values around 270 nm. The cyclization reaction of Boc-Hpi-D-Ala-D-Cys(STrt)OCH3, along with the cyclic tripeptide, afforded a cyclic hexapeptide by dimerization. The CD spectrum of the dimer is very similar to that of phalloidin, thus pointing to a positive helicity of its two tryptathionine moieties. The dimeric thioether peptide forms a rather strong complex with Cu2+ ions.

  9. Coffee, hunger, and peptide YY.

    Science.gov (United States)

    Greenberg, James A; Geliebter, Allan

    2012-06-01

    There is evidence from several empirical studies suggesting that coffee may help people control body weight. Our objective was to assess the effects of caffeine, caffeinated coffee, and decaffeinated coffee, both alone and in combination with 75 g of glucose, on perceived hunger and satiety and related peptides. We conducted a placebo-controlled single-blinded randomized 4-way crossover trial. Eleven healthy male volunteers (mean age, 23.5 ± 5.7 years; mean BMI, 23.6 ± 4.2 kg/m(2)) ingested 1 of 3 test beverages (caffeine in water, caffeinated coffee, or decaffeinated coffee) or placebo (water), and 60 minutes later they ingested the glucose. Eight times during each laboratory visit, hunger and satiety were assessed by visual analog scales, and blood samples were drawn to measure 3 endogenous peptides associated with hunger and satiety: ghrelin, peptide YY (PYY), and leptin. Compared to placebo, decaffeinated coffee yielded significantly lower hunger during the whole 180-minute study period and higher plasma PYY for the first 90 minutes (p hunger or PYY. Caffeinated coffee showed a pattern between that of decaffeinated coffee and caffeine in water. These findings suggest that one or more noncaffeine ingredients in coffee may have the potential to decrease body weight. Glucose ingestion did not change the effects of the beverages. Our randomized human trial showed that decaffeinated coffee can acutely decrease hunger and increase the satiety hormone PYY.

  10. SVSVGMKPSPRP: a broad range adhesion peptide.

    Science.gov (United States)

    Estephan, Elias; Dao, Jérôme; Saab, Marie-Belle; Panayotov, Ivan; Martin, Marta; Larroque, Christian; Gergely, Csilla; Cuisinier, Frédéric J G; Levallois, Bernard

    2012-12-01

    A combinatorial phage display approach was previously used to evolve a 12-mer peptide (SVSVGMKPSPRP) with the highest affinity for different semiconductor surfaces. The discovery of the multiple occurrences of the SVSVGMKPSPRP sequence in an all-against-all basic local alignment search tool search of PepBank sequences was unexpected, and a Google search using the peptide sequence recovered 58 results concerning 12 patents and 16 scientific publications. The number of patent and articles indicates that the peptide is perhaps a broad range adhesion peptide. To evaluate peptide properties, we conducted a study to investigate peptide adhesion on different inorganic substrates by mass spectrometry and atomic force microscopy for gold, carbon nanotubes, cobalt, chrome alloy, titanium, and titanium alloy substrates. Our results showed that the peptide has a great potential as a linker to functionalize metallic surfaces if specificity is not a key factor. This peptide is not specific to a particular metal surface, but it is a good linker for the functionalization of a wide range of metallic materials. The fact that this peptide has the potential to adsorb on a large set of inorganic surfaces suggests novel promising directions for further investigation. Affinity determination of SVSVGMKPSPRP peptide would be an important issue for eventual commercial uses.

  11. Bioprospecting open reading frames for peptide effectors.

    Science.gov (United States)

    Xiong, Ling; Scott, Charles

    2014-01-01

    Recent successes in the development of small-molecule antagonists of protein-protein interactions designed based on co-crystal structures of peptides bound to their biological targets confirm that short peptides derived from interacting proteins can be high-value ligands for pharmacologic validation of targets and for identification of druggable sites. Evolved sequence space is likely to be enriched for interacting peptides, but identifying minimal peptide effectors within genomic sequence can be labor intensive. Here we describe the use of incremental truncation to diversify genetic material on the scale of open reading frames into comprehensive libraries of constituent peptides. The approach is capable of generating peptides derived from both continuous and discontinuous sequence elements, and is compatible with the expression of free linear or backbone cyclic peptides, with peptides tethered to amino- or carboxyl-terminal fusion partners or with the expression of peptides displayed within protein scaffolds (peptide aptamers). Incremental truncation affords a valuable source of molecular diversity to interrogate the druggable genome or evaluate the therapeutic potential of candidate genes.

  12. Chemical Methods for Peptide and Protein Production

    Directory of Open Access Journals (Sweden)

    Istvan Toth

    2013-04-01

    Full Text Available Since the invention of solid phase synthetic methods by Merrifield in 1963, the number of research groups focusing on peptide synthesis has grown exponentially. However, the original step-by-step synthesis had limitations: the purity of the final product decreased with the number of coupling steps. After the development of Boc and Fmoc protecting groups, novel amino acid protecting groups and new techniques were introduced to provide high quality and quantity peptide products. Fragment condensation was a popular method for peptide production in the 1980s, but unfortunately the rate of racemization and reaction difficulties proved less than ideal. Kent and co-workers revolutionized peptide coupling by introducing the chemoselective reaction of unprotected peptides, called native chemical ligation. Subsequently, research has focused on the development of novel ligating techniques including the famous click reaction, ligation of peptide hydrazides, and the recently reported a-ketoacid-hydroxylamine ligations with 5-oxaproline. Several companies have been formed all over the world to prepare high quality Good Manufacturing Practice peptide products on a multi-kilogram scale. This review describes the advances in peptide chemistry including the variety of synthetic peptide methods currently available and the broad application of peptides in medicinal chemistry.

  13. Pharmaceutical and pharmacological importance of peptide transporters.

    Science.gov (United States)

    Brandsch, Matthias; Knütter, Ilka; Bosse-Doenecke, Eva

    2008-05-01

    Peptide transport is currently a prominent topic in membrane research. The transport proteins involved are under intense investigation because of their physiological importance in protein absorption and also because peptide transporters are possible vehicles for drug delivery. Moreover, in many tissues peptide carriers transduce peptidic signals across membranes that are relevant in information processing. The focus of this review is on the pharmaceutical relevance of the human peptide transporters PEPT1 and PEPT2. In addition to their physiological substrates, both carriers transport many beta-lactam antibiotics, valaciclovir and other drugs and prodrugs because of their sterical resemblance to di- and tripeptides. The primary structure, tissue distribution and substrate specificity of PEPT1 and PEPT2 have been well characterized. However, there is a dearth of knowledge on the substrate binding sites and the three-dimensional structure of these proteins. Until this pivotal information becomes available by X-ray crystallography, the development of new drug substrates relies on classical transport studies combined with molecular modelling. In more than thirty years of research, data on the interaction of well over 700 di- and tripeptides, amino acid and peptide derivatives, drugs and prodrugs with peptide transporters have been gathered. The aim of this review is to put the reports on peptide transporter-mediated drug uptake into perspective. We also review the current knowledge on pharmacogenomics and clinical relevance of human peptide transporters. Finally, the reader's attention is drawn to other known or proposed human peptide-transporting proteins.

  14. Prediction of twin-arginine signal peptides

    Directory of Open Access Journals (Sweden)

    Widdick David

    2005-07-01

    Full Text Available Abstract Background Proteins carrying twin-arginine (Tat signal peptides are exported into the periplasmic compartment or extracellular environment independently of the classical Sec-dependent translocation pathway. To complement other methods for classical signal peptide prediction we here present a publicly available method, TatP, for prediction of bacterial Tat signal peptides. Results We have retrieved sequence data for Tat substrates in order to train a computational method for discrimination of Sec and Tat signal peptides. The TatP method is able to positively classify 91% of 35 known Tat signal peptides and 84% of the annotated cleavage sites of these Tat signal peptides were correctly predicted. This method generates far less false positive predictions on various datasets than using simple pattern matching. Moreover, on the same datasets TatP generates less false positive predictions than a complementary rule based prediction method. Conclusion The method developed here is able to discriminate Tat signal peptides from cytoplasmic proteins carrying a similar motif, as well as from Sec signal peptides, with high accuracy. The method allows filtering of input sequences based on Perl syntax regular expressions, whereas hydrophobicity discrimination of Tat- and Sec-signal peptides is carried out by an artificial neural network. A potential cleavage site of the predicted Tat signal peptide is also reported. The TatP prediction server is available as a public web server at http://www.cbs.dtu.dk/services/TatP/.

  15. Natriuretic Peptides: Biochemistry, Physiology, Clinical Implication

    Directory of Open Access Journals (Sweden)

    I. A. Kozlova

    2009-01-01

    Full Text Available In the past years, the interest of theorists and clinicians has steadily increased in the myocardially secreted hormones – natriuretic peptides. At the Congress of the European Society of Anesthesiology (Munich, 2007, B-type natriuretic peptides were included into the list of the parameters of perioperative laboratory monitoring that is expedient in the practice of anesthetists and resuscitation specialists. The literature review shows the history of discovery and identification of different types of natriuretic peptides and considers the matters of their biochemistry. It also details information on the synthesis, secretion, and clearance of these peptides, as well as their receptor apparatus in various organs and tissues. The physiology of the regulatory system is described, as applied to the cardiovascular, excretory, central nervous systems, and the neuroendocrine one. Special attention is given to the current publications on the control of B-type natriuretic peptides as biomarkers of cardiac dysfunction. The diagnostic and prognostic values of peptides are analyzed in chronic circulatory insufficiency, coronary heart disease, and other car-diological and non-cardiological diseases. The prognostic value of elevated B-type natriuretic peptide levels in cardiac surgery is separately considered. It is concluded that the changes in the level of B-type natriuretic peptides in different clinical situations are the subject of numerous researches mainly made in foreign countries. The bulk of these researches are devoted to the study of peptides in cardiology and other areas of therapy. Studies on the use of peptides in reanimatology are relatively few and their results are rather discordant. The foregoing opens up wide prospects for studying the use of B-type natriuretic peptides in Russian intensive care and anesthesiology. Key words: natriuretic peptides, brain nautriuretic peptides, NT-proBNP.

  16. Regulation of Dopamine Uptake by Vasoactive Peptides in the Kidney

    Directory of Open Access Journals (Sweden)

    N. L. Rukavina Mikusic

    2016-01-01

    Full Text Available Considering the key role of renal dopamine in tubular sodium handling, we hypothesized that c-type natriuretic peptide (CNP and Ang-(1-7 may regulate renal dopamine availability in tubular cells, contributing to Na+, K+-ATPase inhibition. Present results show that CNP did not affect either 3H-dopamine uptake in renal tissue or Na+, K+-ATPase activity; meanwhile, Ang-(1-7 was able to increase 3H-dopamine uptake and decreased Na+, K+-ATPase activity in renal cortex. Ang-(1-7 and dopamine together decreased further Na+, K+-ATPase activity showing an additive effect on the sodium pump. In addition, hydrocortisone reversed Ang-(1-7-dopamine overinhibition on the enzyme, suggesting that this inhibition is closely related to Ang-(1-7 stimulation on renal dopamine uptake. Both anantin and cANP (4-23-amide did not modify CNP effects on 3H-dopamine uptake by tubular cells. The Mas receptor antagonist, A-779, blocked the increase elicited by Ang-(1-7 on 3H-dopamine uptake. The stimulatory uptake induced by Ang-(1-7 was even more pronounced in the presence of losartan, suggesting an inhibitory effect of Ang-(1-7 on AT1 receptors on 3H-dopamine uptake. By increasing dopamine bioavailability in tubular cells, Ang-(1-7 enhances Na+, K+-ATPase activity inhibition, contributing to its natriuretic and diuretic effects.

  17. Functional receptors for atrial natriuretic peptide in the rat mammary gland during lactation.

    Science.gov (United States)

    Cvek, K; Ridderstråle, Y; Gerstberger, R

    1998-05-01

    The present study was undertaken: 1) to localize and characterize atrial natriuretic peptide (ANP) receptors in the rat mammary gland; and 2) to elucidate ANP-induced cellular formation of cyclic GMP (cGMP) and alterations in alveolar morphology during both early and late lactation. Receptor autoradiography, employing rat-specific [125I]ANP as radioligand, demonstrated binding sites in the secretory tissue and larger blood vessels of the mammary gland. Binding of [125I]rANP to membrane fractions was completely displaced by unlabeled ANP and brain natriuretic peptide. C-type natriuretic peptide and cANP(4-23) revealed limited competition with radiolabeled ANP only during early lactation, indicating a more heterogeneous receptor population at that time. Systemically administered ANP induced cGMP formation in the alveolar epithelium, as shown with immunohistochemistry, and increased mammary tissue cGMP concentrations in vivo throughout the lactation period. Image analysis revealed enlargement of alveolar (but not epithelial) cell area after ANP stimulation in late lactation, suggesting altered alveolar filling or myoepithelial cell relaxation. These results indicate that ANP induces biological effects in the rat mammary gland through specific ANP-A receptor interaction with subsequent intracellular cGMP formation. ANP may therefore play a regulatory role in the control of mammary gland blood supply and secretory function.

  18. CLEC4F is an inducible C-type lectin in F4/80-positive cells and is involved in alpha-galactosylceramide presentation in liver.

    Directory of Open Access Journals (Sweden)

    Chih-Ya Yang

    Full Text Available CLEC4F, a member of C-type lectin, was first purified from rat liver extract with high binding affinity to fucose, galactose (Gal, N-acetylgalactosamine (GalNAc, and un-sialylated glucosphingolipids with GalNAc or Gal terminus. However, the biological functions of CLEC4F have not been elucidated. To address this question, we examined the expression and distribution of murine CLEC4F, determined its binding specificity by glycan array, and investigated its function using CLEC4F knockout (Clec4f-/- mice. We found that CLEC4F is a heavily glycosylated membrane protein co-expressed with F4/80 on Kupffer cells. In contrast to F4/80, CLEC4F is detectable in fetal livers at embryonic day 11.5 (E11.5 but not in yolk sac, suggesting the expression of CLEC4F is induced as cells migrate from yolk cells to the liver. Even though CLEC4F is not detectable in tissues outside liver, both residential Kupffer cells and infiltrating mononuclear cells surrounding liver abscesses are CLEC4F-positive upon Listeria monocytogenes (L. monocytogenes infection. While CLEC4F has strong binding to Gal and GalNAc, terminal fucosylation inhibits CLEC4F recognition to several glycans such as Fucosyl GM1, Globo H, Bb3∼4 and other fucosyl-glycans. Moreover, CLEC4F interacts with alpha-galactosylceramide (α-GalCer in a calcium-dependent manner and participates in the presentation of α-GalCer to natural killer T (NKT cells. This suggests that CLEC4F is a C-type lectin with diverse binding specificity expressed on residential Kupffer cells and infiltrating monocytes in the liver, and may play an important role to modulate glycolipids presentation on Kupffer cells.

  19. Structure of a glycomimetic ligand in the carbohydrate recognition domain of C-type lectin DC-SIGN. Structural requirements for selectivity and ligand design.

    Science.gov (United States)

    Thépaut, Michel; Guzzi, Cinzia; Sutkeviciute, Ieva; Sattin, Sara; Ribeiro-Viana, Renato; Varga, Norbert; Chabrol, Eric; Rojo, Javier; Bernardi, Anna; Angulo, Jesus; Nieto, Pedro M; Fieschi, Franck

    2013-02-20

    In genital mucosa, different fates are described for HIV according to the subtype of dendritic cells (DCs) involved in its recognition. This notably depends on the C-type lectin receptor, langerin or DC-SIGN, involved in gp120 interaction. Langerin blocks HIV transmission by its internalization in specific organelles of Langerhans cells. On the contrary, DC-SIGN enhances HIV trans-infection of T lymphocytes. Thus, approaches aiming to inhibit DC-SIGN, without blocking langerin, represent attractive anti-HIV strategies. We previously demonstrated that dendrons bearing multiple copies of glycomimetic compounds were able to block DC-SIGN-dependent HIV infection in cervical explant models. Optimization of such ligand requires detailed characterization of its binding mode. In the present work, we determined the first high-resolution structure of a glycomimetic/DC-SIGN complex by X-ray crystallography. This glycomimetic, pseudo-1,2-mannobioside, shares shape and conformational properties with Manα1-2Man, its natural counterpart. However, it uses the binding epitope previously described for Lewis X, a ligand specific for DC-SIGN among the C-type lectin family. Thus, selectivity gain for DC-SIGN versus langerin is observed with pseudo-1,2-mannobioside as shown by surface plasmon resonance analysis. In parallel, ligand binding was also analyzed by TR-NOESY and STD NMR experiments, combined with the CORCEMA-ST protocol. These studies demonstrate that the complex, defined by X-ray crystallography, represents the unique binding mode of this ligand as opposed to the several binding orientations described for the natural ligand. This exclusive binding mode and its selective interaction properties position this glycomimetic as a good lead compound for rational improvement based on a structurally driven approach.

  20. The cartilage-specific lectin C-type lectin domain family 3 member A (CLEC3A) enhances tissue plasminogen activator-mediated plasminogen activation.

    Science.gov (United States)

    Lau, Daniela; Elezagic, Dzemal; Hermes, Gabriele; Mörgelin, Matthias; Wohl, Alexander P; Koch, Manuel; Hartmann, Ursula; Höllriegl, Stefan; Wagener, Raimund; Paulsson, Mats; Streichert, Thomas; Klatt, Andreas R

    2018-01-05

    C-type lectin domain family 3 member A (CLEC3A) is a poorly characterized protein belonging to the superfamily of C-type lectins. Its closest homologue tetranectin binds to the kringle 4 domain of plasminogen and enhances its association with tissue plasminogen activator (tPA) thereby enhancing plasmin production, but whether CLEC3A contributes to plasminogen activation is unknown. Here, we recombinantly expressed murine and human full-length CLEC3As as well as truncated forms of CLEC3A in HEK-293 Epstein-Barr nuclear antigen (EBNA) cells. We analyzed the structure of recombinant CLEC3A by SDS-PAGE and immunoblot, glycan analysis, matrix-assisted laser desorption ionization time-of-flight mass spectrometry, size-exclusion chromatography, circular dichroism spectroscopy, and electron microscopy; compared the properties of the recombinant protein with those of CLEC3A extracted from cartilage; and investigated its tissue distribution and extracellular assembly by immunohistochemistry and immunofluorescence microscopy. We found that CLEC3A mainly occurs as a monomer, but also forms dimers and trimers, potentially via a coiled-coil α-helix. We also noted that CLEC3A can be modified with chondroitin/dermatan sulfate side chains and tends to oligomerize to form higher aggregates. We show that CLEC3A is present in resting, proliferating, and hypertrophic growth-plate cartilage and assembles into an extended extracellular network in cultures of rat chondrosarcoma cells. Further, we found that CLEC3A specifically binds to plasminogen and enhances tPA-mediated plasminogen activation. In summary, we have determined the structure, tissue distribution, and molecular function of the cartilage-specific lectin CLEC3A and show that CLEC3A binds to plasminogen and participates in tPA-mediated plasminogen activation. © 2018 by The American Society for Biochemistry and Molecular Biology, Inc.

  1. Unifying protein inference and peptide identification with feedback to update consistency between peptides.

    Science.gov (United States)

    Shi, Jinhong; Chen, Bolin; Wu, Fang-Xiang

    2013-01-01

    We first propose a new method to process peptide identification reports from databases search engines. Then via it we develop a method for unifying protein inference and peptide identification by adding a feedback from protein inference to peptide identification. The feedback information is a list of high-confidence proteins, which is used to update an adjacency matrix between peptides. The adjacency matrix is used in the regularization of peptide scores. Logistic regression (LR) is used to compute the probability of peptide identification with the regularized scores. Protein scores are then calculated with the LR probability of peptides. Instead of selecting the best peptide match for each MS/MS, we select multiple peptides. By testing on two datasets, the results have shown that the proposed method can robustly assign accurate probabilities to peptides, and have a higher discrimination power than PeptideProphet to distinguish correct and incorrect identified peptides. Additionally, not only can our method infer more true positive proteins but also infer less false positive proteins than ProteinProphet at the same false positive rate. The coverage of inferred proteins is also significantly increased due to the selection of multiple peptides for each MS/MS and the improvement of their scores by the feedback from the inferred proteins. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Recent development of peptide drugs and advance on theory and methodology of peptide inhibitor design.

    Science.gov (United States)

    Du, Qi-Shi; Xie, Neng-Zhong; Huang, Ri-Bo

    2015-01-01

    Due to the low toxicity, easy synthesis, rapid elimination, and less side effect, more and more peptide inhibitors are emerging as the effective drugs that are clinically used in therapies of a number of diseases. At the same time the computer-aided drug design (CADD) methods have remarkably developed. In this mini review the newly developed peptide inhibitors and drugs are introduced, including peptide vaccines for cancers, peptide inhibitors for HIV, Alzheimer's disease and related diseases, and the peptides as the leading compounds of drugs. The recent progress in the theory and methodology of peptide inhibitor design is reviewed. (1) The flexible protein-peptide docking model is introduced, in which the peptide structures are treated as segment-flexible chains using genetic algorithm and special force field parameters. (2) The "Wenxiang diagram" is illustrated for protein-peptide interaction analysis that has been successfully used in the coiled-coil interaction analysis. (3) The "Distorted key" theory is reviewed, which is an effective method to convert the peptide inhibitors to the small chemical drugs. (4) The amino acid property-based peptide prediction method (AABPP) is described that is a twolevel QSAR prediction network for the bioactivity prediction of peptide inhibitors. (5) Finally, several types of molecular interactions between protein and peptide ligands are summarized, including cation-π interactions; polar hydrogen-π interactions; and π-π stocking interactions.

  3. Multi-modal in cellulo evaluation of NPR-C targeted C-ANF-peptide and C-ANF-comb nanoparticles

    Science.gov (United States)

    Shokeen, Monica; Pressly, Eric; Connal, Luke; Liu, Yongjian; Hawker, Craig J.; Woodard, Pamela K.; Anderson, Carolyn J.; Achilefu, Samuel; Welch, Michael J.

    2012-03-01

    Natriuretic peptides (NPs) are clinical markers of heart disease that have anti-proliferative and anti-migratory effects on vascular smooth-muscle cells (VSMCs). In atherosclerosis, NPs participate in vascular remodeling, where the expression of NP clearance receptors (NPR-Cs) is upregulated both in the endothelium and in VSMCs[1-3]. In this study, we investigated the enhanced targeting potential of novel multifunctional nanoprobes conjugated with multiple copies of a C-type atrial natriuretic factor (C-ANF) peptide fragment to target NPR-C transfected cells. The cell binding results of the NPR-C targeted nanoprobes were compared with that of the C-ANF peptide fragment alone. The nanoprobe and peptide structures contain the chelator DOTA (1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid) for labeling with the PET tracer, 64Cu, for radioactive assays and luminescent Eu (III) for confocal cell imaging. Cell assays performed with the radioactive nanoprobe and peptide demonstrated higher cell binding of the targeted nanoprobe comapred with the peptide alone (8.63+/-1.67 vs. 1.13+/-0.06). The targeting specificity of both moieties was tested by using the control cell lines NPR-A and NPR-B, and receptor mediated uptake was demonstrated by reduced uptake in the presence of excess unlabeled respective probes.

  4. Peptide Bond Formations through Flow Chemistry.

    Science.gov (United States)

    Ahmed, N

    2017-10-04

    Peptides and proteins play important roles in body functions(1) ,(2) and are used exclusively in drug discoveries, having advantages because of their high biological activity, high specificity, and low toxicity. For peptide synthesis, researchers mostly use the solid-phase peptide synthesis (SPPS)(3) with modern modifications.(4) However, scientists failed to overcome two main factors; the concentration and time required for peptide coupling. The flow-based technology may help in the rapid production of peptides due to having advantages over batch reactions(5-7) in terms of productivity, heat and mixing efficiency, safety, and reproducibility. Herein, we discussed both solution and solid phase synthesis of peptides in flow.(8-12) This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  5. Synthesis of peptide .alpha.-thioesters

    Science.gov (United States)

    Camarero, Julio A [Livermore, CA; Mitchell, Alexander R [Livermore, CA; De Yoreo, James J [Clayton, CA

    2008-08-19

    Disclosed herein is a new method for the solid phase peptide synthesis (SPPS) of C-terminal peptide .alpha. thioesters using Fmoc/t-Bu chemistry. This method is based on the use of an aryl hydrazine linker, which is totally stable to conditions required for Fmoc-SPPS. When the peptide synthesis has been completed, activation of the linker is achieved by mild oxidation. The oxidation step converts the acyl-hydrazine group into a highly reactive acyl-diazene intermediate which reacts with an .alpha.-amino acid alkylthioester (H-AA-SR) to yield the corresponding peptide .alpha.-thioester in good yield. A variety of peptide thioesters, cyclic peptides and a fully functional Src homology 3 (SH3) protein domain have been successfully prepared.

  6. Potent peptidic fusion inhibitors of influenza virus

    Energy Technology Data Exchange (ETDEWEB)

    Kadam, Rameshwar U.; Juraszek, Jarek; Brandenburg, Boerries; Buyck, Christophe; Schepens, Wim B. G.; Kesteleyn, Bart; Stoops, Bart; Vreeken, Rob J.; Vermond, Jan; Goutier, Wouter; Tang, Chan; Vogels, Ronald; Friesen, Robert H. E.; Goudsmit, Jaap; van Dongen, Maria J. P.; Wilson, Ian A.

    2017-09-28

    Influenza therapeutics with new targets and mechanisms of action are urgently needed to combat potential pandemics, emerging viruses, and constantly mutating strains in circulation. We report here on the design and structural characterization of potent peptidic inhibitors of influenza hemagglutinin. The peptide design was based on complementarity-determining region loops of human broadly neutralizing antibodies against the hemagglutinin (FI6v3 and CR9114). The optimized peptides exhibit nanomolar affinity and neutralization against influenza A group 1 viruses, including the 2009 H1N1 pandemic and avian H5N1 strains. The peptide inhibitors bind to the highly conserved stem epitope and block the low pH–induced conformational rearrangements associated with membrane fusion. These peptidic compounds and their advantageous biological properties should accelerate the development of new small molecule– and peptide-based therapeutics against influenza virus.

  7. Anti-angiogenic peptides for cancer therapeutics.

    Science.gov (United States)

    Rosca, Elena V; Koskimaki, Jacob E; Rivera, Corban G; Pandey, Niranjan B; Tamiz, Amir P; Popel, Aleksander S

    2011-08-01

    Peptides have emerged as important therapeutics that are being rigorously tested in angiogenesis-dependent diseases due to their low toxicity and high specificity. Since the discovery of endogenous proteins and protein fragments that inhibit microvessel formation (thrombospondin, endostatin) several peptides have shown promise in pre-clinical and clinical studies for cancer. Peptides have been derived from thrombospondin, collagens, chemokines, coagulation cascade proteins, growth factors, and other classes of proteins and target different receptors. Here we survey recent developments for anti-angiogenic peptides with length not exceeding 50 amino acid residues that have shown activity in pre-clinical models of cancer or have been tested in clinical trials; some of the peptides have been modified and optimized, e.g., through L-to-D and non-natural amino acid substitutions. We highlight technological advances in peptide discovery and optimization including computational and bioinformatics tools and novel experimental techniques.

  8. Computer-Aided Design of Antimicrobial Peptides

    DEFF Research Database (Denmark)

    Fjell, Christopher D.; Hancock, Robert E.W.; Jenssen, Håvard

    2010-01-01

    An increasing number of reported cases of drug resistant Staphylococcus aureus and Pseudomonas aeruginosa, demonstrate the urgent need for new therapeutics that are effective against such and other multi-drug resistant bacteria. Antimicrobial peptides have for two decades now been looked upon...... in antimicrobial activity. Consequently, the majority of peptides put into clinical trials have failed at some point, underlining the importance of a thorough peptide optimization. An important tool in peptide design and optimization is quantitative structure-activity relationship (QSAR) analysis, correlating...... library, to ensure a successful prediction. In contrast, the neural network model, though significantly less explored in relation to antimicrobial peptide design, has proven extremely promising, demonstrating impressive prediction success and ranking of random peptide libraries correlating well...

  9. Prediction of twin-arginine signal peptides

    DEFF Research Database (Denmark)

    Bendtsen, Jannick Dyrløv; Nielsen, Henrik; Widdick, D.

    2005-01-01

    a publicly available method, TatP, for prediction of bacterial Tat signal peptides. Results: We have retrieved sequence data for Tat substrates in order to train a computational method for discrimination of Sec and Tat signal peptides. The TatP method is able to positively classify 91% of 35 known Tat signal...... peptides and 84% of the annotated cleavage sites of these Tat signal peptides were correctly predicted. This method generates far less false positive predictions on various datasets than using simple pattern matching. Moreover, on the same datasets TatP generates less false positive predictions than...... expressions, whereas hydrophobicity discrimination of Tat- and Sec- signal peptides is carried out by an artificial neural network. A potential cleavage site of the predicted Tat signal peptide is also reported. The TatP prediction server is available as a public web server at http://www.cbs.dtu.dk/services/TatP/....

  10. Microarray Selection of Cooperative Peptides for Modulating Enzyme Activities

    Directory of Open Access Journals (Sweden)

    Jinglin Fu

    2017-04-01

    Full Text Available Recently, peptide microarrays have been used to distinguish proteins, antibodies, viruses, and bacteria based on their binding to random sequence peptides. We reported on the use of peptide arrays to identify enzyme modulators that involve screening an array of 10,000 defined and addressable peptides on a microarray. Primary peptides were first selected to inhibit the enzyme at low μM concentrations. Then, new peptides were found to only bind strongly with the enzyme–inhibitor complex, but not the native enzyme. These new peptides served as secondary inhibitors that enhanced the inhibition of the enzyme together with the primary peptides. Without the primary peptides, the secondary effect peptides had little effect on the enzyme activity. Conversely, we also selected peptides that recovered the activities of inhibited enzyme–peptide complex. The selection of cooperative peptide pairs will provide a versatile toolkit for modulating enzyme functions, which may potentially be applied to drug discovery and biocatalysis.

