Change of the structure and the digestibility of myofibrillar proteins in Nanjing dry-cured duck during processing.

Science.gov (United States)

Du, Xiaojing; Sun, Yangying; Pan, Daodong; Wang, Ying; Ou, Changrong; Cao, Jinxuan

2018-06-01

To investigate the change of bioavailability and structure of myofibrillar proteins during Nanjing dry-cured duck processing, carbonyl content, sulfhydryl (SH) group, disulfide (SS) group, sodium dodecyl sulfate polyacrylamide gel electrophoresis, surface hydrophobicity, secondary structures and in vitro digestibility were determined. During processing, carbonyl content and surface hydrophobicity increased; SH turned into SS group; α-helix turned into β-sheet and random coil fractions. Protein degradation occurred during dry-curing and drying-ripening stages. The in vitro digestibility of pepsin and pancreatic proteases increased during the salt curing stage and decreased during the drying-ripening stage. The increase of digestibility could be attributed to the mild oxidation, degradation and unfolding of proteins while the decrease of digestibility was related to the intensive oxidation and aggregation of proteins. Protein degradation was not a main factor of digestibility during the drying-ripening stage. Results demonstrated that the bioavailability loss of myofibrillar proteins in Nanjing dry-cured duck occurred during the stage of drying-ripening instead of curing. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

Ca2+-dependent proteolytic activity in crab claw muscle: effects of inhibitors and specificity for myofibrillar proteins

International Nuclear Information System (INIS)

Mykles, D.L.; Skinner, D.M.

1983-01-01

The claw closer muscle of the Bermuda land crab, Gecarcinus lateralis, undergoes a sequential atrophy and restoration during each molting cycle. The role of Ca 2+ -dependent proteinases in the turn-over of myofibrillar protein in normal anecdysial (intermolt) claw muscle is described. Crab Ca 2+ -dependent proteinase degrades the myofibrillar proteins actin, myosin heavy and light chains, paramyosin, tropomyosin, and troponin-T and -I. Ca 2+ -dependent proteinase activity in whole homogenates and 90,000 x g supernatant fractions from muscle homogenates has been characterized with respect to Ca 2+ requirement, substrate specificity, and effects of proteinase inhibitors. The enzyme is inhibited by antipain, leupeptin, E-64, and iodoacetamide; it is insensitive to pepstatin A. The specificity of crab Ca 2+ -dependent proteinase was examined with native myosin with normal ATPase activity as well as with radioiodinated myosin and radioiodinated hemolymph proteins. Hydrolysis of 125 I-myosin occurs in two phases, both Ca 2+ -dependent: (1) heavy chain (M/sub r/ = 200,000) is cleaved into four large fragments (M/sub r/ = 160,000, 110,000, 73,000, 60,000) and numerous smaller fragments; light chain (M/sub r/ = 18,000) is cleaved to a 15,000-Da fragment; (2) the fragments produced in the first phase are hydrolyzed to acid-soluble material. Although radioiodinated native hemolymph proteins are not susceptible to the Ca 2+ -dependent proteinase, those denatured by carboxymethylation are degraded. These data suggest that crab Ca 2+ -dependent proteinase is involved in turnover of myofibrillar protein in normal muscle and muscle undergoing proecdysial atrophy

Filmes biodegradáveis à base de proteínas miofibrilares de pescado Biodegradable films based on myofibrillar proteins of fish

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Elessandra da Rosa Zavareze

2012-05-01

Full Text Available O objetivo deste trabalho foi estudar as propriedades físicas, mecânicas e de barreira dos filmes produzidos a partir de diferentes concentrações de proteínas miofibrilares de pescado de baixo valor comercial. O pescado utilizado foi a corvina (Micropogonias furnieri, que foi eviscerada e filetada. As proteínas miofibrilares foram obtidas do músculo, em sucessivas lavagens com água destilada. Os filmes foram produzidos com 3, 4 e 5% de proteínas miofibrilares pelo método de casting. Os filmes foram analisados nos seguintes aspectos: espessura, solubilidade, opacidade, resistência à tração, elongação e permeabilidade ao vapor de água (PVA. O aumento da concentração de proteínas miofibrilares atribuiu aos filmes maior espessura, opacidade, resistência à tração e PVA; no entanto, conferiu menor elongação na ruptura dos mesmos.The objective of this work was to study the physical, mechanical and barrier properties of the films produced from different concentrations of myofibrillar proteins of fish. The fish used was croaker (Micropogonias furnieri, which was gutted and filleted. The myofibrillar proteins were obtained through the muscle with successive washes with distilled water. The films were made with 3, 4 and 5% of myofibrillar proteins by the method of casting. The films were analyzed by thickness, solubility, opacity, tensile strength, elongation and water vapor permeability (PVA. The increase of myofibrillar proteins concentration in the films increased thickness, opacity, tensile strength and water vapor permeability and reduced elongation at break of the film.

Zebrafish models of BAG3 myofibrillar myopathy suggest a toxic gain of function leading to BAG3 insufficiency.

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Ruparelia, Avnika A; Oorschot, Viola; Vaz, Raquel; Ramm, Georg; Bryson-Richardson, Robert J

2014-12-01

Mutations in the co-chaperone Bcl2-associated athanogene 3 (BAG3) can cause myofibrillar myopathy (MFM), a childhood-onset progressive muscle disease, characterized by the formation of protein aggregates and myofibrillar disintegration. In contrast to other MFM-causing proteins, BAG3 has no direct structural role, but regulates autophagy and the degradation of misfolded proteins. To investigate the mechanism of disease in BAG3-related MFM, we expressed wild-type BAG3 or the dominant MFM-causing BAG3 (BAG3(P209L)) in zebrafish. Expression of the mutant protein results in the formation of aggregates that contain wild-type BAG3. Through the stimulation and inhibition of autophagy, we tested the prevailing hypothesis that impaired autophagic function is responsible for the formation of protein aggregates. Contrary to the existing theory, our studies reveal that inhibition of autophagy is not sufficient to induce protein aggregation. Expression of the mutant protein, however, did not induce myofibrillar disintegration and we therefore examined the effect of knocking down Bag3 function. Loss of Bag3 resulted in myofibrillar disintegration, but not in the formation of protein aggregates. Remarkably, BAG3(P209L) is able to rescue the myofibrillar disintegration phenotype, further demonstrating that its function is not impaired. Together, our knockdown and overexpression experiments identify a mechanism whereby BAG3(P209L) aggregates form, gradually reducing the pool of available BAG3, which eventually results in BAG3 insufficiency and myofibrillar disintegration. This mechanism is consistent with the childhood onset and progressive nature of MFM and suggests that reducing aggregation through enhanced degradation or inhibition of nucleation would be an effective therapy for this disease.

Polymorphism of myofibrillar proteins of rabbit skeletal-muscle fibres. An electrophoretic study of single fibres.

OpenAIRE

Salviati, G; Betto, R; Danieli Betto, D

1982-01-01

Rabbit predominantly fast-twitch-fibre and predominantly slow-twitch-fibre skeletal muscles of the hind limbs, the psoas, the diaphragm and the masseter muscles were fibre-typed by one-dimensional polyacrylamide-gel electrophoresis of the myofibrillar proteins of chemically skinned single fibres. Investigation of the distribution of fast-twitch-fibre and slow-twitch-fibre isoforms of myosin light chains and the type of myosin heavy chains, based on peptide 'maps' published in Cleveland. Fisch...

Water binding of proteins in the processing frankfurter-type sausages. Part. 1. Water-binding ability of freeze-dried meat fractions containing myofibrillar and stromal proteins.

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Heinevetter, L; Gassmann, B; Kroll, J

1987-01-01

As soon as possible and 48 h after slaughter respectively, from both blade-bone muscle groups of cattle and pig carcasses the "thick pieces" were excised, extracted, and fractionated. Residues and precipitates from water and salt extracts resulted were freeze-dried, and an improved Baumann capillary suction apparatus was used to measure their water binding capacity (WBC) with and without addition of 2% sodium chloride and/or heating to 80 degrees C. With one exception the WBC results followed a relative pattern demonstrating the final residues (stromal proteins and leavings of myofibrillar proteins) binding the highest amount of added water, precipitates of dialysis (mainly containing myofibrillar proteins) a remarkable amount and powdered meats the least. As scanning electron micrographs confirmed, there were no fibrous structures in the precipitates resulted from dialysis of salt solutions (1.0 mol/1). Heating decreased the spontaneous water uptake of all fractions. Addition of sodium chloride had only a noticeable capillary-suction and swelling effect on unheated samples. Hence swelling of undissolved protein structures (extraction of myosin and possibly of actomyosin) is therefore not the only way for water binding in frankfurter-type sausages.

Quantity and functionality of protein fractions in chicken breast fillets affected by white striping.

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Mudalal, S; Babini, E; Cavani, C; Petracci, M

2014-08-01

Recently, white striations parallel to muscle fibers direction have been observed on the surface of chicken breast, which could be ascribed to intensive growth selection. The aim of this study was to evaluate the effect of white striping on chemical composition with special emphasis on myofibrillar and sarcoplasmic protein fractions that are relevant to the processing features of chicken breast meat. During this study, a total of 12 pectoralis major muscles from both normal and white striped fillets were used to evaluate chemical composition, protein solubility (sarcoplasmic, myofibrillar, and total protein solubility), protein quantity (sarcoplasmic, myofibrillar, and stromal proteins), water holding capacity, and protein profile by SDS-PAGE analysis. White-striped fillets exhibited a higher percentage of moisture (75.4 vs. 73.8%; P cooking loss (33.7 vs. 27.4%; P chicken breast meat with white striping defect had different chemical composition (more fat and less protein) and protein quality and quantity (low content of myofibrillar proteins and high content of stromal proteins) with respect to normal meat. Furthermore, white striped fillets had lower protein functionality (higher cooking loss). All the former changes indicate that white striping has great impact on quality characteristics of chicken breast meat. © Poultry Science Association Inc.

Effect of resistance training and protein intake pattern on myofibrillar protein synthesis and proteome kinetics in older men in energy restriction.

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Murphy, Caoileann H; Shankaran, Mahalakshmi; Churchward-Venne, Tyler A; Mitchell, Cameron J; Kolar, Nathan M; Burke, Louise M; Hawley, John A; Kassis, Amira; Karagounis, Leonidas G; Li, Kelvin; King, Chelsea; Hellerstein, Marc; Phillips, Stuart M

2018-06-01

Strategies to enhance the loss of fat while preserving muscle mass during energy restriction are of great importance to prevent sarcopenia in overweight older adults. We show for the first time that the integrated rate of synthesis of numerous individual contractile, cytosolic and mitochondrial skeletal muscle proteins was increased by resistance training (RT) and unaffected by dietary protein intake pattern during energy restriction in free-living, obese older men. We observed a correlation between the synthetic rates of skeletal muscle-derived proteins obtained in serum (creatine kinase M-type, carbonic anhydrase 3) and the synthetic rates of proteins obtained via muscle sampling; and that the synthesis rates of these proteins in serum revealed the stimulatory effects of RT. These results have ramifications for understanding the influence of RT on skeletal muscle and are consistent with the role of RT in maintaining muscle protein synthesis and potentially supporting muscle mass preservation during weight loss. We determined how the pattern of protein intake and resistance training (RT) influenced longer-term (2 weeks) integrated myofibrillar protein synthesis (MyoPS) during energy restriction (ER). MyoPS and proteome kinetics were measured during 2 weeks of ER alone and 2 weeks of ER plus RT (ER + RT) in overweight/obese older men. Participants were randomized to consume dietary protein in a balanced (BAL: 25% daily protein per meal × 4 meals) or skewed (SKEW: 7:17:72:4% daily protein per meal) pattern (n = 10 per group). Participants ingested deuterated water during the consecutive 2-week periods, and skeletal muscle biopsies and serum were obtained at the beginning and conclusion of ER and ER + RT. Bulk MyoPS (i.e. synthesis of the myofibrillar protein sub-fraction) and the synthetic rates of numerous individual skeletal muscle proteins were quantified. Bulk MyoPS was not affected by protein distribution during ER or ER + RT (ER: BAL = 1.24�

Masseter muscle myofibrillar protein synthesis and degradation in an experimental critical illness myopathy model.

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Hazem Akkad

Full Text Available Critical illness myopathy (CIM is a debilitating common consequence of modern intensive care, characterized by severe muscle wasting, weakness and a decreased myosin/actin (M/A ratio. Limb/trunk muscles are primarily affected by this myopathy while cranial nerve innervated muscles are spared or less affected, but the mechanisms underlying these muscle-specific differences remain unknown. In this time-resolved study, the cranial nerve innervated masseter muscle was studied in a unique experimental rat intensive care unit (ICU model, where animals were exposed to sedation, neuromuscular blockade (NMB, mechanical ventilation, and immobilization for durations varying between 6 h and 14d. Gel electrophoresis, immunoblotting, RT-PCR and morphological staining techniques were used to analyze M/A ratios, myofiber size, synthesis and degradation of myofibrillar proteins, and levels of heat shock proteins (HSPs. Results obtained in the masseter muscle were compared with previous observations in experimental and clinical studies of limb muscles. Significant muscle-specific differences were observed, i.e., in the masseter, the decline in M/A ratio and muscle fiber size was small and delayed. Furthermore, transcriptional regulation of myosin and actin synthesis was maintained, and Akt phosphorylation was only briefly reduced. In studied degradation pathways, only mRNA, but not protein levels of MuRF1, atrogin-1 and the autophagy marker LC3b were activated by the ICU condition. The matrix metalloproteinase MMP-2 was inhibited and protective HSPs were up-regulated early. These results confirm that the cranial nerve innervated masticatory muscles is less affected by the ICU-stress response than limb muscles, in accordance with clinical observation in ICU patients with CIM, supporting the model' credibility as a valid CIM model.

Whey protein supplementation preserves postprandial myofibrillar protein synthesis during short-term energy restriction in overweight and obese adults.

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Hector, Amy J; Marcotte, George R; Churchward-Venne, Tyler A; Murphy, Caoileann H; Breen, Leigh; von Allmen, Mark; Baker, Steven K; Phillips, Stuart M

2015-02-01

Higher dietary energy as protein during weight loss results in a greater loss of fat mass and retention of muscle mass; however, the impact of protein quality on the rates of myofibrillar protein synthesis (MPS) and lipolysis, processes that are important in the maintenance of muscle and loss of fat, respectively, are unknown. We aimed to determine how the consumption of different sources of proteins (soy or whey) during a controlled short-term (14-d) hypoenergetic diet affected MPS and lipolysis. Men (n = 19) and women (n = 21) (age 35-65 y; body mass index 28-50 kg/m(2)) completed a 14-d controlled hypoenergetic diet (-750 kcal/d). Participants were randomly assigned, double blind, to receive twice-daily supplements of isolated whey (27 g/supplement) or soy (26 g/supplement), providing a total protein intake of 1.3 ± 0.1 g/(kg · d), or isoenergetic carbohydrate (25 g maltodextrin/supplement) resulting in a total protein intake of 0.7 ± 0.1 g/(kg · d). Before and after the dietary intervention, primed continuous infusions of L-[ring-(13)C6] phenylalanine and [(2)H5]-glycerol were used to measure postabsorptive and postprandial rates of MPS and lipolysis. Preintervention, MPS was stimulated more (P whey than with soy or carbohydrate. Postintervention, postabsorptive MPS decreased similarly in all groups (all P whey group, which was less (P whey. We conclude that whey protein supplementation attenuated the decline in postprandial rates of MPS after weight loss, which may be of importance in the preservation of lean mass during longer-term weight loss interventions. This trial was registered at clinicaltrials.gov as NCT01530646. © 2015 American Society for Nutrition.

Acute post-exercise myofibrillar protein synthesis is not correlated with resistance training-induced muscle hypertrophy in young men.

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Mitchell, Cameron J; Churchward-Venne, Tyler A; Parise, Gianni; Bellamy, Leeann; Baker, Steven K; Smith, Kenneth; Atherton, Philip J; Phillips, Stuart M

2014-01-01

Muscle hypertrophy following resistance training (RT) involves activation of myofibrillar protein synthesis (MPS) to expand the myofibrillar protein pool. The degree of hypertrophy following RT is, however, highly variable and thus we sought to determine the relationship between the acute activation of MPS and RT-induced hypertrophy. We measured MPS and signalling protein activation after the first session of resistance exercise (RE) in untrained men (n = 23) and then examined the relation between MPS with magnetic resonance image determined hypertrophy. To measure MPS, young men (24±1 yr; body mass index  = 26.4±0.9 kg•m²) underwent a primed constant infusion of L-[ring-¹³C₆] phenylalanine to measure MPS at rest, and acutely following their first bout of RE prior to 16 wk of RT. Rates of MPS were increased 235±38% (Pmuscle volume and acute rates of MPS measured over 1-3 h (r = 0.02), 3-6 h (r = 0.16) or the aggregate 1-6 h post-exercise period (r = 0.10). Hypertrophy after chronic RT was correlated (r = 0.42, P = 0.05) with phosphorylation of 4E-BP1(Thr37/46) at 1 hour post RE. We conclude that acute measures of MPS following an initial exposure to RE in novices are not correlated with muscle hypertrophy following chronic RT.

The Study of Effect of Surimi Production Steps on Chemical Composition and Electrophoresis Pattern of Myofibrillar Proteins of Mechanically Deboned poultry meat (MDPM

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Sh Haji BagherNaeeni

2013-08-01

Full Text Available Mechanically deboning poultry meat (MDPM is widely used due to its suitable technological properties as well as low lipids and saturated fatty acids contents. Besides, production processes applied during the surimi production can improve the technological properties of MDPM. That is to say, the production steps of surimi can change chemical composition and concentration of myofibrillar proteins and improve functional properties of MDPM. In this study, MDPM was prepared from the poultry meat. The production process consisted of 2 washing steps with sodium bicarbonate solution followed by another washing step with 4°C water. Afterwards, chemical properties of MDPM and surimi (moisture content, protein, lipid, and ash content as well as electrophoresis pattern were evaluated. Result showed that surimi production steps could significantly decrease protein, lipid and ash contents; however, moisture content of MDPM increased significantly. The result of electrophoresis indicated a significant increase in heavy chain myosin with 200 KDa and actin with 45 KDa molecular weights. It was concluded that the production steps improved the chemical properties and increased the concentration of MDPM myofibrillar proteins.

Fish oil supplementation suppresses resistance exercise and feeding-induced increases in anabolic signaling without affecting myofibrillar protein synthesis in young men.

Science.gov (United States)

McGlory, Chris; Wardle, Sophie L; Macnaughton, Lindsay S; Witard, Oliver C; Scott, Fraser; Dick, James; Bell, J Gordon; Phillips, Stuart M; Galloway, Stuart D R; Hamilton, D Lee; Tipton, Kevin D

2016-03-01

Fish oil (FO) supplementation potentiates muscle protein synthesis (MPS) in response to a hyperaminoacidemic-hyperinsulinemic infusion. Whether FO supplementation potentiates MPS in response to protein ingestion or when protein ingestion is combined with resistance exercise (RE) remains unknown. In a randomized, parallel group design, 20 healthy males were randomized to receive 5 g/day of either FO or coconut oil control (CO) for 8 weeks. After supplementation, participants performed a bout of unilateral RE followed by ingestion of 30 g of whey protein. Skeletal muscle biopsies were obtained before and after supplementation for assessment of muscle lipid composition and relevant protein kinase activities. Infusion of L-[ring-(13)C6] phenylalanine was used to measure basal myofibrillar MP Sat rest (REST), in a nonexercised leg following protein ingestion (FED) and following RE and protein ingestion (FEDEX).MPS was significantly elevated above REST during FEDEX in both the FO and CO groups, but there was no effect of supplementation. There was a significant increase in MPS in both groups above REST during FED but no effect of supplementation. Supplementation significantly decreased pan PKB activity at RESTin the FO group but not the CO group. There was a significant increase from REST at post-RE for PKB and AMPKα2 activity in the CO group but not in the FO group. In FEDEX, there was a significant increase in p70S6K1 activity from REST at 3 h in the CO group only. These data highlight that 8 weeks of FO supplementation alters kinase signaling activity in response to RE plus protein ingestion without influencing MPS. © 2016 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of the American Physiological Society and The Physiological Society.

Regulation of myofibrillar accumulation in chick muscle cultures - Evidence for the involvement of calcium and lysosomes in non-uniform turnover of contractile proteins

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Silver, Geri; Etlinger, Joseph D.

1985-01-01

The effects of calcium on the synthesis and the degradation of individual myofibrillar proteins were investigated using primary chick-leg skeletal muscle cultures labeled with S-35-methionine (for protein accumulation experiments) or Ca(2+)-45 (for calcium efflux experiments). It was found that the turnover of individual contractile proteins is regulated nonuniformly by a calcium-dependent mechanism involving lysosomes. The results also indicate that contractile proteins are released from the myofibril before their breakdown to amino acids.

Cardiac myofibrillar contractile properties during the progression from hypertension to decompensated heart failure.

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Hanft, Laurin M; Emter, Craig A; McDonald, Kerry S

2017-07-01

Heart failure arises, in part, from a constellation of changes in cardiac myocytes including remodeling, energetics, Ca 2+ handling, and myofibrillar function. However, little is known about the changes in myofibrillar contractile properties during the progression from hypertension to decompensated heart failure. The aim of the present study was to provide a comprehensive assessment of myofibrillar functional properties from health to heart disease. A rodent model of uncontrolled hypertension was used to test the hypothesis that myocytes in compensated hearts exhibit increased force, higher rates of force development, faster loaded shortening, and greater power output; however, with progression to overt heart failure, we predicted marked depression in these contractile properties. We assessed contractile properties in skinned cardiac myocyte preparations from left ventricles of Wistar-Kyoto control rats and spontaneous hypertensive heart failure (SHHF) rats at ~3, ~12, and >20 mo of age to evaluate the time course of myofilament properties associated with normal aging processes compared with myofilaments from rats with a predisposition to heart failure. In control rats, the myofilament contractile properties were virtually unchanged throughout the aging process. Conversely, in SHHF rats, the rate of force development, loaded shortening velocity, and power all increased at ~12 mo and then significantly fell at the >20-mo time point, which coincided with a decrease in left ventricular fractional shortening. Furthermore, these changes occurred independent of changes in β-myosin heavy chain but were associated with depressed phosphorylation of myofibrillar proteins, and the fall in loaded shortening and peak power output corresponded with the onset of clinical signs of heart failure. NEW & NOTEWORTHY This novel study systematically examined the power-generating capacity of cardiac myofilaments during the progression from hypertension to heart disease. Previously

Potential Biomarker of Myofibrillar Protein Oxidation in Raw and Cooked Ham: 3-Nitrotyrosine Formed by Nitrosation.

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Feng, Xianchao; Li, Chenyi; Ullah, Niamat; Hackman, Robert M; Chen, Lin; Zhou, Guanghong

2015-12-30

The stability of cured meat products is increased by the protection of its proteins from oxidation by sodium nitrite (NaNO2) during processing. This study investigated the effects of NaNO2 (0, 50, 100, 200, and 400 mg/kg) on the physiochemical and structural characteristics of myofibrillar protein (MP) in raw and cooked ham. The NaNO2 showed a dose-dependent antioxidant effect, by inhibiting carbonyl formation, dityrosine formation, and denaturation of MP, and a nitrosative effect, through the formation of 3-Nitrotyrosine (3-NT). The 3-NT content within MP of raw ham had distinct negative correlations with sulfhydryl content and surface hydrophobicity. The 3-NT content within MP of cooked ham had significantly negative correlations with carbonyl, sulfhydryl content and turbidity and had significantly positive correlations with disulfide content. These results indicated that 3-NT may be a potential marker for protein oxidation in raw and cooked cured meat products.

Comparison of myofibrillar protein degradation, antioxidant profile, fatty acids, metmyoglobin reducing activity, physicochemical properties and sensory attributes of gluteus medius and infraspinatus muscles in goats

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Kazeem D. Adeyemi

2016-06-01

Full Text Available Abstract Background The functionality of myofibrillar proteins is a major factor influencing the quality attributes of muscle foods. Nonetheless, the relationships between muscle type and oxidative changes in chevon during ageing are meagrely elucidated. Postmortem changes in antioxidant status and physicochemical properties of glycolytic gluteus medius (GM and oxidative infraspinatus (IS muscles in goats were compared. Methods Twenty Boer bucks (9–10 months old, body weight of 36.9 ± 0.725 kg were slaughtered and the carcasses were subjected to chill storage (4 ± 0.5 °C. Analyses were conducted on GM and IS muscles sampled on 0, 1, 4 and 7 d postmortem. Results Chill storage did not affect the antioxidant enzyme activities in both muscles. The IS had greater (P  0.05 on free thiol, MRA and TBARS. The GM had lower (P  0.05 on consumer preference for flavour, juiciness and overall acceptability. However, IS had higher (P < 0.05 tenderness score than GM on d 1 and 4 postmortem. Intramuscular fat was higher (P < 0.05 in IS compared with GM. Fatty acid composition did not differ between the muscles. However, GM had lower (P < 0.05 n-6/n-3 ratio than IS. The n-3 and n-6 PUFA declined (P < 0.05 while the SFA increased (P < 0.05 over storage. Conclusion The changes in myofibrillar proteins and physicochemical properties of goat meat during postmortem chill storage are muscle-dependent.

Acute post-exercise myofibrillar protein synthesis is not correlated with resistance training-induced muscle hypertrophy in young men.

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Cameron J Mitchell

Full Text Available Muscle hypertrophy following resistance training (RT involves activation of myofibrillar protein synthesis (MPS to expand the myofibrillar protein pool. The degree of hypertrophy following RT is, however, highly variable and thus we sought to determine the relationship between the acute activation of MPS and RT-induced hypertrophy. We measured MPS and signalling protein activation after the first session of resistance exercise (RE in untrained men (n = 23 and then examined the relation between MPS with magnetic resonance image determined hypertrophy. To measure MPS, young men (24±1 yr; body mass index  = 26.4±0.9 kg•m² underwent a primed constant infusion of L-[ring-¹³C₆] phenylalanine to measure MPS at rest, and acutely following their first bout of RE prior to 16 wk of RT. Rates of MPS were increased 235±38% (P<0.001 above rest 60-180 min post-exercise and 184±28% (P = 0.037 180-360 min post exercise. Quadriceps volume increased 7.9±1.6% (-1.9-24.7% (P<0.001 after training. There was no correlation between changes in quadriceps muscle volume and acute rates of MPS measured over 1-3 h (r = 0.02, 3-6 h (r = 0.16 or the aggregate 1-6 h post-exercise period (r = 0.10. Hypertrophy after chronic RT was correlated (r = 0.42, P = 0.05 with phosphorylation of 4E-BP1(Thr37/46 at 1 hour post RE. We conclude that acute measures of MPS following an initial exposure to RE in novices are not correlated with muscle hypertrophy following chronic RT.

Rheological Enhancement of Pork Myofibrillar Protein-Lipid Emulsion Composite Gels via Glucose Oxidase Oxidation/Transglutaminase Cross-Linking Pathway.

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Wang, Xu; Xiong, Youling L; Sato, Hiroaki

2017-09-27

Porcine myofibrillar protein (MP) was modified with glucose oxidase (GluOx)-iron that produces hydroxyl radicals then subjected to microbial transglutaminase (TGase) cross-linking in 0.6 M NaCl at 4 °C. The resulting aggregation and gel formation of MP were examined. The GluOx-mediated oxidation promoted the formation of both soluble and insoluble protein aggregates via disulfide bonds and occlusions of hydrophobic groups. The subsequent TGase treatment converted protein aggregates into highly cross-linked polymers. MP-lipid emulsion composite gels formed with such polymers exhibited markedly enhanced gelling capacity: up to 4.4-fold increases in gel firmness and 3.5-fold increases in gel elasticity over nontreated protein. Microstructural examination showed small oil droplets dispersed in a densely packed gel matrix when MP was oxidatively modified, and the TGase treatment further contributed to such packing. The enzymatic GluOx oxidation/TGase treatment shows promise to improve the textural properties of emulsified meat products.

Controlled formation of emulsion gels stabilized by salted myofibrillar protein under malondialdehyde (MDA)-induced oxidative stress.

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Zhou, Feibai; Sun, Weizheng; Zhao, Mouming

2015-04-15

This study presented the cold-set gelation of emulsions stabilized by salted myofibrillar protein (MP) under oxidative stress originated from malondialdehyde (MDA). Gel properties were compared over a range of MDA/NaCl concentrations including gel viscoelastic properties, strength, water-holding capacity (WHC), amount of protein entrapped, and microstructure. The oxidative stability of emulsion gels as indicated by lipid hydroperoxide was further determined and compared. Results indicated that emulsion stabilized by MP at swollen state under certain ionic strengths (0.2-0.6 M) was the premise of gel formation under MDA. In the presence of intermediate MDA concentrations (2.5-10 mM), the emulsion gels showed an improved elasticity, strength, WHC, and oxidative stability. This improvement should be mainly attributed to the enhanced protein-protein cross-linkings via MDA, which were homogeneously formed among absorbed and/or unabsorbed proteins, entrapping a greater amount and fractions of protein within network. Therefore, the oil droplets were better adherent to the gel matrix. Nevertheless, addition of high MDA concentrations (25-50 mM) led to the formation of excessive covalent bonds, which might break protein-protein bonds and trigger the desorption of protein from the interface. This ultimately caused "oil leak" phenomena as well as the collapse of gel structure and, thus, overall decreased gel properties and oxidative stability.

Myofibrillar protein synthesis following ingestion of soy protein isolate at rest and after resistance exercise in elderly men

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Yang Yifan

2012-06-01

Full Text Available Abstract Background Increased amino acid availability stimulates muscle protein synthesis, however, aged muscle appears less responsive to the anabolic effects of amino acids when compared to the young. We aimed to compare changes in myofibrillar protein synthesis (MPS in elderly men at rest and after resistance exercise following ingestion of different doses of soy protein and compare the responses to those we previously observed with ingestion of whey protein isolate. Methods Thirty elderly men (age 71 ± 5 y completed a bout of unilateral knee-extensor resistance exercise prior to ingesting no protein (0 g, or either 20 g or 40 g of soy protein isolate (0, S20, and S40 respectively. We compared these responses to previous responses from similar aged men who had ingested 20 g and 40 g of whey protein isolate (W20 and W40. A primed constant infusion of L-[1-13 C]leucine and L-[ring-13 C6]phenylalanine and skeletal muscle biopsies were used to measure whole-body leucine oxidation and MPS over 4 h post-protein consumption in both exercised and non-exercised legs. Results Whole-body leucine oxidation increased with protein ingestion and was significantly greater for S20 vs. W20 (P = 0.003. Rates of MPS for S20 were less than W20 (P = 0.02 and not different from 0 g (P = 0.41 in both exercised and non-exercised leg muscles. For S40, MPS was also reduced compared with W40 under both rested and post-exercise conditions (both P P = 0.04. Conclusions The relationship between protein intake and MPS is both dose and protein source-dependent, with isolated soy showing a reduced ability, as compared to isolated whey protein, to stimulate MPS under both rested and post-exercise conditions. These differences may relate to the lower postprandial leucinemia and greater rates of amino acid oxidation following ingestion of soy versus whey protein.

Exome sequencing identifies variants in two genes encoding the LIM-proteins NRAP and FHL1 in an Italian patient with BAG3 myofibrillar myopathy.

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D'Avila, Francesca; Meregalli, Mirella; Lupoli, Sara; Barcella, Matteo; Orro, Alessandro; De Santis, Francesca; Sitzia, Clementina; Farini, Andrea; D'Ursi, Pasqualina; Erratico, Silvia; Cristofani, Riccardo; Milanesi, Luciano; Braga, Daniele; Cusi, Daniele; Poletti, Angelo; Barlassina, Cristina; Torrente, Yvan

2016-06-01

Myofibrillar myopathies (MFMs) are genetically heterogeneous dystrophies characterized by the disintegration of Z-disks and myofibrils and are associated with mutations in genes encoding Z-disk or Z-disk-related proteins. The c.626 C > T (p.P209L) mutation in the BAG3 gene has been described as causative of a subtype of MFM. We report a sporadic case of a 26-year-old Italian woman, affected by MFM with axonal neuropathy, cardiomyopathy, rigid spine, who carries the c.626 C > T mutation in the BAG3 gene. The patient and her non-consanguineous healthy parents and brother were studied with whole exome sequencing (WES) to further investigate the genetic basis of this complex phenotype. In the patient, we found that the BAG3 mutation is associated with variants in the NRAP and FHL1 genes that encode muscle-specific, LIM domain containing proteins. Quantitative real time PCR, immunohistochemistry and Western blot analysis of the patient's muscular biopsy showed the absence of NRAP expression and FHL1 accumulation in aggregates in the affected skeletal muscle tissue. Molecular dynamic analysis of the mutated FHL1 domain showed a modification in its surface charge, which could affect its capability to bind its target proteins. To our knowledge this is the first study reporting, in a BAG3 MFM, the simultaneous presence of genetic variants in the BAG3 and FHL1 genes (previously described as independently associated with MFMs) and linking the NRAP gene to MFM for the first time.

Adverse effects of cyclosporine A on HSP25, alpha B-crystallin and myofibrillar cytoskeleton in rat heart

International Nuclear Information System (INIS)

Stacchiotti, Alessandra; Bonomini, Francesca; Lavazza, Antonio; Rodella, Luigi Fabrizio; Rezzani, Rita

2009-01-01

Cyclosporine (CsA) is a universally used immunosuppressive drug which induces adverse side effects in several organs, but its impact on the heart is still controversial. Small heat shock proteins (sHSPs), such as HSP25 and alpha B-crystallin, are cytoprotective stress proteins exceptionally represented in the heart. They act as myofibrillar chaperones that help actin and desmin to maintain their optimum configuration and stability, thereby antagonizing oxidative damage. The present study examined: (1) the cardiac distribution and abundance of HSP25 and alpha B-crystallin in rats receiving CsA at a therapeutic dosage (15 mg/kg/day) for 42 days and 63 days; (2) the presence of myofibrillar proteins, such as actin, alpha-actinin and desmin following the CsA treatments; (3) the subcellular effects of prolonged CsA exposure on the cardiomyocytes by histopathology and transmission electron microscopy. After 63 days CsA intake, sHSPs translocated from a regular sarcomeric pattern to peripheral sarcolemma and intercalated discs, together with actin and desmin. In contrast, the sarcomeric alpha-actinin pattern did not change in all experimental groups. The abundance of actin and HSP25 was unchanged in every time point of treatment while after 63 days CsA, alpha B-crystallin and desmin levels significantly decreased. Furthermore CsA induced fibrosis, irregular sarcomeric alignment and damaged desmosomes. These findings indicate that following prolonged CsA exposure, the cardiac muscle network was affected. In particular, the translocation of sHSPs to intercalated discs merits special consideration as a direct compensatory mechanism to limit CsA cardiotoxicity.

Effects of prerigor pressurization on the emulsifying capacity of muscle protein

Energy Technology Data Exchange (ETDEWEB)

Elgasim, E.A.; Kennick, W.H.; Anglemier, A.F.; Elkhalifa, E.A.; Koohmaraie, M.

1982-05-01

The emulsifying capacities of pressure treated and control muscle homogenates, sarcoplasmic protein and myofibrillar proteins of ovine and bovine longissimus muscles were determined at 2, 6, 24 and 168 hr postmortem. The pH of the intact muscle, muscle homogenate and myofibrillar protein extract were taken at these times. Before onset of rigor mortis, the emulsifying capacity of muscle homogenate from the control samples was higher than the pressure treated samples. At 24 and 168 hr postmortem, the pressure treated and control samples were not significantly different (P>0.05) for emulsifying capacity. At 2 hr postmortem, the emulsifying capacity of myofibrillar protein extract from control samples was higher (P<0.05) than that from pressure treated samples; thereafter, the emulsification curve for the pressure treated samples was higher than that of the control. The emulsification capacity of sarcoplasmic proteins from control muscles was slightly, but consistently, higher than that from pressure treated muscles throughout the test period. Overall, the emulsification capacity of muscle proteins was not detrimentally affected by pressure treatment.

Effects of elevated temperature on protein breakdown in muscles from septic rats

International Nuclear Information System (INIS)

Hall-Angeras, M.A.; Angeras, U.H.; Hasselgren, P.O.; Fischer, J.E.

1990-01-01

Elevated temperature has been proposed to contribute to accelerated muscle protein degradation during fever and sepsis. The present study examined the effect of increased temperature in vitro on protein turnover in skeletal muscles from septic and control rats. Sepsis was induced by cecal ligation and puncture (CLP); control rats were sham operated. After 16 h, the extensor digitorum longus (EDL) and soleus (SOL) muscles were incubated at 37 or 40 degrees C. Protein synthesis was determined by measuring incorporation of [14C]phenylalanine into protein. Total and myofibrillar protein breakdown was assessed from release of tyrosine and 3-methylhistidine (3-MH), respectively. Total protein breakdown was increased at 40 degrees C by 15% in EDL and by 29% in SOL from control rats, whereas 3-MH release was not affected. In muscles from septic rats, total and myofibrillar protein breakdown was increased by 22 and 30%, respectively, at 40 degrees C in EDL but was not altered in SOL. Protein synthesis was unaffected by high temperature both in septic and nonseptic muscles. The present results suggest that high temperature is not the primary mechanism of increased muscle protein breakdown in sepsis because the typical response to sepsis, i.e., a predominant increase in myofibrillar protein breakdown, was not induced by elevated temperature in normal muscle. It is possible, however, that increased temperature may potentiate protein breakdown that is already stimulated by sepsis because elevated temperature increased both total and myofibrillar protein breakdown in EDL from septic rats

Solubilization of myofibrillar proteins in water or low ionic strength media: Classical techniques, basic principles, and novel functionalities.

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Chen, Xing; Tume, Ron K; Xu, Xinglian; Zhou, Guanghong

2017-10-13

The qualitative characteristics of meat products are closely related to the functionality of muscle proteins. Myofibrillar proteins (MPs), comprising approximately 50% of total muscle proteins, are generally considered to be insoluble in solutions of low ionic strength ( 0.3 M) for solubilization. These soluble proteins are the ones which determine many functional properties of meat products, including emulsification and thermal gelation. In order to increase the utilization of meat and meat products, many studies have investigated the solubilization of MPs in water or low ionic strength media and determining their functionality. However, there still remains a lack of systematic information on the functional properties of MPs solubilized in this manner. Hence, this review will explore some typical techniques that have been used. The main procedures used for their solubilization, the fundamental principles and their functionalities in water (low ionic strength medium) are comprehensively discussed. In addition, advantages and disadvantages of each technique are summarized. Finally, future considerations are presented to facilitate progress in this new area and to enable water soluble muscle MPs to be utilized as novel meat ingredients in the food industry.

Emulsifying and gelling properties of weakfish myofibrillar proteins as affected by squid mantle myofibrillar proteins in a model system

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Daniela Mariel Suarez

2014-03-01

Full Text Available The aim of the present work was to investigate the physicochemical, biochemical and functional characteristics of both the myofibrils (MF and actomyosin (AM of squid mantle (Illex argentinus and weakfish (Cynoscion guatucupa muscles, and evaluate the influence of the addition of myofibrilar proteins from the squid mantle on the physicochemical and functional properties of those of the weakfish. After extraction, purification and characterization of the MF and AM of both species, emulsions of each protein fraction from each muscle were formulated. Mixtures of the MF or AM of both species were also analyzed. The emulsifying properties were monitoring using the Emulsifying Activity Index (EAI and Emulsion Stability (ES. In addition, gel pastes were formulated from the squid mantle, weakfish muscle and the mixture of both species, and the following functional properties of the gels assessed: water holding capacity, colour, textural profile analysis (TPA (hardness, elasticity, cohesiveness, gumminess and gel strength. The EAI values of emulsions formulated with the MF of the mantle were significantly (p<0.05 higher than those formulated from those of weakfish. The incorporation of squid MF in the mixture increased the EAI values. Conversely, the highest ES values were obtained with weakfish MF, and the incorporation of MF weakfish in the mixture increased the ES values. Similar EAI and ES behaviours were observed for the AM of the corresponding species. Irrespective of the thermal treatment, the gel strength of the gelled paste of squid muscle was significantly (p<0.05 lower than that of weakfish muscle and of those obtained with the different mixtures. The behaviours of the expressible moisture (EM from the gelled pastes were similar to those of gel strength. Irrespective of the thermal treatment, the pastes formulated with a high weakfish: mantle ratio showed less water loss. The gelled pastes of squid mantle showed the highest values for whiteness

Emulsion properties of pork myofibrillar protein in combination with microbial transglutaminase and calcium alginate under various pH conditions.

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Hong, Geun Pyo; Min, Sang-Gi; Chin, Koo Bok

2012-01-01

In this study, the effects of microbial transglutaminase (MTG) and calcium alginate (CA) systems in combination with soybean oil on the emulsion properties of porcine myofibrillar protein (MP) were evaluated under various pH conditions. MTG was shown to improve emulsifying capacity and creaming stability, which increased with increasing pH values up to 6.5. The CA did not influence emulsifying capacity, but it improved the creaming stability of the MP-stabilized emulsions. Both MTG and CA enhanced the rheological properties, but their effects on the physical characteristics of the protein evidenced an opposite trend in relation to pH, i.e., the MTG system improved both the emulsion and gelling properties with increasing pH, whereas the CA system was effective when the pH was lowered. By combining the two MP gelling systems, a stable and pH-insensible emulsion could be produced. Copyright © 2011 Elsevier Ltd. All rights reserved.

Preparo e caracterização de proteínas miofibrilares de tilápia-do-nilo para elaboração de biofilmes Extraction and properties of nile tilapia myofibrillar proteins for edible films

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Ednelí Soraya Monterrey-Quintero

2000-01-01

Full Text Available A elaboração de filmes comestíveis à base de biopolímeros implica conhecimento das propriedades físico-químicas da macromolécula. Os objetivos deste trabalho foram a descrição de um método de preparo de proteínas miofibrilares de tilápia-do-nilo (Oreochromis niloticus, o estudo das propriedades relacionadas com a formação de filmes, e a caracterização dos biofilmes elaborados com a proteína. Músculo moído de tilápia-do-nilo, recém-abatida, foi lavado e processado até formação de uma pasta homogênea. A evolução das frações protéicas, durante o processamento, foi acompanhada por calorimetria diferencial de varredura. Estudou-se a solubilidade das proteínas miofibrilares liofilizadas (PML em função do pH (2-7. A identificação das frações protéicas e dos aminoácidos foi realizada por SDS-PAGE e cromatografia de troca iônica, respectivamente. Os biofilmes formados foram submetidos a testes de perfuração, de solubilidade e microscopia eletrônica. A amostra de PML, constituída apenas de proteínas miofibrilares, apresentou uma região de máxima solubilidade (96,9% em torno do pH 3,0 e elevado potencial de interações iônicas (74,4 kJ/100 kJ. Os biofilmes à base das PML de tilápia-do-nilo são pouco solúveis (abaixo de 20 g/100 g matéria seca. O glicerol influencia fortemente as propriedades mecânicas e a solubilidade dos biofilmes.The elaboration of edible films based on biopolymers, implies the knowledge of physicochemical properties of macromolecules. The objectives of this work were to describe a methodology of preparing Nile Tilapia myofibrillar proteins and study the properties related to formation and characterization of edible film elaborated with these proteins. Freshly slaughtered ground Nile Tilapia (Oreochromis niloticus muscle was washed and processed until the formation of a homogeneous paste. Evolution of protein fractions during processing was followed by scanning differential

BAG3 myofibrillar myopathy presenting with cardiomyopathy.