  11. Study of coherent diffractive production reactions of p + C --> [Y$^{0}$K$^{+}$] + C type and observation of the new baryonic states X(2050) --> $\\Sigma$(1385)$^{0}$K$^{+}$ and X(2000) --> $\\Sigma^{0}$K$^{+}$

    CERN Document Server

    Golovkin, S V; Kozhevnikov, A A; Kubarovskii, V P; Kulyavtsev, A I; Kurshetsov, V F; Kushnirenko, A Yu; Landsberg, G L; Molchanov, V V; Mukkin, V A; Solyanik, V I; Vavilov, D V; Victorov, V A; Balats, M Ya; Dzubenko, G B; Kamenskii, A D; Kliger, G K; Kolganov, V Z; Lakaev, V S; Lomkatsi, G S; Nilov, A P; Smolyankin, V T; Vishniakov, V V

    1994-01-01

    Study of coherent diffractive production reactions of p + C --> [Y$^{0}$K$^{+}$] + C type and observation of the new baryonic states X(2050) --> $\\Sigma$(1385)$^{0}$K$^{+}$ and X(2000) --> $\\Sigma^{0}$K$^{+}$

  12. Use of Galerina marginata genes and proteins for peptide production

    Energy Technology Data Exchange (ETDEWEB)

    Hallen-Adams, Heather E.; Scott-Craig, John S.; Walton, Jonathan D.; Luo, Hong

    2017-03-21

    The present invention relates to compositions and methods comprising genes and peptides associated with cyclic peptides and cyclic peptide production in mushrooms. In particular, the present invention relates to using genes and proteins from Galerina species encoding peptides specifically relating to amatoxins in addition to proteins involved with processing cyclic peptide toxins. In a preferred embodiment, the present invention also relates to methods for making small peptides and small cyclic peptides including peptides similar to amanitin. Further, the present inventions relate to providing kits for making small peptides.

  13. Use of Galerina marginata genes and proteins for peptide production

    Energy Technology Data Exchange (ETDEWEB)

    Hallen-Adams, Heather E.; Scott-Craig, John S.; Walton, Jonathan D.; Luo, Hong

    2016-03-01

    The present invention relates to compositions and methods comprising genes and peptides associated with cyclic peptides and cyclic peptide production in mushrooms. In particular, the present invention relates to using genes and proteins from Galerina species encoding peptides specifically relating to amatoxins in addition to proteins involved with processing cyclic peptide toxins. In a preferred embodiment, the present invention also relates to methods for making small peptides and small cyclic peptides including peptides similar to amanitin. Further, the present inventions relate to providing kits for making small peptides.

  14. An Evaluation of Peptide-Bond Isosteres

    OpenAIRE

    Choudhary, Amit; Raines, Ronald T.

    2011-01-01

    Peptide-bond isosteres can enable a deep interrogation of the structure and function of a peptide or protein by amplifying or attenuating particular chemical properties. In this minireview, the electronic, structural, and conformational attributes of four such isosteres—thioamides, esters, alkenes, and fluoroalkenes—are examined in detail. In particular, the ability of these isosteres to partake in noncovalent interactions is compared with that of the peptide bond. The consequential perturbat...

  15. Opioid Peptides: Potential for Drug Development

    OpenAIRE

    Aldrich, Jane V.; McLaughlin, Jay P.

    2012-01-01

    Opioid receptors are important targets for the treatment of pain and potentially for other disease states (e.g. mood disorders and drug abuse) as well. Significant recent advances have been made in identifying opioid peptide analogs that exhibit promising in vivo activity for treatment of these maladies. This review focuses on the development and evaluation of opioid peptide analogs demonstrating activity after systemic administration, and recent clinical evaluations of opioid peptides for po...

  16. Novel Disulfide Formation Strategies in Peptide Synthesis

    OpenAIRE

    Postma, Tobias Maria

    2014-01-01

    Cysteine (Cys) is a unique amino acid due to its ability to form reversible covalent disulfide bonds. These bonds cause conformational constraints which make peptides or proteins more rigid and stable. In addition, the conformational constraints induced by disulfide bonds can result in highly potent molecules as illustrated by the vast number of disulfide-rich plant and animal peptide toxins. Furthermore, disulfide-rich peptides are gaining importance as pharmaceuticals and therefore powerful...

  17. Bioactive peptides in plant-derived foodstuffs.

    Science.gov (United States)

    Maestri, Elena; Marmiroli, Marta; Marmiroli, Nelson

    2016-09-16

    A literature survey covering the presence of bioactive peptides in plant-derived foodstuffs is presented. Examples are given of plant peptides associated with a beneficial effect on human health. The main bioactive effects of these peptides are defined and their mechanism of action described, when known. Current understanding of the way in which these molecules are adsorbed, distributed, metabolized and finally excreted is discussed. A particular focus is given to potentially immunomodulatory peptides. The leading analytical assay methods used to evaluate their activity are outlined. Inspection of crop proteomic data revealed that at least 6000 proteins may harbour bioactive peptides. The analysis of these proteins using a Gene Ontology approach has provided a number of insights regarding their occurrence and relevance. The review reports an updated survey on bioactive peptides present in food crop plants, with a particular focus on immunomodulatory peptides which might be relevant for therapeutic applications. It employs a bioinformatic approach to search for proteins of crop plants potentially harboring bioactive peptides, summarising through Gene Ontology the main classes of peptide-containing proteins in food. Copyright © 2016 Elsevier B.V. All rights reserved.

  18. Neuroprotective peptides fused to arginine-rich cell penetrating peptides: Neuroprotective mechanism likely mediated by peptide endocytic properties.

    Science.gov (United States)

    Meloni, Bruno P; Milani, Diego; Edwards, Adam B; Anderton, Ryan S; O'Hare Doig, Ryan L; Fitzgerald, Melinda; Palmer, T Norman; Knuckey, Neville W

    2015-09-01

    Several recent studies have demonstrated that TAT and other arginine-rich cell penetrating peptides (CPPs) have intrinsic neuroprotective properties in their own right. Examples, we have demonstrated that in addition to TAT, poly-arginine peptides (R8 to R18; containing 8-18 arginine residues) as well as some other arginine-rich peptides are neuroprotective in vitro (in neurons exposed to glutamic acid excitotoxicity and oxygen glucose deprivation) and in the case of R9 in vivo (after permanent middle cerebral artery occlusion in the rat). Based on several lines of evidence, we propose that this neuroprotection is related to the peptide's endocytosis-inducing properties, with peptide charge and arginine residues being critical factors. Specifically, we propose that during peptide endocytosis neuronal cell surface structures such as ion channels and transporters are internalised, thereby reducing calcium influx associated with excitotoxicity and other receptor-mediated neurodamaging signalling pathways. We also hypothesise that a peptide cargo can act synergistically with TAT and other arginine-rich CPPs due to potentiation of the CPPs endocytic traits rather than by the cargo-peptide acting directly on its supposedly intended intracellular target. In this review, we systematically consider a number of studies that have used CPPs to deliver neuroprotective peptides to the central nervous system (CNS) following stroke and other neurological disorders. Consequently, we critically review evidence that supports our hypothesis that neuroprotection is mediated by carrier peptide endocytosis. In conclusion, we believe that there are strong grounds to regard arginine-rich peptides as a new class of neuroprotective molecules for the treatment of a range of neurological disorders. Crown Copyright © 2015. Published by Elsevier Inc. All rights reserved.

  19. Antimicrobial peptides (AMPs): peptide structure and mode of action.

    Science.gov (United States)

    Park, Yoonkyung; Hahm, Kyung-Soo

    2005-09-30

    Antimicrobial peptides (AMPs) have been isolated and characterized from tissues and organisms representing virtually every kingdom and phylum. Their amino acid composition, amphipathicity, cationic charge, and size allow them to attach to and insert into membrane bilayers to form pores by 'barrel-stave', 'carpet' or 'toroidal-pore' mechanisms. Although these models are helpful for defining mechanisms of AMP activity, their relevance to resolving how peptides damage and kill microorganisms still needs to be clarified. Moreover, many AMPs employ sophisticated and dynamic mechanisms of action to carry out their likely roles in antimicrobial host defense. Recently, it has been speculated that transmembrane pore formation is not the only mechanism of microbial killing by AMPs. In fact, several observations suggest that translocated AMPs can alter cytoplasmic membrane septum formation, reduce cell-wall, nucleic acid, and protein synthesis, and inhibit enzymatic activity. In this review, we present the structures of several AMPs as well as models of how AMPs induce pore formation. AMPs have received special attention as a possible alternative way to combat antibiotic-resistant bacterial strains. It may be possible to design synthetic AMPs with enhanced activity for microbial cells, especially those with antibiotic resistance, as well as synergistic effects with conventional antibiotic agents that lack cytotoxic or hemolytic activity.

  20. Atrial natriuretic peptides in plasma

    DEFF Research Database (Denmark)

    Goetze, Jens P; Holst Hansen, Lasse; Terzic, Dijana

    2015-01-01

    Measurement of cardiac natriuretic peptides in plasma has gained a diagnostic role in the assessment of heart failure. Plasma measurement is though hampered by the marked instability of the hormones, which has led to the development of analyses that target N-terminal fragments from the prohormone....... These fragments are stable in plasma and represent surrogate markers of the actual natriuretic hormone. Post-translational processing of the precursors, however, is revealing itself to be a complex event with new information still being reported on proteolysis, covalent modifications, and amino acid...

  1. Peptide Antibiotics for ESKAPE Pathogens

    DEFF Research Database (Denmark)

    Thomsen, Thomas Thyge

    is considered poor compared to medicines for lifestyle diseases. According to the WHO we could be moving towards a post-antibiotic era in which previously treatable infections become fatal. Of special importance are multidrug resistant bacteria from the ESKAPE group (Enterococcus faecium, Staphylococcus aureus......, Klebsiella pneumoniae, Acinetobacter, Pseudomonas aeruginosa and Enterobacter). As a consequence of widespread multi-drug resistance, researchers have sought for alternative sources of antimicrobials. Antimicrobial peptides are produced by almost all living organisms as part of their defense or innate immune...

  2. Glucagon-like peptide-1

    DEFF Research Database (Denmark)

    Deacon, C F; Holst, Jens Juul; Carr, R D

    1999-01-01

    Type 2 diabetes mellitus is a metabolic disease resulting in raised blood sugar which, if not satisfactorily controlled, can cause severe and often debilitating complications. Unfortunately, for many patients, the existing therapies do not give adequate control. Glucagon-like peptide-1 (GLP-1......) is an incretin hormone which has a spectrum of activities which oppose the symptoms of diabetes. Of particular significance is the fact that these actions are glucose-dependent, meaning that the risk of severe hypoglycemia is practically eliminated. The recent elucidation of the key role of dipeptidyl peptidase...

  3. Production of peptide antisera specific for mouse and rat proinsulin C-peptide 2

    DEFF Research Database (Denmark)

    Blume, N; Madsen, O D; Kofod, Hans

    1990-01-01

    Mice and rats have two functional non-allelic insulin genes. By using a synthetic peptide representing a common sequence in mouse and rat C-peptide 2 as antigen, we have produced rabbit antisera specific for an epitope which is not present in mouse or rat C-peptide 1. Long-term immunization did n...

  4. Synthetic peptide vaccines: palmitoylation of peptide antigens by a thioester bond increases immunogenicity

    DEFF Research Database (Denmark)

    Beekman, N.J.C.M.; Schaaper, W.M.M.; Tesser, G.I.

    1997-01-01

    Synthetic peptides have frequently been used to immunize animals. However, peptides less than about 20 to 30 amino acids long are poor immunogens. In general, to increase its immunogenicity, the presentation of the peptide should be improved, and molecular weight needs to be increased. Many attem...

  5. TAPBPR alters MHC class I peptide presentation by functioning as a peptide exchange catalyst

    Science.gov (United States)

    Hermann, Clemens; van Hateren, Andy; Trautwein, Nico; Neerincx, Andreas; Duriez, Patrick J; Stevanović, Stefan; Trowsdale, John; Deane, Janet E; Elliott, Tim; Boyle, Louise H

    2015-01-01

    Our understanding of the antigen presentation pathway has recently been enhanced with the identification that the tapasin-related protein TAPBPR is a second major histocompatibility complex (MHC) class I-specific chaperone. We sought to determine whether, like tapasin, TAPBPR can also influence MHC class I peptide selection by functioning as a peptide exchange catalyst. We show that TAPBPR can catalyse the dissociation of peptides from peptide-MHC I complexes, enhance the loading of peptide-receptive MHC I molecules, and discriminate between peptides based on affinity in vitro. In cells, the depletion of TAPBPR increased the diversity of peptides presented on MHC I molecules, suggesting that TAPBPR is involved in restricting peptide presentation. Our results suggest TAPBPR binds to MHC I in a peptide-receptive state and, like tapasin, works to enhance peptide optimisation. It is now clear there are two MHC class I specific peptide editors, tapasin and TAPBPR, intimately involved in controlling peptide presentation to the immune system. DOI: http://dx.doi.org/10.7554/eLife.09617.001 PMID:26439010

  6. Connecting peptide (c-peptide) and the duration of diabetes mellitus ...

    African Journals Online (AJOL)

    Objective: C-peptide is derived from proinsulin and it is secreted in equimolar concentration with insulin. Plasma C-peptide is more stable than insulin and it provides an indirect measure of insulin secretory reserve and beta cell function. To determine relationship between C-peptide and duration of diabetes mellitus, age, ...

  7. Synthetic peptide vaccines: palmitoylation of peptide antigens by an thioester bond increases immunogenicity

    NARCIS (Netherlands)

    Beekman, N.J.C.M.; Schaaper, W.M.M.; Tesser, G.I.; Dalsgaard, K.; Langeveld, J.P.M.; Boshuizen, R.S.; Meloen, R.H.

    1997-01-01

    Synthetic peptides have frequently been used to immunize animals. However, peptides less than about 20 to 30 amino acids long are poor immunogens. In general, to increase its immunogenicity, the presentation of the peptide should be improved, and molecular weight needs to be increased. Many attempts

  8. peptide

    Indian Academy of Sciences (India)

    Prakash

    have shown that while infusion of β-amyloid has effects on behaviour, it does not necessarily induce neurodegenerative effects. The effects on memory formation and cognitive abilities due to injection of amyloid fragments into the brain have been very inconsistent until now. It has been proposed that the aggregation state of ...

  9. Effect of a Fusion Peptide by Covalent Conjugation of a Mitochondrial Cell-Penetrating Peptide and a Glutathione Analog Peptide

    Directory of Open Access Journals (Sweden)

    Carmine Pasquale Cerrato

    2017-06-01

    Full Text Available Previously, we designed and synthesized a library of mitochondrial antioxidative cell-penetrating peptides (mtCPPs superior to the parent peptide, SS31, to protect mitochondria from oxidative damage. A library of antioxidative glutathione analogs called glutathione peptides (UPFs, exceptional in hydroxyl radical elimination compared with glutathione, were also designed and synthesized. Here, a follow-up study is described, investigating the effects of the most promising members from both libraries on reactive oxidative species scavenging ability. None of the peptides influenced cell viability at the concentrations used. Fluorescence microscopy studies showed that the fluorescein-mtCPP1-UPF25 (mtgCPP internalized into cells, and spectrofluorometric analysis determined the presence and extent of peptide into different cell compartments. mtgCPP has superior antioxidative activity compared with mtCPP1 and UPF25 against H2O2 insult, preventing ROS formation by 2- and 3-fold, respectively. Moreover, we neither observed effects on mitochondrial membrane potential nor production of ATP. These data indicate that mtgCPP is targeting mitochondria, protecting them from oxidative damage, while also being present in the cytosol. Our hypothesis is based on a synergistic effect resulting from the fused peptide. The mitochondrial peptide segment is targeting mitochondria, whereas the glutathione analog peptide segment is active in the cytosol, resulting in increased scavenging ability.

  10. Peptide amphiphile self-assembly

    Science.gov (United States)

    Iscen, Aysenur; Schatz, George C.

    2017-08-01

    Self-assembly is a process whereby molecules organize into structures with hierarchical order and complexity, often leading to functional materials. Biomolecules such as peptides, lipids and DNA are frequently involved in self-assembly, and this leads to materials of interest for a wide variety of applications in biomedicine, photonics, electronics, mechanics, etc. The diversity of structures and functions that can be produced provides motivation for developing theoretical models that can be used for a molecular-level description of these materials. Here we overview recently developed computational methods for modeling the self-assembly of peptide amphiphiles (PA) into supramolecular structures that form cylindrical nanoscale fibers using molecular-dynamics simulations. Both all-atom and coarse-grained force field methods are described, and we emphasize how these calculations contribute insight into fiber structure, including the importance of β-sheet formation. We show that the temperature at which self-assembly takes place affects the conformations of PA chains, resulting in cylindrical nanofibers with higher β-sheet content as temperature increases. We also present a new high-density PA model that shows long network formation of β-sheets along the long axis of the fiber, a result that correlates with some experiments. The β-sheet network is mostly helical in nature which helps to maintain strong interactions between the PAs both radially and longitudinally. Contribution to Focus Issue Self-assemblies of Inorganic and Organic Nanomaterials edited by Marie-Paule Pileni.

  11. Diagnostic potential of circulating natriuretic peptides in chronic kidney disease

    NARCIS (Netherlands)

    Mark, PB; Stewart, GA; Gansevoort, RT; Petrie, CJ; McDonagh, TA; Dargie, HJ; Rodger, RSC; Jardine, AG

    Background. Measurement of natriuretic peptides, particularly brain natriuretic peptide (BNP) is an established method for the diagnosis of cardiovascular disorders, chiefly left ventricular (LV) dysfunction. The influence of renal function on the diagnostic utility of natriuretic peptides is

  12. Peptide-stabilized, fluorescent silver nanoclusters

    DEFF Research Database (Denmark)

    Gregersen, Simon; Vosch, Tom André Jos; Jensen, Knud Jørgen

    2016-01-01

    on a hydroxymethyl-benzoic acid (HMBA) polyethylene glycol polyacrylamide copolymer (PEGA) resin enabled on-resin screening and evaluation of a peptide library, leading to identification of novel peptide-stabilized, fluorescent AgNCs. Using systematic amino acid substitutions, we synthesized and screened a 144...

  13. New Biodegradable Peptide-based Polymer Constructs

    NARCIS (Netherlands)

    van Dijk, M.|info:eu-repo/dai/nl/32581127X

    2009-01-01

    Peptide-based polymers are of increasing interest, since they can be applied for a variety of purposes such as drug delivery devices, scaffolds for tissue engineering and -repair, and as novel biomaterials. Peptide-based polymers are common in nature and often exhibit special characteristics.

  14. Soybean peptide: optimal preparatory conditions, chemical and ...

    African Journals Online (AJOL)

    The study investigated the optimal condition for preparing soybean peptide from soybean isolates using digestive enzyme systems, comprising pepsin, trypsin and α-chymotrypsin set at different pH and temperatures. It was evaluated for closeness of characteristics to the control peptide (a TEK® oligopeptide, designated ...

  15. Protein identification by peptide mass fingerprinting

    DEFF Research Database (Denmark)

    Hjernø, Karin

    2007-01-01

      Peptide mass fingerprinting is an effective way of identifying, e.g., gel-separated proteins, by matching experimentally obtained peptide mass data against large databases. However, several factors are known to influence the quality of the resulting matches, such as proteins contaminating...

  16. A cyclic peptidic serine protease inhibitor

    DEFF Research Database (Denmark)

    Zhao, Baoyu; Xu, Peng; Jiang, Longguang

    2014-01-01

    Peptides are attracting increasing interest as protease inhibitors. Here, we demonstrate a new inhibitory mechanism and a new type of exosite interactions for a phage-displayed peptide library-derived competitive inhibitor, mupain-1 (CPAYSRYLDC), of the serine protease murine urokinase...

  17. Constrained Peptides as Miniature Protein Structures

    Science.gov (United States)

    Yin, Hang

    2012-01-01

    This paper discusses the recent developments of protein engineering using both covalent and noncovalent bonds to constrain peptides, forcing them into designed protein secondary structures. These constrained peptides subsequently can be used as peptidomimetics for biological functions such as regulations of protein-protein interactions. PMID:25969758

  18. One Hundred Years of Peptide Chemistry*

    Indian Academy of Sciences (India)

    tion of proteins. Poisonous Peptides: The most important component of snake venoms are polypeptide neurotoxins such as cobrotoxin, which produce lethal flaccid paralysis through a neuromuscle block. The peptides of amanita mushrooms such as antamanides are. Two hormones of the pos- terior pituitary gland. They.

  19. Peptide Mass Fingerprinting of Egg White Proteins

    Science.gov (United States)

    Alty, Lisa T.; LaRiviere, Frederick J.

    2016-01-01

    Use of advanced mass spectrometry techniques in the undergraduate setting has burgeoned in the past decade. However, relatively few undergraduate experiments examine the proteomics tools of protein digestion, peptide accurate mass determination, and database searching, also known as peptide mass fingerprinting. In this experiment, biochemistry…

  20. Peptide ligands for targeting the extracellular domain of EGFR: Comparison between linear and cyclic peptides.

    Science.gov (United States)

    Williams, Tyrslai M; Sable, Rushikesh; Singh, Sitanshu; Vicente, Maria Graca H; Jois, Seetharama D

    2017-10-20

    Colorectal cancer (CRC) is the third most common solid internal malignancy among cancers. Early detection of cancer is key to increasing the survival rate of colorectal cancer patients. Overexpression of the EGFR protein is associated with CRC. We have designed a series of peptides that are highly specific for the extracellular domain of EGFR, based on our earlier studies on linear peptides. The previously reported linear peptide LARLLT, known to bind to EGFR, was modified with the goals of increasing its stability and its specificity toward EGFR. Peptide modifications, including D-amino acid substitution, cyclization, and chain reversal, were investigated. In addition, to facilitate labeling of the peptide with a fluorescent dye, an additional lysine residue was introduced onto the linear (KLARLLT) and cyclic peptides cyclo(KLARLLT) (Cyclo.L1). The lysine residue was also converted into an azide group in both a linear and reversed cyclic peptide sequences cyclo(K(N3)larllt) (Cyclo.L1.1) to allow for subsequent "click" conjugation. The cyclic peptides showed enhanced binding to EGFR by SPR. NMR and molecular modeling studies suggest that the peptides acquire a β-turn structure in solution. In vitro stability studies in human serum show that the cyclic peptide is more stable than the linear peptide. © 2017 John Wiley & Sons A/S.

  1. Peptide based diagnostics: are random-sequence peptides more useful than tiling proteome sequences?

    Science.gov (United States)

    Navalkar, Krupa Arun; Johnston, Stephan Albert; Stafford, Phillip

    2015-02-01

    Diagnostics using peptide ligands have been available for decades. However, their adoption in diagnostics has been limited, not because of poor sensitivity but in many cases due to diminished specificity. Numerous reports suggest that protein-based rather than peptide-based disease detection is more specific. We examined two different approaches to peptide-based diagnostics using Coccidioides (aka Valley Fever) as the disease model. Although the pathogen was discovered more than a century ago, a highly sensitive diagnostic remains unavailable. We present a case study where two different approaches to diagnosing Valley Fever were used: first, overlapping Valley Fever epitopes representing immunodominant Coccidioides antigens were tiled using a microarray format of presynthesized peptides. Second, a set of random sequence peptides identified using a 10,000 peptide immunosignaturing microarray was compared for sensitivity and specificity. The scientific hypothesis tested was that actual epitope peptides from Coccidioides would provide sufficient sensitivity and specificity as a diagnostic. Results demonstrated that random sequence peptides exhibited higher accuracy when classifying different stages of Valley Fever infection vs. epitope peptides. The epitope peptide array did provide better performance than the existing immunodiffusion array, but when directly compared to the random sequence peptides, reported lower overall accuracy. This study suggests that there are competing aspects of antibody recognition that involve conservation of pathogen sequence and aspects of mimotope recognition and amino acid substitutions. These factors may prove critical when developing the next generation of high-performance immunodiagnostics. Copyright © 2014 Elsevier B.V. All rights reserved.

  2. Involvement of viral envelope GP2 in Ebola virus entry into cells expressing the macrophage galactose-type C-type lectin

    Energy Technology Data Exchange (ETDEWEB)

    Usami, Katsuaki [Laboratory of Cancer Biology and Molecular Immunology, Graduate School of Pharmaceutical Sciences, University of Tokyo, Tokyo 113-0033 (Japan); Matsuno, Keita; Igarashi, Manabu [Department of Global Epidemiology, Hokkaido University Research Center for Zoonosis Control, Sapporo 001-0020 (Japan); Denda-Nagai, Kaori [Laboratory of Cancer Biology and Molecular Immunology, Graduate School of Pharmaceutical Sciences, University of Tokyo, Tokyo 113-0033 (Japan); Takada, Ayato [Department of Global Epidemiology, Hokkaido University Research Center for Zoonosis Control, Sapporo 001-0020 (Japan); Irimura, Tatsuro, E-mail: irimura@mol.f.u-tokyo.ac.jp [Laboratory of Cancer Biology and Molecular Immunology, Graduate School of Pharmaceutical Sciences, University of Tokyo, Tokyo 113-0033 (Japan)

    2011-04-01

    Highlights: {yields} Ebola virus infection is mediated by binding to and fusion with the target cells. {yields} Structural feature of the viral glycoprotein determines the infectivity. {yields} Surface C-type lectin, MGL, of macrophages and dendritic cells mediate the infection. {yields} GP2, one of glycoprotein subunits, plays an essential role in MGL-mediated infection. {yields} There is a critical amino acid residue involved in high infectivity. -- Abstract: Ebola virus (EBOV) infection is initiated by the interaction of the viral surface envelope glycoprotein (GP) with the binding sites on target cells. Differences in the mortality among different species of the Ebola viruses, i.e., Zaire ebolavirus (ZEBOV) and Reston ebolavirus (REBOV), correspond to the in vitro infectivity of the pseudo-typed virus constructed with the GPs in cells expressing macrophage galactose-type calcium-type lectin (MGL/CD301). Through mutagenesis of GP2, the transmembrane-anchored subunit of GP, we found that residues 502-527 of the GP2 sequence determined the different infectivity between VSV-ZEBOV GP and -REBOV GP in MGL/CD301-expressing cells and a histidine residue at position 516 of ZEBOV GP2 appeared essential in the differential infectivity. These findings may provide a clue to clarify a molecular basis of different pathogenicity among EBOV species.

  3. Vixapatin (VP12, a C-Type Lectin-Protein from Vipera xantina palestinae Venom: Characterization as a Novel Anti-angiogenic Compound

    Directory of Open Access Journals (Sweden)

    Philip Lazarovici

    2012-10-01

    Full Text Available A C-type lectin-like protein (CTL, originally identified as VP12 and lately named Vixapatin, was isolated and characterized from Israeli viper Vipera xantina palestinae snake venom. This CTL was characterized as a selective α2β1 integrin inhibitor with anti-melanoma metastatic activity. The major aim of the present study was to prove the possibility that this protein is also a potent novel anti-angiogenic compound. Using an adhesion assay, we demonstrated that Vixapatin selectively and potently inhibited the α2 mediated adhesion of K562 over-expressing cells, with IC50 of 3 nM. 3 nM Vixapatin blocked proliferation of human dermal microvascular endothelial cells (HDMEC; 25 nM inhibited collagen I induced migration of human fibrosarcoma HT-1080 cells; and 50 nM rat C6 glioma and human breast carcinoma MDA-MB-231 cells. 1 µM Vixapatin reduced HDMEC tube formation by 75% in a Matrigel assay. Furthermore, 1 µM Vixapatin decreased by 70% bFGF-induced physiological angiogenesis, and by 94% C6 glioma-induced pathological angiogenesis, in shell-less embryonic quail chorioallantoic membrane assay. Vixapatin’s ability to inhibit all steps of the angiogenesis process suggest that it is a novel pharmacological tool for studying α2β1 integrin mediated angiogenesis and a lead compound for the development of a novel anti-angiogenic/angiostatic/anti-cancer drug.

  4. Primary structure of cytochrome c' of Methylococcus capsulatus Bath: evidence of a phylogenetic link between P460 and c'-type cytochromes.

    Science.gov (United States)

    Bergmann, D J; Zahn, J A; DiSpirito, A A

    2000-01-01

    Cytochrome c' of Methylococcus capsulatus Bath is involved in electron flow from the enzyme responsible for hydroxylamine oxidation, cytochrome P460, to cytochrome C555. This cytochrome is spectrally similar to other cytochromes c' but is larger (16,000 Da) and has a lower midpoint potential (-205 mV). By a combination of Edman degradation, mass spectroscopy, and gene sequencing, we have obtained the primary structure of cytochrome c' from M. capsulatus Bath. The cytochrome shows low sequence similarity to other cytochromes c', only residues R12, Y53, G56, and the C-terminal heme-binding region (GXXCXXCHXXXK) being conserved. In contrast, cytochrome c' from M. capsulatus Bath shows considerable sequence similarity to cytochromes P460 from M. capsulatus Bath (31% identity) and from Nitrosomonas europaea (18% identity). This suggests that P460-type cytochromes may have originated from a c'-type cytochrome which developed a covalent cross-link between a lysine residue and the c'-heme.

  5. Spectroscopic Studies of Abiotic and Biological Nanomaterials: Silver Nanoparticles, Rhodamine 6G Adsorbed on Graphene, and c-Type Cytochromes and Type IV Pili in Geobacter sulfurreducens

    Science.gov (United States)

    Thrall, Elizabeth S.