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Konersman, Chamindra G; Bordini, Brett J; Scharer, Gunter; Lawlor, Michael W; Zangwill, Steven; Southern, James F; Amos, Louella; Geddes, Gabrielle C; Kliegman, Robert; Collins, Michael P

2015-05-01

Myofibrillar myopathies (MFMs) are a heterogeneous group of neuromuscular disorders distinguished by the pathological hallmark of myofibrillar dissolution. Most patients present in adulthood, but mutations in several genes including BCL2-associated athanogene 3 (BAG3) cause predominantly childhood-onset disease. BAG3-related MFM is particularly severe, featuring weakness, cardiomyopathy, neuropathy, and early lethality. While prior cases reported either neuromuscular weakness or concurrent weakness and cardiomyopathy at onset, we describe the first case in which cardiomyopathy and cardiac transplantation (age eight) preceded neuromuscular weakness by several years (age 12). The phenotype comprised distal weakness and severe sensorimotor neuropathy. Nerve biopsy was primarily axonal with secondary demyelinating/remyelinating changes without "giant axons." Muscle biopsy showed extensive neuropathic changes that made myopathic changes difficult to interpret. Similar to previous cases, a p.Pro209Leu mutation in exon 3 of BAG3 was found. This case underlines the importance of evaluating for MFMs in patients with combined neuromuscular weakness and cardiomyopathy. Copyright © 2015 Elsevier B.V. All rights reserved.

Characterisation of kiwifruit and asparagus enzyme extracts, and their activities toward meat proteins.

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Ha, Minh; Bekhit, Alaa El-Din; Carne, Alan; Hopkins, David L

2013-01-15

Two plant enzyme extracts from kiwifruit and asparagus were evaluated for their ability to hydrolyse commercially available substrates and proteins present in both beef connective tissue and topside myofibrillar extracts. The results show significant differences in protease activity depending on the assay used. Protease assays with connective tissue and meat myofibrillar extracts provide a more realistic evaluation of the potential of the enzymes for application in meat tenderization. Overall, the kiwifruit protease extract was found to be more effective at hydrolysing myofibrillar and collagen proteins than the asparagus protease extract. The two protease extracts appeared to target meat myofibrillar and collagen proteins differently, suggesting the potential of a synergistic effect of these proteases in improving the tenderness of specific cuts of meat, based on their intrinsic protein composition. Copyright © 2012 Elsevier Ltd. All rights reserved.

Nutritional value and digestion rate of rhea meat proteins in association with storage and cooking processes.

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Filgueras, Renata S; Gatellier, Philippe; Ferreira, Claude; Zambiazi, Rui C; Santé-Lhoutellier, Véronique

2011-09-01

The nutritional value of proteins was investigated after the storage and cooking of rhea M. Gastrocnemius pars interna. Oxidation of basic and aromatic amino acids, surface hydrophobicity and aggregation state of proteins, were determined in raw and cooked meat. In addition, myofibrillar proteins were exposed in vitro to proteases of the digestive tract. Cooking markedly affected the protein surface hydrophobicity. The BBP bound content was three times greater in cooked than in fresh rhea meat. A small increment in tryptophan content after cooking was observed. Storage influenced Schiff bases formation indicating the presence of protein-aldehyde adducts after cooking. High content of Schiff bases was found after cooking of samples stored for 5 days, demonstrating a probable implication of free amino groups, most likely from lysine. Cooking decreased the myofibrillar protein susceptibility to pepsin activity. After cooking, the proteolysis rate by pancreatic enzymes increased. Our findings support the importance of protein aggregation in the nutritional value of meat proteins. Copyright © 2011 Elsevier Ltd. All rights reserved.

Mechanosensitive molecular networks involved in transducing resistance exercise-signals into muscle protein accretion

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Emil Rindom

2016-11-01

Full Text Available Loss of skeletal muscle myofibrillar protein with disease and/or inactivity can severely deteriorate muscle strength and function. Strategies to counteract wasting of muscle myofibrillar protein are therefore desirable and invite for considerations on the potential superiority of specific modes of resistance exercise and/or the adequacy of low load resistance exercise regimens as well as underlying mechanisms. In this regard, delineation of the potentially mechanosensitive molecular mechanisms underlying muscle protein synthesis (MPS, may contribute to understanding on how differentiated resistance exercise can transduce a mechanical signal into stimulation of muscle accretion. Recent findings suggest specific upstream exercise-induced mechano-sensitive myocellular signaling pathways to converge on mammalian target of rapamycin complex 1 (mTORC1, to influence MPS. This may e.g. implicate mechanical activation of signaling through a diacylglycerol kinase (DGKζ-phosphatidic acid (PA axis or implicate integrin deformation to signal through a Focal adhesion kinase (FAK-Tuberous Sclerosis Complex 2TSC2-Ras homolog enriched in brain (Rheb axis. Moreover, since initiation of translation is reliant on mRNA, it is also relevant to consider potentially mechanosensitive signaling pathways involved in muscle myofibrillar gene transcription and whether some of these pathways converge with those affecting mTORC1 activation for MPS. In this regard, recent findings suggest how mechanical stress may implicate integrin deformation and/or actin dynamics to signal through a Ras homolog gene family member A protein (RhoA-striated muscle activator of Rho signaling (STARS axis or how it may implicate deformation of Notch to affect Bone Morphogenetic Protein (BMP signaling through a small mother of decapentaplegic (Smad axis.

Inhibition of interaction between epigallocatechin-3-gallate and myofibrillar protein by cyclodextrin derivatives improves gel quality under oxidative stress.

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Zhang, Yumeng; Chen, Lin; Lv, Yuanqi; Wang, Shuangxi; Suo, Zhiyao; Cheng, Xingguang; Xu, Xinglian; Zhou, Guanghong; Li, Zhixi; Feng, Xianchao

2018-06-01

High levels of polyphenols can interact with myofibrillar proteins (MPs), causing damage to a MP emulsion gel. In this study, β-cyclodextrins were used to reduce covalent and non-covalent interaction between epigallocatechin-3-gallate (EGCG) and MPs under oxidative stress. The loss of both thiol and free amine groups and the unfolding of MPs caused by EGCG (80 μM/g protein) were significantly prevented by β-cyclodextrins, and the structural stability and solubility were improved. MP emulsion gel treated with EGCG (80 μM/g protein) had the highest cooking loss (68.64%) and gel strength (0.51 N). Addition of β-cyclodextrins significantly reduced cooking loss (26.24-58.20%) and improved gel strength (0.31-0.41 N) of MP emulsion gel jeopardized by EGCG under oxidative stress. Damage to the emulsifying properties of MPs caused by EGCG was significantly prevented by addition of β-cyclodextrins. β-cyclodextrins reduced interaction between EGCG and MPs in the order Methyl-β-cyclodextrin > (2-Hydroxypropyl)-β-cyclodextrin > β-cyclodextrin. In absence of EGCG, addition of β-cyclodextrins partly protected MPs from oxidative attack and improved its solubility. It is concluded that β-cyclodextrins does not markedly reduce the antioxidant ability of EGCG according to carbonyl analysis, and can effectively increase EGCG loading to potentially provide more durable antioxidant effect for meat products during processing, transportation and storage. Copyright © 2018 Elsevier Ltd. All rights reserved.

Extração de proteínas miofibrilares de carne bovina para elaboração de filmes comestíveis Extraction of bovine meat myofibrillar proteins for elaboration edible films

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Sílvia M. A. de Souza

2004-12-01

Full Text Available A utilização de proteínas miofibrilares de carne na elaboração de filmes comestíveis implica, inicialmente, na obtenção desta macromolécula, uma vez que ela é indisponível comercialmente. Assim, os objetivos deste trabalho foram a obtenção e caracterização de proteínas miofibrilares de carne bovina, em escala de laboratório, e a elaboração e caracterização da microestrutura de filmes à base dessas proteínas. As proteínas miofibrilares foram extraídas do músculo Semitendinosus bovino, pós rigor mortis, empregando-se uma técnica de extração por centrifugação diferencial em solução tampão, com diferentes concentrações salinas, segundo metodologia de EISELE & BREKKE [13] modificada neste trabalho. As proteínas, assim obtidas, foram liofilizadas (PML e analisadas para determinação do teor de proteínas, de lipídios, de sais minerais, de cinzas e da umidade. A composição de aminoácidos foi determinada por cromatografia de troca iônica e o perfil eletroforético foi determinado em gel de poliacrilamida. Alguns filmes foram elaborados com 1g de PML/100g de solução, 60g de glicerol/100g de proteínas e ácido acético glacial para ajuste do pH=2,8. A microestrutura desses filmes foram analisadas por microscopia eletrônica de varredura. A PML, que apresentou teor de proteínas de 84,3%, foi composta de diversas frações de proteínas miofibrilares, com destaque para frações da miosina e da actina, segundo os resultados da eletroforese. Trabalhando-se a composição de aminoácidos, verificou-se que a maior contribuição energética das interações potenciais dos aminoácidos, foram as provenientes de ligações covalentes (58,3%, seguidas das interações iônicas (35,72%. A microestrutura do filme revelou uma estrutura pouco homogênea, porém coesa e densa e uma matriz protéica compacta e fina.The use of meat myofibrillar proteins for edible film production involves initially the extraction of the

Exercise & NSAID: Effect on muscle protein synthesis in knee osteoarthritis patients?

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Petersen, S.G.; Miller, Ben F; Hansen, M

2011-01-01

the contralateral leg remained rested. Twenty-four hours after exercise, we determined circulating concentrations of inflammatory parameters and measured FSR of myofibrillar and sarcoplasmic protein fractions of vastus lateralis muscle and patellar tendon collagen protein by the direct incorporation method using...... a flooding dose of 13C/12C-proline.RESULTS:Circulating levels of prostaglandin F2α were lower in the NSAID group compared with the placebo group (P effect of exercise on FSR in muscle myofibrillar (P = 0.003) and sarcoplasmic protein (P = 0.026) but not in tendon...... collagen protein (P = 0.52). No overall significant effect of the drug was seen on either of the tissue protein fractions (P > 0.05) or on the interaction between the drug and exercise on FSR in tendon collagen (P = 0.21), muscle myofibrillar (P = 0.68), or sarcoplasmic protein, FSR (P = 0.16).CONCLUSION...

Alcohol ingestion impairs maximal post-exercise rates of myofibrillar protein synthesis following a single bout of concurrent training.

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Evelyn B Parr

Full Text Available INTRODUCTION: The culture in many team sports involves consumption of large amounts of alcohol after training/competition. The effect of such a practice on recovery processes underlying protein turnover in human skeletal muscle are unknown. We determined the effect of alcohol intake on rates of myofibrillar protein synthesis (MPS following strenuous exercise with carbohydrate (CHO or protein ingestion. METHODS: In a randomized cross-over design, 8 physically active males completed three experimental trials comprising resistance exercise (8×5 reps leg extension, 80% 1 repetition maximum followed by continuous (30 min, 63% peak power output (PPO and high intensity interval (10×30 s, 110% PPO cycling. Immediately, and 4 h post-exercise, subjects consumed either 500 mL of whey protein (25 g; PRO, alcohol (1.5 g·kg body mass⁻¹, 12±2 standard drinks co-ingested with protein (ALC-PRO, or an energy-matched quantity of carbohydrate also with alcohol (25 g maltodextrin; ALC-CHO. Subjects also consumed a CHO meal (1.5 g CHO·kg body mass⁻¹ 2 h post-exercise. Muscle biopsies were taken at rest, 2 and 8 h post-exercise. RESULTS: Blood alcohol concentration was elevated above baseline with ALC-CHO and ALC-PRO throughout recovery (P<0.05. Phosphorylation of mTOR(Ser2448 2 h after exercise was higher with PRO compared to ALC-PRO and ALC-CHO (P<0.05, while p70S6K phosphorylation was higher 2 h post-exercise with ALC-PRO and PRO compared to ALC-CHO (P<0.05. Rates of MPS increased above rest for all conditions (∼29-109%, P<0.05. However, compared to PRO, there was a hierarchical reduction in MPS with ALC-PRO (24%, P<0.05 and with ALC-CHO (37%, P<0.05. CONCLUSION: We provide novel data demonstrating that alcohol consumption reduces rates of MPS following a bout of concurrent exercise, even when co-ingested with protein. We conclude that alcohol ingestion suppresses the anabolic response in skeletal muscle and may therefore impair recovery and adaptation

Chymase inhibition prevents fibronectin and myofibrillar loss and improves cardiomyocyte function and LV torsion angle in dogs with isolated mitral regurgitation.

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Pat, Betty; Chen, Yuanwen; Killingsworth, Cheryl; Gladden, James D; Shi, Ke; Zheng, Junying; Powell, Pamela C; Walcott, Greg; Ahmed, Mustafa I; Gupta, Himanshu; Desai, Ravi; Wei, Chih-Chang; Hase, Naoki; Kobayashi, Tsunefumi; Sabri, Abdelkarim; Granzier, Henk; Denney, Thomas; Tillson, Michael; Dillon, A Ray; Husain, Ahsan; Dell'italia, Louis J

2010-10-12

The left ventricular (LV) dilatation of isolated mitral regurgitation (MR) is associated with an increase in chymase and a decrease in interstitial collagen and extracellular matrix. In addition to profibrotic effects, chymase has significant antifibrotic actions because it activates matrix metalloproteinases and kallikrein and degrades fibronectin. Thus, we hypothesize that chymase inhibitor (CI) will attenuate extracellular matrix loss and LV remodeling in MR. We studied dogs with 4 months of untreated MR (MR; n=9) or MR treated with CI (MR+CI; n=8). Cine MRI demonstrated a >40% increase in LV end-diastolic volume in both groups, consistent with a failure of CI to improve a 25% decrease in interstitial collagen in MR. However, LV cardiomyocyte fractional shortening was decreased in MR versus normal dogs (3.71±0.24% versus 4.81±0.31%; P<0.05) and normalized in MR+CI dogs (4.85±0.44%). MRI with tissue tagging demonstrated an increase in LV torsion angle in MR+CI versus MR dogs. CI normalized the significant decrease in fibronectin and FAK phosphorylation and prevented cardiomyocyte myofibrillar degeneration in MR dogs. In addition, total titin and its stiffer isoform were increased in the LV epicardium and paralleled the changes in fibronectin and FAK phosphorylation in MR+CI dogs. These results suggest that chymase disrupts cell surface-fibronectin connections and FAK phosphorylation that can adversely affect cardiomyocyte myofibrillar structure and function. The greater effect of CI on epicardial versus endocardial titin and noncollagen cell surface proteins may be responsible for the increase in torsion angle in chronic MR.

Resistance training-induced changes in integrated myofibrillar protein synthesis are related to hypertrophy only after attenuation of muscle damage.

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Damas, Felipe; Phillips, Stuart M; Libardi, Cleiton A; Vechin, Felipe C; Lixandrão, Manoel E; Jannig, Paulo R; Costa, Luiz A R; Bacurau, Aline V; Snijders, Tim; Parise, Gianni; Tricoli, Valmor; Roschel, Hamilton; Ugrinowitsch, Carlos

2016-09-15

Skeletal muscle hypertrophy is one of the main outcomes from resistance training (RT), but how it is modulated throughout training is still unknown. We show that changes in myofibrillar protein synthesis (MyoPS) after an initial resistance exercise (RE) bout in the first week of RT (T1) were greater than those seen post-RE at the third (T2) and tenth week (T3) of RT, with values being similar at T2 and T3. Muscle damage (Z-band streaming) was the highest during post-RE recovery at T1, lower at T2 and minimal at T3. When muscle damage was the highest, so was the integrated MyoPS (at T1), but neither were related to hypertrophy; however, integrated MyoPS at T2 and T3 were correlated with hypertrophy. We conclude that muscle hypertrophy is the result of accumulated intermittent increases in MyoPS mainly after a progressive attenuation of muscle damage. Skeletal muscle hypertrophy is one of the main outcomes of resistance training (RT), but how hypertrophy is modulated and the mechanisms regulating it are still unknown. To investigate how muscle hypertrophy is modulated through RT, we measured day-to-day integrated myofibrillar protein synthesis (MyoPS) using deuterium oxide and assessed muscle damage at the beginning (T1), at 3 weeks (T2) and at 10 weeks of RT (T3). Ten young men (27 (1) years, mean (SEM)) had muscle biopsies (vastus lateralis) taken to measure integrated MyoPS and muscle damage (Z-band streaming and indirect parameters) before, and 24 h and 48 h post resistance exercise (post-RE) at T1, T2 and T3. Fibre cross-sectional area (fCSA) was evaluated using biopsies at T1, T2 and T3. Increases in fCSA were observed only at T3 (P = 0.017). Changes in MyoPS post-RE at T1, T2 and T3 were greater at T1 (P Muscle damage was the highest during post-RE recovery at T1, attenuated at T2 and further attenuated at T3. The change in MyoPS post-RE at both T2 and T3, but not at T1, was strongly correlated (r ≈ 0.9, P muscle hypertrophy. Initial Myo

Coordinated collagen and muscle protein synthesis in human patella tendon and quadriceps muscle after exercise

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Miller, Benjamin F; Olesen, Jens L; Hansen, Mette

2005-01-01

We hypothesized that an acute bout of strenuous, non-damaging exercise would increase rates of protein synthesis of collagen in tendon and skeletal muscle but these would be less than those of muscle myofibrillar and sarcoplasmic proteins. Two groups (n = 8 and 6) of healthy young men were studied...... collagen (0.077% h(-1)), muscle collagen (0.054% h(-1)), myofibrillar protein (0.121% h(-1)), and sarcoplasmic protein (0.134% h(-1))). The rates decreased toward basal values by 72 h although rates of tendon collagen and myofibrillar protein synthesis remained elevated. There was no tissue damage...... of muscle visible on histological evaluation. Neither tissue microdialysate nor serum concentrations of IGF-I and IGF binding proteins (IGFBP-3 and IGFBP-4) or procollagen type I N-terminal propeptide changed from resting values. Thus, there is a rapid increase in collagen synthesis after strenuous exercise...

Analysis of myofibrillar proteins and transcripts in adult skeletal muscles of the American lobster Homarus americanus: variable expression of myosins, actin and troponins in fast, slow-twitch and slow-tonic fibres.

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Medler, Scott; Mykles, Donald L

2003-10-01

Skeletal muscles are diverse in their contractile properties, with many of these differences being directly related to the assemblages of myofibrillar isoforms characteristic of different fibers. Crustacean muscles are similar to other muscles in this respect, although the majority of information about differences in muscle organization comes from vertebrate species. In the present study, we examined the correlation between myofibrillar protein isoforms and the patterns of myofibrillar gene expression in fast, slow-phasic (S(1)) and slow-tonic (S(2)) fibers of the American lobster Homarus americanus. SDS-PAGE and western blotting were used to identify isoform assemblages of myosin heavy chain (MHC), P75, troponin T (TnT) and troponin I (TnI). RT-PCR was used to monitor expression of fast and slow (S(1)) MHC, P75 and actin in different fiber types, and the MHC and actin levels were quantified by real-time PCR. Fast and slow fibers from the claw closers predominantly expressed fast and S(1) MHC, respectively, but also lower levels of the alternate MHC. By contrast, fast fibers from the deep abdominal muscle expressed fast MHC exclusively. In addition, slow muscles expressed significantly higher levels of actin than fast fibers. A distal bundle of fibers in the cutter claw closer muscle was found to be composed of a mixture of S(1) and S(2) fibers, many of which possessed a mixture of S(1) and S(2) MHC isoforms. This pattern supports the idea that S(1) and S(2) fibers represent extremes in a continuum of slow muscle phenotype. Overall, these patterns demonstrate that crustacean skeletal muscles cannot be strictly categorized into discrete fiber types, but a muscle's properties probably represent a point on a continuum of fiber types. This trend may result from differences in innervation pattern, as each muscle is controlled by a unique combination of phasic, tonic or both phasic and tonic motor nerves. In this respect, future studies examining how muscle phenotype

Proteomic evaluation of myofibrillar carbonylation in chilled fish mince and its inhibition by catechin.

Science.gov (United States)

Pazos, Manuel; Maestre, Rodrigo; Gallardo, José M; Medina, Isabel

2013-01-01

The present study investigates the susceptibility of individual myofibrillar proteins from mackerel (Scomber scombrus) mince to undergo carbonylation reactions during chilled storage, and the antioxidant capacity of (+)-catechin to prevent oxidative processes of proteins. The carbonylation of each particular protein was quantified by combining the labelling of protein carbonyls by fluorescein-5-thiosemicarbazide (FTSC) with 1-D or 2-D gel electrophoresis. Alpha skeletal actin, glycogen phosphorylase, unnamed protein product (UNP) similar to enolase, pyruvate kinase, isoforms of creatine kinase, aldolase A and an isoform of glyceraldehyde 3-phosphate dehydrogenase (G3PDH) showed elevated oxidation in chilled non-supplemented mince. Myosin heavy chain (MHC) was not carbonylated in chilled muscle, but an extensive MHC degradation was observed in those samples. The supplementation of catechin reduced protein oxidation and lipid oxidation in a concentration-dependent manner: control>25>100≈200ppm. Therefore, the highest catechin concentrations (100 and 200ppm) exhibited the strongest antioxidant activity. Catechin (200ppm) reduced significantly carbonylation of protein spots identified as glycogen phosphorylase, pyruvate kinase muscle isozyme, isoforms of creatine kinase. Conversely, catechin was ineffective to inhibit the oxidation of actin and UNP similar to enolase. These results draw attention to the inefficiency of catechin to prevent actin oxidation, in contrast to the extremely high efficiency of catechin in inhibiting oxidation of lipids and other proteins. Copyright © 2012 Elsevier Ltd. All rights reserved.

Effects of starvation on protein synthesis and nucleic acid metabolism in the muscle of the barred sand bass Paralabrax nebulifer

Energy Technology Data Exchange (ETDEWEB)

Lowery, M.S.

1987-01-01

Starvation induced different protein synthesis responses in red and white muscle of the barred sand bass Paralabrax nebulifer. Red muscle had /sup 14/C-leucine incorporation rates into total protein which were several times higher than white muscle in both the fed and starved states. Muscle was separated into a myofibrillar fraction consisting of the structural proteins and a sarcoplasmic fraction consisting of soluble proteins. Synthesis of the myofibrillar fraction of white muscle decreased by 90%, while red muscle myofibrillar synthesis remained essentially unchanged. Changes in the labeling of several enzymes purified from the sarcoplasmic fraction were different even though the overall loss of enzyme activity was similar, suggesting that changes in synthesis rates were important in maintaining appropriate relative enzyme concentrations.

Incorporation of DL(1-14C)-leucine into muscle proteins in buffalo calves and its response to exogenous insulin

International Nuclear Information System (INIS)

Vivekanandan, R.; Singh, L.N.

1976-01-01

Protein synthesis and the effect of insulin on this process have been studied in buffalo skeletal muscles using DL(1- 14 C)-leucine. The muscle fibres isolated from triceps, showed highest specific radioactivity (SRA) in the sarcoplasmic proteins followed by myofibrillar and stroma proteins. Exogenous insulin stimulated the incorporation in the myofibrillar and stroma fractions but not in the sarcoplasmic proteins. Radioscanning of the polyacrylamide gel electrophorograms further revealed preferential labelling of only some of the myofibrillar proteins in the presence of exogenous insulin. Statistically significant differences in the SRA were observed between nuclear, mitochondrial and post-mitochondrial proteins without exogenous insulin the post-mitochondrial proteins showing highest SRA. Addition of insulin to the assay medium significantly stimulated the incorporation in the nuclear fraction whereas mitochondrial and post-mitochondrial fractions did not respond. Intramuscular injection of insulin, 3 hours prior to collection of tissue, stimulated the incorporation in nuclear as well as post-mitochondrial fractions but had no effect on the mitochondrial protein synthesis. (author)

Local NSAID infusion does not affect protein synthesis and gene expression in human muscle after eccentric exercise

DEFF Research Database (Denmark)

Mikkelsen, U R; Schjerling, P; Helmark, Ida Carøe

2010-01-01

models, and inhibit the exercise-induced satellite cell proliferation and protein synthesis in humans. However, the cellular mechanisms eliciting these responses remain unknown. Eight healthy male volunteers performed 200 maximal eccentric contractions with each leg. To block prostaglandin synthesis...... locally in the skeletal muscle, indomethacin (NSAID) was infused for 7.5 h via microdialysis catheters into m. vastus lateralis of one leg. Protein synthesis was determined by the incorporation of 1,2-(13)C(2) leucine into muscle protein from 24 to 28 h post-exercise. Furthermore, mRNA expression...... of selected genes was measured in muscle biopsies (5 h and 8 days post-exercise) by real-time reverse transcriptase PCR. Myofibrillar and collagen protein synthesis were unaffected by the local NSAID infusion. Five hours post-exercise, the mRNA expression of cyclooxygenase-2 (COX2) was sixfold higher...

Konjac flour improved textural and water retention properties of transglutaminase-mediated, heat-induced porcine myofibrillar protein gel: Effect of salt level and transglutaminase incubation.

Science.gov (United States)

Chin, Koo B; Go, Mi Y; Xiong, Youling L

2009-03-01

Functional properties of heat-induced gels prepared from microbial transglutaminase (TG)-treated porcine myofibrillar protein (MP) containing sodium caseinate with or without konjac flour (KF) under various salt concentrations (0.1, 0.3 and 0.6MNaCl) were evaluated. The mixed MP gels with KF exhibited improved cooking yields at all salt concentrations. TG treatment greatly enhanced gel strength and elasticity (storage modulus, G') at 0.6M NaCl, but not at lower salt concentrations. The combination of KF and TG improved the gel strength at 0.1 and 0.3M NaCl and G' at all salt concentrations, when compared with non-TG controls. Incubation of MP suspensions (sols) with TG promoted the disappearance of myosin heavy chain and the production of polymers. The TG-treated MP mixed gels had a compact structure, compared to those without TG, and the KF incorporation modified the gel matrix and increased its water-holding capacity. Results from differential scanning calorimetry suggested possible interactions of MP with KF, which may explain the changes in the microstructure of the heat-induced gels.

Contraction intensity and feeding affect collagen and myofibrillar protein synthesis rates differently in human skeletal muscle

DEFF Research Database (Denmark)

Holm, Lars; Hall, Gerrit van; Rose, Adam John

2010-01-01

Exercise stimulates muscle protein fractional synthesis rate (FSR) but the importance of contractile intensity and whether it interplays with feeding is not understood. This was investigated following two distinct resistance exercise (RE) contraction intensities using an intra-subject design...... to feeding. Further, although functionally linked, the contractile and the supportive matrix structures upregulate their protein synthesis rate quite differently in response to feeding and contractile-activity and -intensity....

Whey and casein labelled with L-[1-13C]-leucine and muscle protein synthesis: effect of resistance exercise and protein ingestion

DEFF Research Database (Denmark)

Reitelseder, Søren; Agergaard, Jakob; Doessing, Simon

2011-01-01

to a single bolus intake of whey or casein after performance of heavy resistance exercise. Young male individuals were randomly assigned to participate in two protein trials (n = 9) or one control trial (n = 8). Infusion of l-[1-(13)C]leucine was carried out, and either whey, casein (0.3 g/kg lean body mass......), or a noncaloric control drink was ingested immediately after exercise. l-[1-(13)C]leucine-labeled whey and casein were used while muscle protein synthesis (MPS) was assessed. Blood and muscle tissue samples were collected to measure systemic hormone and amino acid concentrations, tracer enrichments......, and myofibrillar protein synthesis. Western blots were used to investigate the Akt signaling pathway. Plasma insulin and branched-chain amino acid concentrations increased to a greater extent after ingestion of whey compared with casein. Myofibrillar protein synthesis was equally increased 1-6 h postexercise after...

Suspected myofibrillar myopathy in Arabian horses with a history of exertional rhabdomyolysis.

Science.gov (United States)

Valberg, S J; McKenzie, E C; Eyrich, L V; Shivers, J; Barnes, N E; Finno, C J

2016-09-01

Although exertional rhabdomyolysis (ER) is common in Arabian horses, there are no dedicated studies describing histopathological characteristics of muscle from Arabian horses with ER. To prospectively identify distinctive histopathological features of muscle from Arabian endurance horses with a history of ER (pro-ER) and to retrospectively determine their prevalence in archived samples from Arabian horses with exertional myopathies (retro-ER). Prospective and retrospective histopathological description. Middle gluteal muscle biopsies obtained from Arabian controls (n = 14), pro-ER (n = 13) as well as archived retro-ER (n = 25) muscle samples previously classified with type 2 polysaccharide storage myopathy (15/25), recurrent exertional rhabdomyolysis (7/25) and no pathology (3/25) were scored for histopathology and immunohistochemical staining of cytoskeletal proteins. Glutaraldehyde-fixed samples (2 pro-ER, one control) were processed for electron microscopy. Pro-ER and retro-ER groups were compared with controls using Mann-Whitney U and Fisher's exact tests. Centrally located myonuclei in mature myofibres were found in significantly more (Prhabdomyolysis, ectopic accumulation of cytoskeletal proteins and Z-disc degeneration bear a strong resemblance to a myofibrillar myopathy. While many of these horses were previously diagnosed with type 2 polysaccharide storage myopathy, pools of glycogen forming within disrupted myofibrils appeared to give the false appearance of a glycogen storage disorder. © 2015 EVJ Ltd.

Myofibrillar myopathies: State of the art, present and future challenges.

Science.gov (United States)

Béhin, A; Salort-Campana, E; Wahbi, K; Richard, P; Carlier, R-Y; Carlier, P; Laforêt, P; Stojkovic, T; Maisonobe, T; Verschueren, A; Franques, J; Attarian, S; Maues de Paula, A; Figarella-Branger, D; Bécane, H-M; Nelson, I; Duboc, D; Bonne, G; Vicart, P; Udd, B; Romero, N; Pouget, J; Eymard, B

2015-10-01

Myofibrillar myopathies (MFM) have been described in the mid-1990s as a group of diseases sharing common histological features, including an abnormal accumulation of intrasarcoplasmic proteins, the presence of vacuoles and a disorganization of the intermyofibrillar network beginning at the Z-disk. The boundaries of this concept are still uncertain, and whereas six genes (DES, CRYAB, LDB3/ZASP, MYOT, FLNC and BAG3) are now classically considered as responsible for MFM, other entities such as FHL1 myopathy or Hereditary Myopathy with Early Respiratory Failure linked to mutations of titin can now as well be included in this group. The diagnosis of MFM is not always easy; as histological lesions can be focal, and muscle biopsy may be disappointing; this has led to a growing importance of muscle imaging, and the selectivity of muscle involvement has now been described in several disorders. Due to the rarity of these myopathies, if some clinical patterns (such as distal myopathy associated with cardiomyopathy due to desmin mutations) are now well known, surprises remain possible and should lead to systematic testing of the known genes in case of a typical histological presentation. In this paper, we aim at reviewing the data acquired on the six main genes listed above as well as presenting the experience from two French reference centres, Paris and Marseilles. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

Effect of biostimulator on the incorporation of DL(1-14C)leucine into skeletal muscle proteins of buffalo

International Nuclear Information System (INIS)

Nath, N.C.; Singh, L.N.

1982-01-01

Incorporation of 14 C-leucine into muscle proteins of buffalo calves was studied in vitro using muscle fibre preparations from biceps femoris. Biostimulator (a spleen tissue extract) stimulated the incorporation of 14 C-leucine into total proteins to some extent, but inhibited the synthesis of sarcoplasmic proteins. There was no significant difference in the relative proportion of the individual sarcoplasmic and myofibrillar proteins in the presence or absence of biostimulator. In one major sarcoplasmic protein there was higher specific activity in the presence of biostimulator. In all the remaining 4 proteins the incorporation was inhibited. Among the myofibrillar proteins, the incorporation into troponins, myosin light chains and tropomyosin was stimulated in the presence of biostimulator. Myosin heavy chain and acting did not show any change in incorporation of 14 C-leucine after addition of the biostimulator. (author)

Gross and true ileal digestible amino acid contents of several animal body proteins and their hydrolysates.

Science.gov (United States)

Cui, J; Chong, B; Rutherfurd, S M; Wilkinson, B; Singh, H; Moughan, P J

2013-07-01

Amino acid compositions of ovine muscle, ovine myofibrillar protein, ovine spleen, ovine liver, bovine blood plasma, bovine blood globulins and bovine serum albumin and the amino acid compositions and in vivo (laboratory rat) true ileal amino acid digestibilities of hydrolysates (sequential hydrolysis with Neutrase, Alcalase and Flavourzyme) of these protein sources were determined. True ileal amino acid digestibility differed (Pprotein hydrolysates. The ovine myofibrillar protein and liver hydrolysates were the most digestible, with a mean true ileal digestibility across all amino acids of 99%. The least digestible protein hydrolysate was bovine serum albumin with a comparable mean true ileal digestibility of 93%. When the digestible amino acid contents were expressed as proportions relative to lysine, considerable differences, across the diverse protein sources, were found in the pattern of predicted absorbed amino acids. Copyright © 2013 Elsevier Ltd. All rights reserved.

Comparison of protein degradation, protein oxidation, and μ-calpain activation between pale, soft, and exudative and red, firm, and nonexudative pork during postmortem aging.

Science.gov (United States)

Yin, Y; Zhang, W G; Zhou, G H; Guo, B

2014-08-01

The objective of this study was to investigate the differences in protein modifications between pale, soft, and exudative (PSE) and red, firm, and nonexudative (RFN) pork during postmortem (PM) aging. Longissimus dorsi (LD) including 8 PSE and 8 RFN muscles were individually removed from 16 carcasses. These 16 LD muscles were vacuum packaged at 24 h after slaughter and stored at 4°C for 1, 3, and 5 d. The centrifugation loss, drip loss, color, protein solubility, protein oxidation, protein degradation including desmin, troponin T, and integrin, and μ-calpain activation were determined. The pH of PSE samples was significantly lower than that of RFN samples at both 1 and 24 h PM (P 0.05). In addition, PSE pork presented a lower solubility of sarcoplasmic protein, myofibrillar protein, and total protein than RFN pork except the solubility of myofibrillar protein at d 1 (P firm, and nonexudative pork presented lower intensity of intact 80 kDa calpain and greater intensity of autolyzed 76 kDa product compared to PSE pork (P < 0.01). The results indicate that the degree of μ-calpain activation, the extent of protein degradation including desmin and integrin, and the level of protein solubility in PSE pork could contribute to its low water holding capacity during PM storage.

No effect of anti-inflammatory medication on postprandial and postexercise muscle protein synthesis in elderly men with slightly elevated systemic inflammation

DEFF Research Database (Denmark)

Dideriksen, Kasper Juel; Reitelseder, Søren; Malmgaard-Clausen, Nikolai Mølkjær

2016-01-01

BACKGROUND: Based on circulating C-reactive protein (CRP) levels, some individuals develop slightly increased inflammation as they age. In elderly inflamed rats, the muscle response to protein feeding is impaired, whereas it can be maintained by treatment with non-steroidal anti-inflammatory drugs...... (NSAIDs). It is unknown whether this applies to elderly humans with increased inflammation. Thus, the muscle response to whey protein bolus ingestion with and without acute resistance exercise was compared between healthy elderly individuals and elderly individuals with slightly increased inflammation......protein synthetic response was measured as the fractional synthetic rate (FSR) and p70S6K phosphorylation-to-total protein ratio. RESULTS: The basal myofibrillar FSR and the myofibrillar FSR responses to whey protein bolus ingestion with and without acute resistance exercise were...

Effect of experimental hyperthyroidism on protein turnover in skeletal and cardiac muscle.

Science.gov (United States)

Carter, W J; Van Der Weijden Benjamin, W S; Faas, F H

1980-10-01

Since experimental hyperthyroidism reduces skeletal muscle mass while simultaneously increasing cardiac muscle mass, the effect of hyperthyroidism on muscle protein degradation was compared in skeletal and cardiac muscle. Pulse-labeling studies using (3H) leucine and (14C) carboxyl labeled aspartate and glutamate were carried out. Hyperthyroidism caused a 25%-29% increase in protein breakdown in both sarcoplasmic and myofibrillar fractions of skeletal muscle. Increased muscle protein degradation may be a major factor in the development of skeletal muscle wasting and weakness in hyperthyroidism. In contrast, protein breakdown appeared to be reduced 22% in the sarcoplasmic fraction of hyperthyroid heart muscle and was unchanged in the myofibrillar fraction. Possible reasons for the contrasting effects of hyperthyroidism on skeletal and cardiac muscle include increased sensitivity of the hyperthyroid heart to catecholamines, increased cardiac work caused by the hemodynamic effects of hyperthyroidism, and a different direct effect of thyroid hormone at the nuclear level in cardiac as opposed to skeletal muscle.

Effects of gamma irradiation on physicochemical properties of heat-induced gel prepared with chicken salt-soluble proteins

International Nuclear Information System (INIS)

Choi, Yun-Sang; Kim, Hyun-Wook; Hwang, Ko-Eun; Song, Dong-Heon; Jeong, Tae-Jun; Seo, Kwang-Wook; Kim, Young-Boong; Kim, Cheon-Jei

2015-01-01

The technological effects of gamma irradiation (0, 3, 7, and 10 kGy) on chicken salt-soluble meat proteins in a model system were investigated. There were no significant differences in protein, fat, and ash content, and sarcoplasmic protein solubility among all samples. The samples with increasing gamma irradiation levels had higher pH, lightness, yellowness, and apparent viscosity, whereas moisture content, water holding capacity, redness, myofibrillar protein solubility, total protein solubility, hardness, springiness, cohesiveness, gumminess, and chewiness were the highest in the unirradiated control. The result from meat products using gamma irradiation was intended to provide a basic resource processing technology. - Highlights: • The effect of gamma irradiation on salt-soluble meat proteins was investigated. • Gelling properties of salt-soluble protein affected by gamma irradiation. • Gamma irradiation of meat products provides a basic resource processing technology

Effect of sepsis on calcium uptake and content in skeletal muscle and regulation in vitro by calcium of total and myofibrillar protein breakdown in control and septic muscle: Results from a preliminary study

International Nuclear Information System (INIS)

Benson, D.W.; Hasselgren, P.O.; Hiyama, D.T.; James, J.H.; Li, S.; Rigel, D.F.; Fischer, J.E.

1989-01-01

Because high calcium concentration in vitro stimulates muscle proteolysis, calcium has been implicated in the pathogenesis of increased muscle breakdown in different catabolic conditions. Protein breakdown in skeletal muscle is increased during sepsis, but the effect of sepsis on muscle calcium uptake and content is not known. In this study the influence of sepsis, induced in rats by cecal ligation and puncture, on muscle calcium uptake and content was studied. Sixteen hours after cecal ligation and puncture or sham operation, calcium content of the extensor digitorum longus (EDL) and soleus (SOL) muscles was determined with an atomic absorption spectrometer. Calcium uptake was measured in intact SOL muscles incubated in the presence of calcium 45 (45Ca) for between 1 and 120 minutes. Total and myofibrillar protein breakdown was determined in SOL muscles, incubated in the presence of different calcium concentrations (0; 2.5; 5.0 mmol/L), and measured as release into the incubation medium of tyrosine and 3-methylhistidine (3-MH), respectively. Calcium content was increased by 51% (p less than 0.001) during sepsis in SOL and by 10% (p less than 0.05) in EDL muscle. There was no difference in 45Ca uptake between control and septic muscles during the early phase (1 to 5 minutes) of incubation. During more extended incubation (30 to 120 minutes), muscles from septic rats took up significantly more 45Ca than control muscles (p less than 0.05). Tyrosine release by incubated SOL muscles from control and septic rats was increased when calcium was added to the incubation medium, and at a calcium concentration of 2.5 mmol/L, the increase in tyrosine release was greater in septic than in control muscle. Addition of calcium to the incubation medium did not affect 3-MH release in control or septic muscle

Differences in postprandial protein handling after beef compared with milk ingestion during postexercise recovery: a randomized controlled trial.

Science.gov (United States)

Burd, Nicholas A; Gorissen, Stefan H; van Vliet, Stephan; Snijders, Tim; van Loon, Luc Jc

2015-10-01

Protein consumed after resistance exercise increases postexercise muscle protein synthesis rates. To date, dairy protein has been studied extensively, with little known about the capacity of other protein-dense foods to augment postexercise muscle protein synthesis rates. We aimed to compare protein digestion and absorption kinetics, postprandial amino acid availability, anabolic signaling, and the subsequent myofibrillar protein synthetic response after the ingestion of milk compared with beef during recovery from resistance-type exercise. In crossover trials, 12 healthy young men performed a single bout of resistance exercise. Immediately after cessation of exercise, participants ingested 30 g protein by consuming isonitrogenous amounts of intrinsically l-[1-(13)C]phenylalanine-labeled beef or milk. Blood and muscle biopsy samples were collected at rest and after exercise during primed continuous infusions of l-[ring-(2)H5]phenylalanine and l-[ring-3,5-(2)H2]tyrosine to assess protein digestion and absorption kinetics, plasma amino acid availability, anabolic signaling, and subsequent myofibrillar protein synthesis rates in vivo in young men. Beef protein-derived phenylalanine appeared more rapidly in circulation compared with milk ingestion (P Nutrition.

Inhibition of ErbB2 by receptor tyrosine kinase inhibitors causes myofibrillar structural damage without cell death in adult rat cardiomyocytes

International Nuclear Information System (INIS)

Pentassuglia, Laura; Graf, Michael; Lane, Heidi; Kuramochi, Yukio; Cote, Gregory; Timolati, Francesco; Sawyer, Douglas B.; Zuppinger, Christian; Suter, Thomas M.

2009-01-01

Inhibition of ErbB2 (HER2) with monoclonal antibodies, an effective therapy in some forms of breast cancer, is associated with cardiotoxicity, the pathophysiology of which is poorly understood. Recent data suggest, that dual inhibition of ErbB1 (EGFR) and ErbB2 signaling is more efficient in cancer therapy, however, cardiac safety of this therapeutic approach is unknown. We therefore tested an ErbB1-(CGP059326) and an ErbB1/ErbB2-(PKI166) tyrosine kinase inhibitor in an in-vitro system of adult rat ventricular cardiomyocytes and assessed their effects on 1. cell viability, 2. myofibrillar structure, 3. contractile function, and 4. MAPK- and Akt-signaling alone or in combination with Doxorubicin. Neither CGP nor PKI induced cardiomyocyte necrosis or apoptosis. PKI but not CGP caused myofibrillar structural damage that was additive to that induced by Doxorubicin at clinically relevant doses. These changes were associated with an inhibition of excitation-contraction coupling. PKI but not CGP decreased p-Erk1/2, suggesting a role for this MAP-kinase signaling pathway in the maintenance of myofibrils. These data indicate that the ErbB2 signaling pathway is critical for the maintenance of myofibrillar structure and function. Clinical studies using ErbB2-targeted inhibitors for the treatment of cancer should be designed to include careful monitoring for cardiac dysfunction.

On protein quality control, myofibrillar myopathies, and neurodegeneration

NARCIS (Netherlands)

Meister, Melanie

2017-01-01

Eiwitten zijn bouwstenen van de cel en het is noodzakelijk dat zij in specifieke -vooraf bepaalde – 3-dimensionale vormen ‘gevouwen’ worden om hun functies binnen de cel te kunnen vervullen. De cel heeft een speciaal netwerk (Protein Quality Control [PQC] netwerk) die de kwaliteit van dergelijke

Influence of pre-cooking protein paste gelation conditions and post-cooking gel storage conditions on gel texture.