    This thesis describes spectroscopic studies of three different systems: silver nanoparticles, the dye molecule rhodamine 6G adsorbed on graphene, and the type IV pili and c-type cytochromes produced by the dissimilatory metal-reducing bacterium Geobacter sulfurreducens. Although these systems are quite different in some ways, they can all be considered examples of nanomaterials. A nanomaterial is generally defined as having at least one dimension below 100 nm in size. Silver nanoparticles, with sub-100 nm size in all dimensions, are examples of zero-dimensional nanomaterials. Graphene, a single atomic layer of carbon atoms, is the paradigmatic two-dimensional nanomaterial. And although bacterial cells are on the order of 1 μm in size, the type IV pili and multiheme c-type cytochromes produced by G. sulfurreducens can be considered to be one- and zero-dimensional nanomaterials respectively. A further connection between these systems is their strong interaction with visible light, allowing us to study them using similar spectroscopic tools. The first chapter of this thesis describes research on the plasmon-mediated photochemistry of silver nanoparticles. Silver nanoparticles support coherent electron oscillations, known as localized surface plasmons, at resonance frequencies that depend on the particle size and shape and the local dielectric environment. Nanoparticle absorption and scattering cross-sections are maximized at surface plasmon resonance frequencies, and the electromagnetic field is amplified near the particle surface. Plasmonic effects can enhance the photochemistry of silver particles alone or in conjunction with semiconductors according to several mechanisms. We study the photooxidation of citrate by silver nanoparticles in a photoelectrochemical cell, focusing on the wavelength-dependence of the reaction rate and the role of the semiconductor substrate. We find that the citrate photooxidation rate does not track the plasmon resonance of the silver

  6. C-type starch from high-amylose rice resistant starch granules modified by antisense RNA inhibition of starch branching enzyme.

    Science.gov (United States)

    Wei, Cunxu; Xu, Bin; Qin, Fengling; Yu, Huaguang; Chen, Chong; Meng, Xianglen; Zhu, Lijia; Wang, Youping; Gu, Minghong; Liu, Qiaoquan

    2010-06-23

    High-amylose starch is a source of resistant starch (RS) which has a great benefit on human health. A transgenic rice line (TRS) enriched amylose and RS had been developed by antisense RNA inhibition of starch branching enzymes. In this study, the native starch granules were isolated from TRS grains as well as the wild type, and their crystalline type was carefully investigated before and after acid hydrolysis. In high-amylose TRS rice, the C-type starch, which might result from the combination of both A-type and B-type starch, was observed and subsequently confirmed by multiple physical techniques, including X-ray powder diffraction, solid-state nuclear magnetic resonance, and Fourier transform infrared. Moreover, the change of starch crystalline structure from C- to B-type during acid hydrolysis was also observed in this RS-rich rice. These data could add to our understanding of not only the polymorph structure of cereal starch but also why high-amylose starch is more resistant to digestion.

  7. Gene encoding a c-type cyclin in Mycosphaerella graminicola is involved in aerial mycelium formation, filamentous growth, hyphal swelling, melanin biosynthesis, stress response, and pathogenicity.

    Science.gov (United States)

    Choi, Yoon-E; Goodwin, Stephen B

    2011-04-01

    Mycosphaerella graminicola is an important wheat pathogen causing Septoria tritici blotch. To date, an efficient strategy to control M. graminicola has not been developed. More significantly, we have a limited understanding of the molecular mechanisms of M. graminicola pathogenicity. In this study, we attempted to characterize an MCC1-encoding c-type cyclin, a gene homologous to FCC1 in Fusarium verticillioides. Four independent MCC1 knock-out mutants were generated via Agrobacterium tumefaciens-mediated transformation. All of the MCC1 mutants showed consistent multiple phenotypes. Significant reductions in radial growth on potato dextrose agar (PDA) were observed in all of the MCC1 mutants. In addition, MCC1 gene-deletion mutants produced less aerial mycelium on PDA, showed delayed filamentous growth, had unusual hyphal swellings, produced more melanin, showed an increase in their stress tolerance response, and were reduced significantly in pathogenicity. These results indicate that the MCC1 gene is involved in multiple signaling pathways, including those involved in pathogenicity in M. graminicola.

  8. The C-type lectin receptor SIGNR3 binds to fungi present in commensal microbiota and influences immune regulation in experimental colitis

    Directory of Open Access Journals (Sweden)

    Magdalena eEriksson

    2013-07-01

    Full Text Available Inflammatory bowel disease is a condition of acute and chronic inflammation of the gut. An important factor contributing to pathogenesis is a dysregulated mucosal immunity against commensal bacteria and fungi. Host pattern recognition receptors sense commensals in the gut and are involved in maintaining the balance between controlled responses to pathogens and overwhelming innate immune activation. C-type lectin receptors (CLRs are pattern recognition receptors recognizing glycan structures on pathogens and self-antigens. Here we examined the role of the murine CLR SIGNR3 in the recognition of commensals and its involvement in intestinal immunity. SIGNR3 is the closest murine homologue of the human DC-SIGN receptor recognizing similar carbohydrate ligands such as terminal fucose or high-mannose glycans. We discovered that SIGNR3 recognizes fungi present in the commensal microbiota. To analyze if this interaction impacts the intestinal immunity against microbiota, the dextran sulfate sodium (DSS-induced colitis model was employed. SIGNR3-/- mice exhibited an increased weight loss associated with more severe colitis symptoms compared to wild-type control mice. The increased inflammation in SIGNR3-/- mice was accompanied by a higher level of TNF-α in colon. Our findings demonstrate for the first time that SIGNR3 recognizes intestinal fungi and has an immune regulatory role in colitis.

  9. The Neck Region of the C-type Lectin DC-SIGN Regulates Its Surface Spatiotemporal Organization and Virus-binding Capacity on Antigen-presenting Cells*

    Science.gov (United States)

    Manzo, Carlo; Torreno-Pina, Juan A.; Joosten, Ben; Reinieren-Beeren, Inge; Gualda, Emilio J.; Loza-Alvarez, Pablo; Figdor, Carl G.; Garcia-Parajo, Maria F.; Cambi, Alessandra

    2012-01-01

    The C-type lectin DC-SIGN expressed on dendritic cells (DCs) facilitates capture and internalization of a plethora of different pathogens. Although it is known that DC-SIGN organizes in nanoclusters at the surface of DCs, the molecular mechanisms responsible for this well defined nanopatterning and role in viral binding remain enigmatic. By combining biochemical and advanced biophysical techniques, including optical superresolution and single particle tracking, we demonstrate that DC-SIGN intrinsic nanoclustering strictly depends on its molecular structure. DC-SIGN nanoclusters exhibited free, Brownian diffusion on the cell membrane. Truncation of the extracellular neck region, known to abrogate tetramerization, significantly reduced nanoclustering and concomitantly increased lateral diffusion. Importantly, DC-SIGN nanocluster dissolution exclusively compromised binding to nanoscale size pathogens. Monte Carlo simulations revealed that heterogeneity on nanocluster density and spatial distribution confers broader binding capabilities to DC-SIGN. As such, our results underscore a direct relationship between spatial nanopatterning, driven by intermolecular interactions between the neck regions, and receptor diffusion to provide DC-SIGN with the exquisite ability to dock pathogens at the virus length scale. Insight into how virus receptors are organized prior to virus binding and how they assemble into functional platforms for virus docking is helpful to develop novel strategies to prevent virus entry and infection. PMID:23019323

  10. In Situ Spectral Kinetics of Cr(VI) Reduction by c-Type Cytochromes in A Suspension of Living Shewanella putrefaciens 200

    Science.gov (United States)

    Liu, Tongxu; Li, Xiaomin; Li, Fangbai; Han, Rui; Wu, Yundang; Yuan, Xiu; Wang, Ying

    2016-07-01

    Although c-type cytochromes (c-Cyts) mediating metal reduction have been mainly investigated with in vitro purified proteins of dissimilatory metal reducing bacteria, the in vivo behavior of c-Cyts is still unclear given the difficulty in measuring the proteins of intact cells. Here, c-Cyts in living Shewanella putrefaciens 200 (SP200) was successfully quantified using diffuse-transmission UV/Vis spectroscopy due to the strong absorbance of hemes, and the in situ spectral kinetics of Cr(VI) reduction by c-Cyts were examined over time. The reduced product Cr(III) observed on the cell surface may play a role in inhibiting the Cr(VI) reduction and reducing the cell numbers with high concentrations (>200 μM) of Cr(VI) evidenced by the 16S rRNA analysis. A brief kinetic model was established with two predominant reactions, redox transformation of c-Cyts and Cr(VI) reduction by reduced c-Cyts, but the fitting curves were not well-matched with c-Cyts data. The Cr(III)-induced inhibitory effect to the cellular function of redox transformation of c-Cyts was then added to the model, resulting in substantially improved the model fitting. This study provides a case of directly examining the reaction properties of outer-membrane enzyme during microbial metal reduction processes under physiological conditions.

  11. C-type lectin-like molecule-1 (CLL1)-targeted TRAIL augments the tumoricidal activity of granulocytes and potentiates therapeutic antibody-dependent cell-mediated cytotoxicity.

    Science.gov (United States)

    Wiersma, Valerie R; de Bruyn, Marco; Shi, Ce; Gooden, Marloes J M; Wouters, Maartje C A; Samplonius, Douwe F; Hendriks, Djoke; Nijman, Hans W; Wei, Yunwei; Zhou, Jin; Helfrich, Wijnand; Bremer, Edwin

    2015-01-01

    The therapeutic effect of anti-cancer monoclonal antibodies stems from their capacity to opsonize targeted cancer cells with subsequent phagocytic removal, induction of antibody-dependent cell-mediated cytotoxicity (ADCC) or induction of complement-mediated cytotoxicity (CDC). The major immune effector cells involved in these processes are natural killer (NK) cells and granulocytes. The latter and most prevalent blood cell population contributes to phagocytosis, but is not effective in inducing ADCC. Here, we report that targeted delivery of the tumoricidal protein tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) to granulocyte marker C-type lectin-like molecule-1 (CLL1), using fusion protein CLL1:TRAIL, equips granulocytes with high levels of TRAIL. Upon CLL1-selective binding of this fusion protein, granulocytes acquire additional TRAIL-mediated cytotoxic activity that, importantly, potentiates antibody-mediated cytotoxicity of clinically used therapeutic antibodies (e.g., rituximab, cetuximab). Thus, CLL1:TRAIL could be used as an adjuvant to optimize the clinical potential of anticancer antibody therapy by augmenting tumoricidal activity of granulocytes.

  12. Antioxidant activity of yoghurt peptides: Part 2 – Characterisationof peptide fractions

    DEFF Research Database (Denmark)

    Farvin, Sabeena; Baron, Caroline; Nielsen, Nina Skall

    2010-01-01

    The aim of the present study was to elucidate previous findings showing that peptide fractions isolated from yoghurt had antioxidant effects. Therefore, peptides and free amino acids released during fermentation of milk were characterised. Yoghurt samples were stripped from sugars and lactic acid...... the peptides identified contained at least one proline residue. Some of the identified peptides included the hydrophobic amino acid residues Val or Leu at the N-terminus and Pro, His or Tyr in the amino acid sequence, which is characteristic of antioxidant peptides. In addition, the yoghurt contained...... a considerable amount of free amino acids such as His, Tyr, Thr and Lys, which have been reported to have antioxidant properties. Thus, our findings confirm that the antioxidant effects of the peptide fractions from yoghurt are due to the presence of certain peptides and free amino acids with recognised...

  13. New dendrimer - Peptide host - Guest complexes: Towards dendrimers as peptide carriers

    DEFF Research Database (Denmark)

    Boas, Ulrik; Sontjens, S.H.M.; Jensen, Knud Jørgen

    2002-01-01

    the NH- and CO-stretch signals of the peptide amide moieties shift towards lower wave-numbers upon complexation with the dendrimer. Spatial analysis of the complexes with NOESY spectroscopy generally shows close proximity of the N-terminal Boc group of the peptide to the peripheral adamantyl groups......Adamantyl urea and adamantyl thiourea modified poly(propylene imine) dendrimers act as hosts for N-terminal tert-butoxycarbonyl (Boc)-protected peptides and form chloroform-soluble complexes. investigations with NMR spectroscopy show that the peptide is bound to the dendrimer by ionic interactions...... between the dendrimer outer shell tertiary amines and the C-terminal carboxylic acid of the peptide, and also through host-urea to peptide-amide hydrogen bonding. The hydrogen-bonding nature of the peptide dendrimer interactions was further confirmed by using Fourier transform IR spectroscopy, for which...

  14. Use of Peptide Libraries for Identification and Optimization of Novel Antimicrobial Peptides.

    Science.gov (United States)

    Ashby, Martin; Petkova, Asya; Gani, Jurnorain; Mikut, Ralf; Hilpert, Kai

    2017-01-01

    The increasing rates of resistance among bacteria and to a lesser extent fungi have resulted in an urgent need to find new molecules that hold therapeutic promise against multidrug-resistant strains. Antimicrobial peptides have proven very effective against a variety of multidrug-resistant bacteria. Additionally, the low levels of resistance reported towards these molecules are an attractive feature for antimicrobial drug development. Here we summarise information on diverse peptide libraries used to discover or to optimize antimicrobial peptides. Chemical synthesized peptide libraries, for example split and mix method, tea bag method, multi-pin method and cellulose spot method are discussed. In addition biological peptide library screening methods are summarized, like phage display, bacterial display, mRNA-display and ribosomal display. A few examples are given for small peptide libraries, which almost exclusively follow a rational design of peptides of interest rather than a combinatorial approach.

  15. Current trends and perspectives of bioactive peptides.

    Science.gov (United States)

    Daliri, Eric Banan-Mwine; Lee, Byong H; Oh, Deog H

    2017-06-12

    The remarkable growth of therapeutic peptide development in the past decade has led to a large number of market approvals and the market value is expected to hit $25 billion by 2018. This significant market increase is driven by the increasing incidences of metabolic and cardiovascular diseases and technological advancements in peptide synthesis. For this reason, the search for bioactive peptides has also increased exponentially. Many bioactive peptides from food and nonfood sources have shown positive health effects yet, obstacles such as the need to implement efficient and cost-effective strategies for industrial scale production, good manufacturing practices as well as well-designed clinical trials to provide robust evidence for supporting health claims continue to exist. Several other factors such as the possibility of allergenicity, toxicity and the stability of biological functions of the peptides during gastrointestinal digestion would need to be addressed.

  16. Peptide-Lipid Interactions: Experiments and Applications

    Science.gov (United States)

    Galdiero, Stefania; Falanga, Annarita; Cantisani, Marco; Vitiello, Mariateresa; Morelli, Giancarlo; Galdiero, Massimiliano

    2013-01-01

    The interactions between peptides and lipids are of fundamental importance in the functioning of numerous membrane-mediated cellular processes including antimicrobial peptide action, hormone-receptor interactions, drug bioavailability across the blood-brain barrier and viral fusion processes. Moreover, a major goal of modern biotechnology is obtaining new potent pharmaceutical agents whose biological action is dependent on the binding of peptides to lipid-bilayers. Several issues need to be addressed such as secondary structure, orientation, oligomerization and localization inside the membrane. At the same time, the structural effects which the peptides cause on the lipid bilayer are important for the interactions and need to be elucidated. The structural characterization of membrane active peptides in membranes is a harsh experimental challenge. It is in fact accepted that no single experimental technique can give a complete structural picture of the interaction, but rather a combination of different techniques is necessary. PMID:24036440

  17. The role of RFamide peptides in feeding.

    Science.gov (United States)

    Bechtold, David A; Luckman, Simon M

    2007-01-01

    In the three decades since FMRFamide was isolated from the clam Macrocallista nimbosa, the list of RFamide peptides has been steadily growing. These peptides occur widely across the animal kingdom, including five groups of RFamide peptides identified in mammals. Although there is tremendous diversity in structure and biological activity in the RFamides, the involvement of these peptides in the regulation of energy balance and feeding behaviour appears consistently through evolution. Even so, questions remain as to whether feeding-related actions represent a primary function of the RFamides, especially within mammals. However, as we will discuss here, the study of RFamide function is rapidly expanding and with it so is our understanding of how these peptides can influence food intake directly as well as related aspects of feeding behaviour and energy expenditure.

  18. Novel peptide-based protease inhibitors

    DEFF Research Database (Denmark)

    Roodbeen, Renée

    This thesis describes the design and synthesis of peptide-based serine protease inhibitors. The targeted protease, urokinase-type plasminogen activator (uPA) activates plasminogen, which plays a major role in cancer metastasis. The peptide upain-2 (S 1 ,S 12-cyclo-AcCSWRGLENHAAC-NH2) is a highly......, the disulfide bridge was replaced with amide bonds of various lengths. The novel peptides did not retain their inhibitory activity, but formed the basis for another strategy. Second, bicyclic peptides were obtained by creating head-to-tail cyclized peptides that were made bicyclic by the addition of a covalent...... bond across the ring. The second bridge was made by a disulfide bridge, amide bond formation or via ring-closing metathesis. A, with upain-2 equipotent, bicyclic inhibitor was obtained and its binding to uPA was studied by ITC, NMR and X-ray. The knowledge of how selective inhibitors bind uPA has been...

  19. Harnessing supramolecular peptide nanotechnology in biomedical applications.

    Science.gov (United States)

    Chan, Kiat Hwa; Lee, Wei Hao; Zhuo, Shuangmu; Ni, Ming

    2017-01-01

    The harnessing of peptides in biomedical applications is a recent hot topic. This arises mainly from the general biocompatibility of peptides, as well as from the ease of tunability of peptide structure to engineer desired properties. The ease of progression from laboratory testing to clinical trials is evident from the plethora of examples available. In this review, we compare and contrast how three distinct self-assembled peptide nanostructures possess different functions. We have 1) nanofibrils in biomaterials that can interact with cells, 2) nanoparticles that can traverse the bloodstream to deliver its payload and also be bioimaged, and 3) nanotubes that can serve as cross-membrane conduits and as a template for nanowire formation. Through this review, we aim to illustrate how various peptides, in their various self-assembled nanostructures, possess great promise in a wide range of biomedical applications and what more can be expected.

  20. Antimicrobial Peptides: Mechanisms of Action and Resistance.

    Science.gov (United States)

    Bechinger, B; Gorr, S-U

    2017-03-01

    More than 40 antimicrobial peptides and proteins (AMPs) are expressed in the oral cavity. These AMPs have been organized into 6 functional groups, 1 of which, cationic AMPs, has received extensive attention in recent years for their promise as potential antibiotics. The goal of this review is to describe recent advances in our understanding of the diverse mechanisms of action of cationic AMPs and the bacterial resistance against these peptides. The recently developed peptide GL13K is used as an example to illustrate many of the discussed concepts. Cationic AMPs typically exhibit an amphipathic conformation, which allows increased interaction with negatively charged bacterial membranes. Peptides undergo changes in conformation and aggregation state in the presence of membranes; conversely, lipid conformation and packing can adapt to the presence of peptides. As a consequence, a single peptide can act through several mechanisms depending on the peptide's structure, the peptide:lipid ratio, and the properties of the lipid membrane. Accumulating evidence shows that in addition to acting at the cell membrane, AMPs may act on the cell wall, inhibit protein folding or enzyme activity, or act intracellularly. Therefore, once a peptide has reached the cell wall, cell membrane, or its internal target, the difference in mechanism of action on gram-negative and gram-positive bacteria may be less pronounced than formerly assumed. While AMPs should not cause widespread resistance due to their preferential attack on the cell membrane, in cases where specific protein targets are involved, the possibility exists for genetic mutations and bacterial resistance. Indeed, the potential clinical use of AMPs has raised the concern that resistance to therapeutic AMPs could be associated with resistance to endogenous host-defense peptides. Current evidence suggests that this is a rare event that can be overcome by subtle structural modifications of an AMP.

  1. Antimicrobial peptides interact with peptidoglycan

    Science.gov (United States)

    Neelay, Om P.; Peterson, Christian A.; Snavely, Mary E.; Brown, Taylor C.; TecleMariam, Ariam F.; Campbell, Jennifer A.; Blake, Allison M.; Schneider, Sydney C.; Cremeens, Matthew E.

    2017-10-01

    Traditional therapeutics are losing effectiveness as bacterial resistance increases, and antimicrobial peptides (AMPs) can serve as an alternative source for antimicrobial agents. Their mode of action is commonly hypothesized to involve pore formation in the lipid membrane, thereby leading to cell death. However, bacterial cell walls are much more complex than just the lipid membrane. A large portion of the wall is comprised of peptidoglycan, yet we did not find any report of AMP-peptidoglycan interactions. Consequently, this work evaluated AMP-peptidoglycan and AMP-phospholipid (multilamellar vesicles) interactions through tryptophan fluorescence. Given that peptidoglycan is insoluble and vesicles are large particles, we took advantage of the unique properties of Trp-fluorescence to use one technique for two very different systems. Interestingly, melittin and cecropin A interacted with peptidoglycan to a degree similar to vancomycin, a positive control. Whether these AMP-peptidoglycan interactions relate to a killing mode of action requires further study.

  2. Identification of peptides that selectively bind to myoglobin by biopanning of phage displayed-peptide library.

    Science.gov (United States)

    Padmanaban, Guruprasath; Park, Hyekyung; Choi, Ji Suk; Cho, Yong-Woo; Kang, Woong Chol; Moon, Chan-Il; Kim, In-San; Lee, Byung-Heon

    2014-10-10

    Biopanning of phage displayed-peptide library was performed against myoglobin, a marker for the early assessment of acute myocardial infarction (AMI), to identify peptides that selectively bind to myoglobin. Using myoglobin-conjugated magnetic beads, phages that bound to myoglobin were collected and amplified for the next round of screening. A 148-fold enrichment of phage titer was observed after five rounds of screening relative to the first round. After phage binding ELISA, three phage clones were selected (3R1, 3R7 and 3R10) and the inserted peptides were chemically synthesized. The analysis of binding affinity showed that the 3R7 (CPSTLGASC) peptide had higher binding affinity (Kd=57 nM) than did the 3R1 (CNLSSSWIC) and 3R10 (CVPRLSAPC) peptide (Kd=125 nM and 293 nM, respectively). Cross binding activity to other proteins, such as bovine serum albumin, troponin I, and creatine kinase-MB, was minimal. In a peptide-antibody sandwich ELISA, the selected peptides efficiently captured myoglobin. Moreover, the concentrations of myoglobin in serum samples measured by a peptide-peptide sandwich assay were comparable to those measured by a commercial antibody-based kit. These results indicate that the identified peptides can be used for the detection of myoglobin and may be a cost effective alternative to antibodies. Copyright © 2014 Elsevier B.V. All rights reserved.

  3. Analysis of the endogenous peptide profile of milk: identification of 248 mainly casein-derived peptides.

    Science.gov (United States)

    Baum, Florian; Fedorova, Maria; Ebner, Jennifer; Hoffmann, Ralf; Pischetsrieder, Monika

    2013-12-06

    Milk is an excellent source of bioactive peptides. However, the composition of the native milk peptidome has only been partially elucidated. The present study applied matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) directly or after prefractionation of the milk peptides by reverse-phase high-performance liquid chromatography (RP-HPLC) or OFFGEL fractionation for the comprehensive analysis of the peptide profile of raw milk. The peptide sequences were determined by MALDI-TOF/TOF or nano-ultra-performance liquid chromatography-nanoelectrospray ionization-LTQ-Orbitrap-MS. Direct MALDI-TOF-MS analysis led to the assignment of 57 peptides. Prefractionation by both complementary methods led to the assignment of another 191 peptides. Most peptides originate from α(S1)-casein, followed by β-casein, and α(S2)-casein. κ-Casein and whey proteins seem to play only a minor role as peptide precursors. The formation of many, but not all, peptides could be explained by the activity of the endogenous peptidases, plasmin or cathepsin D, B, and G. Database searches revealed the presence of 22 peptides with established physiological function, including those with angiotensin-converting-enzyme (ACE) inhibitory, immunomodulating, or antimicrobial activity.

  4. Interactions of Bio-Inspired Membranes with Peptides and Peptide-Mimetic Nanoparticles

    Directory of Open Access Journals (Sweden)

    Michael Sebastiano

    2015-08-01

    Full Text Available Via Dissipative Particle Dynamics (DPD and implicit solvent coarse-grained (CG Molecular Dynamics (MD we examine the interaction of an amphiphilic cell-penetrating peptide PMLKE and its synthetic counterpart with a bio-inspired membrane. We use the DPD technique to investigate the interaction of peptide-mimetic nanoparticles, or nanopins, with a three-component membrane. The CG MD approach is used to investigate the interaction of a cell-penetrating peptide PMLKE with single-component membrane. We observe the spontaneous binding and subsequent insertion of peptide and nanopin in the membrane by using CG MD and DPD approaches, respectively. In addition, we find that the insertion of peptide and nanopins is mainly driven by the favorable enthalpic interactions between the hydrophobic components of the peptide, or nanopin, and the membrane. Our study provides insights into the mechanism underlying the interactions of amphiphilic peptide and peptide-mimetic nanoparticles with a membrane. The result of this study can be used to guide the functional integration of peptide and peptide-mimetic nanoparticles with a cell membrane.

  5. Determinants of recombinant production of antimicrobial cationic peptides and creation of peptide variants in bacteria.

    Science.gov (United States)

    Zhang, L; Falla, T; Wu, M; Fidai, S; Burian, J; Kay, W; Hancock, R E

    1998-06-29

    Cationic peptides possessing antibacterial activity are virtually ubiquitous in nature, and offer exciting prospects as new therapeutic agents. We had previously demonstrated that such peptides could be produced by fusion protein technology in bacteria and several carrier proteins had been tested as fusion partners including glutathione-S-transferase, S. aureus protein A, IgG binding protein and P. aeruginosa outer membrane protein OprF. However these fusion partners, while successfully employed in peptide expression, were not optimized for high level production of cationic peptides (Piers, K., Brow, M. L., and Hancock, R. E. W. 1993, Gene 137, 7-13). In this paper we took advantage of a small replication protein RepA from E. coli and used its truncated version to construct fusion partners. The minimal elements required for high level expression of cationic peptide were defined as a DNA sequence encoding a fusion protein comprising, from the N-terminus, a 68 amino acid carrier region, an anionic prepro domain, a single methionine and the peptide of interest. The 68 amino acid carrier region was a block of three polypeptides consisting of a truncated RepA, a synthetic cellulose binding domain and a hexa histidine domain. The improved system showed high level expression and simplified downstream purification. The active peptide could be yielded by CNBr cleavage of the fusion protein. This novel vector was used to express three classes of cationic peptides including the alpha-helical peptide CEMA, the looped peptide bactenecin and the extended peptide indolicidin. In addition, mutagenesis of the peptide gene to produce peptide variants of CEMA and indolicidin using the improved vector system was shown to be successful.

  6. rapmad: Robust analysis of peptide microarray data

    Directory of Open Access Journals (Sweden)

    Rothermel Andrée

    2011-08-01

    Full Text Available Abstract Background Peptide microarrays offer an enormous potential as a screening tool for peptidomics experiments and have recently seen an increased field of application ranging from immunological studies to systems biology. By allowing the parallel analysis of thousands of peptides in a single run they are suitable for high-throughput settings. Since data characteristics of peptide microarrays differ from DNA oligonucleotide microarrays, computational methods need to be tailored to these specifications to allow a robust and automated data analysis. While follow-up experiments can ensure the specificity of results, sensitivity cannot be recovered in later steps. Providing sensitivity is thus a primary goal of data analysis procedures. To this end we created rapmad (Robust Alignment of Peptide MicroArray Data, a novel computational tool implemented in R. Results We evaluated rapmad in antibody reactivity experiments for several thousand peptide spots and compared it to two existing algorithms for the analysis of peptide microarrays. rapmad displays competitive and superior behavior to existing software solutions. Particularly, it shows substantially improved sensitivity for low intensity settings without sacrificing specificity. It thereby contributes to increasing the effectiveness of high throughput screening experiments. Conclusions rapmad allows the robust and sensitive, automated analysis of high-throughput peptide array data. The rapmad R-package as well as the data sets are available from http://www.tron-mz.de/compmed.

  7. Super-resolution imaging of C-type lectin spatial rearrangement within the dendritic cell plasma membrane at fungal microbe contact sites

    Directory of Open Access Journals (Sweden)

    Michelle S Itano

    2014-08-01

    Full Text Available Dendritic cells express DC-SIGN and CD206, C-type lectins (CTLs that bind a variety of pathogens and may facilitate pathogen uptake for subsequent antigen presentation. Both proteins form punctate membrane nanodomains (~80 nm on naïve cells. We analyzed the spatiotemporal distribution of CTLs following host-fungal particle contact using confocal microscopy and three distinct methods of cluster identification and measurement of receptor clusters in super-resolution datasets: DBSCAN, Pair Correlation and a custom implementation of the Getis spatial statistic. Quantitative analysis of confocal and super-resolution images demonstrated that CTL nanodomains become concentrated in the contact site relative to non-contact membrane after the first hour of exposure and established that this recruitment is sustained out to four hours. DC-SIGN nanodomains in fungal contact sites exhibit a 70% area increase and a 38% decrease in interdomain separation. Contact site CD206 nanodomains possess 90% greater area and 42% lower interdomain separation relative to non-contact regions. Contact site CTL clusters appear as disk-shaped domains of approximately 150-175 nm in diameter. The increase in length scale of CTL nanostructure in contact sites suggests that the smaller nanodomains on resting membranes may merge during fungal nanodomain structure, or that they become packed closely enough to achieve sub-resolution inter-domain edge separations of < 30 nm. This study provides evidence of local receptor spatial rearrangements on the nanoscale that occur in the plasma membrane upon pathogen binding and may direct important signaling interactions required to recognize and respond to the presence of a relatively large pathogen.