Science.gov (United States)

Paker, Ilgin; Matak, Kristen E

2016-01-15

Gelation conditions affect the setting of myofibrillar fish protein gels. Therefore the impact of widely applied pre-cooking gelation time/temperature strategies and post-cooking period on the texture and color of final protein gels was determined. Four pre-cooking gelation strategies (no setting time, 30 min at 25 °C, 1 h at 40 °C or 24 h at 4 °C) were applied to protein pastes (fish protein concentrate and standard functional additives). After cooking, texture and color were analyzed either directly or after 24 h at 4 °C on gels adjusted to 25 °C. No-set gels were harder, gummier and chewier (P cooking. Gel-setting conditions had a greater (P cooking stored gels in texture and color, depending on the pre-cooking gelation strategy. Pre-cooking gelation conditions will affect final protein gel texture and color, with gel stability benefiting from a gel-setting period. However, post-cooking storage may have a greater impact on final gels, with textural attributes becoming more consistent between all samples. © 2015 Society of Chemical Industry.

Anabolic sensitivity of postprandial muscle protein synthesis to the ingestion of a protein-dense food is reduced in overweight and obese young adults.

Science.gov (United States)

Beals, Joseph W; Sukiennik, Richard A; Nallabelli, Julian; Emmons, Russell S; van Vliet, Stephan; Young, Justin R; Ulanov, Alexander V; Li, Zhong; Paluska, Scott A; De Lisio, Michael; Burd, Nicholas A

2016-10-01

Excess body fat diminishes muscle protein synthesis rates in response to hyperinsulinemic-hyperaminoacidemic clamps. However, muscle protein synthetic responses after the ingestion of a protein-dense food source across a range of body mass indexes (BMIs) have not been compared. We compared the myofibrillar protein synthetic response and underlying nutrient-sensing mechanisms after the ingestion of lean pork between obese, overweight, and healthy-weight adults. Ten healthy-weight [HW; BMI (in kg/m 2 ): 22.7 ± 0.4], 10 overweight (OW; BMI: 27.1 ± 0.5), and 10 obese (OB; BMI: 35.9 ± 1.3) adults received primed continuous l-[ring- 13 C 6 ]phenylalanine infusions. Blood and muscle biopsy samples were collected before and after the ingestion of 170 g pork (36 g protein and 3 g fat) to assess skeletal muscle anabolic signaling, amino acid transporters [large neutral and small neutral amino acid transporters (LAT1, SNAT2) and CD98], and myofibrillar protein synthesis. At baseline, OW and OB groups showed greater relative amounts of mammalian target of rapamycin complex 1 (mTORC1) protein than the HW group. Pork ingestion increased mTORC1 phosphorylation only in the HW group (P = 0.001). LAT1 and SNAT2 protein content increased during the postprandial period in all groups (time effect, P anabolic signals, that reduces muscle sensitivity to food ingestion. This trial was registered at clinicaltrials.gov as NCT02613767. © 2016 American Society for Nutrition.

Methodical investigation of the protein metabolism and of the bioenergetics of protein retention in growing animals. 1

International Nuclear Information System (INIS)

Schiemann, R.; Bock, H.D.; Keller, J.; Hoffmann, L.; Krawielitzki, K.; Klein, M.

1983-01-01

The influence of different protein levels in the feed (group R1 20%, R2 38% crude protein) and of different energy levels (group J1 low, J2 high energy level) on the composition of the carcass and the apparent half-life periods of the body proteins were determined in 4 groups of 15 male broiler chickens labelled with 15 NH 4 acetate. In all slaughtering phases the higher protein level resulted in a higher weight of the feathers, breast and leg muscles, higher amounts of N in all parts of the body and a higher percentage of feathers, breast and leg muscles of the total carcass than the lower protein level. Between 13 and 19% of the N in the carcass contributed to the feathers, 24-31% to the breast and leg muscles and 50-63% to the rest of the carcass. The relative quotas of the sum of breast and leg muscles in the carcass were higher for the low energy level than for the high energy level. There were no remarkable differences as to the protein content of the muscles in dependence on the energy level, the quota of sarcoplasmatic proteins, however, was higher on the high level in contrast to the low energy level, that of the myofibrillar proteins was lower. The apparent half-life period of the total body protein after normal protein supply was 22 days (group R1) and 14 after high protein supply. The energy levels in groups J1 and J2 had no significant influence on the half-life period of the total body protein. In the body fractions examined the apparent half-life periods were highest in the breast muscle and lowest in the rest of the carcass. The protein stored in the feathers did not undergo decomposition. The protein fractions 'sarcoplasmatic protein' and 'myofibrillar protein' of breast and leg muscle neither differed from one another nor from the respective total muscle fractions as regards their half-life period. (author)

Protein metabolism in slow- and fast-twitch skeletal muscle during turpentine-induced inflammation.

Science.gov (United States)

Muthny, Tomas; Kovarik, Miroslav; Sispera, Ludek; Tilser, Ivan; Holecek, Milan

2008-02-01

The aim of our study was to evaluate the differences in protein and amino acid metabolism after subcutaneous turpentine administration in the soleus muscle (SOL), predominantly composed of red fibres, and the extensor digitorum longus muscle (EDL) composed of white fibres. Young rats (40-60 g) were injected subcutaneously with 0.2 ml of turpentine oil/100 g body weight (inflammation) or with the same volume of saline solution (control). Twenty-four hours later SOL and EDL were dissected and incubated in modified Krebs-Heinseleit buffer to estimate total and myofibrillar proteolysis, chymotrypsin-like activity of proteasome (CHTLA), leucine oxidation, protein synthesis and amino acid release into the medium. The data obtained demonstrate that in intact rats, all parameters measured except protein synthesis are significantly higher in SOL than in EDL. In turpentine treated animals, CHTLA increased and protein synthesis decreased significantly more in EDL. Release of leucine was inhibited significantly more in SOL. We conclude that turpentine-induced inflammation affects more CHTLA, protein synthesis and leucine release in EDL compared to SOL.

Towards generation of bioactive peptides from meat industry waste proteins: Generation of peptides using commercial microbial proteases.

Science.gov (United States)

Ryder, Kate; Bekhit, Alaa El-Din; McConnell, Michelle; Carne, Alan

2016-10-01

Five commercially available food-grade microbial protease preparations were evaluated for their ability to hydrolyse meat myofibrillar and connective tissue protein extracts to produce bioactive peptides. A bacterial-derived protease (HT) extensively hydrolysed both meat protein extracts, producing peptide hydrolysates with significant in vitro antioxidant and ACE inhibitor activities. The hydrolysates retained bioactivity after simulated gastrointestinal hydrolysis challenge. Gel permeation chromatography sub-fractionation of the crude protein hydrolysates showed that the smaller peptide fractions exhibited the highest antioxidant and ACE inhibitor activities. OFFGEL electrophoresis of the small peptides of both hydrolysates showed that low isoelectric point peptides had antioxidant activity; however, no consistent relationship was observed between isoelectric point and ACE inhibition. Cell-based assays indicated that the hydrolysates present no significant cytotoxicity towards Vero cells. The results indicate that HT protease hydrolysis of meat myofibrillar and connective tissue protein extracts produces bioactive peptides that are non-cytotoxic, should be stable in the gastrointestinal tract and may contain novel bioactive peptide sequences. Copyright © 2016 Elsevier Ltd. All rights reserved.

Angiotensin I-Converting Enzyme (ACE Inhibitory Activity and ACE Inhibitory Peptides of Salmon (Salmo salar Protein Hydrolysates Obtained by Human and Porcine Gastrointestinal Enzymes

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Małgorzata Darewicz

2014-08-01

Full Text Available The objectives of the present study were two-fold: first, to detect whether salmon protein fractions possess angiotensin I-converting enzyme (ACE inhibitory properties and whether salmon proteins can release ACE inhibitory peptides during a sequential in vitro hydrolysis (with commercial porcine enzymes and ex vivo digestion (with human gastrointestinal enzymes. Secondly, to evaluate the ACE inhibitory activity of generated hydrolysates. A two-step ex vivo and in vitro model digestion was performed to simulate the human digestion process. Salmon proteins were degraded more efficiently by porcine enzymes than by human gastrointestinal juices and sarcoplasmic proteins were digested/hydrolyzed more easily than myofibrillar proteins. The ex vivo digested myofibrillar and sarcoplasmic duodenal samples showed IC50 values (concentration required to decrease the ACE activity by 50% of 1.06 and 2.16 mg/mL, respectively. The in vitro hydrolyzed myofibrillar and sarcoplasmic samples showed IC50 values of 0.91 and 1.04 mg/mL, respectively. Based on the results of in silico studies, it was possible to identify 9 peptides of the ex vivo hydrolysates and 7 peptides of the in vitro hydrolysates of salmon proteins of 11 selected peptides. In both types of salmon hydrolysates, ACE-inhibitory peptides IW, IY, TVY and VW were identified. In the in vitro salmon protein hydrolysates an ACE-inhibitory peptides VPW and VY were also detected, while ACE-inhibitory peptides ALPHA, IVY and IWHHT were identified in the hydrolysates generated with ex vivo digestion. In our studies, we documented ACE inhibitory in vitro effects of salmon protein hydrolysates obtained by human and as well as porcine gastrointestinal enzymes.

Ingestion of Wheat Protein Increases In Vivo Muscle Protein Synthesis Rates in Healthy Older Men in a Randomized Trial.

Science.gov (United States)

Gorissen, Stefan Hm; Horstman, Astrid Mh; Franssen, Rinske; Crombag, Julie Jr; Langer, Henning; Bierau, Jörgen; Respondek, Frederique; van Loon, Luc Jc

2016-09-01

Muscle mass maintenance is largely regulated by basal muscle protein synthesis and the capacity to stimulate muscle protein synthesis after food intake. The postprandial muscle protein synthetic response is modulated by the amount, source, and type of protein consumed. It has been suggested that plant-based proteins are less potent in stimulating postprandial muscle protein synthesis than animal-derived proteins. However, few data support this contention. We aimed to assess postprandial plasma amino acid concentrations and muscle protein synthesis rates after the ingestion of a substantial 35-g bolus of wheat protein hydrolysate compared with casein and whey protein. Sixty healthy older men [mean ± SEM age: 71 ± 1 y; body mass index (in kg/m(2)): 25.3 ± 0.3] received a primed continuous infusion of l-[ring-(13)C6]-phenylalanine and ingested 35 g wheat protein (n = 12), 35 g wheat protein hydrolysate (WPH-35; n = 12), 35 g micellar casein (MCas-35; n = 12), 35 g whey protein (Whey-35; n = 12), or 60 g wheat protein hydrolysate (WPH-60; n = 12). Plasma and muscle samples were collected at regular intervals. The postprandial increase in plasma essential amino acid concentrations was greater after ingesting Whey-35 (2.23 ± 0.07 mM) than after MCas-35 (1.53 ± 0.08 mM) and WPH-35 (1.50 ± 0.04 mM) (P protein synthesis rates increased after ingesting MCas-35 (P protein synthesis rates above basal rates (0.049% ± 0.007%/h; P = 0.02). The myofibrillar protein synthetic response to the ingestion of 35 g casein is greater than after an equal amount of wheat protein. Ingesting a larger amount of wheat protein (i.e., 60 g) substantially increases myofibrillar protein synthesis rates in healthy older men. This trial was registered at clinicaltrials.gov as NCT01952639. © 2016 American Society for Nutrition.

High pressure processing of meat

DEFF Research Database (Denmark)

Grossi, Alberto; Christensen, Mette; Ertbjerg, Per

the rheological properties of pork meat batters by inducing formation of protein gels. HP induced protein gels are suggested to be formed by high molecular weight myofibrillar protein aggregates and by peptides formed by lysosomal enzyme-induced cleavage of myofibrillar proteins. Perspectives: The data presented...

Investigating the role of uncoupling of Troponin I phosphorylation from changes in myofibrillar Ca2+-sensitivity in the pathogenesis of Cardiomyopathy

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Andrew Easton Messer

2014-08-01

Full Text Available Contraction in the mammalian heart is controlled by the intracellular Ca2+ concentration as it is in all striated muscle, but the heart has an additional signalling system that comes into play to increase heart rate and cardiac output during exercise or stress. β-adrenergic stimulation of heart muscle cells leads to release of cyclic-AMP and the activation of protein kinase A which phosphorylates key proteins in the sarcolemma, sarcoplasmic reticulum and contractile apparatus. Troponin I (TnI and Myosin Binding Protein C (MyBP-C are the prime targets in the myofilaments. TnI phosphorylation lowers myofibrillar Ca2+-sensitivity and increases the speed of Ca2+-dissociation and relaxation (lusitropic effect.Recent studies have shown that this relationship between Ca2+-sensitivity and TnI phosphorylation may be unstable. In familial cardiomyopathies, both dilated and hypertrophic (DCM and HCM, a mutation in one of the proteins of the thin filament often results in the loss of the relationship (uncoupling and blunting of the lusitropic response. For familial dilated cardiomyopathy in thin filament proteins it has been proposed that this uncoupling is causative of the phenotype. Uncoupling has also been found in human heart tissue from patients with hypertrophic obstructive cardiomyopathy as a secondary effect. Recently, it has been found that Ca2+-sensitizing drugs can promote uncoupling, whilst one Ca2+-desensitising drug Epigallocatechin 3-Gallate (EGCG can reverse uncoupling.We will discuss recent findings about the role of uncoupling in the development of cardiomyopathies and the molecular mechanism of the process.

Protein turnover, amino acid requirements and recommendations for athletes and active populations

Energy Technology Data Exchange (ETDEWEB)

Poortmans, J.R.; Carpentier, A. [Laboratory for Biometry and Sport Nutrition, Faculty of Motor Sciences, Free University of Brussels, Brussels (Belgium); Pereira-Lancha, L.O. [Departamento de Nutrição, Instituto Vita, São Paulo, SP (Brazil); Lancha, A. Jr. [Laboratório de Nutrição Aplicada à Atividade Motora, Escola de Educação Física e Esporte, Universidade de São Paulo, São Paulo, SP (Brazil)

2012-06-08

Skeletal muscle is the major deposit of protein molecules. As for any cell or tissue, total muscle protein reflects a dynamic turnover between net protein synthesis and degradation. Noninvasive and invasive techniques have been applied to determine amino acid catabolism and muscle protein building at rest, during exercise and during the recovery period after a single experiment or training sessions. Stable isotopic tracers ({sup 13}C-lysine, {sup 15}N-glycine, {sup 2}H{sub 5}-phenylalanine) and arteriovenous differences have been used in studies of skeletal muscle and collagen tissues under resting and exercise conditions. There are different fractional synthesis rates in skeletal muscle and tendon tissues, but there is no major difference between collagen and myofibrillar protein synthesis. Strenuous exercise provokes increased proteolysis and decreased protein synthesis, the opposite occurring during the recovery period. Individuals who exercise respond differently when resistance and endurance types of contractions are compared. Endurance exercise induces a greater oxidative capacity (enzymes) compared to resistance exercise, which induces fiber hypertrophy (myofibrils). Nitrogen balance (difference between protein intake and protein degradation) for athletes is usually balanced when the intake of protein reaches 1.2 g·kg{sup −1}·day{sup −1} compared to 0.8 g·kg{sup −1}·day{sup −1} in resting individuals. Muscular activities promote a cascade of signals leading to the stimulation of eukaryotic initiation of myofibrillar protein synthesis. As suggested in several publications, a bolus of 15-20 g protein (from skimmed milk or whey proteins) and carbohydrate (± 30 g maltodextrine) drinks is needed immediately after stopping exercise to stimulate muscle protein and tendon collagen turnover within 1 h.

Protein turnover, amino acid requirements and recommendations for athletes and active populations

International Nuclear Information System (INIS)

Poortmans, J.R.; Carpentier, A.; Pereira-Lancha, L.O.; Lancha, A. Jr.

2012-01-01

Skeletal muscle is the major deposit of protein molecules. As for any cell or tissue, total muscle protein reflects a dynamic turnover between net protein synthesis and degradation. Noninvasive and invasive techniques have been applied to determine amino acid catabolism and muscle protein building at rest, during exercise and during the recovery period after a single experiment or training sessions. Stable isotopic tracers ( 13 C-lysine, 15 N-glycine, 2 H 5 -phenylalanine) and arteriovenous differences have been used in studies of skeletal muscle and collagen tissues under resting and exercise conditions. There are different fractional synthesis rates in skeletal muscle and tendon tissues, but there is no major difference between collagen and myofibrillar protein synthesis. Strenuous exercise provokes increased proteolysis and decreased protein synthesis, the opposite occurring during the recovery period. Individuals who exercise respond differently when resistance and endurance types of contractions are compared. Endurance exercise induces a greater oxidative capacity (enzymes) compared to resistance exercise, which induces fiber hypertrophy (myofibrils). Nitrogen balance (difference between protein intake and protein degradation) for athletes is usually balanced when the intake of protein reaches 1.2 g·kg −1 ·day −1 compared to 0.8 g·kg −1 ·day −1 in resting individuals. Muscular activities promote a cascade of signals leading to the stimulation of eukaryotic initiation of myofibrillar protein synthesis. As suggested in several publications, a bolus of 15-20 g protein (from skimmed milk or whey proteins) and carbohydrate (± 30 g maltodextrine) drinks is needed immediately after stopping exercise to stimulate muscle protein and tendon collagen turnover within 1 h

Protein turnover, amino acid requirements and recommendations for athletes and active populations

Directory of Open Access Journals (Sweden)

J.R. Poortmans

2012-10-01

Full Text Available Skeletal muscle is the major deposit of protein molecules. As for any cell or tissue, total muscle protein reflects a dynamic turnover between net protein synthesis and degradation. Noninvasive and invasive techniques have been applied to determine amino acid catabolism and muscle protein building at rest, during exercise and during the recovery period after a single experiment or training sessions. Stable isotopic tracers (13C-lysine, 15N-glycine, ²H5-phenylalanine and arteriovenous differences have been used in studies of skeletal muscle and collagen tissues under resting and exercise conditions. There are different fractional synthesis rates in skeletal muscle and tendon tissues, but there is no major difference between collagen and myofibrillar protein synthesis. Strenuous exercise provokes increased proteolysis and decreased protein synthesis, the opposite occurring during the recovery period. Individuals who exercise respond differently when resistance and endurance types of contractions are compared. Endurance exercise induces a greater oxidative capacity (enzymes compared to resistance exercise, which induces fiber hypertrophy (myofibrils. Nitrogen balance (difference between protein intake and protein degradation for athletes is usually balanced when the intake of protein reaches 1.2 g·kg-1·day-1 compared to 0.8 g·kg-1·day-1 in resting individuals. Muscular activities promote a cascade of signals leading to the stimulation of eukaryotic initiation of myofibrillar protein synthesis. As suggested in several publications, a bolus of 15-20 g protein (from skimmed milk or whey proteins and carbohydrate (± 30 g maltodextrine drinks is needed immediately after stopping exercise to stimulate muscle protein and tendon collagen turnover within 1 h.

Impact of Resistance Training on Skeletal Muscle Mitochondrial Biogenesis, Content, and Function

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Thomas Groennebaek

2017-09-01

Full Text Available Skeletal muscle metabolic and contractile properties are reliant on muscle mitochondrial and myofibrillar protein turnover. The turnover of these specific protein pools is compromised during disease, aging, and inactivity. Oppositely, exercise can accentuate muscle protein turnover, thereby counteracting decay in muscle function. According to a traditional consensus, endurance exercise is required to drive mitochondrial adaptations, while resistance exercise is required to drive myofibrillar adaptations. However, concurrent practice of traditional endurance exercise and resistance exercise regimens to achieve both types of muscle adaptations is time-consuming, motivationally demanding, and contended to entail practice at intensity levels, that may not comply with clinical settings. It is therefore of principle interest to identify effective, yet feasible, exercise strategies that may positively affect both mitochondrial and myofibrillar protein turnover. Recently, reports indicate that traditional high-load resistance exercise can stimulate muscle mitochondrial biogenesis and mitochondrial respiratory function. Moreover, fatiguing low-load resistance exercise has been shown capable of promoting muscle hypertrophy and expectedly entails greater metabolic stress to potentially enhance mitochondrial adaptations. Consequently, fatiguing low-load resistance exercise regimens may possess the ability to stimulate muscle mitochondrial adaptations without compromising muscle myofibrillar accretion. However, the exact ability of resistance exercise to drive mitochondrial adaptations is debatable, not least due to some methodological challenges. The current review therefore aims to address the evidence on the effects of resistance exercise on skeletal muscle mitochondrial biogenesis, content and function. In prolongation, a perspective is taken on the specific potential of low-load resistance exercise on promoting mitochondrial adaptations.

Galalpha1-->4Gal-glycans are expressed on myofibrillar associated proteins

DEFF Research Database (Denmark)

Kirkeby, S; Moe, D; Cläesson, M H

1998-01-01

NAcbeta- were used to detect terminal alpha-galactosylated glycoconjugates on muscle proteins. Electrotransfer of proteins, extracted from human masseter and biceps muscles, to nitrocellulose after polyacrylamide gel electrophoresis (PAGE) and incubation with anti-Pk (CD77) consistently showed two bands...... with apparent molecular weights of 66 kDa and 64 kDa. In fresh frozen muscle sections from some humans there was endothelial reaction with anti-CD77 in capillaries, venules and veins but not in arterioles and arteries. In muscle samples from other humans there was no staining of endothelial cells. Formalin......-fixed human muscle displayed a CD77 reaction with highest accumulation of reaction product at the periphery of the fibers. This may be explained by the presence of Pk glycoconjugates on intermediate filaments in muscle fibers. In preparations of cat masseter muscle proteins the antibodies against P1Pk...

Methodical investigation of the protein metabolism and of the bioenergetics of protein retention in growing animals. 1. Determination of parameters of growth and protein retention of chickens after long-term labelling with /sup 15/NH/sub 4/ acetate

Energy Technology Data Exchange (ETDEWEB)

Schiemann, R.; Bock, H.D.; Keller, J.; Hoffmann, L.; Krawielitzki, K.; Klein, M. (Akademie der Landwirtschaftswissenschaften der DDR, Dummerstorf-Rostock. Forschungszentrum fuer Tierproduktion)

1983-01-01

The influence of different protein levels in the feed (group R1 20%, R2 38% crude protein) and of different energy levels (group J1 low, J2 high energy level) on the composition of the carcass and the apparent half-life periods of the body proteins were determined in 4 groups of 15 male broiler chickens labelled with /sup 15/NH/sub 4/ acetate. In all slaughtering phases the higher protein level resulted in a higher weight of the feathers, breast and leg muscles, higher amounts of N in all parts of the body and a higher percentage of feathers, breast and leg muscles of the total carcass than the lower protein level. Between 13 and 19% of the N in the carcass contributed to the feathers, 24-31% to the breast and leg muscles and 50-63% to the rest of the carcass. The relative quotas of the sum of breast and leg muscles in the carcass were higher for the low energy level than for the high energy level. There were no remarkable differences as to the protein content of the muscles in dependence on the energy level, the quota of sarcoplasmatic proteins, however, was higher on the high level in contrast to the low energy level, that of the myofibrillar proteins was lower. The apparent half-life period of the total body protein after normal protein supply was 22 days (group R1) and 14 after high protein supply. The energy levels in groups J1 and J2 had no significant influence on the half-life period of the total body protein. In the body fractions examined the apparent half-life periods were highest in the breast muscle and lowest in the rest of the carcass. The protein stored in the feathers did not undergo decomposition. The protein fractions 'sarcoplasmatic protein' and 'myofibrillar protein' of breast and leg muscle neither differed from one another nor from the respective total muscle fractions as regards their half-life period.

Consumption of Milk Protein or Whey Protein Results in a Similar Increase in Muscle Protein Synthesis in Middle Aged Men.

Science.gov (United States)

Mitchell, Cameron J; McGregor, Robin A; D'Souza, Randall F; Thorstensen, Eric B; Markworth, James F; Fanning, Aaron C; Poppitt, Sally D; Cameron-Smith, David

2015-10-21

The differential ability of various milk protein fractions to stimulate muscle protein synthesis (MPS) has been previously described, with whey protein generally considered to be superior to other fractions. However, the relative ability of a whole milk protein to stimulate MPS has not been compared to whey. Sixteen healthy middle-aged males ingested either 20 g of milk protein (n = 8) or whey protein (n = 8) while undergoing a primed constant infusion of ring (13)C₆ phenylalanine. Muscle biopsies were obtained 120 min prior to consumption of the protein and 90 and 210 min afterwards. Resting myofibrillar fractional synthetic rates (FSR) were 0.019% ± 0.009% and 0.021% ± 0.018% h(-1) in the milk and whey groups respectively. For the first 90 min after protein ingestion the FSR increased (p whey groups respectively with no difference between groups (p = 0.810). FSR returned to baseline in both groups between 90 and 210 min after protein ingestion. Despite evidence of increased rate of digestion and leucine availability following the ingestion of whey protein, there was similar activation of MPS in middle-aged men with either 20 g of milk protein or whey protein.

Consumption of whole eggs promotes greater stimulation of postexercise muscle protein synthesis than consumption of isonitrogenous amounts of egg whites in young men.

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van Vliet, Stephan; Shy, Evan L; Abou Sawan, Sidney; Beals, Joseph W; West, Daniel Wd; Skinner, Sarah K; Ulanov, Alexander V; Li, Zhong; Paluska, Scott A; Parsons, Carl M; Moore, Daniel R; Burd, Nicholas A

2017-12-01

Background: Protein in the diet is commonly ingested from whole foods that contain various macro- and micronutrients. However, the effect of consuming protein within its natural whole-food matrix on postprandial protein metabolism remains understudied in humans. Objective: We aimed to compare the whole-body and muscle protein metabolic responses after the consumption of whole eggs with egg whites during exercise recovery in young men. Design: In crossover trials, 10 resistance-trained men [aged 21 ± 1 y; 88 ± 3 kg; body fat: 16% ± 1% (means ± SEMs)] received primed continuous l-[ ring - 2 H 5 ]phenylalanine and l-[1- 13 C]leucine infusions and performed a single bout of resistance exercise. After exercise, participants consumed intrinsically l-[5,5,5- 2 H 3 ]leucine-labeled whole eggs (18 g protein, 17 g fat) or egg whites (18 g protein, 0 g fat). Repeated blood and muscle biopsy samples were collected to assess whole-body leucine kinetics, intramuscular signaling, and myofibrillar protein synthesis. Results: Plasma appearance rates of protein-derived leucine were more rapid after the consumption of egg whites than after whole eggs ( P = 0.01). Total plasma availability of leucine over the 300-min postprandial period was similar ( P = 0.75) between the ingestion of whole eggs (68% ± 1%) and egg whites (66% ± 2%), with no difference in whole-body net leucine balance ( P = 0.27). Both whole-egg and egg white conditions increased the phosphorylation of mammalian target of rapamycin complex 1, ribosomal protein S6 kinase 1, and eukaryotic translation initiation factor 4E-binding protein 1 during postexercise recovery (all P egg ingestion increased the postexercise myofibrillar protein synthetic response to a greater extent than did the ingestion of egg whites ( P = 0.04). Conclusions: We show that the ingestion of whole eggs immediately after resistance exercise resulted in greater stimulation of myofibrillar protein synthesis than did the ingestion of egg whites

Protein Molecular Structures, Protein SubFractions, and Protein Availability Affected by Heat Processing: A Review

International Nuclear Information System (INIS)

Yu, P.

2007-01-01

The utilization and availability of protein depended on the types of protein and their specific susceptibility to enzymatic hydrolysis (inhibitory activities) in the gastrointestine and was highly associated with protein molecular structures. Studying internal protein structure and protein subfraction profiles leaded to an understanding of the components that make up a whole protein. An understanding of the molecular structure of the whole protein was often vital to understanding its digestive behavior and nutritive value in animals. In this review, recently obtained information on protein molecular structural effects of heat processing was reviewed, in relation to protein characteristics affecting digestive behavior and nutrient utilization and availability. The emphasis of this review was on (1) using the newly advanced synchrotron technology (S-FTIR) as a novel approach to reveal protein molecular chemistry affected by heat processing within intact plant tissues; (2) revealing the effects of heat processing on the profile changes of protein subfractions associated with digestive behaviors and kinetics manipulated by heat processing; (3) prediction of the changes of protein availability and supply after heat processing, using the advanced DVE/OEB and NRC-2001 models, and (4) obtaining information on optimal processing conditions of protein as intestinal protein source to achieve target values for potential high net absorbable protein in the small intestine. The information described in this article may give better insight in the mechanisms involved and the intrinsic protein molecular structural changes occurring upon processing.

Proteomic analysis of processing by-products from canned and fresh tuna: identification of potentially functional food proteins.

Science.gov (United States)

Sanmartín, Esther; Arboleya, Juan Carlos; Iloro, Ibon; Escuredo, Kepa; Elortza, Felix; Moreno, F Javier

2012-09-15

Proteomic approaches have been used to identify the main proteins present in processing by-products generated by the canning tuna-industry, as well as in by-products derived from filleting of skeletal red muscle of fresh tuna. Following fractionation by using an ammonium sulphate precipitation method, three proteins (tropomyosin, haemoglobin and the stress-shock protein ubiquitin) were identified in the highly heterogeneous and heat-treated material discarded by the canning-industry. Additionally, this fractionation method was successful to obtain tropomyosin of high purity from the heterogeneous starting material. By-products from skeletal red muscle of fresh tuna were efficiently fractionated to sarcoplasmic and myofibrillar fractions, prior to the identification based mainly on the combined searching of the peptide mass fingerprint (MALDI-TOF) and peptide fragment fingerprinting (MALDI LIFT-TOF/TOF) spectra of fifteen bands separated by 1D SDS-PAGE. Thus, the sarcoplasmic fraction contained myoglobin and several enzymes that are essential for efficient energy production, whereas the myofibrillar fraction had important contractile proteins, such as actin, tropomyosin, myosin or an isoform of the enzyme creatine kinase. Application of proteomic technologies has revealed new knowledge on the composition of important by-products from tuna species, enabling a better evaluation of their potential applications. Copyright © 2012 Elsevier Ltd. All rights reserved.

Lactobacillus sakei CRL1862 improves safety and protein hydrolysis in meat systems.

Science.gov (United States)

Castellano, P; Aristoy, M C; Sentandreu, M A; Vignolo, G; Toldrá, F

2012-12-01

The capacity of Lactobacillus sakei CRL1862 to prevent the growth of pathogens and its ability to degrade sarcoplasmic and myofibrillar proteins in pork meat systems was evaluated. In addition, basic safety aspects of Lact. sakei CRL1862 such as production of biogenic amines and antibiotic susceptibility were addressed. The bacteriocin-producing Lact. sakei CRL1862 showed respectively bactericide and bacteriostatic effect against Listeria monocytogenes and Staphylococcus aureus in beaker sausage assay during 9 days of storage at 22 °C. The hydrolytic effect of Lact. sakei CRL1862 on protein extracts was evaluated by SDS-PAGE and reverse phase HPLC. A more pronounced proteolysis was evidenced in inoculated sarcoplasmic proteins compared with myofibrillar extracts with the generation of predominantly hydrophilic peptides and increase of total free amino acids concentration. Lactobacillus sakei CRL1862 produced neither histamine nor tyrosine and exhibited no resistance to the antibiotics assayed. Lactobacillus sakei CRL1862 effectively controlled the growth of L. monocytogenes and Staph. aureus; moreover, it was able to hydrolyse pork meat extracts generating peptides and amino acids, which may improve hygienic and sensorial attributes of fermented meat products. The use of an integrated approach to evaluate the major traits of Lact. sakei CRL1862 showed it can be applied as an autochthonous functional starter in meat fermentation. © 2012 The Society for Applied Microbiology.

Effect of prolonged intravenous glucose and essential amino acid infusion on nitrogen balance, muscle protein degradation and ubiquitin-conjugating enzyme gene expression in calves

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Scaife Jes R

2008-02-01

Full Text Available Abstract Background Intravenous infusions of glucose and amino acids increase both nitrogen balance and muscle accretion. We hypothesised that co-infusion of glucose (to stimulate insulin and essential amino acids (EAA would act additively to improve nitrogen balance by decreasing muscle protein degradation in association with alterations in muscle expression of components of the ubiquitin-proteasome proteolytic pathway. Methods We examined the effect of a 5 day intravenous infusions of saline, glucose, EAA and glucose + EAA, on urinary nitrogen excretion and muscle protein degradation. We carried out the study in 6 restrained calves since ruminants offer the advantage that muscle protein degradation can be assessed by excretion of 3 methyl-histidine and multiple muscle biopsies can be taken from the same animal. On the final day of infusion blood samples were taken for hormone and metabolite measurement and muscle biopsies for expression of ubiquitin, the 14-kDa E2 ubiquitin conjugating enzyme, and proteasome sub-units C2 and C8. Results On day 5 of glucose infusion, plasma glucose, insulin and IGF-1 concentrations were increased while urea nitrogen excretion and myofibrillar protein degradation was decreased. Co-infusion of glucose + EAA prevented the loss of urinary nitrogen observed with EAA infusions alone and enhanced the increase in plasma IGF-1 concentration but there was no synergistic effect of glucose + EAA on the decrease in myofibrillar protein degradation. Muscle mRNA expression of the ubiquitin conjugating enzyme, 14-kDa E2 and proteasome sub-unit C2 were significantly decreased, after glucose but not amino acid infusions, and there was no further response to the combined infusions of glucose + EAA. Conclusion Prolonged glucose infusion decreases myofibrillar protein degradation, prevents the excretion of infused EAA, and acts additively with EAA to increase plasma IGF-1 and improve net nitrogen balance. There was no evidence of

Impact of the Fenton process in meat digestion as assessed using an in vitro gastro-intestinal model.

Science.gov (United States)

Oueslati, Khaled; de La Pomélie, Diane; Santé-Lhoutellier, Véronique; Gatellier, Philippe

2016-10-15

The production of oxygen free radicals catalysed by non-haem iron was investigated in an in vitro mimetic model of the digestive tract using specific chemical traps. Superoxide radicals (O2(∗-)) and their protonated form (hydroperoxyl radicals, HO2(∗)) were detected by the reduction of nitroblue tetrazolium into formazan, and hydroxyl radicals (OH(∗)) were detected by the hydroxylation of terephthalate. Under gastric conditions, O2(∗-)/HO2(∗) were detected in higher quantity than OH(∗). Increasing the pH from 3.5 to 6.5 poorly affected the kinetics of free radical production. The oxidations generated by these free radicals were estimated on myofibrils prepared from pork rectus femoris muscle. Myofibrillar lipid and protein oxidation increased with time and oxidant concentration, with a negative impact on the digestibility of myofibrillar proteins. Plant food antioxidants considerably decreased free radical production and lipid oxidation but not protein oxidation. Copyright © 2016 Elsevier Ltd. All rights reserved.

Effect of high pressure on physicochemical properties of meat.

Science.gov (United States)

Buckow, Roman; Sikes, Anita; Tume, Ron

2013-01-01

The application of high pressure offers some interesting opportunities in the processing of muscle-based food products. It is well known that high-pressure processing can prolong the shelf life of meat products in addition to chilling but the pressure-labile nature of protein systems limits the commercial range of applications. High pressure can affect the texture and gel-forming properties of myofibrillar proteins and, hence, has been suggested as a physical and additive-free alternative to tenderize and soften or restructure meat and fish products. However, the rate and magnitude at which pressure and temperature effects take place in muscles are variable and depend on a number of circumstances and conditions that are still not precisely known. This review provides an overview of the current knowledge of the effects of high pressure on muscle tissue over a range of temperatures as it relates to meat texture, microstructure, color, enzymes, lipid oxidation, and pressure-induced gelation of myofibrillar proteins.

Sarcoplasmatic and myofibrillar protein changes caused by acute heat stress in broiler chicken Alterações nas proteínas sarcoplasmáticas e miofibrilares em frangos de corte causadas por estresse térmico agudo

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Carolina de Castro Santos

2008-01-01

Full Text Available Acute heat stress (AHS modifies the structure of myofibrils affecting functional properties of meat, mainly the water holding capacity. This experiment aimed to identify changes in proteolysis and migration between the myofibrillar and sarcoplasmatic fractions due to pre-slaughter AHS. Myofibrillar fragmentation index (MFI, SDS-PAGE, western blot of vinculin (WB and shear force (SF were determined. Six hundred broilers (Gallus gallus were slaughtered in three different days (ST. In each ST, groups of ten animals were placed in transport crates and submitted to AHS (35ºC, 75 - 85% RH for 2 hours. Simultaneously, the non-stressed broilers (NS were kept in thermoneutral environment (22ºC, 83 ± 6.6% RH within the crates in the same density. After slaughter, the breast muscles were kept refrigerated until the withdrawal of all samples (0, 1, 2, 6 and 24 hours after slaughter. Sampling within AHS and NS birds was collected according to lightness value (normal L* 51, except for determination of MFI and SF. The lightness was used later to perform SDS-PAGE and WB analyses. MFI kinetics showed that the fragmentation rate was superior in animals NS, indicating that AHS can harm proteolysis and rate of myofibrillar fragmentation. However, the extent of fragmentation did not change, as well as SF values. SDS-PAGE for Troponin fragments indicated a differentiated pattern between AHS and NS. The WB did not show alterations in vinculin fragmentation. Modifications in sarcoplasmatic fraction are observed in meat with high L*values, independent of environmental condition.O estresse térmico agudo (ET causa alterações na estrutura das miofibrilas, afetando propriedades funcionais da carne, principalmente a capacidade de retenção de água. Identificaram-se mudanças na proteólise e migração entre as frações miofibrilar e sarcoplasmática, decorrentes do ET pré-abate, através do índice de fragmentação miofibrilar (MFI, SDS-PAGE para troponina (SDS

Analysis of troponin I gene polymorphisms and meat quality in ...

African Journals Online (AJOL)

Troponin I is one of myofibrillar proteins required for the calcium regulation of skeletal muscle contraction. The expression of both genes, TNNI1 and TNNI2, in troponin is muscle fibre specific and may affect meat quality traits. In this study, the PCR-RFLP method was applied to genotype 120 Mongcai pigs at three ...

Myowater dynamics and protein secondary structural changes as affected by heating rate in three pork qualities: a combined FT-IR microspectroscopic and 1H NMR relaxometry study.

Science.gov (United States)

Wu, Zhiyun; Bertram, Hanne Christine; Böcker, Ulrike; Ofstad, Ragni; Kohler, Achim

2007-05-16

The objective of this study was to investigate the influence of heating rate on myowater dynamics and protein secondary structures in three pork qualities by proton NMR T2 relaxation and Fourier transform infrared (FT-IR) microspectroscopy measurements. Two oven temperatures at 100 degrees C and 200 degrees C corresponding to slow and fast heating rates were applied on three pork qualities (DFD, PSE, and normal) to an internal center temperature of 65 degrees C. The fast heating induced a higher cooking loss, particularly for PSE meat. The water proton T21 distribution representing water entrapped within the myofibrillar network was influenced by heating rate and meat quality. Fast heating broadened the T21 distribution and decreased the relaxation times of the T21 peak position for three meat qualities. The changes in T21 relaxation times in meat can be interpreted in terms of chemical and diffusive exchange. FT-IR showed that fast heating caused a higher gain of random structures and aggregated beta-sheets at the expense of native alpha-helixes, and these changes dominate the fast-heating-induced broadening of T21 distribution and reduction in T21 times. Furthermore, of the three meat qualities, PSE meat had the broadest T21 distribution and the lowest T21 times for both heating rates, reflecting that the protein aggregation of PSE caused by heating is more extensive than those of DFD and normal, which is consistent with the IR data. The present study demonstrated that the changes in T2 relaxation times of water protons affected by heating rate and raw meat quality are well related to the protein secondary structural changes as probed by FT-IR microspectroscopy.

Protein and lipid oxidation affect the viscoelasticity of whey protein layers at the oil-water interface

NARCIS (Netherlands)

Berton-Carabin, Claire C.; Schroder, Anja; Rovalino-Cordova, Ana; Schroën, Karin; Sagis, Leonard

2016-01-01

Protein and lipid oxidation are prevailing issues that negatively affect the nutritional and sensory quality of food emulsions. It is probable that such oxidative modifications affect the functional properties of proteins, and in particular their ability to form densely packed, interconnected

No additional effect of different types of physical activity on 10-hour muscle protein synthesis in elderly men on a controlled energy- and protein-sufficient diet

DEFF Research Database (Denmark)

Bulow, Jacob; Agergaard, Jakob; Kjær, Michael

2016-01-01

protein synthesis (MPS) are less investigated. The aim of this study was to determine the effects of daily physical activities upon MPS in elderly individuals. Methods: A total of 24 elderly men (70 +/- 1 year) were recruited and randomly assigned: inactivity in form of bed-rest (IA), daily physical......-hour myofibrillar protein fractional synthesis rates (FSR), and typical prerequisites for calculating FSR were fulfilled. Physical activities were monitored, and venous blood and muscle biopsies collected. Results: Physical activity was highest in the DA compared to both the IA and RE groups. Nutrient...... activities (DA), or heavy resistance exercise (RE). All groups undertook a normal eating routine containing carbohydrates (52 E%), fat (32 E%), and protein (16 E%). Ingestion of labeled milk protein ([1-C-13] leucine-labeled whey and caseinate) served to maintain tracer enrichment for determination of 10...

Glucagon-Like Peptide 2 Stimulates Postresection Intestinal Adaptation in Preterm Pigs by Affecting Proteins Related to Protein, Carbohydrate, and Sulphur Metabolism

DEFF Research Database (Denmark)

Jiang, Pingping; Vegge, Andreas; Thymann, Thomas

2017-01-01

cellular structural proteins, while the added GLP-2 treatment affected proteins involved in protein processing and the metabolism of protein, carbohydrate, and sulphur. CONCLUSION: In the first days following resection, proteins affected by resection plus GLP-2 treatment differed markedly from those...

BAG3 Directly Interacts with Mutated alphaB-Crystallin to Suppress Its Aggregation and Toxicity

NARCIS (Netherlands)

Hishiya, Akinori; Salman, Mortada Najem; Carra, Serena; Kampinga, Harm H.; Takayama, Shinichi

2011-01-01

A homozygous disruption or genetic mutation of the bag3 gene causes progressive myofibrillar myopathy in mouse and human skeletal and cardiac muscle disorder while mutations in the small heat shock protein aB-crystallin gene ( CRYAB) are reported to be responsible for myofibrillar myopathy. Here, we

Methodical investigation of the protein metabolism and of the bioenergetics of the protein retention in growing animals. 2

International Nuclear Information System (INIS)

Voelker, T.; Krawielitzki, K.; Klein, M.; Keller, J.

1983-01-01

The amino acid composition of the proteins in selected body fractions of chickens and the 15 N -excess of amino acids isolated from them resulting from a feeding experiment with long-term 15 NH 4 -acetate labelling were determined. The amino acid spectra of feathers, breast and leg muscles are characterized by differences in the content of individual amino acids specific for the organs, the composition of the proteins, however, is independent of the protein content of the ration and the age of the animals. The sarcoplasmatic and myofibrillar proteins also have typical amino acid patterns, which-with the exception of the histidine content-are neither influenced by the extraction of the proteins from the breast or leg muscles nor by the energy level of the feeding or the age of the animals. There are no significant differences in the metabolization of the main protein fraction of the breast and leg muscles. The oral supply of 15 N-ammonium acetate to broilers predominantly labels the non-essential amino acids so that the derived kinetic data chiefly represent the metabolism of the non-essential amino acids. (author)

Phosphoproteomics analysis of postmortem porcine muscle with pH decline rate and time difference

DEFF Research Database (Denmark)

Huang, Honggang; Larsen, Martin R; Karlsson, Anders H

2012-01-01

The aim of this study was to characterize the protein phosphorylation in postmortem (PM) muscle and reveal the change during meat quality development. The gel-based phosphoproteomic analysis of PM porcine muscle was performed in three pig groups with different pH decline rates from PM 1h to 24 h....... The sarcoplasmic and myofibrillar fractions were analyzed using gel electrophoresis in combination with a phosphoprotein specific staining. Globally, the group with fast pH decline rate had the highest phosphorylation level at PM 1 h, but lowest at PM 24 h, whereas the group with slow pH decline rate showed...... the reverse case. The phosphorylation level of 12 bands in sarcoplasmic fraction and 3 bands in myofibrillar fraction were significantly affected by the synergy effects of pH and time (p

Intrinsically Disordered Segments Affect Protein Half-Life in the Cell and during Evolution

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Robin van der Lee

2014-09-01

Full Text Available Precise control of protein turnover is essential for cellular homeostasis. The ubiquitin-proteasome system is well established as a major regulator of protein degradation, but an understanding of how inherent structural features influence the lifetimes of proteins is lacking. We report that yeast, mouse, and human proteins with terminal or internal intrinsically disordered segments have significantly shorter half-lives than proteins without these features. The lengths of the disordered segments that affect protein half-life are compatible with the structure of the proteasome. Divergence in terminal and internal disordered segments in yeast proteins originating from gene duplication leads to significantly altered half-life. Many paralogs that are affected by such changes participate in signaling, where altered protein half-life will directly impact cellular processes and function. Thus, natural variation in the length and position of disordered segments may affect protein half-life and could serve as an underappreciated source of genetic variation with important phenotypic consequences.