  8. Identification of AlcR, an AraC-Type Regulator of Alcaligin Siderophore Synthesis in Bordetella bronchiseptica and Bordetella pertussis

    Science.gov (United States)

    Pradel, Elizabeth; Guiso, Nicole; Locht, Camille

    1998-01-01

    A Fur titration assay was used to isolate DNA fragments bearing putative Fur binding sites (FBS) from a partial Bordetella bronchiseptica genomic DNA library. A recombinant plasmid bearing a 3.5-kb DNA insert was further studied. Successive deletions in the cloned fragment enabled us to map a putative FBS at about 2 kb from one end. Sequence analysis revealed the presence of an FBS upstream from a new gene encoding an AraC-type transcriptional regulator. The deduced protein displays similarity to PchR, an activator of pyochelin siderophore and ferripyochelin receptor synthesis in Pseudomonas aeruginosa. Homologous genes in Bordetella pertussis and Bordetella parapertussis were PCR amplified, and sequence comparisons indicated a very high conservation in the three species. The B. pertussis and B. bronchiseptica chromosomal genes were inactivated by allelic exchange. Under low-iron growth conditions, the mutants did not secrete the alcaligin siderophore and lacked AlcC, an alcaligin biosynthetic enzyme. Alcaligin production was restored after transformation with a plasmid bearing the wild-type gene. On the basis of its role in regulation of alcaligin biosynthesis, the new gene was designated alcR. Additional sequence determination showed that alcR is located about 2 kb downstream from the alcABC operon and is transcribed in the same orientation. Two tightly linked open reading frames, alcD and alcE, were identified between alcC and alcR. AlcE is a putative iron-sulfur protein; AlcD shows no homology with the proteins in the database. The production of major virulence factors and colonization in the mouse respiratory infection model are AlcR independent. PMID:9473041

  9. Super-resolution imaging of C-type lectin spatial rearrangement within the dendritic cell plasma membrane at fungal microbe contact sites

    Science.gov (United States)

    Itano, Michelle; Graus, Matthew; Pehlke, Carolyn; Wester, Michael; Liu, Ping; Lidke, Keith; Thompson, Nancy; Jacobson, Ken; Neumann, Aaron

    2014-08-01

    Dendritic cells express DC-SIGN and CD206, C-type lectins (CTLs) that bind a variety of pathogens and may facilitate pathogen uptake for subsequent antigen presentation. Both proteins form punctate membrane nanodomains (~80 nm) on naïve cells. We analyzed the spatiotemporal distribution of CTLs following host-fungal particle contact using confocal microscopy and three distinct methods of cluster identification and measurement of receptor clusters in super-resolution datasets: DBSCAN, Pair Correlation and a custom implementation of the Getis spatial statistic. Quantitative analysis of confocal and super-resolution images demonstrated that CTL nanodomains become concentrated in the contact site relative to non-contact membrane after the first hour of exposure and established that this recruitment is sustained out to four hours. DC-SIGN nanodomains in fungal contact sites exhibit a 70% area increase and a 38% decrease in interdomain separation. Contact site CD206 nanodomains possess 90% greater area and 42% lower interdomain separation relative to non-contact regions. Contact site CTL clusters appear as disk-shaped domains of approximately 150-175 nm in diameter. The increase in length scale of CTL nanostructure in contact sites suggests that the smaller nanodomains on resting membranes may merge during fungal nanodomain structure, or that they become packed closely enough to achieve sub-resolution inter-domain edge separations of < 30 nm. This study provides evidence of local receptor spatial rearrangements on the nanoscale that occur in the plasma membrane upon pathogen binding and may direct important signaling interactions required to recognize and respond to the presence of a relatively large pathogen.

  10. Characterization of the Decaheme c-Type Cytochrome OmcA in Solution and on Hematite Surfaces by Small Angle X-Ray Scattering and Neutron Reflectometry

    Science.gov (United States)

    Johs, A.; Shi, L.; Droubay, T.; Ankner, J.F.; Liang, L.

    2010-01-01

    Abstract The outer membrane protein OmcA is an 85 kDa decaheme c-type cytochrome located on the surface of the dissimilatory metal-reducing bacterium Shewanella oneidensis MR-1. It is assumed to mediate shuttling of electrons to extracellular acceptors that include solid metal oxides such as hematite (α-Fe2O3). No information is yet available concerning OmcA structure in physiologically relevant conditions such as aqueous environments. We purified OmcA and characterized its solution structure by small angle x-ray scattering (SAXS), and its interaction at the hematite-water interface by neutron reflectometry. SAXS showed that OmcA is a monomer that adopts a flat ellipsoidal shape with an overall dimension of 34 × 90 × 65 Å3. To our knowledge, we obtained the first direct evidence that OmcA undergoes a redox state-dependent conformational change in solution whereby reduction decreases the overall length of OmcA by ∼7 Å (the maximum dimension was 96 Å for oxidized OmcA, and 89 Å for NADH and dithionite-reduced OmcA). OmcA was also found to physically interact with electron shuttle molecules such as flavin mononucleotide, resulting in the formation of high-molecular-weight assemblies. Neutron reflectometry showed that OmcA forms a well-defined monomolecular layer on hematite surfaces, where it assumes an orientation that maximizes its contact area with the mineral surface. These novel insights into the molecular structure of OmcA in solution, and its interaction with insoluble hematite and small organic ligands, demonstrate the fundamental structural bases underlying OmcA's role in mediating redox processes. PMID:20550916

  11. Allelic mRNA expression imbalance in C-type lectins reveals a frequent regulatory SNP in the human surfactant protein A (SP-A) gene.

    Science.gov (United States)

    Azad, A K; Curtis, A; Papp, A; Webb, A; Knoell, D; Sadee, W; Schlesinger, L S

    2013-03-01

    Genetic variation in C-type lectins influences infectious disease susceptibility but remains poorly understood. We used allelic mRNA expression imbalance (AEI) technology for surfactant protein (SP)-A1, SP-A2, SP-D, dendritic cell-specific ICAM-3-grabbing non-integrin (DC-SIGN), macrophage mannose receptor (MRC1) and Dectin-1, expressed in human macrophages and/or lung tissues. Frequent AEI, an indicator of regulatory polymorphisms, was observed in SP-A2, SP-D and DC-SIGN. AEI was measured for SP-A2 in 38 lung tissues using four marker single-nucleotide polymorphisms (SNPs) and was confirmed by next-generation sequencing of one lung RNA sample. Genomic DNA at the SP-A2 DNA locus was sequenced by Ion Torrent technology in 16 samples. Correlation analysis of genotypes with AEI identified a haplotype block, and, specifically, the intronic SNP rs1650232 (30% minor allele frequency); the only variant consistently associated with an approximately twofold change in mRNA allelic expression. Previously shown to alter a NAGNAG splice acceptor site with likely effects on SP-A2 expression, rs1650232 generates an alternative splice variant with three additional bases at the start of exon 3. Validated as a regulatory variant, rs1650232 is in partial linkage disequilibrium with known SP-A2 marker SNPs previously associated with risk for respiratory diseases including tuberculosis. Applying functional DNA variants in clinical association studies, rather than marker SNPs, will advance our understanding of genetic susceptibility to infectious diseases.

  12. An autopsied case of MV2K + C-type sporadic Creutzfeldt-Jakob disease presenting with widespread cerebral cortical involvement and Kuru plaques.

    Science.gov (United States)

    Iwasaki, Yasushi; Saito, Yufuko; Aiba, Ikuko; Kobayashi, Atsushi; Mimuro, Maya; Kitamoto, Tetsuyuki; Yoshida, Mari

    2017-06-01

    MV2-type sporadic Creutzfeldt-Jakob disease (sCJD), which was previously called "Kuru-plaque variant", was gradually revealed to have a wide spectrum and has been classified into three pathological subtypes: MV2K, MV2C and MV2K + C. We herein describe the detailed clinical findings and neuropathologic observations from an autopsied MV2K + C-type Japanese sCJD case with widespread cerebral cortical pathology and Kuru plaques. In the early stages of the disease, the patient exhibited gait disturbance with ataxia and dysarthria as well as gradual appearance of cognitive dysfunction. Diffusion-weighted images (DWI) on MRI revealed extensive cerebral cortical hyperintensity. Pathologic investigation revealed extensive spongiform change in the cerebral cortex, particularly in the deeper layers. Vacuole size varied, and some were confluent. Prion protein (PrP) immunostaining revealed extensive PrP deposition in the cerebral cortex, basal ganglia, thalamus, cerebellum, brainstem and spinal cord. In the cerebral cortex, synaptic-type, Kuru plaque-like, and coarse plaque-type PrP depositions were mainly observed, along with some perivacuolar-type PrP depositions. Kuru plaques and coarse plaque-type PrP depositions also were observed in the cerebellar cortex. PrP gene analysis revealed no mutations, and polymorphic codon 129 exhibited Met/Val heterozygosity. Western blot analysis revealed a mixture of intermediate-type PrPSc and type 2 PrPSc . Based on previous reports regarding MV2-type sCJD and the clinicopathologic findings of the present case, we speculated that it may be possible to clinically distinguish each MV2 subtype. Clinical presentation of the MV2K + C subtype includes predominant cerebral cortical involvement signs with ataxia and DWI hyperintensity of the cerebral cortex on MRI. © 2016 Japanese Society of Neuropathology.

  13. A platform to screen for C-type lectin receptor-binding carbohydrates and their potential for cell-specific targeting and immune modulation.

    Science.gov (United States)

    Maglinao, Maha; Eriksson, Magdalena; Schlegel, Mark K; Zimmermann, Stephanie; Johannssen, Timo; Götze, Sebastian; Seeberger, Peter H; Lepenies, Bernd

    2014-02-10

    Myeloid C-type lectin receptors (CLRs) in innate immunity represent a superfamily of pattern recognition receptors that recognize carbohydrate structures on pathogens and self-antigens. The primary interaction of an antigen-presenting cell and a pathogen shapes the following immune response. Therefore, the identification of CLR ligands that can either enhance or modulate the immune response is of interest. We have developed a screening platform based on glycan arrays to identify immune modulatory carbohydrate ligands of CLRs. A comprehensive library of CLRs was expressed by fusing the extracellular part of each respective CLR, the part containing the carbohydrate-recognition domain (CRD), to the Fc fragment of human IgG1 molecules. CLR-Fc fusion proteins display the CRD in a dimeric form, are properly glycosylated, and can be detected by a secondary antibody with a conjugated fluorophore. Thus, they are valuable tools for high-throughput screening. We were able to identify novel carbohydrate binders of CLRs using the glycan array technology. These CLR-binding carbohydrates were then covalently attached to the model antigen ovalbumin. The ovalbumin neoglycoconjugates were used in a dendritic cell/T cell co-culture assay to stimulate transgenic T cells in vitro. In addition, mice were immunized with these conjugates to analyze the immune modulatory properties of the CLR ligands in vivo. The CLR ligands induced an increased Th1 cytokine production in vitro and modulated the humoral response in vivo. The platform described here allows for the identification of CLR ligands, as well as the evaluation of each ligand's cell-specific targeting and immune modulatory properties. Copyright © 2013 Elsevier B.V. All rights reserved.

  14. Macrophage-inducible C-type lectin Mincle-expressing dendritic cells contribute to control of splenic Mycobacterium bovis BCG infection in mice.

    Science.gov (United States)

    Behler, Friederike; Maus, Regina; Bohling, Jennifer; Knippenberg, Sarah; Kirchhof, Gabriele; Nagata, Masahiro; Jonigk, Danny; Izykowski, Nicole; Mägel, Lavinia; Welte, Tobias; Yamasaki, Sho; Maus, Ulrich A

    2015-01-01

    The macrophage-inducible C-type lectin Mincle has recently been identified to be a pattern recognition receptor sensing mycobacterial infection via recognition of the mycobacterial cell wall component trehalose-6',6-dimycolate (TDM). However, its role in systemic mycobacterial infections has not been examined so far. Mincle-knockout (KO) mice were infected intravenously with Mycobacterium bovis BCG to mimic the systemic spread of mycobacteria under defined experimental conditions. After intravenous infection with M. bovis BCG, Mincle-KO mice responded with significantly higher numbers of mycobacterial CFU in spleen and liver, while reduced granuloma formation was observed only in the spleen. At the same time, reduced Th1 cytokine production and decreased numbers of gamma interferon-producing T cells were observed in the spleens of Mincle-KO mice relative to the numbers in the spleens of wild-type (WT) mice. The effect of adoptive transfer of defined WT leukocyte subsets generated from bone marrow cells of zDC(+/DTR) mice (which bear the human diphtheria toxin receptor [DTR] under the control of the classical dendritic cell-specific zinc finger transcription factor zDC) to specifically deplete Mincle-expressing classical dendritic cells (cDCs) but not macrophages after diphtheria toxin application on the numbers of splenic and hepatic CFU and T cell subsets was then determined. Adoptive transfer experiments revealed that Mincle-expressing splenic cDCs rather than Mincle-expressing macrophages contributed to the reconstitution of attenuated splenic antimycobacterial immune responses in Mincle-KO mice after intravenous challenge with BCG. Collectively, we show that expression of Mincle, particularly by cDCs, contributes to the control of splenic M. bovis BCG infection in mice. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  15. Interaction analysis of grapevine MIKC(c)-type MADS transcription factors and heterologous expression of putative véraison regulators in tomato.

    Science.gov (United States)

    Mellway, Robin D; Lund, Steven T

    2013-11-01

    MIKC(c)-type MADS-domain transcription factors include important regulators of floral development that interact in protein complexes to control the development of floral organs, as described by the ABC model. Members of the SEPALLATA (SEP) and AGAMOUS (AG) MADS clades include proteins involved in stamen and carpel specification and certain members of these families, such as tomato (Solanum lycopersicon) SlRIN and SlTAGL1, have been shown to regulate fruit development and ripening initiation. A number of expression studies have shown that several floral homeotic MADS genes are expressed during grapevine (Vitis vinifera) berry development, including potential homologues of these characterized ripening regulators. To gain insight into the regulation of berry development and ripening in grapevine, we studied the interactions and functions of grapevine floral homeotic MADS genes. Using the yeast 2- and 3-hybrid systems, we determined that the complexes formed during fruit development and ripening may involve several classes of floral homeotic MADS proteins. We found that a heterologously expressed grapevine SEP gene, VviSEP4, is capable of partially complementing the non-ripening phenotype of the tomato rin mutant, indicating that a role for this gene in ripening regulation may be conserved in fleshy fruit ripening. We also found that ectopic expression of a grapevine AG clade gene, VviAG1, in tomato results in the development of fleshy sepals with the chemical characteristics of tomato fruit pericarp. Additionally, we performed 2-hybrid screens on a library prepared from Pinot noir véraison-stage berry and identified proteins that may interact with the MADS factors that are expressed during berry development and that may represent regulatory functions in grape berry development. Copyright © 2013 Elsevier GmbH. All rights reserved.

  16. Bioactive proteins and peptides in foods.

    Science.gov (United States)

    Walther, Barbara; Sieber, Robert

    2011-03-01

    Increasing amounts of data demonstrate a bioactive role of proteins and peptides above and beyond their nutritional impact. The focus of the investigations has mainly been on vitamin- and mineral-binding proteins, on antimicrobial, immunosuppressing/-modulatory proteins, and on proteins with enzyme inhibitory activity as well as on hormones and growth factors from different food proteins; most research has been performed on milk proteins. Because of their molecular size, intact absorption of proteins in the human gastrointestinal tract is limited. Therefore, most of the proteins with biological functions show physiological activity in the gastrointestinal tract by enhancing nutrient absorption, inhibiting enzymes, and modulating the immune system to defend against pathogens. Peptides are released during fermentation or digestion from food proteins by proteolytic enzymes; such peptides have been found mainly in milk. Some of these released peptides exert biological activities such as opiate-like, antihypertensive, mineral-binding, antioxidative, antimicrobial, immuno-, and cytomodulating activity. Intact absorption of these smaller peptides is more likely than that of the larger proteins. Consequently, other organs than the gastrointestinal tract are possible targets for their biological functions. Bioactive proteins as well as bioactive peptides are part of a balanced diet. It is possible to accumulate bioactive peptides in food, for example by using specific microorganisms in fermented dairy products. Although bioactive peptides have been the subject of several studies in vitro and in vivo, their health potential is still under investigation. Up to now, the Commission of European Communities has not (yet) authorized any health claims for bioactive proteins and peptides from food.

  17. MILK PROTEINS-DERIVED BIOACTIVE PEPTIDES

    Directory of Open Access Journals (Sweden)

    Özer KINIK

    2002-02-01

    Full Text Available Milk proteins are a source of various biologically active peptides, which are formed enzymatically either by digestive enzymes or during milk fermentation. These peptides have been shown to have different biochemical and physiological effects, such as binding to opioid receptors, inhibition of angiotensin I-converting enzyme (ACE, antimicrobial, antihypertensive, antioxidative, antithrombotic, immunomodulatory and mineral binding effects. This review will focus on chemical structure, physiological properties, production and formation mechanisms in dairy food of milk-derived bioactive peptides and their usage potential as functional food ingredient.

  18. Imaging tumors with peptide-based radioligands

    Energy Technology Data Exchange (ETDEWEB)

    Behr, T. M.; Gotthardt, M.; Barth, A.; Behe, M. [Philipps-University of Marburg, Dept. of Nuclear Medicine, Marburg (Germany)

    2001-06-01

    Regulatory peptides are small, readily diffusable and potent natural substances with a wide spectrum of receptor-mediated actions in humans. High affinity receptors for these peptides are (over)-expressed in many neoplasms, and these receptors may represent, therefore, new molecular targets for cancer diagnosis and therapy. This review aims to give an overview of the peptide-based radiopharmaceuticals which are presently already commercially available or which are in advanced stages of their clinical testing so that their broader availability is anticipated soon. Physiologically, these peptides bind to and act through G protein-coupled receptors in the cell membrane. Historically, somatostatin analogs are the first class of receptor binding peptides having gained clinical application. In {sup 111}In-DTPA-(D-Phe{sup 1})-octreotide is the first and only radio peptide which has obtained regulatory approval in Europe and the United States to date. Extensive clinical studies involving several thousands of patients have shown that the major clinical application of somatostatin receptor scintigraphy is the detection and the staging of gastroenteropancreatic neuroendocrine tumors (carcinoids). In these tumors, octreotide scintigraphy is superior to any other staging method. However, its sensitivity and accuracy in other, more frequent neoplasms is limited. Radiolabeled vasoactive intestinal peptide (VIP) has been shown to visualize the majority of gastrointestinal adenocarcinomas, as well as some neuroendocrine tumors, including insulinomas (the latter being often missed by somatostatin receptor scintigraphy). Due to the outstanding diagnostic accuracy of the pentagastrin test in detecting the presence, persistence, or recurrence of medullary thyroid cancer (MTC), it was postulated the expression of the corresponding (i.e. cholecystokinin (CCK-)-B) receptor type in human MTC. This receptor is also widely expressed on human small-cell lung. Indeed, {sup 111}In-labeled DTPA

  19. SICLOPPS cyclic peptide libraries in drug discovery.

    Science.gov (United States)

    Tavassoli, Ali

    2017-06-01

    Cyclic peptide libraries have demonstrated significant potential when employed against challenging targets such as protein-protein interactions. While a variety of methods for library generation exist, genetically encoded libraries hold several advantages over their chemically synthesized counterparts; they are more readily accessible and allow straightforward hit deconvolution. One method for the intracellular generation of such libraries is split-intein circular ligation of peptides and proteins (SICLOPPS). Here we detail and discuss the deployment of SICLOPPS libraries for the identification of cyclic peptide inhibitors of a variety of targets. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. Maximin H5 is an anticancer peptide

    OpenAIRE

    Dennison, SR; Harris, F; Phoenix, DA

    2017-01-01

    Here we report the first major example of anionic amphibian host defence peptides (HDPs) with anticancer activity. Maximin H5 is a C-terminally amidated, anionic host defence peptide (MH5N) from toads of the Bombina genus, which was shown to possess activity against the glioma cell line, T98G (EC50 = 125 μM). The peptide adopted high levels of α-helical structure (57.3%) in the presence of model cancer membranes (DMPC:DMPS in a molar ratio of 10:1). MH5N also showed a strong ability to penetr...

  1. Cysteine-containing peptides having antioxidant properties

    Science.gov (United States)

    Bielicki, John K [Castro Valley, CA

    2008-10-21

    Cysteine containing amphipathic alpha helices of the exchangeable apolipoproteins, as exemplified by apolipoprotein (apo) A-I.sub.Milano (R173C) and apoA-I.sub.Paris, (R151C) were found to exhibit potent antioxidant activity on phospholipid surfaces. The addition of a free thiol, at the hydrophobic/hydrophilic interface of an amphipathic alpha helix of synthetic peptides that mimic HDL-related proteins, imparts a unique antioxidant activity to these peptides which inhibits lipid peroxidation and protects phospholipids from water-soluble free radical initiators. These peptides can be used as therapeutic agents to combat cardiovascular disease, ischemia, bone disease and other inflammatory related diseases.

  2. The Potential of Antimicrobial Peptides as Biocides

    Directory of Open Access Journals (Sweden)

    Brendan F. Gilmore

    2011-10-01

    Full Text Available Antimicrobial peptides constitute a diverse class of naturally occurring antimicrobial molecules which have activity against a wide range of pathogenic microorganisms. Antimicrobial peptides are exciting leads in the development of novel biocidal agents at a time when classical antibiotics are under intense pressure from emerging resistance, and the global industry in antibiotic research and development stagnates. This review will examine the potential of antimicrobial peptides, both natural and synthetic, as novel biocidal agents in the battle against multi-drug resistant pathogen infections.

  3. Exploiting protected maleimides to modify oligonucleotides, peptides and peptide nucleic acids.

    Science.gov (United States)

    Paris, Clément; Brun, Omar; Pedroso, Enrique; Grandas, Anna

    2015-04-10

    This manuscript reviews the possibilities offered by 2,5-dimethylfuran-protected maleimides. Suitably derivatized building blocks incorporating the exo Diels-Alder cycloadduct can be introduced at any position of oligonucleotides, peptide nucleic acids, peptides and peptoids, making use of standard solid-phase procedures. Maleimide deprotection takes place upon heating, which can be followed by either Michael-type or Diels-Alder click conjugation reactions. However, the one-pot procedure in which maleimide deprotection and conjugation are simultaneously carried out provides the target conjugate more quickly and, more importantly, in better yield. This procedure is compatible with conjugates involving oligonucleotides, peptides and peptide nucleic acids. A variety of cyclic peptides and oligonucleotides can be obtained from peptide and oligonucleotide precursors incorporating protected maleimides and thiols.

  4. Analysis of residue conformations in peptides in Cambridge structural database and protein-peptide structural complexes.

    Science.gov (United States)

    Raghavender, Upadhyayula Surya

    2017-03-01

    A comprehensive statistical analysis of the geometric parameters of peptide chains in a reduced dataset of protein-peptide complexes in Protein Data Bank (PDB) is presented. The angular variables describing the backbone conformations of amino acid residues in peptide chains shed insights into the conformational preferences of peptide residues interacting with protein partners. Nonparametric statistical approaches are employed to evaluate the interrelationships and associations in structural variables. Grouping of residues based on their structure into chemical classes reveals characteristic trends in parameter relationships. A comparison of canonical amino acid residues in free peptide structures in Cambridge structural database (CSD) with identical residues in PDB complexes, suggests that the information can be integrated from both the structural repositories enabling efficient and accurate modeling of biologically active peptides. © 2016 John Wiley & Sons A/S.

  5. Exploiting Protected Maleimides to Modify Oligonucleotides, Peptides and Peptide Nucleic Acids

    Directory of Open Access Journals (Sweden)

    Clément Paris

    2015-04-01

    Full Text Available This manuscript reviews the possibilities offered by 2,5-dimethylfuran-protected maleimides. Suitably derivatized building blocks incorporating the exo Diels-Alder cycloadduct can be introduced at any position of oligonucleotides, peptide nucleic acids, peptides and peptoids, making use of standard solid-phase procedures. Maleimide deprotection takes place upon heating, which can be followed by either Michael-type or Diels-Alder click conjugation reactions. However, the one-pot procedure in which maleimide deprotection and conjugation are simultaneously carried out provides the target conjugate more quickly and, more importantly, in better yield. This procedure is compatible with conjugates involving oligonucleotides, peptides and peptide nucleic acids. A variety of cyclic peptides and oligonucleotides can be obtained from peptide and oligonucleotide precursors incorporating protected maleimides and thiols.

  6. On the hydrophobicity of peptides: Comparing empirical predictions of peptide log P values

    Science.gov (United States)

    Thompson, Sarah J; Hattotuwagama, Channa K; Holliday, John D; Flower, Darren R

    2006-01-01

    Peptides are of great therapeutic potential as vaccines and drugs. Knowledge of physicochemical descriptors, including the partition coefficient logP, is useful for the development of predictive Quantitative Structure-Activity Relationships (QSARs). We have investigated the accuracy of available programs for the prediction of logP values for peptides with known experimental values obtained from the literature. Eight prediction programs were tested, of which seven programs were fragment-based methods: XLogP, LogKow, PLogP, ACDLogP, AlogP, Interactive Analysis's LogP and MlogP; and one program used a whole molecule approach: QikProp. The predictive accuracy of the programs was assessed using r2 values, with ALogP being the most effective (r 2 = 0.822) and MLogP the least (r2 = 0.090). We also examined three distinct types of peptide structure: blocked, unblocked, and cyclic. For each study (all peptides, blocked, unblocked and cyclic peptides) the performance of programs rated from best to worse is as follows: all peptides – ALogP, QikProp, PLogP, XLogP, IALogP, LogKow, ACDLogP, and MlogP; blocked peptides ­ PLogP, XLogP, ACDLogP, IALogP, LogKow, QikProp, ALogP, and MLogP; unblocked peptides ­ QikProp, IALogP, ALogP, ACDLogP, MLogP, XLogP, LogKow and PLogP; cyclic peptides ­ LogKow, ALogP, XLogP, MLogP, QikProp, ACDLogP, IALogP. In summary, all programs gave better predictions for blocked peptides, while, in general, logP values for cyclic peptides were under-predicted and those of unblocked peptides were over-predicted PMID:17597897

  7. Antimicrobial Peptides for Therapeutic Applications: A Review

    Directory of Open Access Journals (Sweden)

    Tsogbadrakh Mishig-Ochir

    2012-10-01

    Full Text Available Antimicrobial peptides (AMPs have been considered as potential therapeutic sources of future antibiotics because of their broad-spectrum activities and different mechanisms of action compared to conventional antibiotics. Although AMPs possess considerable benefits as new generation antibiotics, their clinical and commercial development still have some limitations, such as potential toxicity, susceptibility to proteases, and high cost of peptide production. In order to overcome those obstacles, extensive efforts have been carried out. For instance, unusual amino acids or peptido-mimetics are introduced to avoid the proteolytic degradation and the design of short peptides retaining antimicrobial activities is proposed as a solution for the cost issue. In this review, we focus on small peptides, especially those with less than twelve amino acids, and provide an overview of the relationships between their three-dimensional structures and antimicrobial activities. The efforts to develop highly active AMPs with shorter sequences are also described.

  8. Peptide-Decorated Dendrimers and Their Bioapplications.

    Science.gov (United States)

    Wan, Jingjing; Alewood, Paul F

    2016-04-18

    Peptide-decorated dendrimers (PDDs) are a class of spherical, regular, branched polymers that are modified by peptides covalently attached to their surface. PDDs have been used as protein mimetics, novel biomaterials, and in a wide range of biomedical applications. Since their design and development in the late eighties, poly-l-lysine has been a preferred core structure for PDDs. However, numerous recent innovations in polymer synthesis and ligation chemistry have re-energized the field and led to the emergence of well-defined peptide dendrimers with more diverse core structures and functions. This Minireview highlights the development of PDDs driven by significantly improved ligation chemistry incorporating structurally well-defined peptides and the emerging use of PDDs in imaging and drug development. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Plant Antimicrobial Peptides as Potential Anticancer Agents

    National Research Council Canada - National Science Library

    Guzmán-Rodríguez, Jaquelina Julia; Ochoa-Zarzosa, Alejandra; López-Gómez, Rodolfo; López-Meza, Joel E

    2015-01-01

      Antimicrobial peptides (AMPs) are part of the innate immune defense mechanism of many organisms and are promising candidates to treat infections caused by pathogenic bacteria to animals and humans...

  10. Marine bioactive peptides as potential antioxidants.

    Science.gov (United States)

    Ngo, Dai-Hung; Kim, Se-Kwon

    2013-05-01

    Bioactive peptides derived from marine organisms are the focus of current studies because of their numerous health beneficial effects. They exert various biological roles, one of the most crucial of which is the antioxidant effect. Reverse relationship between antioxidant intake and diseases has been approved through plenty of studies. Antioxidant activity of marine peptides can be attributed to in vitro and in vivo free radical scavenging activities. Antioxidant peptides isolated from marine sources may be used as functional ingredients in food formulations to promote consumer health and improve the shelf life of food products. This chapter presents an overview of the antioxidant peptides derived marine resources with the potential utilization in the food as well as pharmaceutical industries.

  11. Flourescent Peptide-Stabilized Silver-Nanoclusters

    DEFF Research Database (Denmark)

    Gregersen, Simon

    to their physical and optoelectronic properties. These include great photostability, low toxicity, small size, and tunable spectral properties. Chemical stability of noble metal NCs is, however, very low, and they only exist transiently without a stabilizing scaffold. This has to date been done in solution using...... ligands in the synthesis of fluorescent NCs. To date, this class of ligands remains practically unexplored and consequently, not much is known on composition of good peptide ligands for this application. For the first time, we show that employing a solid-phase methodology in this context can increase...... throughput dramatically with regards to discovery of novel ligands. Our approach employs Fmoc solid-phase peptide synthesis on a PEGA resin which allows for on-resin screening of peptide ligands which, in turn, removes the tedious and labor-intensive work-up of synthesized peptides. The method allows for on...

  12. Peptides and methods for producing them

    NARCIS (Netherlands)

    Vos, de W.M.; Palva, A.; Palva, I.; Reunanen, J.; Ossowski, von I.; Satokari, R.M.; Vesterlund, S.; Kankainen, M.; Salusjärvi, T.; Tynkkynen, S.

    2013-01-01

    The present invention relates to the fields of life sciences and food, feed or pharmaceutical industry. Specifically, the invention relates to novel peptides, pilus structures, polynucleotides as well as vectors, host cells, products and pharmaceutical compositions comprising the polynucleotides,

  13. Peptide binding specificity of the chaperone calreticulin

    DEFF Research Database (Denmark)

    Sandhu, N.; Duus, K.; Jorgensen, C.S.

    2007-01-01

    Calreticulin is a molecular chaperone with specificity for polypeptides and N-linked monoglucosylated glycans. In order to determine the specificity of polypeptide binding, the interaction of calreticulin with polypeptides was investigated using synthetic peptides of different length and composit...