A kinetic model to simulate the effect of cooking time-temperature on the gastric digestion of meat

OpenAIRE

Kondjoyan, Alain; Daudin, Jean-Dominique; Portanguen, Stéphane; Aubry, Laurent; Sante-Lhoutellier, Veronique

2014-01-01

A kinetic model was developed to predict the effect of cooking time and temperature on the digestibility of myofibrillar proteins. The predictions were confronted to the measurement of the in vitro digestibility of myofibrillar proteins coming from either slices of beef meat heated in water bath or from a piece of meat roasted in a domestic oven. The model was able to simulate the in vitro measurements for the meat pieces of different sizes cooked under different condi...

Levetiracetam Affects Differentially Presynaptic Proteins in Rat Cerebral Cortex

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Daniele Marcotulli

2017-12-01

Full Text Available Presynaptic proteins are potential therapeutic targets for epilepsy and other neurological diseases. We tested the hypothesis that chronic treatment with the SV2A ligand levetiracetam affects the expression of other presynaptic proteins. Results showed that in rat neocortex no significant difference was detected in SV2A protein levels in levetiracetam treated animals compared to controls, whereas levetiracetam post-transcriptionally decreased several vesicular proteins and increased LRRK2, without any change in mRNA levels. Analysis of SV2A interactome indicates that the presynaptic proteins regulation induced by levetiracetam reported here is mediated by this interactome, and suggests that LRRK2 plays a role in forging the pattern of effects.

Plant protein and animal proteins: do they differentially affect cardiovascular disease risk?

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Richter, Chesney K; Skulas-Ray, Ann C; Champagne, Catherine M; Kris-Etherton, Penny M

2015-11-01

Proteins from plant-based compared with animal-based food sources may have different effects on cardiovascular disease (CVD) risk factors. Numerous epidemiologic and intervention studies have evaluated their respective health benefits; however, it is difficult to isolate the role of plant or animal protein on CVD risk. This review evaluates the current evidence from observational and intervention studies, focusing on the specific protein-providing foods and populations studied. Dietary protein is derived from many food sources, and each provides a different composite of nonprotein compounds that can also affect CVD risk factors. Increasing the consumption of protein-rich foods also typically results in lower intakes of other nutrients, which may simultaneously influence outcomes. Given these complexities, blanket statements about plant or animal protein may be too general, and greater consideration of the specific protein food sources and the background diet is required. The potential mechanisms responsible for any specific effects of plant and animal protein are similarly multifaceted and include the amino acid content of particular foods, contributions from other nonprotein compounds provided concomitantly by the whole food, and interactions with the gut microbiome. Evidence to date is inconclusive, and additional studies are needed to further advance our understanding of the complexity of plant protein vs. animal protein comparisons. Nonetheless, current evidence supports the idea that CVD risk can be reduced by a dietary pattern that provides more plant sources of protein compared with the typical American diet and also includes animal-based protein foods that are unprocessed and low in saturated fat. © 2015 American Society for Nutrition.

Protein Availability and Satellite Cell Dynamics in Skeletal Muscle.

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Shamim, Baubak; Hawley, John A; Camera, Donny M

2018-06-01

Human skeletal muscle satellite cells are activated in response to both resistance and endurance exercise. It was initially proposed that satellite cell proliferation and differentiation were only required to support resistance exercise-induced hypertrophy. However, satellite cells may also play a role in muscle fibre remodelling after endurance-based exercise and extracellular matrix regulation. Given the importance of dietary protein, particularly branched chain amino acids, in supporting myofibrillar and mitochondrial adaptations to both resistance and endurance-based training, a greater understanding of how protein intake impacts satellite cell activity would provide further insight into the mechanisms governing skeletal muscle remodelling with exercise. While many studies have investigated the capacity for protein ingestion to increase post-exercise rates of muscle protein synthesis, few investigations have examined the role for protein ingestion to modulate satellite cell activity. Here we review the molecular mechanisms controlling the activation of satellite cells in response to mechanical stress and protein intake in both in vitro and in vivo models. We provide a mechanistic framework that describes how protein ingestion may enhance satellite activity and promote exercise adaptations in human skeletal muscle.

Alternative splicing affects the targeting sequence of peroxisome proteins in Arabidopsis.

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An, Chuanjing; Gao, Yuefang; Li, Jinyu; Liu, Xiaomin; Gao, Fuli; Gao, Hongbo

2017-07-01

A systematic analysis of the Arabidopsis genome in combination with localization experiments indicates that alternative splicing affects the peroxisomal targeting sequence of at least 71 genes in Arabidopsis. Peroxisomes are ubiquitous eukaryotic cellular organelles that play a key role in diverse metabolic functions. All peroxisome proteins are encoded by nuclear genes and target to peroxisomes mainly through two types of targeting signals: peroxisomal targeting signal type 1 (PTS1) and PTS2. Alternative splicing (AS) is a process occurring in all eukaryotes by which a single pre-mRNA can generate multiple mRNA variants, often encoding proteins with functional differences. However, the effects of AS on the PTS1 or PTS2 and the targeting of the protein were rarely studied, especially in plants. Here, we systematically analyzed the genome of Arabidopsis, and found that the C-terminal targeting sequence PTS1 of 66 genes and the N-terminal targeting sequence PTS2 of 5 genes are affected by AS. Experimental determination of the targeting of selected protein isoforms further demonstrated that AS at both the 5' and 3' region of a gene can affect the inclusion of PTS2 and PTS1, respectively. This work underscores the importance of AS on the global regulation of peroxisome protein targeting.

Influência da espessura de biofilmes feitos à base de proteínas miofibrilares sobre suas propriedades funcionais Thickness effects of myofibrillar protein based edible films on their functional properties

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PAULO JOSÉ DO AMARAL SOBRAL

2000-06-01

Full Text Available O emprego potencial de filmes comestíveis e biodegradáveis em embalagens é condicionado pelas suas propriedades funcionais, que são influenciadas por muitos fatores, inclusive pela espessura. O objetivo deste trabalho foi estudar a influência da espessura dos biofilmes feitos à base de proteínas miofibrilares (de carne bovina e de tilápia-do-nilo sobre suas propriedades funcionais. Os biofilmes foram preparados a partir de uma solução filmogênica com 1 g de proteínas/100 g de solução. A concentração de plastificante foi de 45 g de glicerina/100 g de proteínas, e o pH foi mantido em 2,7. Após secagem, os filmes foram acondicionados em dessecadores a 58% de umidade relativa e 22°C, por quatro dias. As propriedades mecânicas foram determinadas por teste de perfuração; a permeabilidade ao vapor de água, por um método gravimétrico, e a cor e a opacidade, com colorímetro HunterLab, a 22°C. A força na perfuração, a permeabilidade ao vapor de água, a diferença de cor e a opacidade dos dois biofilmes aumentaram linearmente com a espessura dos corpos-de-prova. A deformação na perfuração foi pouco dependente da espessura e apresentou grande dispersão, em ambos os filmes. A taxa de permeabilidade ao vapor de água diminuiu linearmente com a espessura.Research on edible and biodegradable films had been promoted recently because of environmental concerns. The use of these materials for packaging applications is conditioned by their functional properties, which are influenced by many factors, including thickness. The objective of this work was to study the influence of thickness of myofibrillar protein-based biofilms on some of their functional properties. Biofilms were prepared from film forming solutions (FFS containing 1 g of protein/100 g of FFS. The plasticizer concentration was 45 g glycerin/100 g of protein and the pH was kept at 2.7. After drying, biofilms were conditioned in desiccators at 58% relative humidity and

Dietary protein level affects iridescent coloration in Anna's hummingbirds, Calypte anna.

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Meadows, Melissa G; Roudybush, Thomas E; McGraw, Kevin J

2012-08-15

Many animal displays involve colorful ornamental traits that signal an individual's quality as a mate or rival. Brilliant iridescent ornaments are common, but little is currently known about their production cost and signaling value. One potential cost of colorful ornaments is the acquisition of limited dietary resources that may be involved, directly or indirectly, in their production. Protein, the primary component of bird feathers and of many nanostructural components of iridescent traits, is naturally restricted in hummingbird diets (comprised mostly of sugars), suggesting that iridescent coloration may be especially challenging to produce in these animals. In this study, we experimentally investigated the effect of dietary protein availability during molt on iridescent color expression in male Anna's hummingbirds (Calypte anna). We fed captive birds either a 6% (high) or a 3% (low) protein diet and stimulated molt by plucking half the gorget and crown ornaments on each bird as well as the non-ornamental iridescent green tail feathers. We found that birds receiving more protein grew significantly more colorful crown feathers (higher red chroma and redder hue) than those fed the low-protein diet. Diet did not affect gorget coloration, but regrowth of feathers in captivity affected both gorget and crown coloration. Additionally, birds on the high-protein diet grew yellower (higher hue) green tail feathers than birds on the low-protein diet. These results indicate that iridescent ornamental feathers are sensitive to diet quality and may serve as honest signals of nutrition to mates or rivals. Further, because both ornamental and non-ornamental iridescent coloration were affected by conditions during their growth, iridescent color in these birds appears to be generally condition dependent.

Phasing of muscle gene expression with fasting-induced recovery growth in Atlantic salmon

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Bower Neil I

2009-08-01

Full Text Available Abstract Background Many fish species experience long periods of fasting in nature often associated with seasonal reductions in water temperature and prey availability or spawning migrations. During periods of nutrient restriction, changes in metabolism occur to provide cellular energy via catabolic processes. Muscle is particularly affected by prolonged fasting as myofibrillar proteins act as a major energy source. To investigate the mechanisms of metabolic reorganisation with fasting and refeeding in a saltwater stage of Atlantic salmon (Salmo salar L. we analysed the expression of genes involved in myogenesis, growth signalling, lipid biosynthesis and myofibrillar protein degradation and synthesis pathways using qPCR. Results Hierarchical clustering of gene expression data revealed three clusters. The first cluster comprised genes involved in lipid metabolism and triacylglycerol synthesis (ALDOB, DGAT1 and LPL which had peak expression 3-14d after refeeding. The second cluster comprised ADIPOQ, MLC2, IGF-I and TALDO1, with peak expression 14-32d after refeeding. Cluster III contained genes strongly down regulated as an initial response to feeding and included the ubiquitin ligases MuRF1 and MAFbx, myogenic regulatory factors and some metabolic genes. Conclusion Early responses to refeeding in fasted salmon included the synthesis of triacylglycerols and activation of the adipogenic differentiation program. Inhibition of MuRF1 and MAFbx respectively may result in decreased degradation and concomitant increased production of myofibrillar proteins. Both of these processes preceded any increase in expression of myogenic regulatory factors and IGF-I. These responses could be a necessary strategy for an animal adapted to long periods of food deprivation whereby energy reserves are replenished prior to the resumption of myogenesis.

Effects of heat on meat proteins - Implications on structure and quality of meat products.

Science.gov (United States)

Tornberg, E

2005-07-01

Globular and fibrous proteins are compared with regard to structural behaviour on heating, where the former expands and the latter contracts. The meat protein composition and structure is briefly described. The behaviour of the different meat proteins on heating is discussed. Most of the sarcoplasmic proteins aggregate between 40 and 60 °C, but for some of them the coagulation can extend up to 90°C. For myofibrillar proteins in solution unfolding starts at 30-32°C, followed by protein-protein association at 36-40°C and subsequent gelation at 45-50°C (conc.>0.5% by weight). At temperatures between 53 and 63°C the collagen denaturation occurs, followed by collagen fibre shrinkage. If the collagen fibres are not stabilised by heat-resistant intermolecular bonds, it dissolves and forms gelatine on further heating. The structural changes on cooking in whole meat and comminuted meat products, and the alterations in water-holding and texture of the meat product that it leads to, are then discussed.

Abrupt onset of muscle dysfunction after treatment for Grave's disease: a case report.

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Hernán Martínez, José; Sánchez, Alfredo; Torres, Oberto; Palermo, Coromoto; Santiago, Mónica; Figueroa, Carlos; Trinidad, Rafael; Mangual, Michelle; Gutierrez, Madeleine; González, Eva; Miranda, María de Lourdes

2014-01-01

Myopathy is a known complication of hypothyroidism, commonly characterized by an elevation in Creatine Kinase (CPK) due to increase capillary permeability proportional to the hypothyroid state. Thyroid hormone is important for the expression of fast myofibrillar proteins in the muscle. In hypothyroidism the expression of these proteins are deficient and there is an increase accumulation of slow myofibrillar proteins. A rapid or abrupt descend in thyroid hormones caused by radioiodine therapy after prolonged hyperthyroidism can lead to local hypothyroid state within the muscle tissue, resulting in CPK elevation and hypothyroid myopathy. Hormone replacement leads to resolution of symptoms and normalization of muscle enzymes serum levels.

Nicotine affects protein complex rearrangement in Caenorhabditis elegans cells.

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Sobkowiak, Robert; Zielezinski, Andrzej; Karlowski, Wojciech M; Lesicki, Andrzej

2017-10-01

Nicotine may affect cell function by rearranging protein complexes. We aimed to determine nicotine-induced alterations of protein complexes in Caenorhabditis elegans (C. elegans) cells, thereby revealing links between nicotine exposure and protein complex modulation. We compared the proteomic alterations induced by low and high nicotine concentrations (0.01 mM and 1 mM) with the control (no nicotine) in vivo by using mass spectrometry (MS)-based techniques, specifically the cetyltrimethylammonium bromide (CTAB) discontinuous gel electrophoresis coupled with liquid chromatography (LC)-MS/MS and spectral counting. As a result, we identified dozens of C. elegans proteins that are present exclusively or in higher abundance in either nicotine-treated or untreated worms. Based on these results, we report a possible network that captures the key protein components of nicotine-induced protein complexes and speculate how the different protein modules relate to their distinct physiological roles. Using functional annotation of detected proteins, we hypothesize that the identified complexes can modulate the energy metabolism and level of oxidative stress. These proteins can also be involved in modulation of gene expression and may be crucial in Alzheimer's disease. The findings reported in our study reveal putative intracellular interactions of many proteins with the cytoskeleton and may contribute to the understanding of the mechanisms of nicotinic acetylcholine receptor (nAChR) signaling and trafficking in cells.

Light-load resistance exercise increases muscle protein synthesis and hypertrophy signaling in elderly men

DEFF Research Database (Denmark)

Agergaard, Jakob; Bülow, Jacob; Jensen, Jacob K

2017-01-01

to 13 h of supine rest. After 2.5 h of rest, unilateral LL-RE, consisting of leg extensions (10 sets, 36 repetitions) at 16% of 1 repetition maximum (RM), was conducted. Subsequently, the subjects were randomized to oral intake of 4 g of whey protein per hour (PULSE, n = 10), 28 g of whey protein at 0 h...... and 12 g of whey protein at 7 h postexercise (BOLUS, n = 10), or 4 g of maltodextrin per hour (placebo, n = 10). Quadriceps muscle biopsies were taken at 0, 3, 7, and 10 h postexercise from the resting and the exercised leg of each subject. Myofibrillar FSR and activity of select targets from...... persisted in the placebo group only. Levels of phosphorylated (T37/46) eukaryotic translation initiation factor 4E-binding protein 1 increased throughout the postexercise period in the exercised leg in the placebo and BOLUS groups and peaked at 7 h. In all three groups, phosphorylated (T56) eukaryotic...

A case report: a heterozygous deletion (2791_2805 del) in exon 18 of the filamin C gene causing filamin C-related myofibrillar myopathies in a Chinese family.

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Miao, Jing; Su, Fei-Fei; Liu, Xue-Mei; Wei, Xiao-Jing; Yuan, Yun; Yu, Xue-Fan

2018-06-04

Filamin C-related myofibrillar myopathies (MFM) are progressive skeletal myopathies with an autosomal dominant inheritance pattern. The conditions are caused by mutations of the filamin C gene (FLNC) located in the chromosome 7q32-q35 region. Genetic variations in the FLNC gene result in various clinical phenotypes. We describe a 43-year-old woman who suffered filamin C-related MFM, with symptoms first presenting in the proximal muscles of the lower limbs and eventually spreading to the upper limbs and distal muscles. The patient's serum level of creatine kinase was mildly increased. Mildy myopathic changes in the electromyographic exam and moderate lipomatous alterations in lower limb MRI were found. Histopathological examination revealed increased muscle fiber size variability, disturbances in oxidative enzyme activity, and the presence of abnormal protein aggregates and vacuoles in some muscle fibers. Ultrastructural analysis showed inclusions composed of thin filaments and interspersed granular densities. DNA sequencing analysis detected a novel 15-nucleotide deletion (c.2791_2805del, p.931_935del) in the FLNC gene. The patient's father, sister, brother, three paternal aunts, one paternal uncle, and the uncle's son also had slowly progressive muscle weakness, and thus, we detected an autosomal dominant inheritance pattern of the disorder. A novel heterogeneous 15-nucleotide deletion (c.2791_2805del, p.931_935del) in the Ig-like domain 7 of the FLNC gene was found to cause filamin C-related MFM. This deletion in the FLNC gene causes protein aggregation, abnormalities in muscle structure, and impairment in muscle fiber function, which leads to muscle weakness.

Neuromuscular electrical stimulation prior to presleep protein feeding stimulates the use of protein-derived amino acids for overnight muscle protein synthesis.

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Dirks, Marlou L; Groen, Bart B L; Franssen, Rinske; van Kranenburg, Janneau; van Loon, Luc J C

2017-01-01

Short periods of muscle disuse result in substantial skeletal muscle atrophy. Recently, we showed that both neuromuscular electrical stimulation (NMES) as well as presleep dietary protein ingestion represent effective strategies to stimulate muscle protein synthesis rates. In this study, we test our hypothesis that NMES can augment the use of presleep protein-derived amino acids for overnight muscle protein synthesis in older men. Twenty healthy, older [69 ± 1 (SE) yr] men were subjected to 24 h of bed rest, starting at 8:00 AM. In the evening, volunteers were subjected to 70-min 1-legged NMES, while the other leg served as nonstimulated control (CON). Immediately following NMES, 40 g of intrinsically l-[1- 13 C]-phenylalanine labeled protein was ingested prior to sleep. Blood samples were taken throughout the night, and muscle biopsies were obtained from both legs in the evening and the following morning (8 h after protein ingestion) to assess dietary protein-derived l-[1- 13 C]-phenylalanine enrichments in myofibrillar protein. Plasma phenylalanine concentrations and plasma l-[1- 13 C]-phenylalanine enrichments increased significantly following protein ingestion and remained elevated for up to 6 h after protein ingestion (P protein-bound l-[1- 13 C]-phenylalanine enrichments (MPE) increased to a greater extent in the stimulated compared with the control leg (0.0344 ± 0.0019 vs. 0.0297 ± 0.0016 MPE, respectively; P protein-derived amino acids in the NMES compared with CON leg. In conclusion, application of NMES prior to presleep protein feeding stimulates the use of dietary protein-derived amino acids for overnight muscle protein synthesis in older men. Neuromuscular electrical stimulation (NMES) as well as presleep dietary protein ingestion represent effective strategies to stimulate muscle protein synthesis rates. Here we demonstrate that in older men after a day of bed rest, the application of NMES prior to presleep protein feeding stimulates the use of

Analysis of soybean root proteins affected by gibberellic acid treatment under flooding stress.

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Oh, Myeong Won; Nanjo, Yohei; Komatsu, Setsuko

2014-01-01

Flooding is a serious abiotic stress for soybean because it restricts growth and reduces grain yields. To investigate the effect of gibberellic acid (GA) on soybean under flooding stress, root proteins were analyzed using a gel-free proteomic technique. Proteins were extracted from the roots of 4-days-old soybean seedlings exposed to flooding stress in the presence and absence of exogenous GA3 for 2 days. A total of 307, 324, and 250 proteins were identified from untreated, and flooding-treated soybean seedlings without or with GA3, respectively. Secondary metabolism- and cell-related proteins, and proteins involved in protein degradation/synthesis were decreased by flooding stress; however, the levels of these proteins were restored by GA3 supplementation under flooding. Fermentation- and cell wall-related proteins were not affected by GA3 supplementation. Furthermore, putative GA-responsive proteins, which were identified by the presence of a GA-responsive element in the promoter region, were less abundant by flooding stress; however, these proteins were more abundant by GA3 supplementation under flooding. Taken together, these results suggest that GA3 affects the abundance of proteins involved in secondary metabolism, cell cycle, and protein degradation/synthesis in soybeans under flooding stress.

Protein synthesis and degradation during starvation-induced cardiac atrophy in rabbits

International Nuclear Information System (INIS)

Samarel, A.M.; Parmacek, M.S.; Magid, N.M.; Decker, R.S.; Lesch, M.