  14. Peptide catalysed prebiotic polymerization of RNA

    DEFF Research Database (Denmark)

    Wieczorek, Rafal; Luisi, Pier Luigi; Monnard, Pierre-Alain

    A short peptide composed of only two amino acid residues, serine and histidine, is here reported to enable oligomerization of RNA monomers. SerHis dipeptide was previously reported to catalyse formation of peptide bonds (Gorlero et al. 2009) as well as possessing broad hydrolytic activities...... these conditions, most of the water is in the form of ice crystals and the other reactants are upconcentrated in the remaining liquid micro-inclusions, hence creating an environment with low water activity in which condensation reactions can occur. The ability of simple peptides to catalyse RNA synthesis could...... stage of chemical evolution. References Gorlero M, Wieczorek R, Adamala K, Giorgi A, Schininà ME, Stano P, Luisi PL. (2009) Ser-His catalyses the formation of peptides and PNAs. FEBS Lett. 583(1):153-6. Li Y, Zhao Y, Hatfield S, Wan R, Zhu Q, Li X, McMills M, Ma Y, Li J, Brown KL, He C, Liu F, Chen X...

  15. Biologically Active and Antimicrobial Peptides from Plants

    Directory of Open Access Journals (Sweden)

    Carlos E. Salas

    2015-01-01

    Full Text Available Bioactive peptides are part of an innate response elicited by most living forms. In plants, they are produced ubiquitously in roots, seeds, flowers, stems, and leaves, highlighting their physiological importance. While most of the bioactive peptides produced in plants possess microbicide properties, there is evidence that they are also involved in cellular signaling. Structurally, there is an overall similarity when comparing them with those derived from animal or insect sources. The biological action of bioactive peptides initiates with the binding to the target membrane followed in most cases by membrane permeabilization and rupture. Here we present an overview of what is currently known about bioactive peptides from plants, focusing on their antimicrobial activity and their role in the plant signaling network and offering perspectives on their potential application.

  16. 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.

  17. Bioactive Proteins and Peptides from Soybeans.

    Science.gov (United States)

    Agyei, Dominic

    2015-01-01

    Dietary proteins from soybeans have been shown to offer health benefits in vivo and/or in vitro either as intact proteins or in partially digested forms also called bioactive peptides. Upon oral administration and absorption, soy-derived bioactive peptides may induce several physiological responses such as antioxidative, antimicrobial, antihypertensive, anticancer and immunomodulatory effects. There has therefore been a mounting research interest in the therapeutic potential of soy protein hydrolysates and their subsequent incorporation in functional foods and 'Food for Specified Health Uses' (FOSHU) related products where their biological activities may assist in the promotion of good health or in the control and prevention of diseases. This mini review discusses relevant patents and gives an overview on bioactive proteins and peptides obtainable from soybeans. Processes for the production and formulation of these peptides are given, together with specific examples of their therapeutic potential and possible areas of application.

  18. Screening and identification of a renal carcinoma specific peptide from a phage display peptide library

    Directory of Open Access Journals (Sweden)

    Tu Xiangan

    2011-11-01

    Full Text Available Abstract Background Specific peptide ligands to cell surface receptors have been extensively used in tumor research and clinical applications. Phage display technology is a powerful tool for the isolation of cell-specific peptide ligands. To screen and identify novel markers for renal cell carcinoma, we evaluated a peptide that had been identified by phage display technology. Methods A renal carcinoma cell line A498 and a normal renal cell line HK-2 were used to carry out subtractive screening in vitro with a phage display peptide library. After three rounds of panning, there was an obvious enrichment for the phages specifically binding to the A498 cells, and the output/input ratio of phages increased about 100 fold. A group of peptides capable of binding specifically to the renal carcinoma cells were obtained, and the affinity of these peptides to the targeting cells and tissues was studied. Results Through a cell-based ELISA, immunocytochemical staining, immunohistochemical staining, and immunofluorescence, the Phage ZT-2 and synthetic peptide ZT-2 were shown to specifically bind to the tumor cell surfaces of A498 and incision specimens, but not to normal renal tissue samples. Conclusion A peptide ZT-2, which binds specifically to the renal carcinoma cell line A498 was selected from phage display peptide libraries. Therefore, it provides a potential tool for early diagnosis of renal carcinoma or targeted drug delivery in chemotherapy.

  19. cis-Peptide Bonds: A Key for Intestinal Permeability of Peptides? .

    Science.gov (United States)

    Marelli, Udaya Kiran; Ovadia, Oded; Frank, Andreas Oliver; Chatterjee, Jayanta; Gilon, Chaim; Hoffman, Amnon; Kessler, Horst

    2015-10-19

    Recent structural studies on libraries of cyclic hexapeptides led to the identification of common backbone conformations that may be instrumental to the oral availability of peptides. Furthermore, the observation of differential Caco-2 permeabilities of enantiomeric pairs of some of these peptides strongly supports the concept of conformational specificity driven uptake and also suggests a pivotal role of carrier-mediated pathways for peptide transport, especially for scaffolds of polar nature. This work presents investigations on the Caco-2 and PAMPA permeability profiles of 13 selected N-methylated cyclic pentaalanine peptides derived from the basic cyclo(-D-Ala-Ala4 -) template. These molecules generally showed moderate to low transport in intestinal epithelia with a few of them exhibiting a Caco-2 permeability equal to or slightly higher than that of mannitol, a marker for paracellular permeability. We identified that the majority of the permeable cyclic penta- and hexapeptides possess an N-methylated cis-peptide bond, a structural feature that is also present in the orally available peptides cyclosporine A and the tri-N-methylated analogue of the Veber-Hirschmann peptide. Based on these observations it appears that the presence of N-methylated cis-peptide bonds at certain locations may promote the intestinal permeability of peptides through a suitable conformational preorganization. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Encapsulation of bioactive whey peptides in soy lecithin-derived nanoliposomes: Influence of peptide molecular weight.

    Science.gov (United States)

    Mohan, Aishwarya; McClements, David Julian; Udenigwe, Chibuike C

    2016-12-15

    Encapsulation of peptides can be used to enhance their stability, delivery and bioavailability. This study focused on the effect of the molecular weight range of whey peptides on their encapsulation within soy lecithin-derived nanoliposomes. Peptide molecular weight did not have a major impact on encapsulation efficiency or liposome size. However, it influenced peptide distribution amongst the surface, core, and bilayer regions of the liposomes, as determined by electrical charge (ζ-potential) and FTIR analysis. The liposome ζ-potential depended on peptide molecular weight, suggesting that the peptide charged groups were in different locations relative to the liposome surfaces. FTIR analysis indicated that the least hydrophobic peptide fractions interacted more strongly with choline on the liposome surfaces. The results suggested that the peptides were unequally distributed within the liposomes, even at the same encapsulation efficiency. These findings are important for designing delivery systems for commercial production of encapsulated peptides with improved functional attributes. Copyright © 2016 Elsevier Ltd. All rights reserved.

  1. Evolution of Antimicrobial Peptides to Self-Assembled Peptides for Biomaterial Applications

    Directory of Open Access Journals (Sweden)

    Alice P. McCloskey

    2014-10-01

    Full Text Available Biomaterial-related infections are a persistent burden on patient health, recovery, mortality and healthcare budgets. Self-assembled antimicrobial peptides have evolved from the area of antimicrobial peptides. Peptides serve as important weapons in nature, and increasingly medicine, for combating microbial infection and biofilms. Self-assembled peptides harness a “bottom-up” approach, whereby the primary peptide sequence may be modified with natural and unnatural amino acids to produce an inherently antimicrobial hydrogel. Gelation may be tailored to occur in the presence of physiological and infective indicators (e.g. pH, enzymes and therefore allow local, targeted antimicrobial therapy at the site of infection. Peptides demonstrate inherent biocompatibility, antimicrobial activity, biodegradability and numerous functional groups. They are therefore prime candidates for the production of polymeric molecules that have the potential to be conjugated to biomaterials with precision. Non-native chemistries and functional groups are easily incorporated into the peptide backbone allowing peptide hydrogels to be tailored to specific functional requirements. This article reviews an area of increasing interest, namely self-assembled peptides and their potential therapeutic applications as innovative hydrogels and biomaterials in the prevention of biofilm-related infection.

  2. Synthesizing and modifying peptides for chemoselective ligation and assembly into quantum dot-peptide bioconjugates.

    Science.gov (United States)

    Algar, W Russ; Blanco-Canosa, Juan B; Manthe, Rachel L; Susumu, Kimihiro; Stewart, Michael H; Dawson, Philip E; Medintz, Igor L

    2013-01-01

    Quantum dots (QDs) are well-established as photoluminescent nanoparticle probes for in vitro or in vivo imaging, sensing, and even drug delivery. A critical component of this research is the need to reliably conjugate peptides, proteins, oligonucleotides, and other biomolecules to QDs in a controlled manner. In this chapter, we describe the conjugation of peptides to CdSe/ZnS QDs using a combination of polyhistidine self-assembly and hydrazone ligation. The former is a high-affinity interaction with the inorganic surface of the QD; the latter is a highly efficient and chemoselective reaction that occurs between 4-formylbenzoyl (4FB) and 2-hydrazinonicotinoyl (HYNIC) moieties. Two methods are presented for modifying peptides with these functional groups: (1) solid phase peptide synthesis; and (2) solution phase modification of pre-synthesized, commercial peptides. We further describe the aniline-catalyzed ligation of 4FB- and HYNIC-modified peptides, in the presence of a fluorescent label on the latter peptide, as well as subsequent assembly of the ligated peptide to water-soluble QDs. Many technical elements of these protocols can be extended to labeling peptides with other small molecule reagents. Overall, the bioconjugate chemistry is robust, selective, and modular, thereby potentiating the controlled conjugation of QDs with a diverse array of biomolecules for various applications.

  3. Plasmatocyte spreading peptide (PSP1) and growth blocking peptide (GBP) are multifunctional homologs.

    Science.gov (United States)

    Strand; Hayakawa; Clark

    2000-05-01

    Recently, we identified Plasmatocyte spreading peptide (PSP1) from the moth Pseudoplusia includens and reported that it mediates adhesion of hemocytes to foreign surfaces. PSP1 is structurally very similar to three classes of peptides identified earlier from other species of Lepidoptera: growth blocking peptide (GBP) originally identified in Pseudaletia separata, and a series of related peptides from other species designated as paralytic (PP) or cardioactive (CAP) peptides. In this study, we conducted parallel experiments in P. includens and P. separata to determine whether PSP1 and GBP have distinct or multiple biological activities. Both peptides affected the adhesive state of hemocytes from each moth very similarly. PSP1 and GBP exhibited significant growth blocking and paralytic activity in P. separata. Both peptides also had growth blocking activity in P. includens although larvae had to be injected with higher doses of each peptide to reduce weight gain than was observed for P. separata. However, GBP and PSP1 had little paralytic activity in P. includens. Collectively, our results indicate that GBP and PSP1 are multifunctional, but that some interspecific variation also exists in their growth blocking and paralytic activities. We suggest that all PSP1, GBP, PP and CAP family members are homologs that likely have multiple biological activities. Based upon the unique consensus sequence of their N termini, we propose that these molecules be henceforth referred to as members of the "ENF" peptide family.

  4. Imaging tumors with peptide-based radioligands.

    Science.gov (United States)

    Behr, T M; Gotthardt, M; Barth, A; Béhé, M

    2001-06-01

    Regulatory peptides are small, readily diffusable and potent natural substances with a wide spectrum of receptor-mediated actions in humans. High affinity receptors for these peptides are (over-) expressed in many neoplasms, and these receptors may represent, therefore, new molecular targets for cancer diagnosis and therapy. This review aims to give an overview of the peptide-based radiopharmaceuticals which are presently already commercially available or which are in advanced stages of their clinical testing so that their broader availability is anticipated soon. Physiologically, these peptides bind to and act through G protein-coupled receptors in the cell membrane. Historically, somatostatin analogs are the first class of receptor binding peptides having gained clinical application. 111In-DTPA-[D-Phe1]-octreotide is the first and only radiopeptide which has obtained regulatory approval in Europe and the United States to date. Extensive clinical studies involving several thousands of patients have shown that the major clinical application of somatostatin receptor scintigraphy is the detection and the staging of gastroenteropancreatic neuroendocrine tumors (carcinoids). In these tumors, octreotide scintigraphy is superior to any other staging method. However, its sensitivity and accuracy in other, more frequent neoplasms is limited. Radiolabeled vasoactive intestinal peptide (VIP) has been shown to visualize the majority of gastrointestinal adenocarcinomas, as well as some neuroendocrine tumors, including insulinomas (the latter being often missed by somatostatin receptor scintigraphy). Due to the outstanding diagnostic accuracy of the pentagastrin test in detecting the presence, persistence, or recurrence of medullary thyroid cancer (MTC), we postulated the expression of the corresponding (ie. cholecystokinin [CCK-] -B) receptor type in human MTC. This receptor is also widely expressed on human small-cell lung cancer. Indeed, 111In-labeled DTPA derivatives of

  5. Effect of Gold Nanoparticle Conjugation on Peptide Dynamics and Structure

    Directory of Open Access Journals (Sweden)

    F. Marty Ytreberg

    2012-03-01

    Full Text Available Molecular dynamics simulations were used to characterize the structure and dynamics for several peptides and the effect of conjugating them to a gold nanoparticle. Peptide structure and dynamics were compared for two cases: unbound peptides in water, and peptides bound to the gold nanoparticle surface in water. The results show that conjugating the peptides to the gold nanoparticle usually decreases conformational entropy, but sometimes increases entropy. Conjugating the peptides can also result in more extended structures or more compact structures depending on the amino acid sequence of the peptide. The results also suggest that if one wishes to use peptide-nanoparticle conjugates for drug delivery it is important that the peptides contain secondary structure in solution because in our simulations the peptides with little to no secondary structure adsorbed to the nanoparticle surface.

  6. In Silico Models for Designing and Discovering Novel Anticancer Peptides

    Science.gov (United States)

    Tyagi, Atul; Kapoor, Pallavi; Kumar, Rahul; Chaudhary, Kumardeep; Gautam, Ankur; Raghava, G. P. S.

    2013-10-01

    Use of therapeutic peptides in cancer therapy has been receiving considerable attention in the recent years. Present study describes the development of computational models for predicting and discovering novel anticancer peptides. Preliminary analysis revealed that Cys, Gly, Ile, Lys, and Trp are dominated at various positions in anticancer peptides. Support vector machine models were developed using amino acid composition and binary profiles as input features on main dataset that contains experimentally validated anticancer peptides and random peptides derived from SwissProt database. In addition, models were developed on alternate dataset that contains antimicrobial peptides instead of random peptides. Binary profiles-based model achieved maximum accuracy 91.44% with MCC 0.83. We have developed a webserver, which would be helpful in: (i) predicting minimum mutations required for improving anticancer potency; (ii) virtual screening of peptides for discovering novel anticancer peptides, and (iii) scanning natural proteins for identification of anticancer peptides (http://crdd.osdd.net/raghava/anticp/).

  7. Prevalence of AmpC type extended spectrum beta lactamases genes in clinical Samples of E.coli Isolated from Poultry and Humans

    Directory of Open Access Journals (Sweden)

    Elham Farrokhnazar

    2016-07-01

    Full Text Available Emergence of antibiotic resistance among pathogens, particularly in health centers and hospitals, has become a major public health problem. This study identified AmpC-type beta-lactamase against the antibiotic ceftazidime, cefotaxime and cefpodoxime in E.coli isolated from human and poultry and types of producing genes were studied by PCR. In this study, 500 clinical human samples of urine from hospitals of Tehran during 5 months as well as 300 poultry samples were collected and transferred to the microbiology laboratory. Biochemical tests such as TSI, Urea and IMViC were performed on suspected colonies with E.coli. To identify ESBL producing strains, beta-lactamase samples were cultured on Mueller-Hinton agar through antimicrobial susceptibility test by disk agar diffusion based on the standard CLSI for initial screening. PCR reactions were done using specific primers CITM, EBCM, DHAM and MOXM to identify the beta-lactamase AmpC. A number of 200 human and 55 poultry E.coli samples were screened. In human samples, 105 (52.5% were resistant and potential producers of ESBL and AmpC; out of those, 102 (51% produced ESBL and 3 (1.5% potentially produced AmpC. In the study on 55 E.coli isolates from poultry samples based on the results of disk agar diffusion test, 4 (7.2% samples were resistant and potential producers of ESBL. None of the samples were AmpC producers. Through PCR, 2 human samples (1% were CITM positive and one sample (0.5% was DHAM positive. Through the PCR carried out on poultry samples, there were no bands with 4 primers. There was AmpC in human samples; while further studies are required for poultry samples, because poultry significantly contribute in production of food for humans and can be an important source for dissemination of antibiotic resistance. Given the significance of Ampc in providing high levels of beta-lactam antibiotic resistance, particularly third generation cephalosporins which are very common treatments, more

  8. A novel C-type lectin, Nattectin-like protein, with a wide range of bacterial agglutination activity in large yellow croaker Larimichthys crocea.

    Science.gov (United States)

    Lv, Changhuan; Zhang, Dongling; Wang, Zhiyong

    2016-03-01

    C-type lectins (CTLs) are generally recognized as a superfamily of Ca(2+)-dependent carbohydrate-binding proteins, which serve as pattern recognition receptors (PRRs) in innate immunity of vertebrates. In this study, the molecular characterization and immune roles of a novel CTL from Larimichthys crocea (designated as LcNTC) were investigated. LcNTC is a novel protein that shared 33%-49% homology with other teleosts CTLs. The full-length cDNA of LcNTC was composed of 859 bp with a 465 bp open reading frame encoding a putative protein of 154 residues. LcNTC contained a single CRD with four conserved disulfide-bonded cysteine residues (Cys(57)-Cys(148), Cys(126)-Cys(140)) and EPN/AND motifs instead of invariant EPN/WND motifs required for carbohydrate-binding specificity and constructing Ca(2+)-binding sites. LcNTC mRNA was detected in all examined tissues with the most abundant in the gill. After challenged with poly I:C and Vibrio parahaemolyticus, the temporal expression of LcNTC was significantly up-regulated in the liver, spleen and head-kidney. LcNTC transcripts were also induced in the gill, skin, spleen and head-kidney post-infection with Cryptocaryon irritans. The recombinant LcNTC (rLcNTC) purified from Escherichia coli BL21 (DE3) exhibited strong agglutination activity against erythrocytes from human, rabbit and large yellow croaker in a Ca(2+)-dependent manner, and the agglutination could be inhibited by D-Mannose, D-Glucose, D-Fructose, α-Lactose, D-Maltose and LPS. Positive microbial agglutination activities of rLcNTC were observed against all tested bacteria in the presence of Ca(2+), including Gram-positive bacteria (Bacillus subtilis, Staphylococcus aureus and Micrococcus lysoleikticus) and Gram-negative bacteria (E. coli, V. parahaemolyticus, Vibrio alginolyticus and Aeromonas hydrophila). These findings collectively indicated that LcNTC might be involved in the innate immunity of L. crocea as a PRR. Copyright © 2016 Elsevier Ltd. All rights

  9. Dissemination of SHV-12 and Characterization of New AmpC-Type Beta-Lactamase Genes among Clinical Isolates of Enterobacter Species in Korea

    Science.gov (United States)

    Lee, Sang Hee; Kim, Jae Young; Shin, Sang Heum; An, Young Jun; Choi, Young Wook; Jung, Yeun Chang; Jung, Ha Il; Sohn, Eui Suk; Jeong, Seok Hoon; Lee, Kye Joon

    2003-01-01

    To determine the prevalence and genotype of an extended-spectrum beta-lactamase and new chromosomal AmpC beta-lactamases among clinical isolates of Enterobacter species, we performed antibiotic susceptibility testing, pI determination, induction tests, transconjugation, enterobacterial repetitive consensus (ERIC) PCR, sequencing, and phylogenetic analysis. Among the 51 clinical isolates collected from a university hospital in Korea, 6 isolates have been shown to produce SHV-12 and inducible AmpC beta-lactamases. These also included three isolates producing TEM-1b and one strain carrying TEM-1b and CMY-type beta-lactamases with a pI of 8.0. The results from ERIC PCR revealed that six isolates were genetically unrelated, suggesting that dissemination of SHV-12 was responsible for the spread of resistance to extended-spectrum beta-lactams in Korea. Six genes of inducible AmpC beta-lactamases that are responsible for the resistance to cephamycins (cefoxitin and cefotetan), amoxicillin, cephalothin, and amoxicillin-clavulanic acid were cloned and characterized. A 1,165-bp DNA fragment containing the ampC genes was sequenced and found to have an open reading frame coding for a 381-amino-acid beta-lactamase. The nucleotide sequence of four ampC genes (blaEcloK992004.1, blaEcloK995120.1, blaEcloK99230, and blaEareK9911729) shared considerable homology with that of AmpC-type class C beta-lactamase genes of gram-negative bacteria, especially that of the chromosomal ampC gene (blaEcloMHN1) of Enterobacter cloacae MHN1 (99.9, 99.7, 99.6, and 99.6% identity, respectively). The sequences of two ampC genes (blaEcloK9973 and blaEcloK9914325) showed close similarity to the chromosomal ampC gene (blaEcloQ908R) of E. cloacae Q908R (99.7% identity). The results from phylogenetic analysis suggested that six ampC genes could originate from blaEcloMHN1 or blaEcloQ908R. PMID:12791868

  10. AraC-Type Regulator Rbf Controls the Staphylococcus epidermidis Biofilm Phenotype by Negatively Regulating the icaADBC Repressor SarR.

    Science.gov (United States)

    Rowe, Sarah E; Campbell, Christopher; Lowry, Colm; O'Donnell, Sinead T; Olson, Michael E; Lindgren, Jill K; Waters, Elaine M; Fey, Paul D; O'Gara, James P

    2016-11-01

    Regulation of icaADBC-encoded polysaccharide intercellular adhesin (PIA)/poly-N-acetylglucosasmine (PNAG) production in staphylococci plays an important role in biofilm-associated medical-device-related infections. Here, we report that the AraC-type transcriptional regulator Rbf activates icaADBC operon transcription and PIA production in Staphylococcus epidermidis Purified recombinant Rbf did not bind to the ica operon promoter region in electrophoretic mobility shift assays (EMSAs), indicating that Rbf regulates ica transcription indirectly. To identify the putative transcription factor(s) involved in Rbf-mediated icaADBC regulation, the ability of recombinant Rbf to interact with the promoter sequences of known icaADBC regulators was investigated. Recombinant Rbf bound to the sarR promoter and not the sarX, sarA, sarZ, spx, and srrA promoters. Reverse transcription (RT)-PCR demonstrated that Rbf acts as a repressor of sarR transcription. PIA expression and biofilm production were restored to wild-type levels in an rbf sarR double mutant grown in brain heart infusion (BHI) medium supplemented with NaCl, which is known to activate the ica locus, but not in BHI medium alone. RT-PCR further demonstrated that although Rbf does not bind the sarX promoter, it nevertheless exerted a negative effect on sarX expression. Apparently, direct downregulation of the SarR repressor by Rbf has a dominant effect over indirect repression of the SarX activator by Rbf in the control of S. epidermidis PIA production and biofilm formation. The importance of Staphylococcus epidermidis as an opportunistic pathogen in hospital patients with implanted medical devices derives largely from its capacity to form biofilm. Expression of the icaADBC-encoded extracellular polysaccharide is the predominant biofilm mechanism in S. epidermidis clinical isolates and is tightly regulated. Here, we report that the transcriptional regulator Rbf promotes icaADBC expression by negatively regulating

  11. Antimicrobial Peptides with Differential Bacterial Binding Characteristics

    Science.gov (United States)

    2013-03-01

    Aedes albopictus cecropin A (CA), were synthesized by New England Peptide (batches NEP1, NEP2, and NEP3) and purified by SPE prior to screening...Eccleston, E. D., & Fallon, A. M. (1998). Peptide Sequence of an Antibiotic Cecropin from the Vector Mosquito, Aedes albopictus . Biochemical and...RGLRRLGRKIAHGVKKYGPTVLRIIRIAG Strong Strong Cecropin A, A. albopictus [18] GGLKKLGKKLEGVGKRVFKASEKALPVAVGIKALG n.d. qual. [19] Cecropin P1 [20

  12. Anticancer peptides and proteins: a panoramic view.

    Science.gov (United States)

    Libério, M S; Joanitti, G A; Fontes, W; Castro, M S

    2013-04-01

    Despite progress in understanding carcinogenesis, cancer is still a major cause of morbidity and mortality worldwide. Treatment is complicated by the resistance to chemotherapeutics acquired by tumors, ability to repair damaged DNA, alteration of the interaction between drug and its target, and defects in the machinery that leads to apoptosis. The development of novel therapies based on biologically active peptides, especially antimicrobial peptides (AMPs), and proteins has emerged as a new strategy to defeat cancer.

  13. Bioactive peptides and proteins in disease

    OpenAIRE

    Refai, Essam

    2004-01-01

    Regulatory peptides and marker proteins are important to study in order to understand disease mechanisms. This applies of course also to our common diseases where all relationships are not yet known. Cancer and diabetes are two such complex diseases that affect hundreds of millions of people worldwide. This thesis addresses particular aspects of these two diseases, regarding one regulatory peptide (VIP, vasoactive intestinal polypeptide) that may be useful for tumor tracing ...

  14. Membrane manufacture for peptide separations

    KAUST Repository

    Kim, Dooli

    2016-06-07

    Nanostructured polymeric membranes are key tools in biomedical applications such as hemodialysis, protein separations, in the food industry, and drinking water supply from seawater. Despite of the success in different separation processes, membrane manufacture itself is at risk, since the most used solvents are about to be banned in many countries due to environmental and health issues. We propose for the first time the preparation of polyethersulfone membranes based on dissolution in the ionic liquid 1-ethyl-3-methylimidazolium dimethylphosphate ([EMIM]DEP). We obtained a series of membranes tailored for separation of solutes with molecular weight of 30, 5, 1.3, and 1.25 kg mol-1 with respective water permeances of 140, 65, 30 and 20 Lm-2h-1bar-1. We demonstrate their superior efficiency in the separation of complex mixtures of peptides with molecular weights in the range of 800 to 3500 gmol-1. Furthermore, the thermodynamics and kinetics of phase separation leading to the pore formation in the membranes were investigated. The rheology of the solutions and the morphology of the prepared membranes were examed and compared to those of polyethersulfone in organic solvents currently used for membrane manufacture.

  15. Glucagon-Like Peptide-1

    Directory of Open Access Journals (Sweden)

    Joel P. Giblett, BM, BSc

    2016-06-01

    Full Text Available Glucagon-like peptide-1-(7-36 amide (GLP-1 is a human incretin hormone responsible for the release of insulin in response to food. Pre-clinical and human physiological studies have demonstrated cardioprotection from ischemia-reperfusion injury. It can reduce infarct size, ischemic left ventricular dysfunction, and myocardial stunning. GLP-1 receptor agonists have also been shown to reduce infarct size in myocardial infarction. The mechanism through which this protection occurs is uncertain but may include hijacking the subcellular pathways of ischemic preconditioning, modulation of myocardial metabolism, and hemodynamic effects including peripheral, pulmonary, and coronary vasodilatation. This review will assess the evidence for each of these mechanisms in turn. Challenges remain in successfully translating cardioprotective interventions from bench-to-bedside. The window of cardioprotection is short and timing of cardioprotection in the appropriate clinical setting is critically important. We will emphasize the need for high-quality, well-designed research to evaluate GLP-1 as a cardioprotective agent for use in real-world practice.

  16. New tachykinin peptides and nociception

    Directory of Open Access Journals (Sweden)

    Toshikazu Nishimori

    2013-02-01

    Full Text Available Hemokinin-1 (HK-1 and endokinins are peptides predicted from a new mammalian tachykinin gene, TAC4. The amino acid sequences derived from rat/mouse HK-1 and human HK-1 are not identical; however, the effects induced by intracerebroventricular or intrathecal administration of HK-1 are attenuated by treatment with antagonists of neurokinin 1 (NK1 receptor, substance P (SP receptor, indicating that HK-1 is an agonist of the NK1 receptor. On the other hand, a growing body of evidence indicates that pharmacological characteristics of HK-1 and SP are always not identical, suggesting that the HK-1-preferred receptor may be involved in the effects of HK-1. Endokinins are derived from human TAC4 and consist of four endokinins, endokinin A (EKA, endokinin B (EKB, endokinin C (EKC and endokinin D (EKD. Effects induced by intrathecal administration of EKA/B (the common C-terminal decapeptide in EKA and EKB and SP were very similar, while the effects of SP and EKA/B were inhibited by EKC/D (the common C-terminal duodecapeptide in EKC and EKD. This inhibitory effect of EKC/D was derived from leucine at the carboxyl-terminus. These findings suggest that HK-1 and EKA/B have an agonistic effect, while EKC/D has an antagonistic effect on the NK1 receptor in nociceptive processing.

  17. Liquid-phase synthesis of bridged peptides using olefin metathesis of a protected peptide with a long aliphatic chain anchor.

    Science.gov (United States)

    Aihara, Keisuke; Komiya, Chiaki; Shigenaga, Akira; Inokuma, Tsubasa; Takahashi, Daisuke; Otaka, Akira

    2015-02-06

    Bridged peptides including stapled peptides are attractive tools for regulating protein-protein interactions (PPIs). An effective synthetic methodology in a heterogeneous system for the preparation of these peptides using olefin metathesis and hydrogenation of protected peptides with a long aliphatic chain anchor is reported.

  18. Multifunctionalized gold nanoparticles with peptides targeted to gastrin-releasing peptide receptor of a tumor cell line.

    NARCIS (Netherlands)

    Hosta-Rigau, L.; Olmedo, I.; Arbiol, J.; Cruz, L.J.; Kogan, M.J.; Albericio, F.

    2010-01-01

    Functionalization of gold nanoparticles (AuNPs) with both a targeting peptide (an analogue of the peptide Bombesin) and a drug peptide ligand (an analogue of the RAF peptide) with the aim of improving selectivity in the delivery of the conjugates as well as the antitumor activity is described.

  19. Peptide-modified surfaces for enzyme immobilization.

    Directory of Open Access Journals (Sweden)

    Jinglin Fu

    Full Text Available BACKGROUND: Chemistry and particularly enzymology at surfaces is a topic of rapidly growing interest, both in terms of its role in biological systems and its application in biocatalysis. Existing protein immobilization approaches, including noncovalent or covalent attachments to solid supports, have difficulties in controlling protein orientation, reducing nonspecific absorption and preventing protein denaturation. New strategies for enzyme immobilization are needed that allow the precise control over orientation and position and thereby provide optimized activity. METHODOLOGY/PRINCIPAL FINDINGS: A method is presented for utilizing peptide ligands to immobilize enzymes on surfaces with improved enzyme activity and stability. The appropriate peptide ligands have been rapidly selected from high-density arrays and when desirable, the peptide sequences were further optimized by single-point variant screening to enhance both the affinity and activity of the bound enzyme. For proof of concept, the peptides that bound to β-galactosidase and optimized its activity were covalently attached to surfaces for the purpose of capturing target enzymes. Compared to conventional methods, enzymes immobilized on peptide-modified surfaces exhibited higher specific activity and stability, as well as controlled protein orientation. CONCLUSIONS/SIGNIFICANCE: A simple method for immobilizing enzymes through specific interactions with peptides anchored on surfaces has been developed. This approach will be applicable to the immobilization of a wide variety of enzymes on surfaces with optimized orientation, location and performance, and provides a potential mechanism for the patterned self-assembly of multiple enzymes on surfaces.

  20. SPdb – a signal peptide database

    Directory of Open Access Journals (Sweden)

    Tan Tin

    2005-10-01

    Full Text Available Abstract Background The signal peptide plays an important role in protein targeting and protein translocation in both prokaryotic and eukaryotic cells. This transient, short peptide sequence functions like a postal address on an envelope by targeting proteins for secretion or for transfer to specific organelles for further processing. Understanding how signal peptides function is crucial in predicting where proteins are translocated. To support this understanding, we present SPdb signal peptide database http://proline.bic.nus.edu.sg/spdb, a repository of experimentally determined and computationally predicted signal peptides. Results SPdb integrates information from two sources (a Swiss-Prot protein sequence database which is now part of UniProt and (b EMBL nucleotide sequence database. The database update is semi-automated with human checking and verification of the data to ensure the correctness of the data stored. The latest release SPdb release 3.2 contains 18,146 entries of which 2,584 entries are experimentally verified signal sequences; the remaining 15,562 entries are either signal sequences that fail to meet our filtering criteria or entries that contain unverified signal sequences. Conclusion SPdb is a manually curated database constructed to support the understanding and analysis of signal peptides. SPdb tracks the major updates of the two underlying primary databases thereby ensuring that its information remains up-to-date.

  1. Peptides with Dual Antimicrobial and Anticancer Activities

    Science.gov (United States)

    Felício, Mário R.; Silva, Osmar N.; Gonçalves, Sônia; Santos, Nuno C.; Franco, Octávio L.

    2017-02-01

    In recent years, the number of people suffering from cancer and multi-resistant infections has increased, such that both diseases are already seen as current and future major causes of death. Moreover, chronic infections are one of the main causes of cancer, due to the instability in the immune system that allows cancer cells to proliferate. Likewise, the physical debility associated with cancer or with anticancer therapy itself often paves the way for opportunistic infections. It is urgent to develop new therapeutic methods, with higher efficiency and lower side effects. Antimicrobial peptides (AMPs) are found in the innate immune system of a wide range of organisms. Identified as the most promising alternative to conventional molecules used nowadays against infections, some of them have been shown to have dual activity, both as antimicrobial and anticancer peptides (ACPs). Highly cationic and amphipathic, they have demonstrated efficacy against both conditions, with the number of nature-driven or synthetically designed peptides increasing year by year. With similar properties, AMPs that can also act as ACPs are viewed as future chemotherapeutic drugs, with the advantage of low propensity to resistance, which started this paradigm in the pharmaceutical market. These peptides have already been described as molecules presenting killing mechanisms at the membrane level, but also acting towards intracellular targets, which increases their success comparatively to specific one-target drugs. This review will approach the desirable characteristics of small peptides that demonstrated dual activity against microbial infections and cancer, as well as the peptides engaged in clinical trials.

  2. Bioactive peptides of animal origin: a review.

    Science.gov (United States)

    Bhat, Z F; Kumar, Sunil; Bhat, Hina Fayaz

    2015-09-01

    Bioactive peptides are specific protein fragments which, above and beyond their nutritional capabilities, have a positive impact on the body's function or condition which may ultimately influence health. Although, inactive within the sequence of the parent proteins, these peptides can be released during proteolysis or fermentation and play an important role in human health by affecting the digestive, endocrine, cardiovascular, immune and nervous systems. Several peptides that are released in vitro or in vivo from animal proteins have been attributed to different health effects, including antimicrobial properties, blood pressure-lowering (ACE inhibitory) effects, cholesterol-lowering ability, antithrombotic and antioxidant activities, opioid activities, enhancement of mineral absorption and/or bioavailability, cytomodulatory and immunomodulatory effects, antiobesity, and anti-genotoxic activity. Several functional foods based on the bioactivities of these peptides with scientifically evidenced health claims are already on the market or under development by food companies. Consumer's increasing interest in these products has given an impetus to the food industry and scientific sector who are continuously exploring the possibilities for the development of new functional products based on these peptides. In this review, we describe above stated properties of bioactive peptides of animal origin.

  3. III. Organometallic and Bioorganometallic Chemistry - Ferrocene Peptides

    Directory of Open Access Journals (Sweden)

    Kovačević, M.

    2012-02-01

    Full Text Available This paper is devoted to the bioconjugates of ferrocene with naturally occuring amino acids/peptides - mostly dealing with authors' results accompanied, to a lesser degree, by the relevant literature data. Chapter 2 deals with natural peptides and peptidomimetics, mainly focusing on α-helix and β pleated sheet (as the most important elements of peptide secondary and tertiary structure, and artificial β-sheets nucleated by non-amino acid turn inducers. Chapter 3 describes peptides generated from ferrocenecarboxylic acid and ferroceneamine, as well as with the bioconjugates of heteroannulary substituted ferrocene-1,1'-dicarboxylic acid (Fcd and ferrocene-1,1'-diamine (Fcda. Chapter 4 elaborates authors' papers about peptides based on 1'-aminoferrocene-1-carboxylic acid (Fca. Chapter 5 is devoted to the new monosubstituted Fcd and Fcda conjugates with amino acids, while Chapter 6 describes our publications in the field of very topical peptidomimetics - ferrocene ureidopeptides and β peptides. Conformational analysis of the newly prepared ferrocene bioconjugates in solution and solid state was performed by means of spectroscopic methods (CD, IR, 1D- NMR, 2D-NMR, v. r. NMR, and temperature and concentration dependent NMR and DFT calculations.

  4. Antimicrobial peptides with stability toward tryptic degradation.

    Science.gov (United States)

    Svenson, Johan; Stensen, Wenche; Brandsdal, Bjørn-Olav; Haug, Bengt Erik; Monrad, Johnny; Svendsen, John S

    2008-03-25

    The inherent instability of peptides toward metabolic degradation is an obstacle on the way toward bringing potential peptide drugs onto the market. Truncation can be one way to increase the proteolytic stability of peptides, and in the present study the susceptibility against trypsin, which is one of the major proteolytic enzymes in the gastrointestinal tract, was investigated for several short and diverse libraries of promising cationic antimicrobial tripeptides. Quite surprisingly, trypsin was able to cleave very small cationic antimicrobial peptides at a substantial rate. Isothermal titration calorimetry studies revealed stoichiometric interactions between selected peptides and trypsin, with dissociation constants ranging from 1 to 20 microM. Introduction of hydrophobic C-terminal amide modifications and likewise bulky synthetic side chains on the central amino acid offered an effective way to increased half-life in our assays. Analysis of the degradation products revealed that the location of cleavage changed when different end-capping strategies were employed to increase the stability and the antimicrobial potency. This suggests that trypsin prefers a bulky hydrophobic element in S1' in addition to a positively charged side chain in S1 and that this binding dictates the mode of cleavage for these substrates. Molecular modeling studies supported this hypothesis, and it is shown that small alterations of the tripeptide result in two very different modes of trypsin binding and degradation. The data presented allows for the design of stable cationic antibacterial peptides and/or peptidomimetics based on several novel design principles.

  5. Biomathematical Description of Synthetic Peptide Libraries

    Science.gov (United States)

    Trepel, Martin

    2015-01-01

    Libraries of randomised peptides displayed on phages or viral particles are essential tools in a wide spectrum of applications. However, there is only limited understanding of a library's fundamental dynamics and the influences of encoding schemes and sizes on their quality. Numeric properties of libraries, such as the expected number of different peptides and the library's coverage, have long been in use as measures of a library's quality. Here, we present a graphical framework of these measures together with a library's relative efficiency to help to describe libraries in enough detail for researchers to plan new experiments in a more informed manner. In particular, these values allow us to answer-in a probabilistic fashion-the question of whether a specific library does indeed contain one of the "best" possible peptides. The framework is implemented in a web-interface based on two packages, discreteRV and peptider, to the statistical software environment R. We further provide a user-friendly web-interface called PeLiCa (Peptide Library Calculator, http://www.pelica.org), allowing scientists to plan and analyse their peptide libraries. PMID:26042419

  6. Comprehensive computational design of ordered peptide macrocycles

    Energy Technology Data Exchange (ETDEWEB)

    Hosseinzadeh, Parisa; Bhardwaj, Gaurav; Mulligan, Vikram Khipple; Shortridge, Matthew D.; Craven, Timothy W.; Pardo-Avila, Fátima; Rettie, Stephen A.; Kim, David E.; Silva, Daniel-Adriano; Ibrahim, Yehia M.; Webb, Ian K.; Cort, John R.; Adkins, Joshua N.; Varani, Gabriele; Baker, David

    2017-12-14

    Mixed chirality peptide macrocycles such as cyclosporine are among the most potent therapeutics identified to-date, but there is currently no way to systematically search through the structural space spanned by such compounds for new drug candidates. Natural proteins do not provide a useful guide: peptide macrocycles lack regular secondary structures and hydrophobic cores and have different backbone torsional constraints. Hence the development of new peptide macrocycles has been approached by modifying natural products or using library selection methods; the former is limited by the small number of known structures, and the latter by the limited size and diversity accessible through library-based methods. To overcome these limitations, here we enumerate the stable structures that can be adopted by macrocyclic peptides composed of L and D amino acids. We identify more than 200 designs predicted to fold into single stable structures, many times more than the number of currently available unbound peptide macrocycle structures. We synthesize and characterize by NMR twelve 7-10 residue macrocycles, 9 of which have structures very close to the design models in solution. NMR structures of three 11-14 residue bicyclic designs are also very close to the computational models. Our results provide a nearly complete coverage of the rich space of structures possible for short peptide based macrocycles unparalleled for other molecular systems, and vastly increase the available starting scaffolds for both rational drug design and library selection methods.

  7. Preparation of peptide thioesters through fmoc-based solid-phase peptide synthesis by using amino thioesters

    DEFF Research Database (Denmark)

    Stuhr-Hansen, N.; Wilbek, T.S.; Strømgaard, K.

    2013-01-01

    An effective procedure for the synthesis of peptide alkyl thioesters by 9-fluorenylmethoxycarbonyl (Fmoc) solid-phase peptide synthesis was developed. The free C terminus of a fully protected peptide was coupled in solution with the free amino group of an amino thioester. This furnished the fully...... protected peptide thioester, which was globally deprotected to afford the desired unprotected peptide thioester. The method is compatible with labile groups such as phosphoryl and glycosyl moieties. The synthesis of peptide alkyl thioesters by 9-fluorenylmethoxycarbonyl (Fmoc) solid-phase peptide synthesis...... (SPPS) is developed. The free C terminus of a fully protected peptide is coupled in solution with the free amino group of an amino thioester. This furnishes the fully protected peptide thioester, which can be globally deprotected to afford the desired unprotected peptide thioester....

  8. Sequential and competitive adsorption of peptides at pendant PEO layers.

    Science.gov (United States)

    Wu, Xiangming; Ryder, Matthew P; McGuire, Joseph; Snider, Joshua L; Schilke, Karl F

    2015-06-01

    Earlier work provided direction for development of responsive drug delivery systems based on modulation of the structure, amphiphilicity, and surface density of bioactive peptides entrapped within pendant polyethylene oxide (PEO) brush layers. In this work, we describe the sequential and competitive adsorption behavior of such peptides at pendant PEO layers. Three cationic peptides were used for this purpose: the arginine-rich, amphiphilic peptide WLBU2, a peptide chemically identical to WLBU2 but of scrambled sequence (S-WLBU2), and the non-amphiphilic peptide poly-L-arginine (PLR). Optical waveguide lightmode spectroscopy (OWLS) was used to quantify the rate and extent of peptide adsorption and elution at surfaces coated with PEO. UV spectroscopy and time-of-flight secondary ion mass spectrometry (TOF-SIMS) were used to quantify the extent of peptide exchange during the course of sequential and competitive adsorption. Circular dichroism (CD) was used to evaluate conformational changes after adsorption of peptide mixtures at PEO-coated silica nanoparticles. Results indicated that amphiphilic peptides are able to displace adsorbed, non-amphiphilic peptides in PEO layers, while non-amphiphilic peptides were not able to displace more amphiphilic peptides. In addition, peptides of greater amphiphilicity dominated the adsorption at the PEO layer from mixtures with less amphiphilic or non-amphiphilic peptides. Copyright © 2015 Elsevier B.V. All rights reserved.

  9. Peptide library synthesis on spectrally encoded beads for multiplexed protein/peptide bioassays

    Science.gov (United States)

    Nguyen, Huy Q.; Brower, Kara; Harink, Björn; Baxter, Brian; Thorn, Kurt S.; Fordyce, Polly M.

    2017-02-01

    Protein-peptide interactions are essential for cellular responses. Despite their importance, these interactions remain largely uncharacterized due to experimental challenges associated with their measurement. Current techniques (e.g. surface plasmon resonance, fluorescence polarization, and isothermal calorimetry) either require large amounts of purified material or direct fluorescent labeling, making high-throughput measurements laborious and expensive. In this report, we present a new technology for measuring antibody-peptide interactions in vitro that leverages spectrally encoded beads for biological multiplexing. Specific peptide sequences are synthesized directly on encoded beads with a 1:1 relationship between peptide sequence and embedded code, thereby making it possible to track many peptide sequences throughout the course of an experiment within a single small volume. We demonstrate the potential of these bead-bound peptide libraries by: (1) creating a set of 46 peptides composed of 3 commonly used epitope tags (myc, FLAG, and HA) and single amino-acid scanning mutants; (2) incubating with a mixture of fluorescently-labeled antimyc, anti-FLAG, and anti-HA antibodies; and (3) imaging these bead-bound libraries to simultaneously identify the embedded spectral code (and thus the sequence of the associated peptide) and quantify the amount of each antibody bound. To our knowledge, these data demonstrate the first customized peptide library synthesized directly on spectrally encoded beads. While the implementation of the technology provided here is a high-affinity antibody/protein interaction with a small code space, we believe this platform can be broadly applicable to any range of peptide screening applications, with the capability to multiplex into libraries of hundreds to thousands of peptides in a single assay.

  10. Molecular basis of the differences in binding properties of the highly related C-type lectins DC-SIGN and L-SIGN to Lewis X trisaccharide and Schistosoma mansoni egg antigens

    NARCIS (Netherlands)

    van Liempt, Ellis; Imberty, Anne; Bank, Christine M. C.; van Vliet, Sandra J.; van Kooyk, Yvette; Geijtenbeek, Teunis B. H.; van Die, Irma

    2004-01-01

    The dendritic cell-specific C-type lectin DC-SIGN functions as a pathogen receptor that recognizes Schistosoma mansoni egg antigens through its major glycan epitope Galbeta1,4(Fucalpha1,3)GlcNAc (Lex). Here we report that L-SIGN, a highly related homologue of DC-SIGN found on liver sinusoidal

  11. Molecular basis of the differences in binding properties of the highly related C-type lectins DC-SIGN and L-SIGN to Lewis X trisaccharide and Schistosoma mansoni egg antigens.

    NARCIS (Netherlands)

    Liempt, P.A.G.; Imberty, A; Bank, CM; Vliet, van SJ; Kooijk, van Y.; Geijtenbeek, T.B.H.; Die, van I.M.

    2004-01-01

    The dendritic cell-specific C-type lectin DC-SIGN functions as a pathogen receptor that recognizes Schistosoma mansoni egg antigens through its major glycan epitope Galbeta1,4(Fucalpha1,3)GlcNAc (Lex). Here we report that L-SIGN, a highly related homologue of DC-SIGN found on liver sinusoidal

  12. Interaction of antimicrobial peptides with lipid membranes

    Energy Technology Data Exchange (ETDEWEB)

    Hanulova, Maria

    2008-12-15

    This study aims to investigate the difference in the interaction of antimicrobial peptides with two classes of zwitterionic peptides, phosphatidylethanolamines (PE) and phosphatidylcholines (PC). Further experiments were performed on model membranes prepared from specific bacterial lipids, lipopolysaccharides (LPS) isolated from Salmonella minnesota. The structure of the lipid-peptide aqueous dispersions was studied by small-and wide-angle X-ray diffraction during heating and cooling from 5 to 85 C. The lipids and peptides were mixed at lipid-to-peptide ratios 10-10000 (POPE and POPC) or 2-50 (LPS). All experiments were performed at synchrotron soft condensed matter beamline A2 in Hasylab at Desy in Hamburg, Germany. The phases were identified and the lattice parameters were calculated. Alamethicin and melittin interact in similar ways with the lipids. Pure POPC forms only lamellar phases. POPE forms lamellar phases at low temperatures that upon heating transform into a highly curved inverse hexagonal phase. Insertion of the peptide induced inverse bicontinuous cubic phases which are an ideal compromise between the curvature stress and the packing frustration. Melittin usually induced a mixture of two cubic phases, Im3m and Pn3m, with a ratio of lattice parameters close to 1.279, related to the underlying minimal surfaces. They formed during the lamellar to hexagonal phase transition and persisted during cooling till the onset of the gel phase. The phases formed at different lipid-to-peptide ratios had very similar lattice parameters. Epitaxial relationships existed between coexisting cubic phases and hexagonal or lamellar phases due to confinement of all phases to an onion vesicle, a vesicle with several layers consisting of different lipid phases. Alamethicin induced the same cubic phases, although their formation and lattice parameters were dependent on the peptide concentration. The cubic phases formed during heating from the lamellar phase and their onset

  13. A Dde resin based strategy for inverse solid-phase synthesis of amino terminated peptides, peptide mimetics and protected peptide intermediates.

    Science.gov (United States)

    Rai, Aman; Gutheil, William G

    2005-02-01

    This report describes a Dde resin based attachment strategy for inverse solid-phase peptide synthesis (ISPPS). This attachment strategy can be used for the synthesis of amino terminated peptides with side chains and the carboxyl terminus either protected or deprotected. Amino acid t-butyl esters were attached through their free amino group to the Dde resin. The t-butyl carboxyl protecting group was removed by 50% TFA, and inverse peptide synthesis cycles performed using an HATU/TMP based coupling method. Protected peptides were cleaved from the resin with dilute hydrazine. Side chain protecting groups could then be removed by treatment with TFMSA/TFA. The potential of this approach was demonstrated by the synthesis of several short protected and unprotected peptides in good yield and with low epimerization. Its potential for peptide mimetic synthesis was demonstrated by the synthesis of two peptide trifluoromethylketones. Copyright 2004 European Peptide Society and John Wiley & Sons, Ltd.

  14. Urodilatin. A renal natriuretic peptide

    Energy Technology Data Exchange (ETDEWEB)

    Carstens, Jan [Aarhus Univ. Hospital, Research Lab. of Nephrology and Hypertension (Denmark)

    1998-12-31

    Development and validation of a radioimmunoassay for endogenous URO in urine and synthetic URO in plasma is described. The first obstacle to overcome was to produce an antibody specific for URO. A polyclonal URO antibody with a cross-reactivity with the structural highly homologous atrial natriuretic peptide (ANP) was developed by immunization of rabbits with the whole URO(95-126). Purification of the polyclonal URO antiserum with CNBr-activated Sepharose affinity chromatography was a simple way of producing a URO-specific antibody without cross-reactivity with ANP analogues. A reliable {sup 125}I-labelled URO tracer was made with the Iodo-Gen method. Prior to the assay, the urine samples were prepared by ethanol with a recovery of unlabelled URO between 80 - 100% and the plasma samples were Sep-Pak C{sub 18} extracted with a recovery of about 50%. The radioimmunoassay is performed in 3 days, using polyethylene glycol for separation. The sensitivity of the assay was improved by sample preparation and concentration, reducing the amount of tracer and late addition, reducing the amount of antibody and increasing the incubation time and lowering the temperature of incubation. The infusion rate of 20 ng URO kg{sup -1} min{sup -1} was most potential and well tolerated in healthy subjects. The short-term natriuretic and diuretic effects were closely associated with a significant diminished sodium reabsorption in the distal nephron. Further studies are needed to exploit the therapeutical potential of URO, for example in patients with sodium-water retaining disorders. The therapeutical dose range will probably be narrow due to the blood pressure lowering effect of URO with infusion rates higher than 20-30 ng kg{sup -1} min{sup -1}. (EHS) 134 refs.

  15. Peptide dot immunoassay and immunoblotting: electroblotting from aluminum thin-layer chromatography plates and isoelectric focusing gels to activated nitrocellulose

    DEFF Research Database (Denmark)

    Bjerrum, O.J.; Holm, A.; Lauritzen, Edgar

    1993-01-01

    Peptide dot immunoassay, electroblotting, activated nitrocellulose, dot blot, membranes, peptides and proteins......Peptide dot immunoassay, electroblotting, activated nitrocellulose, dot blot, membranes, peptides and proteins...

  16. Peptide-membrane interactions of arginine-tryptophan peptides probed using quartz crystal microbalance with dissipation monitoring.

    Science.gov (United States)

    Rydberg, Hanna A; Kunze, Angelika; Carlsson, Nils; Altgärde, Noomi; Svedhem, Sofia; Nordén, Bengt

    2014-07-01

    Membrane-active peptides include peptides that can cross cellular membranes and deliver macromolecular cargo as well as peptides that inhibit bacterial growth. Some of these peptides can act as both transporters and antibacterial agents. It is desirable to combine the knowledge from these two different fields of membrane-active peptides into design of new peptides with tailored actions, as transporters of cargo or as antibacterial substances, targeting specific membranes. We have previously shown that the position of the amino acid tryptophan in the peptide sequence of three arginine-tryptophan peptides affects their uptake and intracellular localization in live mammalian cells, as well as their ability to inhibit bacterial growth. Here, we use quartz crystal microbalance with dissipation monitoring to assess the induced changes caused by binding of the three peptides to supported model membranes composed of POPC, POPC/POPG, POPC/POPG/cholesterol or POPC/lactosyl PE. Our results indicate that the tryptophan position in the peptide sequence affects the way these peptides interact with the different model membranes and that the presence of cholesterol in particular seems to affect the membrane interaction of the peptide with an even distribution of tryptophans in the peptide sequence. These results give mechanistic insight into the function of these peptides and may aid in the design of membrane-active peptides with specified cellular targets and actions.

  17. Peptide-membrane interactions of arginine-tryptophan peptides probed using quartz crystal microbalance with dissipation monitoring.

    KAUST Repository

    Rydberg, Hanna A

    2014-04-18

    Membrane-active peptides include peptides that can cross cellular membranes and deliver macromolecular cargo as well as peptides that inhibit bacterial growth. Some of these peptides can act as both transporters and antibacterial agents. It is desirable to combine the knowledge from these two different fields of membrane-active peptides into design of new peptides with tailored actions, as transporters of cargo or as antibacterial substances, targeting specific membranes. We have previously shown that the position of the amino acid tryptophan in the peptide sequence of three arginine-tryptophan peptides affects their uptake and intracellular localization in live mammalian cells, as well as their ability to inhibit bacterial growth. Here, we use quartz crystal microbalance with dissipation monitoring to assess the induced changes caused by binding of the three peptides to supported model membranes composed of POPC, POPC/POPG, POPC/POPG/cholesterol or POPC/lactosyl PE. Our results indicate that the tryptophan position in the peptide sequence affects the way these peptides interact with the different model membranes and that the presence of cholesterol in particular seems to affect the membrane interaction of the peptide with an even distribution of tryptophans in the peptide sequence. These results give mechanistic insight into the function of these peptides and may aid in the design of membrane-active peptides with specified cellular targets and actions.

  18. THE USE OF DEDICATED PEPTIDE LIBRARIES PERMITS THE DISCOVERY OF HIGH-AFFINITY BINDING PEPTIDES

    NARCIS (Netherlands)

    DEKOSTER, HS; AMONS, R; BENCKHUIJSEN, WE; FEIJLBRIEF, M; SCHELLEKENS, GA; DRIJFHOUT, JW

    1995-01-01

    The motif for peptide binding to monoclonal antibody mAb A16, which is known to be directed against glycoprotein D of Herpes simplex virus type 1, was determined using two dedicated peptide libraries. As a starting point for this study we used an A-16 binding lead sequence, which had previously been

  19. Identification of Short Hydrophobic Cell-Penetrating Peptides for Cytosolic Peptide Delivery by Rational Design.

    Science.gov (United States)

    Schmidt, Samuel; Adjobo-Hermans, Merel J W; Kohze, Robin; Enderle, Thilo; Brock, Roland; Milletti, Francesca

    2017-02-15

    Cell-penetrating peptides (CPPs) enhance the cellular uptake of membrane-impermeable molecules. Most CPPs are highly cationic, potentially increasing the risk of toxic side effects and leading to accumulation in organs such as the liver. As a consequence, there is an unmet need for less cationic CPPs. However, design principles for effective CPPs are still missing. Here, we demonstrate a design principle based on a classification of peptides according to accumulated side-chain polarity and hydrophobicity. We show that in comparison to randomly selected peptides, CPPs cover a distinct parameter space. We designed peptides of only six to nine amino acids with a maximum of three positive charges covering this property space. All peptides were tested for cellular uptake and subcellular distribution. Following an initial round of screening we enriched the collection with short and hydrophobic peptides and introduced d-amino acid substitutions and lactam bridges which increased cell uptake, in particular for long-term incubation. Using a GFP complementation assay, for the most active peptides we demonstrate cytosolic delivery of a biologically active cargo peptide.

  20. Application of synthetic peptides for detection of anti-citrullinated peptide antibodies

    DEFF Research Database (Denmark)

    Trier, Nicole Hartwig; Holm, Bettina Eide; Slot, Ole

    2016-01-01

    (n=40), systemic lupus erythematosus (n=20), Sjögren's syndrome (n=40)) were screened for antibody reactivity. Antibodies to a panel of five citrullinated EBNA-1 peptides were found in 67% of RA sera, exclusively of the IgG isotype, while 53% of the patient sera reacted with a single peptide...

  1. Peptide-MHC class I stability is a stronger predictor of CTL immunogenicity than peptide affinity

    DEFF Research Database (Denmark)

    Harndahl, Mikkel Nors; Rasmussen, Michael; Nielsen, Morten

    2012-01-01

    Peptide-MHC class I stability is a stronger predictor of CTL immunogenicity than peptide affinity Mikkel Harndahla, Michael Rasmussena, Morten Nielsenb, Soren Buusa,∗ a Laboratory of Experimental Immunology, Faculty of Health Sciences, University of Copenhagen, Denmark b Center for Biological Seq...... al., 2007. J. Immunol. 178, 7890–7901. doi:10.1016/j.molimm.2012.02.025...

  2. The non-peptidic part determines the internalization mechanism and intracellular trafficking of peptide amphiphiles.

    Directory of Open Access Journals (Sweden)

    Dimitris Missirlis

    Full Text Available BACKGROUND: Peptide amphiphiles (PAs are a class of amphiphilic molecules able to self-assemble into nanomaterials that have shown efficient in vivo targeted delivery. Understanding the interactions of PAs with cells and the mechanisms of their internalization and intracellular trafficking is critical in their further development for therapeutic delivery applications. METHODOLOGY/PRINCIPAL FINDINGS: PAs of a novel, cell- and tissue-penetrating peptide were synthesized possessing two different lipophilic tail architectures and their interactions with prostate cancer cells were studied in vitro. Cell uptake of peptides was greatly enhanced post-modification. Internalization occurred via lipid-raft mediated endocytosis and was common for the two analogs studied. On the contrary, we identified the non-peptidic part as the determining factor of differences between intracellular trafficking and retention of PAs. PAs composed of di-stearyl lipid tails linked through poly(ethylene glycol to the peptide exhibited higher exocytosis rates and employed different recycling pathways compared to ones consisting of di-palmitic-coupled peptides. As a result, cell association of the former PAs decreased with time. CONCLUSIONS/SIGNIFICANCE: Control over peptide intracellular localization and retention is possible by appropriate modification with synthetic hydrophobic tails. We propose this as a strategy to design improved peptide-based delivery systems.

  3. Peptide and Peptide-Dependent Motions in MHC Proteins: Immunological Implications and Biophysical Underpinnings

    Directory of Open Access Journals (Sweden)

    Cory M. Ayres

    2017-08-01

    Full Text Available Structural biology of peptides presented by class I and class II MHC proteins has transformed immunology, impacting our understanding of fundamental immune mechanisms and allowing researchers to rationalize immunogenicity and design novel vaccines. However, proteins are not static structures as often inferred from crystallographic structures. Their components move and breathe individually and collectively over a range of timescales. Peptides bound within MHC peptide-binding grooves are no exception and their motions have been shown to impact recognition by T cell and other receptors in ways that influence function. Furthermore, peptides tune the motions of MHC proteins themselves, which impacts recognition of peptide/MHC complexes by other proteins. Here, we review the motional properties of peptides in MHC binding grooves and discuss how peptide properties can influence MHC motions. We briefly review theoretical concepts about protein motion and highlight key data that illustrate immunological consequences. We focus primarily on class I systems due to greater availability of data, but segue into class II systems as the concepts and consequences overlap. We suggest that characterization of the dynamic “energy landscapes” of peptide/MHC complexes and the resulting functional consequences is one of the next frontiers in structural immunology.

  4. Acyl peptide hydrolase degrades monomeric and oligomeric amyloid-beta peptide

    Directory of Open Access Journals (Sweden)

    O'Connor Peter B

    2009-07-01

    Full Text Available Abstract Background The abnormal accumulation of amyloid-beta peptide is believed to cause malfunctioning of neurons in the Alzheimer's disease brain. Amyloid-beta exists in different assembly forms in the aging mammalian brain including monomers, oligomers, and aggregates, and in senile plaques, fibrils. Recent findings suggest that soluble amyloid-beta oligomers may represent the primary pathological species in Alzheimer's disease and the most toxic form that impairs synaptic and thus neuronal function. We previously reported the isolation of a novel amyloid-beta-degrading enzyme, acyl peptide hydrolase, a serine protease that degrades amyloid-beta, and is different in structure and activity from other amyloid-beta-degrading enzymes. Results Here we report the further characterization of acyl peptide hydrolase activity using mass spectrometry. Acyl peptide hydrolase cleaves the amyloid-beta peptide at amino acids 13, 14 and 19. In addition, by real-time PCR we found elevated acyl peptide hydrolase expression in brain areas rich in amyloid plaques suggesting that this enzyme's levels are responsive to increases in amyloid-beta levels. Lastly, tissue culture experiments using transfected CHO cells expressing APP751 bearing the V717F mutation indicate that acyl peptide hydrolase preferentially degrades dimeric and trimeric forms of amyloid-beta. Conclusion These data suggest that acyl peptide hydrolase is involved in the degradation of oligomeric amyloid-beta, an activity that, if induced, might present a new tool for therapy aimed at reducing neurodegeneration in the Alzheimer's brain.

  5. Antimicrobial peptides design by evolutionary multiobjective optimization.

    Science.gov (United States)

    Maccari, Giuseppe; Di Luca, Mariagrazia; Nifosí, Riccardo; Cardarelli, Francesco; Signore, Giovanni; Boccardi, Claudia; Bifone, Angelo

    2013-01-01

    Antimicrobial peptides (AMPs) are an abundant and wide class of molecules produced by many tissues and cell types in a variety of mammals, plant and animal species. Linear alpha-helical antimicrobial peptides are among the most widespread membrane-disruptive AMPs in nature, representing a particularly successful structural arrangement in innate defense. Recently, AMPs have received increasing attention as potential therapeutic agents, owing to their broad activity spectrum and their reduced tendency to induce resistance. The introduction of non-natural amino acids will be a key requisite in order to contrast host resistance and increase compound's life. In this work, the possibility to design novel AMP sequences with non-natural amino acids was achieved through a flexible computational approach, based on chemophysical profiles of peptide sequences. Quantitative structure-activity relationship (QSAR) descriptors were employed to code each peptide and train two statistical models in order to account for structural and functional properties of alpha-helical amphipathic AMPs. These models were then used as fitness functions for a multi-objective evolutional algorithm, together with a set of constraints for the design of a series of candidate AMPs. Two ab-initio natural peptides were synthesized and experimentally validated for antimicrobial activity, together with a series of control peptides. Furthermore, a well-known Cecropin-Mellitin alpha helical antimicrobial hybrid (CM18) was optimized by shortening its amino acid sequence while maintaining its activity and a peptide with non-natural amino acids was designed and tested, demonstrating the higher activity achievable with artificial residues.

  6. Antimicrobial peptides design by evolutionary multiobjective optimization.

    Directory of Open Access Journals (Sweden)

    Giuseppe Maccari

    Full Text Available Antimicrobial peptides (AMPs are an abundant and wide class of molecules produced by many tissues and cell types in a variety of mammals, plant and animal species. Linear alpha-helical antimicrobial peptides are among the most widespread membrane-disruptive AMPs in nature, representing a particularly successful structural arrangement in innate defense. Recently, AMPs have received increasing attention as potential therapeutic agents, owing to their broad activity spectrum and their reduced tendency to induce resistance. The introduction of non-natural amino acids will be a key requisite in order to contrast host resistance and increase compound's life. In this work, the possibility to design novel AMP sequences with non-natural amino acids was achieved through a flexible computational approach, based on chemophysical profiles of peptide sequences. Quantitative structure-activity relationship (QSAR descriptors were employed to code each peptide and train two statistical models in order to account for structural and functional properties of alpha-helical amphipathic AMPs. These models were then used as fitness functions for a multi-objective evolutional algorithm, together with a set of constraints for the design of a series of candidate AMPs. Two ab-initio natural peptides were synthesized and experimentally validated for antimicrobial activity, together with a series of control peptides. Furthermore, a well-known Cecropin-Mellitin alpha helical antimicrobial hybrid (CM18 was optimized by shortening its amino acid sequence while maintaining its activity and a peptide with non-natural amino acids was designed and tested, demonstrating the higher activity achievable with artificial residues.

  7. Venom peptides as therapeutics: advances, challenges and the future of venom-peptide discovery.

    Science.gov (United States)

    Robinson, Samuel D; Undheim, Eivind A B; Ueberheide, Beatrix; King, Glenn F

    2017-10-01

    Animal venoms are complex chemical arsenals. Most venoms are rich in bioactive peptides with proven potential as research tools, drug leads and drugs. Areas covered: We review recent advances in venom-peptide discovery, particularly the adoption of combined transcriptomic/proteomic approaches for the exploration of venom composition. Expert commentary: Advances in transcriptomics and proteomics have dramatically altered the manner and rate of venom-peptide discovery. The increasing trend towards a toxin-driven approach, as opposed to traditional target-based screening of venoms, is likely to expedite the discovery of venom-peptides with novel structures and new and unanticipated mechanisms of action. At the same time, these advances will drive the development of higher-throughput approaches for target identification. Taken together, these approaches should enhance our understanding of the natural ecological function of venom peptides and increase the rate of identification of novel venom-derived pharmacological tools, drug leads and drugs.

  8. Putting microbes to work: dairy fermentation, cell factories and bioactive peptides. Part II: bioactive peptide functions.

    Science.gov (United States)

    Hayes, Maria; Stanton, Catherine; Fitzgerald, Gerald F; Ross, R Paul

    2007-04-01

    A variety of milk-derived biologically active peptides have been shown to exert both functional and physiological roles in vitro and in vivo, and because of this are of particular interest for food science and nutrition applications. Biological activities associated with such peptides include immunomodulatory, antibacterial, anti-hypertensive and opioid-like properties. Milk proteins are recognized as a primary source of bioactive peptides, which can be encrypted within the amino acid sequence of dairy proteins, requiring proteolysis for release and activation. Fermentation of milk proteins using the proteolytic systems of lactic acid bacteria is an attractive approach for generation of functional foods enriched in bioactive peptides given the low cost and positive nutritional image associated with fermented milk drinks and yoghurt. In Part II of this review, we focus on examples of milk-derived bioactive peptides and their associated health benefits, to illustrate the potential of this area for the design and improvement of future functional foods.

  9. Acetone-Linked Peptides: A Convergent Approach for Peptide Macrocyclization and Labeling.

    Science.gov (United States)

    Assem, Naila; Ferreira, David J; Wolan, Dennis W; Dawson, Philip E

    2015-07-20

    Macrocyclization is a broadly applied approach for overcoming the intrinsically disordered nature of linear peptides. Herein, it is shown that dichloroacetone (DCA) enhances helical secondary structures when introduced between peptide nucleophiles, such as thiols, to yield an acetone-linked bridge (ACE). Aside from stabilizing helical structures, the ketone moiety embedded in the linker can be modified with diverse molecular tags by oxime ligation. Insights into the structure of the tether were obtained through co-crystallization of a constrained S-peptide in complex with RNAse S. The scope of the acetone-linked peptides was further explored through the generation of N-terminus to side chain macrocycles and a new approach for generating fused macrocycles (bicycles). Together, these studies suggest that acetone linking is generally applicable to peptide macrocycles with a specific utility in the synthesis of stabilized helices that incorporate functional tags. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Synthesis, molecular docking and anticancer studies of peptides and iso-peptides.

    Science.gov (United States)

    Jabeen, Farukh; Panda, Siva S; Kondratyuk, Tamara P; Park, Eun-Jung; Pezzuto, John M; Ihsan-ul-Haq; Hall, C Dennis; Katritzky, Alan R

    2015-08-01

    Chiral peptides and iso-peptides were synthesized in excellent yield by using benzotriazole mediated solution phase synthesis. Benzotriazole acted both as activating and leaving group, eliminating frequent use of protection and subsequent deprotection. The procedure was based on the hypothesis that epimerization should be suppressed in solution due to a faster coupling rate than SPPS. All the synthesized peptides complied with Lipinski's Ro5 except for the rotatable bonds. Inhibition of cell proliferation of cancer cell lines is one of the most commonly used methods to study the effectiveness of any anticancer agents. Synthesized peptides and iso-peptides were tested against three cancer cell lines (MCF-7, MDA-MB 231) to determine their anti-proliferative potential. NFkB was also determined. Molecular docking studies were also carried out to complement the experimental results. Copyright © 2015 Elsevier Ltd. All rights reserved.

  11. Urinary Peptide Levels in Patients with Chronic Renal Failure

    Directory of Open Access Journals (Sweden)

    Mungli Prakash

    2010-10-01

    Full Text Available Introduction: Peptide levels in urine are found to be decreased in renal failure. In the current study urinary peptide levels were determined in chronic renal failure (CRF patients. Method: 86 CRF patients and 80 healthy controls were selected for the study. Urinary proteins and peptide levels were determined by spectrophotometer based Lowry and Bradford methods. Urinary creatinine levels were determined by clinical chemistry analyzer. Results: There was significant decrease in urinary peptide levels in CRF patients and Urinary % peptides were significantly decreased in CRF patients as compared to healthy controls. Urinary % peptides correlated negatively with proteinuria. Conclusion: we have found decrease in urinary peptides and % urinary peptides in CRF patients and possibly measurement of % urinary peptides may possibly serve as better indicator in early detection of impairment in renal function.

  12. Recent Advances in Peptide-Based Approaches for Cancer Treatment.

    Science.gov (United States)

    Conibear, Anne C; Schmid, Alanca; Kamalov, Meder; Becker, Christian F W; Bello, Claudia

    2017-11-23

    Peptide-based pharmaceuticals have recently experienced a renaissance due to their ability to fill the gap between the two main classes of available drugs, small molecules and biologics. Peptides combine the high potency and selectivity typical of large proteins with some of the characteristic advantages of small molecules such as synthetic accessibility, stability and the potential of oral bioavailability. One of the applications in which peptide-based approaches have grown rapidly is cancer therapy, with a focus on new and established targets. Many novel peptide-based methods for cancer treatment have been developed in the last few years, ranging from naturally-occurring and modified peptides to peptide-drug conjugates, peptide nanomaterials and peptide-based vaccines. This review focuses on recent advances, advantages and challenges of these selected peptide-based approaches for cancer treatment. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  13. Handles for Fmoc solid-phase synthesis of protected peptides.

    Science.gov (United States)

    Góngora-Benítez, Miriam; Tulla-Puche, Judit; Albericio, Fernando

    2013-05-13

    Protected peptide fragments are valuable building blocks for the assembly of large peptide sequences through fragment condensation approaches, whereas protected peptides are typically synthesized for the preparation of amide-bridge cyclic peptides in solution. Efficient synthesis of both protected peptides and protected peptide fragments by solid-phase peptide synthesis methodology requires handles that attach the growing peptides to the polymeric support and can be cleaved under appropriate conditions, while maintaining intact the side-chain protecting groups. Here, we provide an overview of attachment methods described in the literature for the preparation of protected peptides using Fmoc/tBu chemistry, including the most commonly used acid-labile linkers along with the most recent and sophisticated.

  14. Biochemical properties of regulatory peptides derived from milk proteins.

    Science.gov (United States)

    Meisel, H

    1997-01-01

    Biologically active peptides derived from milk proteins are inactive within the sequence of the precursor proteins but can be released by enzymatic proteolysis. Based on structure-activity studies, peptides with a defined bioactivity show common structural features. Moreover, many milk protein-derived peptides reveal multifunctional bioactivities. Bioactive peptide fragments originating from milk proteins should be taken into account as potential modulators of various regulatory processes in the body. Opioid peptides are opioid receptor ligands with agonistic or antagonistic activities. Angiotensin converting enzyme (ACE) inhibitory peptides can exert an antihypertensive effect. Immunomodulating casein peptides have been found to stimulate the proliferation of human lymphocytes and the phagocytic activities of macrophages. Antimicrobial peptides have been shown to kill sensitive microorganisms. Antithrombotic peptides inhibit the fibrinogen binding to a specific receptor region on the platelet surface and also inhibit aggregation of platelets. Casein phosphopeptides can form soluble organophosphate salts and may function as carriers for different minerals, especially calcium. In relation to their mode of action, bioactive peptides may reach target sites (e.g., receptors, enzymes) at the luminal side of the intestinal tract or after absorption, in peripheral organs. The physiological significance of bioactive peptides as exogenous regulatory substances is not yet fully understood. Nevertheless, several bioactive peptides derived from milk proteins have been shown to exert beneficial physiological effects. Milk-derived peptides were already produced on an industrial scale and as a consequence these peptides have been considered for application both as dietary supplements in "functional foods" and as drugs.

  15. Peptide inhibition of human cytomegalovirus infection

    Directory of Open Access Journals (Sweden)

    Morris Cindy A

    2011-02-01

    Full Text Available Abstract Background Human cytomegalovirus (HCMV is the most prevalent congenital viral infection in the United States and Europe causing significant morbidity and mortality to both mother and child. HCMV is also an opportunistic pathogen in immunocompromised individuals, including human immunodeficiency virus (HIV- infected patients with AIDS, and solid organ and allogeneic stem cell transplantation recipients. Current treatments for HCMV-associated diseases are insufficient due to the emergence of drug-induced resistance and cytotoxicity, necessitating novel approaches to limit HCMV infection. The aim of this study was to develop therapeutic peptides targeting glycoprotein B (gB, a major glycoprotein of HCMV that is highly conserved across the Herpesviridae family, that specifically inhibit fusion of the viral envelope with the host cell membrane preventing HCMV entry and infection. Results Using the Wimley-White Interfacial Hydrophobicity Scale (WWIHS, several regions within gB were identified that display a high potential to interact with lipid bilayers of cell membranes and hydrophobic surfaces within proteins. The ability of synthetic peptides analogous to WWIHS-positive sequences of HCMV gB to inhibit viral infectivity was evaluated. Human foreskin fibroblasts (HFF were infected with the Towne-GFP strain of HCMV (0.5 MOI, preincubated with peptides at a range of concentrations (78 nm to 100 μM, and GFP-positive cells were visualized 48 hours post-infection by fluorescence microscopy and analyzed quantitatively by flow cytometry. Peptides that inhibited HCMV infection demonstrated different inhibitory concentration curves indicating that each peptide possesses distinct biophysical properties. Peptide 174-200 showed 80% inhibition of viral infection at a concentration of 100 μM, and 51% and 62% inhibition at concentrations of 5 μM and 2.5 μM, respectively. Peptide 233-263 inhibited infection by 97% and 92% at concentrations of 100

  16. Concentration effects on peptide elution from pendant PEO layers.

    Science.gov (United States)

    Wu, Xiangming; Ryder, Matthew P; McGuire, Joseph; Schilke, Karl F

    2014-06-01

    In earlier work, we have provided direction for development of responsive drug delivery systems based on modulation of structure and amphiphilicity of bioactive peptides entrapped within pendant polyethylene oxide (PEO) brush layers. Amphiphilicity promotes retention of the peptides within the hydrophobic inner region of the PEO brush layer. In this work, we describe the effects of peptide surface density on the conformational changes caused by peptide-peptide interactions, and show that this phenomenon substantially affects the rate and extent of peptide elution from PEO brush layers. Three cationic peptides were used in this study: the arginine-rich amphiphilic peptide WLBU2, the chemically identical but scrambled peptide S-WLBU2, and the non-amphiphilic homopolymer poly-l-arginine (PLR). Circular dichroism (CD) was used to evaluate surface density effects on the structure of these peptides at uncoated (hydrophobic) and PEO-coated silica nanoparticles. UV spectroscopy and a quartz crystal microbalance with dissipation monitoring (QCM-D) were used to quantify changes in the extent of peptide elution caused by those conformational changes. For amphiphilic peptides at sufficiently high surface density, peptide-peptide interactions result in conformational changes which compromise their resistance to elution. In contrast, elution of a non-amphiphilic peptide is substantially independent of its surface density, presumably due to the absence of peptide-peptide interactions. The results presented here provide a strategy to control the rate and extent of release of bioactive peptides from PEO layers, based on modulation of their amphiphilicity and surface density. Copyright © 2014 Elsevier B.V. All rights reserved.

  17. Recognition of epoxy with phage displayed peptides.

    Science.gov (United States)

    Swaminathan, Swathi; Cui, Yue

    2013-07-01

    The development of a general approach for non-destructive chemical and biological functionalization of epoxy could expand opportunities for both fundamental studies and creating various device platforms. Epoxy shows unique electrical, mechanical, chemical and biological compatibility and has been widely used for fabricating a variety of devices. Phage display has emerged as a powerful method for selecting peptides that possess enhanced selectivity and binding affinity toward a variety of targets. In this letter, we demonstrate for the first time a powerful yet benign approach for identifying binding motifs to epoxy via comprehensively screened phage displayed peptides. Our results show that the epoxy can be selectively recognized with peptide-displaying phages. Further, along with the development of epoxy-based microstructures; recognition of the epoxy with phage displayed peptides can be specifically localized in these microstructures. We anticipate that these results could open up exciting opportunities in the use of peptide-recognized epoxy in fundamental biochemical recognition studies, as well as in applications ranging from analytical devices, hybrid materials, surface and interface, to cell biology. Copyright © 2013 Elsevier B.V. All rights reserved.

  18. The evolution of Momordica cyclic peptides.

    Science.gov (United States)

    Mahatmanto, Tunjung; Mylne, Joshua S; Poth, Aaron G; Swedberg, Joakim E; Kaas, Quentin; Schaefer, Hanno; Craik, David J

    2015-02-01

    Cyclic proteins have evolved for millions of years across all kingdoms of life to confer structural stability over their acyclic counterparts while maintaining intrinsic functional properties. Here, we show that cyclic miniproteins (or peptides) from Momordica (Cucurbitaceae) seeds evolved in species that diverged from an African ancestor around 19 Ma. The ability to achieve head-to-tail cyclization of Momordica cyclic peptides appears to have been acquired through a series of mutations in their acyclic precursor coding sequences following recent and independent gene expansion event(s). Evolutionary analysis of Momordica cyclic peptides reveals sites that are under selection, highlighting residues that are presumably constrained for maintaining their function as potent trypsin inhibitors. Molecular dynamics of Momordica cyclic peptides in complex with trypsin reveals site-specific residues involved in target binding. In a broader context, this study provides a basis for selecting Momordica species to further investigate the biosynthesis of the cyclic peptides and for constructing libraries that may be screened against evolutionarily related serine proteases implicated in human diseases. © The Author 2014. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  19. Dinosaur Peptides Suggest Mechanisms of Protein Survival

    Energy Technology Data Exchange (ETDEWEB)

    San Antonio, James D.; Schweitzer, Mary H.; Jensen, Shane T.; Kalluri, Raghu; Buckley, Michael; Orgel, Joseph P.R.O. (Harvard-Med); (IIT); (NCSU); (UPENN); (Manchester); (Orthovita)

    2011-09-16

    Eleven collagen peptide sequences recovered from chemical extracts of dinosaur bones were mapped onto molecular models of the vertebrate collagen fibril derived from extant taxa. The dinosaur peptides localized to fibril regions protected by the close packing of collagen molecules, and contained few acidic amino acids. Four peptides mapped to collagen regions crucial for cell-collagen interactions and tissue development. Dinosaur peptides were not represented in more exposed parts of the collagen fibril or regions mediating intermolecular cross-linking. Thus functionally significant regions of collagen fibrils that are physically shielded within the fibril may be preferentially preserved in fossils. These results show empirically that structure-function relationships at the molecular level could contribute to selective preservation in fossilized vertebrate remains across geological time, suggest a 'preservation motif', and bolster current concepts linking collagen structure to biological function. This non-random distribution supports the hypothesis that the peptides are produced by the extinct organisms and suggests a chemical mechanism for survival.

  20. Peptide synthesis in early earth hydrothermal systems

    Science.gov (United States)

    Lemke, K.H.; Rosenbauer, R.J.; Bird, D.K.

    2009-01-01

    We report here results from experiments and thermodynamic calculations that demonstrate a rapid, temperature-enhanced synthesis of oligopeptides from the condensation of aqueous glycine. Experiments were conducted in custom-made hydrothermal reactors, and organic compounds were characterized with ultraviolet-visible procedures. A comparison of peptide yields at 260??C with those obtained at more moderate temperatures (160??C) gives evidence of a significant (13 kJ ?? mol-1) exergonic shift. In contrast to previous hydrothermal studies, we demonstrate that peptide synthesis is favored in hydrothermal fluids and that rates of peptide hydrolysis are controlled by the stability of the parent amino acid, with a critical dependence on reactor surface composition. From our study, we predict that rapid recycling of product peptides from cool into near-supercritical fluids in mid-ocean ridge hydrothermal systems will enhance peptide chain elongation. It is anticipated that the abundant hydrothermal systems on early Earth could have provided a substantial source of biomolecules required for the origin of life. Astrobiology 9, 141-146. ?? 2009 Mary Ann Liebert, Inc. 2009.

  1. New peptides players in metabolic disorders

    Directory of Open Access Journals (Sweden)

    Agata Mierzwicka

    2016-08-01

    Full Text Available Among new peptides responsible for the pathogenesis of metabolic disorders and carbohydrate metabolism, adipokines are of great importance. Adipokines are substances of hormonal character, secreted by adipose tissue. Apart from the well-known adipokines, adropin and preptin are relatively newly discovered, hence their function is not fully understood. They are peptides not secreted by adipose tissue but their role in the metabolic regulations seems to be significant. Preptin is a 34-amino acid peptide, a derivative of proinsulin growth factor II (pro-IGF-II, secreted by pancreatic β cells, considered to be a physiological enhancer of insulin secretion. Additionally, preptin has a stimulating effect on osteoblasts, inducing their proliferation, differentiation and survival. Adropin is a 76-amino acid peptide, encoded by the energy homeostasis associated gene (Enho, mainly in liver and brain, and its expression is dependent on a diet. Adropin is believed to play an important role in metabolic homeostasis, fatty acids metabolism control, insulin resistance prevention, dyslipidemia, and impaired glucose tolerance. The results of studies conducted so far show that the diseases resulting from metabolic syndrome, such as obesity, type 2 diabetes mellitus, polycystic ovary syndrome, non-alcoholic fatty liver disease, or cardiovascular disease are accompanied by significant changes in the concentration of these peptides. It is also important to note that preptin has an anabolic effect on bone tissue, which might be preventive in osteoporosis.

  2. Encoded libraries of chemically modified peptides.

    Science.gov (United States)

    Heinis, Christian; Winter, Greg

    2015-06-01

    The use of powerful technologies for generating and screening DNA-encoded protein libraries has helped drive the development of proteins as pharmaceutical ligands. However the development of peptides as pharmaceutical ligands has been more limited. Although encoded peptide libraries are typically several orders of magnitude larger than classical chemical libraries, can be more readily screened, and can give rise to higher affinity ligands, their use as pharmaceutical ligands is limited by their intrinsic properties. Two of the intrinsic limitations include the rotational flexibility of the peptide backbone and the limited number (20) of natural amino acids. However these limitations can be overcome by use of chemical modification. For example, the libraries can be modified to introduce topological constraints such as cyclization linkers, or to introduce new chemical entities such as small molecule ligands, fluorophores and photo-switchable compounds. This article reviews the chemistry involved, the properties of the peptide ligands, and the new opportunities offered by chemical modification of DNA-encoded peptide libraries. Copyright © 2015. Published by Elsevier Ltd.

  3. Glucagon-Like Peptide-1 Gene Therapy

    Directory of Open Access Journals (Sweden)

    Anne M. Rowzee

    2011-01-01

    Full Text Available Glucagon-like peptide 1 (GLP-1 is a small peptide component of the prohormone, proglucagon, that is produced in the gut. Exendin-4, a GLP-1 receptor agonist originally isolated from the saliva of H. suspectum or Gila monster, is a peptide that shares sequence and functional homology with GLP-1. Both peptides have been demonstrated to stimulate insulin secretion, inhibit glucagon secretion, promote satiety and slow gastric emptying. As such, GLP-1 and Exendin-4 have become attractive pharmaceutical targets as an adjunctive therapy for individuals with type II diabetes mellitus, with several products currently available clinically. Herein we summarize the cell biology leading to GLP-1 production and secretion from intestinal L-cells and the endocrine functions of this peptide and Exendin-4 in humans. Additionally, gene therapeutic applications of GLP-1 and Exendin-4 are discussed with a focus on recent work using the salivary gland as a gene therapy target organ for the treatment of diabetes mellitus.

  4. Synthesis of antimicrobial peptides using the SPOT technique.

    Science.gov (United States)

    Winkler, Dirk F H; Hilpert, Kai

    2010-01-01

    Developing new lead structures for drugs against multiresistant bacteria is an urgent need for modern medicine. Antimicrobial peptides are a class of drugs that can be used to discover such structures. In order to support development of this research, a fast, easy, and inexpensive method to synthesize peptides is necessary. The SPOT synthesis has the potential to produce the required peptide arrays, synthesizing up to 8,000 peptides, peptide mixtures, or other organic compounds on cellulose or other planar surfaces in a positionally addressable and multiple manner. Protocols for the preparation of cellulose membranes and the SPOT synthesis as well as cleavage of peptides from the support are described.

  5. Resetting the neurohormonal balance in heart failure (HF): the relevance of the natriuretic peptide (NP) system to the clinical management of patients with HF.

    Science.gov (United States)

    Rubattu, Speranza; Triposkiadis, Filippos

    2017-05-01

    The natriuretic peptide (NP) system, which includes atrial natriuretic peptide, B-type natriuretic peptide, and C-type natriuretic peptide, has an important role in cardiovascular homeostasis, promoting a number of physiological effects including diuresis, vasodilation, and inhibition of the renin-angiotensin-aldosterone system. Heart failure (HF) is associated with defects in NP processing and synthesis, and there is a strong relationship between NP levels and disease state. NPs are useful biomarkers in HF, and their use in diagnosis and evaluation of prognosis is well established, particularly in patients with HF with reduced ejection fraction (HFrEF). There has also been interest in their use to guide disease management and therapeutic decision making. An understanding of NPs in HF has also resulted in interest in synthetic NPs for the treatment of HF and in treatments that target neprilysin, a protease that degrades NPs. A novel drug, the angiotensin receptor neprilysin inhibitor sacubitril/valsartan (LCZ696), which simultaneously inhibits neprilysin and blocks the angiotensin II type I receptor, was shown to have a favorable efficacy and safety profile in patients with HFrEF and has been approved for use in such patients in Europe and the USA. In light of the development of treatments that target neprilysin and of recent data in relation to synthetic NPs, it is timely to review the current understanding of the role of NPs in HF and their use in diagnosis, evaluating prognosis and guiding treatment, as well as their place in HF therapy.

  6. A Peptide/MHCII conformer generated in the presence of exchange peptide is substrate for HLA-DM editing.

    Science.gov (United States)

    Ferrante, Andrea; Gorski, Jack

    2012-01-01

    The mechanism of HLA-DM (DM) activity is still unclear. We have shown that DM-mediated peptide release from HLA-DR (DR) is dependent on the presence of exchange peptide. However, DM also promotes a small amount of peptide release in the absence of exchange peptide. Here we show that SDS-PAGE separates purified peptide/DR1 complexes (pDR1) into two conformers whose ratio is peptide K(d)-dependent. In the absence of exchange peptide, DM only releases peptide from the slower migrating conformer. Addition of exchange peptide converts the DM-resistant conformer to the slower migrating conformer, which is DM labile. Thus, exchange peptide generates a conformer of pDR1 which constitutes the intermediate for peptide exchange and the substrate for DM activity. The resolution of the intermediate favors the highest affinity peptide. However, once folded into the DM-resistant conformer, even low affinity peptides can be presented in the absence of free peptide, broadening the repertoire available for presentation.

  7. Antimicrobial peptides: promising alternatives to conventional antibiotics.

    Science.gov (United States)

    Baltzer, Sylvia A; Brown, Melissa H

    2011-01-01

    Antimicrobial peptides (APs) have been described as evolutionary ancient weapons. Produced by a wide variety of organisms as part of a non-specific immune response, these peptides are involved in the direct destruction of various microorganisms. Several APs have been shown to have broad activity spectra against microorganisms such as Gram-positive and Gram-negative bacteria, enveloped viruses, fungi and parasites. Given that resistance to a number of antibiotics has developed in a wide range of microbes, the potential of APs as novel therapeutic agents is being evaluated. However, optimisation of APs designed for therapy will need to focus on such factors as their susceptibility to proteolytic degradation and reduction of toxicity to mammalian cells. Strict guidelines pertaining to their use should also be established to prevent or hinder future development of bacterial resistance to such peptides. Copyright © 2011 S. Karger AG, Basel.

  8. Natriuretic peptides in common valvular heart disease.

    Science.gov (United States)

    Steadman, Christopher D; Ray, Simon; Ng, Leong L; McCann, Gerry P

    2010-05-11

    Valvular heart disease, particularly aortic stenosis and mitral regurgitation, accounts for a large proportion of cardiology practice, and their prevalence is predicted to increase. Management of the asymptomatic patient remains controversial. Biomarkers have been shown to have utility in the management of cardiovascular disease such as heart failure and acute coronary syndromes. In this state-of-the-art review, we examine the current evidence relating to natriuretic peptides as potential biomarkers in aortic stenosis and mitral regurgitation. The natriuretic peptides correlate with measures of disease severity and symptomatic status and also can be used to predict outcome. This review shows that natriuretic peptides have much promise as biomarkers in common valvular heart disease, but the impact of their measurement on clinical practice and outcomes needs to be further assessed in prospective studies before routine clinical use becomes a reality. Copyright 2010 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

  9. Radiolabelled RGD peptides for imaging and therapy.

    Science.gov (United States)

    Gaertner, F C; Kessler, H; Wester, H-J; Schwaiger, M; Beer, A J

    2012-02-01

    Imaging of angiogenesis has become increasingly important with the rising use of targeted antiangiogenic therapies like bevacizumab (Avastin). Non-invasive assessment of angiogenic activity is in this respect interesting, e.g. for response assessment of such targeted antiangiogenic therapies. One promising approach of angiogenesis imaging is imaging of specific molecular markers of the angiogenic cascade like the integrin α(v)β(3). For molecular imaging of integrin expression, the use of radiolabelled peptides is still the only approach that has been successfully translated into the clinic. In this review we will summarize the current data on imaging of α(v)β(3) expression using radiolabelled RGD peptides with a focus on tracers already in clinical use. A perspective will be presented on the future clinical use of radiolabelled RGD peptides including an outlook on potential applications for radionuclide therapy.

  10. Radiolabelled RGD peptides for imaging and therapy

    Energy Technology Data Exchange (ETDEWEB)

    Gaertner, F.C.; Schwaiger, M.; Beer, A.J. [Technische Universitaet Muenchen, Department of Nuclear Medicine, Klinikum rechts der Isar, Munich (Germany); Kessler, H. [Technische Universitaet Muenchen, Institute for Advanced Study and Center of Integrated Protein Science, Department of Chemistry, Garching (Germany); King Abdulaziz University, Chemistry Department, Faculty of Science, Jeddah (Saudi Arabia); Wester, H.-J. [Institute for Pharmaceutical Radiochemistry, Garching (Germany)

    2012-02-15

    Imaging of angiogenesis has become increasingly important with the rising use of targeted antiangiogenic therapies like bevacizumab (Avastin). Non-invasive assessment of angiogenic activity is in this respect interesting, e.g. for response assessment of such targeted antiangiogenic therapies. One promising approach of angiogenesis imaging is imaging of specific molecular markers of the angiogenic cascade like the integrin {alpha}{sub v}{beta}{sub 3}. For molecular imaging of integrin expression, the use of radiolabelled peptides is still the only approach that has been successfully translated into the clinic. In this review we will summarize the current data on imaging of {alpha}{sub v}{beta}{sub 3} expression using radiolabelled RGD peptides with a focus on tracers already in clinical use. A perspective will be presented on the future clinical use of radiolabelled RGD peptides including an outlook on potential applications for radionuclide therapy. (orig.)

  11. Gastrin Receptor-Avid Peptide Conjugates

    Energy Technology Data Exchange (ETDEWEB)

    Hoffman, Timothy J. (Columbia, MO); Volkert, Wynn A. (Columbia, MO); Li, Ning (Baltimore, MD); Sieckman, Gary (Ashland, MO); Higginbotham, Chrys-Ann (Columbia, MO)

    2005-07-26

    A compound for use as a therapeutic or diagnostic radiopharmaceutical includes a group capable of complexing a medically useful metal attached to a moiety which is capable of binding to a gastrin releasing peptide receptor. A method for treating a subject having a neoplastic disease includes administering to the subject an effective amount of a radiopharmaceutical having a metal chelated with a chelating group attached to a moiety capable of binding to a gastrin releasing peptide receptor expressed on tumor cells with subsequent internalization inside of the cell. A method of forming a therapeutic or diagnostic compound includes reacting a metal synthon with a chelating group covalently linked with a moiety capable of binding a gastrin releasing peptide receptor.

  12. Gastrin receptor-avid peptide conjugates

    Energy Technology Data Exchange (ETDEWEB)

    Hoffman, Timothy J.; Volkert, Wynn A.; Sieckman, Gary; Smith, Charles J.; Gali, Hariprasad

    2006-06-13

    A compound for use as a therapeutic or diagnostic radiopharmaceutical includes a group capable of complexing a medically useful metal attached to a moiety which is capable of binding to a gastrin releasing peptide receptor. A method for treating a subject having a neoplastic disease includes administering to the subject an effective amount of a radiopharmaceutical having a metal chelated with a chelating group attached to a-moiety capable of binding to a gastrin releasing peptide receptor expressed on tumor cells with subsequent internalization inside of the cell. A method of forming a therapeutic or diagnostic compound includes reacting a metal synthon with a chelating group covalently linked with a moiety capable of binding a gastrin releasing peptide receptor.

  13. Gastrin receptor-avid peptide conjugates

    Energy Technology Data Exchange (ETDEWEB)

    Hoffman, Timothy J.; Volkert, Wynn A.; Li, Ning; Sieckman, Gary; Higginbotham, Chrys-Ann

    2006-12-12

    A compound for use as a therapeutic or diagnostic radiopharmaceutical includes a group capable of complexing a medically useful metal attached to a moiety which is capable of binding to a gastrin releasing peptide receptor. A method for treating a subject having a neoplastic disease includes administering to the subject an effective amount of a radiopharmaceutical having a metal chelated with a chelating group attached to a moiety capable of binding to a gastrin releasing peptide receptor expressed on tumor cells with subsequent internalization inside of the cell. A method of forming a therapeutic or diagnostic compound includes reacting a metal synthon with a chelating group covalently linked with a moiety capable of binding a gastrin releasing peptide receptor.

  14. Coupling of carbon and peptide nanotubes.

    Science.gov (United States)

    Montenegro, Javier; Vázquez-Vázquez, Carlos; Kalinin, Arseny; Geckeler, Kurt E; Granja, Juan R

    2014-02-12

    Two of the main types of nanotubular architectures are the single-walled carbon nanotubes (SWCNTs) and the self-assembling cyclic peptide nanotubes (SCPNs). We here report the preparation of the dual composite resulting from the ordered combination of both tubular motifs. In the resulting architecture, the SWCNTs can act as templates for the assembly of SCPNs that engage the carbon nanotubes noncovalently via pyrene "paddles", each member of the resulting hybrid stabilizing the other in aqueous solution. The particular hybrids obtained in the present study formed highly ordered oriented arrays and display complementary properties such as electrical conductivity. Furthermore, a self-sorting of the cyclic peptides toward semiconducting rather than metallic SWCNTs is also observed in the aqueous dispersions. It is envisaged that a broad range of exploitable properties may be achieved and/or controlled by varying the cyclic peptide components of similar SWCNT/SCPN hybrids.

  15. Design and Application of Antimicrobial Peptide Conjugates.

    Science.gov (United States)

    Reinhardt, Andre; Neundorf, Ines

    2016-05-11

    Antimicrobial peptides (AMPs) are an interesting class of antibiotics characterized by their unique antibiotic activity and lower propensity for developing resistance compared to common antibiotics. They belong to the class of membrane-active peptides and usually act selectively against bacteria, fungi and protozoans. AMPs, but also peptide conjugates containing AMPs, have come more and more into the focus of research during the last few years. Within this article, recent work on AMP conjugates is reviewed. Different aspects will be highlighted as a combination of AMPs with antibiotics or organometallic compounds aiming to increase antibacterial activity or target selectivity, conjugation with photosensitizers for improving photodynamic therapy (PDT) or the attachment to particles, to name only a few. Owing to the enormous resonance of antimicrobial conjugates in the literature so far, this research topic seems to be very attractive to different scientific fields, like medicine, biology, biochemistry or chemistry.

  16. Environmentally responsive peptides as anticancer drug carriers.

    Science.gov (United States)

    Aluri, Suhaas; Janib, Siti M; Mackay, J Andrew

    2009-09-30

    The tumor microenvironment provides multiple cues that may be exploited to improve the efficacy of established chemotherapeutics; furthermore, polypeptides are uniquely situated to capitalize on these signals. Peptides provide: 1) a rich repertoire of biologically specific interactions to draw upon; 2) environmentally responsive phase behaviors, which may be tuned to respond to signatures of disease; 3) opportunities to direct self-assembly; 4) control over routes of biodegradation; 5) the option to seamlessly combine functionalities into a single polymer via a one-step biosynthesis. As development of cancer-targeted nanocarriers expands, peptides provide a unique source of functional units that may target disease. This review explores potential microenvironmental physiology indicative of tumors and peptides that have demonstrated an ability to target and deliver to these signals.

  17. In Silico Design of Anticancer Peptides.

    Science.gov (United States)

    Kumar, Shailesh; Li, Hui

    2017-01-01

    In the past few years, small peptides having anticancer properties have emerged as a potential avenue for cancer therapy. Compared to current anti-cancer chemotherapeutic drugs (or small molecules), anticancer peptides (ACPs) have numerous advantageous properties, such as high specificity, low production cost, high tumor penetration, ease of synthesis and modification. However, in wet lab setups, identification and characterization of novel ACPs is a time-consuming and labor-intensive process. Therefore, in silico designing of anticancer peptides is beneficial, prior to their synthesis and characterization. This approach is less time consuming and more cost-effective. In this chapter, we discuss a web-based tool, AntiCP (http://crdd.osdd.net/raghava/anticp/), for designing ACPs.

  18. Design and Application of Antimicrobial Peptide Conjugates

    Directory of Open Access Journals (Sweden)

    Andre Reinhardt

    2016-05-01

    Full Text Available Antimicrobial peptides (AMPs are an interesting class of antibiotics characterized by their unique antibiotic activity and lower propensity for developing resistance compared to common antibiotics. They belong to the class of membrane-active peptides and usually act selectively against bacteria, fungi and protozoans. AMPs, but also peptide conjugates containing AMPs, have come more and more into the focus of research during the last few years. Within this article, recent work on AMP conjugates is reviewed. Different aspects will be highlighted as a combination of AMPs with antibiotics or organometallic compounds aiming to increase antibacterial activity or target selectivity, conjugation with photosensitizers for improving photodynamic therapy (PDT or the attachment to particles, to name only a few. Owing to the enormous resonance of antimicrobial conjugates in the literature so far, this research topic seems to be very attractive to different scientific fields, like medicine, biology, biochemistry or chemistry.

  19. Kinetics of Peptide Folding in Lipid Membranes

    Science.gov (United States)

    Oh, Kwang-Im; Smith-Dupont, Kathryn B.; Markiewicz, Beatrice N.; Gai, Feng

    2015-01-01

    Despite our extensive understanding of water-soluble protein folding kinetics, much less is known about the folding dynamics and mechanisms of membrane proteins. However, recent studies have shown that for relatively simple systems, such as peptides that form a transmembrane α-helix, helical dimer, or helix-turn-helix, it is possible to assess the kinetics of several important steps, including peptide binding to the membrane from aqueous solution, peptide folding on the membrane surface, helix insertion into the membrane, and helix-helix association inside the membrane. Herein, we provide a brief review of these studies and also suggest new initiation and probing methods that could lead to improved temporal and structural resolution in future experiments. PMID:25808575

  20. Glucagon-like peptides 1 and 2

    DEFF Research Database (Denmark)

    Kissow, Hannelouise

    2015-01-01

    -effects. RECENT FINDINGS: The intestinal glucagon-like peptide-2 (GLP-2) is secreted from the intestinal endocrine L cells after nutrient intake, but recent findings show that the peptide concentration in the plasma also rises after intestinal injury and that GLP-2 receptor activation is crucial for intestinal...... healing. The antidiabetic hormone GLP-1, cosecreted with GLP-2, diminished mucositis in an animal model of the condition. Therefore, both peptides could be involved in the pathophysiology of mucositis. SUMMARY: The intestinal GLPs have shown beneficial effects in experimental trials and have potential...... for therapeutic use. In type 2 diabetic and obese patients, GLP secretion is impaired. Elucidating the role of these endogenous hormones could lead to the identification of mucositis risk factors and an alternative preventive therapy for these patients....

  1. Neoglycolipids for Prolonging the Effects of Peptides

    DEFF Research Database (Denmark)

    van Witteloostuijn, Søren Blok; Mannerstedt, Karin Margareta Sophia; Wismann, Pernille

    2017-01-01

    Novel principles for optimizing the properties of peptide-based drugs are needed in order to leverage their full pharmacological potential. We present the design, synthesis, and evaluation of a library of neoglycolipidated glucagon-like peptide 1 (GLP-1) analogues, which are valuable drug...... candidates for treatment of type 2 diabetes and obesity. Neoglycolipidation of GLP-1 balanced the lipophilicity, directed formation of soluble oligomers, and mediated albumin binding. Moreover, neoglycolipidation did not compromise bioactivity, as in vitro potency of neoglycolipidated GLP-1 analogues...... was maintained or even improved compared to native GLP-1. This translated into pronounced in vivo efficacy in terms of both decreased acute food intake and improved glucose homeostasis in mice. Thus, we propose neoglycolipidation as a novel, general method for modulating the properties of therapeutic peptides...

  2. Aerosolized Medications for Gene and Peptide Therapy.

    Science.gov (United States)

    Laube, Beth L

    2015-06-01

    Inhalation therapy has matured to include drugs that: (1) deliver nucleic acids that either lead to the restoration of a gene construct or protein coding sequence in a population of cells or suppress or disrupt production of an abnormal gene product (gene therapy); (2) deliver peptides that target lung diseases such as asthma, sarcoidosis, pulmonary hypertension, and cystic fibrosis; and (3) deliver peptides to treat diseases outside the lung whose target is the systemic circulation (systemic drug delivery). These newer applications for aerosol therapy are the focus of this paper, and I discuss the status of each and the challenges that remain to their successful development. Drugs that are highlighted include: small interfering ribonucleic acid to treat lung cancer and Mycobacterium tuberculosis; vectors carrying the normal alpha-1 antitrypsin gene to treat alpha-1 antitrypsin deficiency; vectors carrying the normal cystic fibrosis transmembrane conductance regulator gene to treat cystic fibrosis; vasoactive intestinal peptide to treat asthma, pulmonary hypertension, and sarcoidosis; glutathione to treat cystic fibrosis; granulocyte-macrophage colony-stimulating factor to treat pulmonary alveolar proteinosis; calcitonin for postmenopausal osteoporosis; and insulin to treat diabetes. The success of these new aerosol applications will depend on many factors, such as: (1) developing gene therapy formulations that are safe for acute and chronic administrations to the lung, (2) improving the delivery of the genetic material beyond the airway mucus barrier and cell membrane and transferring the material to the cell cytoplasm or the cell nucleus, (3) developing aerosol devices that efficiently deliver genetic material and peptides to their lung targets over a short period of time, (4) developing devices that increase aerosol delivery to the lungs of infants, (5) optimizing the bioavailability of systemically delivered peptides, and (6) developing peptide formulations for

  3. Peptides at the Interface: Self-Assembly of Amphiphilic Designer Peptides and Their Membrane Interaction Propensity.

    Science.gov (United States)

    Kornmueller, Karin; Lehofer, Bernhard; Meindl, Claudia; Fröhlich, Eleonore; Leitinger, Gerd; Amenitsch, Heinz; Prassl, Ruth

    2016-11-14

    Self-assembling amphiphilic designer peptides have been successfully applied as nanomaterials in biomedical applications. Understanding molecular interactions at the peptide-membrane interface is crucial, since interactions at this site often determine (in)compatibility. The present study aims to elucidate how model membrane systems of different complexity (in particular single-component phospholipid bilayers and lipoproteins) respond to the presence of amphiphilic designer peptides. We focused on two short anionic peptides, V4WD2 and A6YD, which are structurally similar but showed a different self-assembly behavior. A6YD self-assembled into high aspect ratio nanofibers at low peptide concentrations, as evidenced by synchrotron small-angle X-ray scattering and electron microscopy. These supramolecular assemblies coexisted with membranes without remarkable interference. In contrast, V4WD2 formed only loosely associated assemblies over a large concentration regime, and the peptide promoted concentration-dependent disorder on the membrane arrangement. Perturbation effects were observed on both membrane systems although most likely induced by different modes of action. These results suggest that membrane activity critically depends on the peptide's inherent ability to form highly cohesive supramolecular structures.

  4. Application of mimotope peptides of fumonisin b1 in Peptide ELISA.

    Science.gov (United States)

    Liu, Xing; Xu, Yang; He, Qing-hua; He, Zhen-yun; Xiong, Zheng-ping

    2013-05-22

    Anti-fumonisin B(1) (FB(1)) McAb 1D11 was used as the target for biopanning from a phage random loop-constrained heptapeptide library. After three cycles of panning, seven phages with three mimotope peptides were selected to mimic the binding of FB(1) to 1D11. After the identification of phage ELISA, the phage clone that showed the best linear range of detection was chosen for further research. One peptide with the inserted peptide sequence of the phage was synthetized, named CT-452. An indirect competitive ELISA (peptide ELISA) for detecting FB(1) was established using the CT-452-bovine serum albumin conjugate as coating antigen. The linear range of the inhibition curve was 1.77-20.73 ng/mL. The half inhibitory concentration (IC50) was 6.06 ng/mL, and the limit of detection was 1.18 ng/mL. This method was compared with conventional indirect ELISA (commercial ELISA kit) and high-performance liquid chromatography (HPLC), and the results showed the reliability of the peptide ELISA for the determination of FB(1) in cereal samples. The relationship between the CT-452 and FB(1) standard concentrations in peptide ELISA was evaluated. The results indicated that synthetic peptide CT-452 can replace the FB(1) standard to establish an immunoassay free of FB(1).

  5. Hydroxyapatite Growth Inhibition Effect of Pellicle Statherin Peptides.

    Science.gov (United States)

    Xiao, Y; Karttunen, M; Jalkanen, J; Mussi, M C M; Liao, Y; Grohe, B; Lagugné-Labarthet, F; Siqueira, W L

    2015-08-01

    In our recent studies, we have shown that in vivo-acquired enamel pellicle is a sophisticated biological structure containing a significant portion of naturally occurring salivary peptides. From a functional aspect, the identification of peptides in the acquired enamel pellicle is of interest because many salivary proteins exhibit functional domains that maintain the activities of the native protein. Among the in vivo-acquired enamel pellicle peptides that have been newly identified, 5 peptides are derived from statherin. Here, we assessed the ability of these statherin pellicle peptides to inhibit hydroxyapatite crystal growth. In addition, atomistic molecular dynamics (MD) simulations were performed to better understand the underlying physical mechanisms of hydroxyapatite growth inhibition. A microplate colorimetric assay was used to quantify hydroxyapatite growth. Statherin protein, 5 statherin-derived peptides, and a peptide lacking phosphate at residues 2 and 3 were analyzed. Statherin peptide phosphorylated on residues 2 and 3 indicated a significant inhibitory effect when compared with the 5 other peptides (P hydroxyapatite for phosphopeptides, whereas unphosphorylated peptides interacted weakly with the hydroxyapatite. Our data suggest that the presence of a covalently linked phosphate group (at residues 2 and 3) in statherin peptides modulates the effect of hydroxyapatite growth inhibition. This study provides a mechanism to account for the composition and function of acquired enamel pellicle statherin peptides that will contribute as a base for the development of biologically stable and functional synthetic peptides for therapeutic use against dental caries and/or periodontal disease. © International & American Associations for Dental Research 2015.

  6. Antimicrobial peptides in innate immune responses

    DEFF Research Database (Denmark)

    Sorensen, O.E.; Borregaard, N.; Cole, A.M.

    2008-01-01

    Antimicrobial peptides (AMPs) are ancient effector molecules in the innate immune response of eukaryotes. These peptides are important for the antimicrobial efficacy of phagocytes and for the innate immune response mounted by epithelia of humans and other mammals. AMPs are generated either by de...... novo synthesis or by proteolytic cleavage from antimicrobially inactive proproteins. Studies of human diseases and animal studies have given important clues to the in vivo role of AMPs. It is now evident that dysregulation of the generation of AMPs in innate immune responses plays a role in certain...

  7. Peptides as catalysts in the RNA world

    DEFF Research Database (Denmark)

    Wieczorek, Rafal; Dörr, Mark; Luisi, Pier Luigi

    peptides, which in turn shifted the equilibrium to produce even more product. In the present work we describe a prebiotically plausible system in which the SerHis dipeptide acts as catalyst for the formation of RNA oligomers from imidazole derivatives of mononucleotides. The thermodynamic shift towards...... was sequestered into ice crystals and the other reactants were up-concentrated in the remaining liquid microinclusions, thus creating an environment with low water activity in which condensation reactions can occur. The ability of simple peptides to catalyze RNA synthesis could represent a link between prebiotic...

  8. Nuclear oncology with monoclonal antibodies and peptides

    Energy Technology Data Exchange (ETDEWEB)

    Hosono, Makoto [Saitama Medical School, Kawagoe (Japan). Saitama Medical Center

    1998-10-01

    Imaging and therapy using radiolabeled monoclonal antibodies have proved useful in many clinical studies. However, immunogenicity of mouse antibodies to human and insufficient tumor-to-normal tissue ratios remained to be solved. Chimerization and humanization by genetic engineering, and multistep targeting techniques have enabled lower immunogenicity and higher tumor-to-normal tissue contrast. Peptides like somatostatin-analogs have been reportedly useful in imaging tumors, which are either somatostatin receptor positive or negative. Elevated normal tissue accumulation of radiolabeled peptides is a drawback in aiming internal radiation therapy. (author). 51 refs.

  9. Peptide signalling during angiosperm seed development.

    Science.gov (United States)

    Ingram, Gwyneth; Gutierrez-Marcos, Jose

    2015-08-01

    Cell-cell communication is pivotal for the coordination of various features of plant development. Recent studies in plants have revealed that, as in animals, secreted signal peptides play critical roles during reproduction. However, the precise signalling mechanisms in plants are not well understood. In this review, we discuss the known and putative roles of secreted peptides present in the seeds of angiosperms as key signalling factors involved in coordinating different aspects of seed development. © The Author 2015. Published by Oxford University Press on behalf of the Society for Experimental Biology. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  10. An automated Teflon microfluidic peptide synthesizer.

    Science.gov (United States)

    Zheng, Hui; Wang, Weizhi; Li, Xiaojun; Wang, Zihua; Hood, Leroy; Lausted, Christopher; Hu, Zhiyuan

    2013-09-07

    We present a microfluidic synthesizer made entirely of Teflon material for solid phase peptide synthesis (SPPS). Solvent-resistant perfluoroalkoxy (PFA) was used to construct chip-sized devices featuring multiple tri-layer pneumatic microvalves. Using these devices, model peptides were automatically synthesized and cleaved in situ in a continuous-flow manner. The total coupling and cleavage time was significantly reduced compared to conventional bulk reactors. The synthesis of a decapeptide, for instance, took less than 6 h using our device while it usually takes more than three days using conventional reactors.

  11. Cysteine-containing peptides having antioxidant properties

    Science.gov (United States)

    Bielicki, John K.

    2007-05-15

    The term "homology" or "homologous" means an amino acid similarity measured by the program, BLAST (Altschul et al (1997), "Gapped BLAST and PSI-BLAST: a new generation of protein database search programs", Nucleic Acids Res. 25:33 89 3402), and expressed as --(% identity n/n). In measuring homology between a peptide and a protein of greater size, homology is measured only in the corresponding region; that is, the protein is regarded as only having the same general length as the peptide, allowing for gaps and insertions.

  12. A cyclic peptidic serine protease inhibitor

    DEFF Research Database (Denmark)

    Zhao, Baoyu; Xu, Peng; Jiang, Longguang

    2014-01-01

    plasminogen activator (uPA). We used X-ray crystal structure analysis, site-directed mutagenesis, liquid state NMR, surface plasmon resonance analysis, and isothermal titration calorimetry and wild type and engineered variants of murine and human uPA. We demonstrate that Arg6 inserts into the S1 specificity......Peptides are attracting increasing interest as protease inhibitors. Here, we demonstrate a new inhibitory mechanism and a new type of exosite interactions for a phage-displayed peptide library-derived competitive inhibitor, mupain-1 (CPAYSRYLDC), of the serine protease murine urokinase-type...

  13. Natriuretic Peptides in Anxiety and Panic Disorder.

    Science.gov (United States)

    Meyer, T; Herrmann-Lingen, C

    2017-01-01

    Natriuretic peptides exert pleiotropic effects on the cardiovascular system, including natriuresis, diuresis, vasodilation, and lusitropy, by signaling through membrane-bound guanylyl cyclases. In addition to their use as diagnostic and prognostic markers for heart failure, accumulating behavioral evidence suggests that these hormones also modulate anxiety symptoms and panic attacks. This review summarizes our current knowledge of the role of natriuretic peptides in animal and human anxiety and highlights some novel aspects from recent clinical studies on this topic. © 2017 Elsevier Inc. All rights reserved.

  14. Novel Zn2+-chelating peptides selected from a fimbria-displayed random peptide library

    DEFF Research Database (Denmark)

    Kjærgaard, Kristian; Schembri, Mark; Klemm, Per

    2001-01-01

    H adhesin. FimH is a component of the fimbrial organelle that can accommodate and display a diverse range of peptide sequences on the E. coli cell surface. In this study we have constructed a random peptide library in FimH. The library, consisting of similar to 40 million individual clones, was screened...... for peptide sequences that conferred on recombinant cells the ability to bind Zn2+. By serial selection, sequences that exhibited various degrees of binding affinity and specificity toward Zn2+ were enriched. None of the isolated sequences showed similarity to known Zn2+-binding proteins, indicating...

  15. Potent Antibacterial Antisense Peptide-Peptide Nucleic Acid Conjugates Against Pseudomonas aeruginosa

    DEFF Research Database (Denmark)

    Ghosal, Anubrata; Nielsen, Peter E

    2012-01-01

    Pseudomonas aeruginosa is an opportunistic pathogen causing severe infections in hospital settings, especially with immune compromised patients, and the increasing prevalence of multidrug resistant strains urges search for new drugs with novel mechanisms of action. In this study we introduce...... antisense peptide-peptide nucleic acid (PNA) conjugates as antibacterial agents against P. aeruginosa. We have designed and optimized antisense peptide-PNA conjugates targeting the translation initiation region of the ftsZ gene (an essential bacterial gene involved in cell division) or the acpP gene (an...... significantly reduced bacterial survival. These results open the possibility of development of antisense antibacterials for treatment of Pseudomonas infections....

  16. Screening And Optimizing Antimicrobial Peptides By Using SPOT-Synthesis

    Science.gov (United States)

    López-Pérez, Paula M.; Grimsey, Elizabeth; Bourne, Luc; Mikut, Ralf; Hilpert, Kai

    2017-04-01

    Peptide arrays on cellulose are a powerful tool to investigate peptide interactions with a number of different molecules, for examples antibodies, receptors or enzymes. Such peptide arrays can also be used to study interactions with whole cells. In this review, we focus on the interaction of small antimicrobial peptides with bacteria. Antimicrobial peptides (AMPs) can kill multidrug-resistant (MDR) human pathogenic bacteria and therefore could be next generation antibiotics targeting MDR bacteria. We describe the screen and the result of different optimization strategies of peptides cleaved from the membrane. In addition, screening of antibacterial activity of peptides that are tethered to the surface is discussed. Surface-active peptides can be used to protect surfaces from bacterial infections, for example implants.

  17. Current trends in the clinical development of peptide therapeutics.

    Science.gov (United States)

    Saladin, Pauline M; Zhang, Bodi D; Reichert, Janice M

    2009-12-01

    The development of peptides as drugs is attracting increasing attention from the pharmaceutical industry. This interest is at least partially a consequence of the widespread acceptance of therapeutic proteins by physicians and patients, and because of improvements to problems such as a short half-life and delivery issues. The markets for peptide-based compounds can be substantial, with six peptide drugs attaining global sales of more than US $750 million in 2008. To track trends in the clinical development and marketing approval of peptides, Tufts Center for the Study of Drug Development and Ferring Research Institute compiled publically available data for peptides that entered clinical trials sponsored by commercial firms, with a focus on peptide therapeutics, but also including peptide vaccines and diagnostics. The results provide an historical overview of the development of peptide therapeutics, and may inform strategic planning in this area.

  18. Self-Assembly and Hydrogelation of Peptide Amphiphiles

    Directory of Open Access Journals (Sweden)

    Wahyudi Priyono Suwarso

    2012-04-01

    Full Text Available Seven peptide amphiphiles were successfully synthesized using solid phase peptide synthesis method. Peptide amphiphiles were characterized using matrix assisted laser desorption/ionization (MALDI. Atomic force microscopy (AFM study showed that peptide amphiphiles having glycine, valine, or proline as linker, self-assembled into 100-200 nm nanofibers structure. According to our research, both peptide amphiphile with positive and negative charges bear similar self-assembly properties. Peptide amphiphile also showed its capability as low molecular weight gelator (LMWG. Peptide amphiphiles bearing C-16 and C-12 as alkyl showed better hydrogelation properties than C-8 alkyl. Five out of seven peptide amphiphiles have minimum gelation concentration (MGC lower than 1% (w/v.

  19. Research progress in structure-activity relationship of bioactive peptides.

    Science.gov (United States)

    Li, Ying; Yu, Jianmei

    2015-02-01

    Bioactive peptides are specific protein fragments that have positive impact on health. They are important sources of new biomedicine, energy and high-performance materials. The beneficial effects of bioactive peptides are due to their antioxidant, antihypertensive, anticarcinogenic, antimicrobial, and immunomodulatory activities. The structure-activity relationship of bioactive peptides plays a significant role in the development of innovative and unconventional synthetic polymeric counterparts. It provides the basis of the stereospecific synthesis, transformation, and development of bioactive peptide products. This review covers the progress of studies in the structure-activity relationship of some bioactive peptides including antioxidant peptides, angiotensin-I-converting enzyme-inhibitory peptides, and anticarcinogenic peptides in the past decade.

  20. Enzymatic transhalogenation of dendritic RGD peptide constructs with the fluorinase.

    Science.gov (United States)

    Thompson, Stephen; Fleming, Ian N; O'Hagan, David

    2016-03-21

    The substrate scope of fluorinase enzyme mediated transhalogenation reactions is extended. Substrate tolerance allows a peptide cargo to be tethered to a 5'-chloro-5'-deoxynucleoside substrate for transhalogenation by the enzyme to a 5'-fluoro-5'-deoxynucleoside. The reaction is successfully extended from that previously reported for a monomeric cyclic peptide (cRGD) to cargoes of dendritic scaffolds carrying two and four cyclic peptide motifs. The RGD peptide sequence is known to bind upregulated αVβ3 integrin motifs on the surface of cancer cells and it is demonstrated that the fluorinated products have a higher affinity to αVβ3 integrin than their monomeric counterparts. Extending the strategy to radiolabelling of the peptide cargoes by tagging the peptides with [(18)F]fluoride was only moderately successful due to the poor water solubility of these higher order peptide scaffolds although the strategy holds promise for peptide constructs with improved solubility.