1987-01-01

To determine the relative importance of protein degradation in the development of starvation-induced cardiac atrophy, in vivo fractional synthetic rates of total cardiac protein, myosin heavy chain, actin, light chain 1, and light chain 2 were measured in fed and fasted rabbits by continuous infusion of [ 3 H] leucine. In addition, the rate of left ventricular protein accumulation and loss were assessed in weight-matched control and fasted rabbits. Rates of total cardiac protein degradation were then estimated as the difference between rates of synthesis and growth. Fasting produced left ventricular atrophy by decreasing the rate of left ventricular protein synthesis (34.8 +/- 1.4, 27.3 +/- 3.0, and 19.3 +/- 1.2 mg/day of left ventricular protein synthesized for 0-, 3-, and 7-day fasted rabbits, respectively). Inhibition of contractile protein synthesis was evident by significant reductions in the fractional synthetic rates of all myofibrillar protein subunits. Although fractional rates of protein degradation increased significantly within 7 days of fasting, actual amounts of left ventricular protein degraded per day were unaffected. Thus, prolonged fasting profoundly inhibits the synthesis of new cardiac protein, including the major protein constituents of the myofibril. Both this inhibition in new protein synthesis as well as a smaller but significant reduction in the average half-lives of cardiac proteins are responsible for atrophy of the heart in response to fasting

Rapid heating of Alaska pollock and chicken breast myofibrillar protein gels as affecting water-holding properties.

Science.gov (United States)

Stevenson, Clinton D; Liu, Wenjie; Lanier, Tyre C

2012-10-10

The gelation response of salted muscle minces to rapid versus slow heating rates is thought to differ between homeotherm and poikilotherm species. This study investigated water-holding (WH) properties of pastes prepared from refined myofibrils, at equal pH, of chicken breast versus Alaska pollock both during [cook loss (CL)] and following [expressible water (EW)] their cooking by rapid [microwave (MW)] versus slow [water bath (WB)] heating and whether such properties were related to gel matrix structure parameters and water mobility. Results did not confirm the industrial experience that pastes of meat from homeotherms benefit from slower cooking. Gels of equally high WH ability (low CL or EW) were made by rapid heating when the holding time did not exceed 5 min prior to cooling, which was sufficient for completion of gelation. Reduced CL and EW correlated with larger and smaller amplitudes of T21 and T22 water pools, respectively, measured by time-domain nuclear magnetic resonance (TD-NMR).

A Drosophila model of dominant inclusion body myopathy type 3 shows diminished myosin kinetics that reduce muscle power and yield myofibrillar defects.

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Suggs, Jennifer A; Melkani, Girish C; Glasheen, Bernadette M; Detor, Mia M; Melkani, Anju; Marsan, Nathan P; Swank, Douglas M; Bernstein, Sanford I

2017-06-01

Individuals with inclusion body myopathy type 3 (IBM3) display congenital joint contractures with early-onset muscle weakness that becomes more severe in adulthood. The disease arises from an autosomal dominant point mutation causing an E706K substitution in myosin heavy chain type IIa. We have previously expressed the corresponding myosin mutation (E701K) in homozygous Drosophila indirect flight muscles and recapitulated the myofibrillar degeneration and inclusion bodies observed in the human disease. We have also found that purified E701K myosin has dramatically reduced actin-sliding velocity and ATPase levels. Since IBM3 is a dominant condition, we now examine the disease state in heterozygote Drosophila in order to gain a mechanistic understanding of E701K pathogenicity. Myosin ATPase activities in heterozygotes suggest that approximately equimolar levels of myosin accumulate from each allele. In vitro actin sliding velocity rates for myosin isolated from the heterozygotes were lower than the control, but higher than for the pure mutant isoform. Although sarcomeric ultrastructure was nearly wild type in young adults, mechanical analysis of skinned indirect flight muscle fibers revealed a 59% decrease in maximum oscillatory power generation and an approximately 20% reduction in the frequency at which maximum power was produced. Rate constant analyses suggest a decrease in the rate of myosin attachment to actin, with myosin spending decreased time in the strongly bound state. These mechanical alterations result in a one-third decrease in wing beat frequency and marginal flight ability. With aging, muscle ultrastructure and function progressively declined. Aged myofibrils showed Z-line streaming, consistent with the human heterozygote phenotype. Based upon the mechanical studies, we hypothesize that the mutation decreases the probability of the power stroke occurring and/or alters the degree of movement of the myosin lever arm, resulting in decreased in vitro

A Drosophila model of dominant inclusion body myopathy type 3 shows diminished myosin kinetics that reduce muscle power and yield myofibrillar defects

Directory of Open Access Journals (Sweden)

Jennifer A. Suggs

2017-06-01

Full Text Available Individuals with inclusion body myopathy type 3 (IBM3 display congenital joint contractures with early-onset muscle weakness that becomes more severe in adulthood. The disease arises from an autosomal dominant point mutation causing an E706K substitution in myosin heavy chain type IIa. We have previously expressed the corresponding myosin mutation (E701K in homozygous Drosophila indirect flight muscles and recapitulated the myofibrillar degeneration and inclusion bodies observed in the human disease. We have also found that purified E701K myosin has dramatically reduced actin-sliding velocity and ATPase levels. Since IBM3 is a dominant condition, we now examine the disease state in heterozygote Drosophila in order to gain a mechanistic understanding of E701K pathogenicity. Myosin ATPase activities in heterozygotes suggest that approximately equimolar levels of myosin accumulate from each allele. In vitro actin sliding velocity rates for myosin isolated from the heterozygotes were lower than the control, but higher than for the pure mutant isoform. Although sarcomeric ultrastructure was nearly wild type in young adults, mechanical analysis of skinned indirect flight muscle fibers revealed a 59% decrease in maximum oscillatory power generation and an approximately 20% reduction in the frequency at which maximum power was produced. Rate constant analyses suggest a decrease in the rate of myosin attachment to actin, with myosin spending decreased time in the strongly bound state. These mechanical alterations result in a one-third decrease in wing beat frequency and marginal flight ability. With aging, muscle ultrastructure and function progressively declined. Aged myofibrils showed Z-line streaming, consistent with the human heterozygote phenotype. Based upon the mechanical studies, we hypothesize that the mutation decreases the probability of the power stroke occurring and/or alters the degree of movement of the myosin lever arm, resulting in

Moisture migration, microstructure damage and protein structure changes in porcine longissimus muscle as influenced by multiple freeze-thaw cycles.

Science.gov (United States)

Zhang, Mingcheng; Li, Fangfei; Diao, Xinping; Kong, Baohua; Xia, Xiufang

2017-11-01

This study investigated the effects of multiple freeze-thaw (F-T) cycles on water mobility, microstructure damage and protein structure changes in porcine longissimus muscle. The transverse relaxation time T 2 increased significantly when muscles were subjected to multiple F-T cycles (Pcycles caused sarcomere shortening, Z line fractures, and I band weakening and also led to microstructural destruction of muscle tissue. The decreased free amino group content and increased dityrosine in myofibrillar protein (MP) revealed that multiple F-T cycles caused protein cross-linking and oxidation. In addition, the results of size exclusion chromatography, circular dichroism spectra, UV absorption spectra, and intrinsic fluorescence spectroscopy indirectly proved that multiple F-T cycles could cause protein aggregation and degradation, α-helix structure disruption, hydrophobic domain exposure, and conformational changes of MP. Overall, repeated F-T cycles changed the protein structure and water distribution within meat. Copyright © 2017 Elsevier Ltd. All rights reserved.

Lipo-protein emulsion structure in the diet affects protein digestion kinetics, intestinal mucosa parameters and microbiota composition

OpenAIRE

Oberli, Marion; Douard, Véronique; Beaumont, Martin; Jaoui, Daphné; Devime, Fabienne; Laurent, Sandy; Chaumontet, Catherine; Mat, Damien; Le Feunteun, Steven; Michon, Camille; Davila, Anne-Marie; Fromentin, Gilles; Tomé, Daniel; Souchon, Isabelle; Leclerc, Marion

2017-01-01

SCOPE: Food structure is a key factor controlling digestion and nutrient absorption. We tested the hypothesis that protein emulsion structure in the diet may affect digestive and absorptive processes. METHODS & RESULTS: Rats (n = 40) were fed for 3 weeks two diets chemically identical but based on lipid-protein liquid-fine (LFE) or gelled-coarse (GCE) emulsions that differ at the macro- and micro-structure levels. After an overnight fasting, they ingested a 15 N-labeled LFE or GCE te...

Role of growth hormone, insulin-like growth factor-I, and insulin-like growth factor binding proteins in the catabolic response to injury and infection.

Science.gov (United States)

Lang, Charles H; Frost, Robert A

2002-05-01

The erosion of lean body mass resulting from protracted critical illness remains a significant risk factor for increased morbidity and mortality in this patient population. Previous studies have documented the well known impairment in nitrogen balance results from both an increase in muscle protein degradation as well as a decreased rate of both myofibrillar and sacroplasmic protein synthesis. This protein imbalance may be caused by an increased presence or activity of various catabolic agents, such as tumor necrosis factor-alpha, interleukin-1 beta, interleukin-6 or glucocorticoids, or may be mediated via a decreased concentration or responsiveness to various anabolic hormones, such as growth hormone or insulin-like growth factor-I. This review focuses on recent developments pertaining to the importance of alterations in the growth hormone-insulin-like growth factor-I axis as a mechanism for the observed defects in muscle protein balance.

Identification of small peptides arising from hydrolysis of meat proteins in dry fermented sausages.

Science.gov (United States)

López, Constanza M; Bru, Elena; Vignolo, Graciela M; Fadda, Silvina G

2015-06-01

In this study, proteolysis and low molecular weight (LMW) peptides (<3kDa) from commercial Argentinean fermented sausages were characterized by applying a peptidomic approach. Protein profiles and peptides obtained by Tricine-SDS-PAGE and RP-HPLC-MS, respectively, allowed distinguishing two different types of fermented sausages, although no specific biomarkers relating to commercial brands or quality were recognized. From electrophoresis, α-actin, myoglobin, creatine kinase M-type and L-lactate dehydrogenase were degraded at different intensities. In addition, a partial characterization of fermented sausage peptidome through the identification of 36 peptides, in the range of 1000-2100 Da, arising from sarcoplasmic (28) and myofibrillar (8) proteins was achieved. These peptides had been originated from α-actin, myoglobin, and creatine kinase M-type, but also from the hydrolysis of other proteins not previously reported. Although muscle enzymes exerted a major role on peptidogenesis, microbial contribution cannot be excluded as it was postulated herein. This work represents a first peptidomic approach for fermented sausages, thereby providing a baseline to define key peptides acting as potential biomarkers. Copyright © 2015 Elsevier Ltd. All rights reserved.

Effects of macro-nutrient, micro-nutrient composition and cooking conditions on in vitro digestibility of meat and aquatic dietary proteins.

Science.gov (United States)

Luo, Jiaqiang; Taylor, Cheryl; Nebl, Thomas; Ng, Ken; Bennett, Louise E

2018-07-15

Animal and aquatic meats represent important sources of dietary protein and micro-nutrients. Although red and processed meats carry some risks for human health, sensory and nutritional advantages drive meat consumption. Therefore, it is important to understand how meat processing and cooking influence healthiness. The research aim was to investigate relationships of meat composition (proximates, amino acids and minerals) and cooking conditions (raw, 90 s microwave, 200 °C oven for 10 or 30 min) on protein digestibility, for a selection of four animal (beef, chicken, pork, kangaroo) and four aquatic meats (salmon, trout, prawn, oyster). Lean meats were minced before cooking followed by in vitro gastro-intestinal digestion and analysed for progress of hydrolysis, and size ranges of peptides using MALDI-TOF-MS. Correlation matrix analysis between compositional and functional parameters indicated that digestibility was significantly linked with protein and metal concentrations, likely reflecting moisture-dependent solubility and inter-mixing of sarcoplasmic metallo-proteins and insoluble myofibrillar proteins. Crown Copyright © 2018. Published by Elsevier Ltd. All rights reserved.

Particle size analysis of lamb meat: Effect of homogenization speed, comparison with myofibrillar fragmentation index and its relationship with shear force.

Science.gov (United States)

Karumendu, L U; Ven, R van de; Kerr, M J; Lanza, M; Hopkins, D L

2009-08-01

The impact of homogenization speed on Particle Size (PS) results was examined using samples from the M.longissimus thoracis et lumborum (LL) of 40 lambs. One gram duplicate samples from meat aged for 1 and 5days were homogenized at five different speeds; 11,000, 13,000, 16,000, 19,000 and 22,000rpm. In addition to this LL samples from 30 different lamb carcases also aged for 1 and 5days were used to study the comparison between PS and myofibrillar fragmentation index (MFI) values. In this case, 1g duplicate samples (n=30) were homogenized at 16,000rpm and the other half (0.5g samples) at 11,000rpm (n=30). The homogenates were then subjected to respective combinations of treatments which included either PS analysis or the determination of MFI, both with or without three cycles of centrifugation. All 140 samples of LL included 65g blocks for subsequent shear force (SF) testing. Homogenization at 16,000rpm provided the greatest ability to detect ageing differences for particle size between samples aged for 1 and 5days. Particle size at the 25% quantile provided the best result for detecting differences due to ageing. It was observed that as ageing increased the mean PS decreased and was significantly (P<0.001) less for 5days aged samples compared to 1day aged samples, while MFI values significantly increased (P<0.001) as ageing period increased. When comparing the PS and MFI methods it became apparent that, as opposed to the MFI method, there was a greater coefficient of variation for the PS method which warranted a quality assurance system. Given this requirement and examination of the mean, standard deviation and the 25% quantile for PS data it was concluded that three cycles of centrifugation were not necessary and this also applied to the MFI method. There were significant correlations (P<0.001) within the same lamb loin sample aged for a given period between mean MFI and mean PS (-0.53), mean MFI and mean SF (-0.38) and mean PS and mean SF (0.23). It was

Thermoplastic processing of proteins for film formation--a review.

Science.gov (United States)

Hernandez-Izquierdo, V M; Krochta, J M

2008-03-01

Increasing interest in high-quality food products with increased shelf life and reduced environmental impact has encouraged the study and development of edible and/or biodegradable polymer films and coatings. Edible films provide the opportunity to effectively control mass transfer among different components in a food or between the food and its surrounding environment. The diversity of proteins that results from an almost limitless number of side-chain amino-acid sequential arrangements allows for a wide range of interactions and chemical reactions to take place as proteins denature and cross-link during heat processing. Proteins such as wheat gluten, corn zein, soy protein, myofibrillar proteins, and whey proteins have been successfully formed into films using thermoplastic processes such as compression molding and extrusion. Thermoplastic processing can result in a highly efficient manufacturing method with commercial potential for large-scale production of edible films due to the low moisture levels, high temperatures, and short times used. Addition of water, glycerol, sorbitol, sucrose, and other plasticizers allows the proteins to undergo the glass transition and facilitates deformation and processability without thermal degradation. Target film variables, important in predicting biopackage performance under various conditions, include mechanical, thermal, barrier, and microstructural properties. Comparisons of film properties should be made with care since results depend on parameters such as film-forming materials, film formulation, fabrication method, operating conditions, testing equipment, and testing conditions. Film applications include their use as wraps, pouches, bags, casings, and sachets to protect foods, reduce waste, and improve package recyclability.

Effects of Preslaughter Stress Levels on the Post-mortem Sarcoplasmic Proteomic Profile of Gilthead Seabream Muscle

DEFF Research Database (Denmark)

Silva, Tomé Santos; Cordeiro, Odete D; Matos, Elisabete D.

2012-01-01

identification was performed by MALDI-TOF-TOF MS. Analysis of the results indicates changes on several cellular pathways, with some of these changes being attributable to oxidative and proteolytic activity on sarcoplasmic proteins, together with leaking of myofibrillar proteins. These processes appear to have...

Soy-dairy protein blend and whey protein ingestion after resistance exercise increases amino acid transport and transporter expression in human skeletal muscle

Science.gov (United States)

Reidy, P. T.; Walker, D. K.; Dickinson, J. M.; Gundermann, D. M.; Drummond, M. J.; Timmerman, K. L.; Cope, M. B.; Mukherjea, R.; Jennings, K.; Volpi, E.

2014-01-01

Increasing amino acid availability (via infusion or ingestion) at rest or postexercise enhances amino acid transport into human skeletal muscle. It is unknown whether alterations in amino acid availability, from ingesting different dietary proteins, can enhance amino acid transport rates and amino acid transporter (AAT) mRNA expression. We hypothesized that the prolonged hyperaminoacidemia from ingesting a blend of proteins with different digestion rates postexercise would enhance amino acid transport into muscle and AAT expression compared with the ingestion of a rapidly digested protein. In a double-blind, randomized clinical trial, we studied 16 young adults at rest and after acute resistance exercise coupled with postexercise (1 h) ingestion of either a (soy-dairy) protein blend or whey protein. Phenylalanine net balance and transport rate into skeletal muscle were measured using stable isotopic methods in combination with femoral arteriovenous blood sampling and muscle biopsies obtained at rest and 3 and 5 h postexercise. Phenylalanine transport into muscle and mRNA expression of select AATs [system L amino acid transporter 1/solute-linked carrier (SLC) 7A5, CD98/SLC3A2, system A amino acid transporter 2/SLC38A2, proton-assisted amino acid transporter 1/SLC36A1, cationic amino acid transporter 1/SLC7A1] increased to a similar extent in both groups (P protein blend resulted in a prolonged and positive net phenylalanine balance during postexercise recovery compared with whey protein (P protein synthesis increased similarly between groups. We conclude that, while both protein sources enhanced postexercise AAT expression, transport into muscle, and myofibrillar protein synthesis, postexercise ingestion of a protein blend results in a slightly prolonged net amino acid balance across the leg compared with whey protein. PMID:24699854

Proteomic investigation of protein profile changes and amino acid residue-level modification in cooked lamb longissimus thoracis et lumborum: The effect of roasting.

Science.gov (United States)

Yu, Tzer-Yang; Morton, James D; Clerens, Stefan; Dyer, Jolon M

2016-09-01

Protein modifications of meat cooked by typical dry-heat methods (e.g., roasting) are currently not well understood. The present study utilised a shotgun proteomic approach to examine the molecular-level effect of roasting on thin lamb longissimus thoracis et lumborum patties, in terms of changes to both the protein profile and amino acid residue side-chain modifications. Cooking caused aggregation of actin, myosin heavy chains and sarcoplasmic proteins. Longer roasting time resulted in significantly reduced protein extractability as well as protein truncation involving particularly a number of myofibrillar and sarcoplasmic proteins, e.g., 6-phosphofructokinase, beta-enolase, l-lactate dehydrogenase A chain, alpha-actinin-3, actin and possibly myosin heavy chains. Modifications that have potential influence on nutritional properties, including carboxyethyllysine and a potentially glucose-derived N-terminal Amadori compound, were observed in actin and myoglobin after roasting. This study provided new insights into molecular changes resulting from the dry-heat treatment of meat, such as commonly used in food preparation. Copyright © 2016 Elsevier Ltd. All rights reserved.

Antioxidant activity of pomegranate peel extract on lipid and protein oxidation in beef meatballs during frozen storage.

Science.gov (United States)

Turgut, Sebahattin Serhat; Işıkçı, Fatma; Soyer, Ayla

2017-07-01

Antioxidant effect of pomegranate peel extract (PE) to retard lipid and protein oxidation in beef meatballs was investigated during frozen storage at -18±1°C. Concentrated and freeze dried aqueous extract of pomegranate peel was incorporated into freshly prepared meatball mix at 0.5% and 1.0% concentrations, and compared with 0.01% butylated hydroxytoluene (BHT) and control (without any antioxidant). In PE treated samples, particularly in high PE concentration, peroxide, malondialdehyde and carbonyl formation, loss of total protein solubility and sulfhydryl groups were significantly lower than control after 6months of storage. A diminution of both myofibrillar (MP) and sarcoplasmic (SP) proteins of high molecular weight was detected after 6months of the storage according to gel electrophoresis patterns. The 1.0% PE led to maintain colour intensity (C) and hue (h°) value. The results from sensory analyses revealed that PE addition to meatballs was effective on preventing rancid odour formation. Addition of both 0.5 and 1% PE in meatballs reduced lipid and protein oxidation and improved sensory scores. These results indicated that PE was effective on retarding lipid and protein oxidations. Copyright © 2017 Elsevier Ltd. All rights reserved.

BAG3 directly interacts with mutated alphaB-crystallin to suppress its aggregation and toxicity.

Directory of Open Access Journals (Sweden)

Akinori Hishiya

Full Text Available A homozygous disruption or genetic mutation of the bag3 gene causes progressive myofibrillar myopathy in mouse and human skeletal and cardiac muscle disorder while mutations in the small heat shock protein αB-crystallin gene (CRYAB are reported to be responsible for myofibrillar myopathy. Here, we demonstrate that BAG3 directly binds to wild-type αB-crystallin and the αB-crystallin mutant R120G, via the intermediate domain of BAG3. Peptides that inhibit this interaction in an in vitro binding assay indicate that two conserved Ile-Pro-Val regions of BAG3 are involved in the interaction with αB-crystallin, which is similar to results showing BAG3 binding to HspB8 and HspB6. BAG3 overexpression increased αB-crystallin R120G solubility and inhibited its intracellular aggregation in HEK293 cells. BAG3 suppressed cell death induced by αB-crystallin R120G overexpression in differentiating C2C12 mouse myoblast cells. Our findings indicate a novel function for BAG3 in inhibiting protein aggregation caused by the genetic mutation of CRYAB responsible for human myofibrillar myopathy.

BAG3 Directly Interacts with Mutated alphaB-Crystallin to Suppress Its Aggregation and Toxicity

Science.gov (United States)

Hishiya, Akinori; Salman, Mortada Najem; Carra, Serena; Kampinga, Harm H.; Takayama, Shinichi

2011-01-01

A homozygous disruption or genetic mutation of the bag3 gene causes progressive myofibrillar myopathy in mouse and human skeletal and cardiac muscle disorder while mutations in the small heat shock protein αB-crystallin gene (CRYAB) are reported to be responsible for myofibrillar myopathy. Here, we demonstrate that BAG3 directly binds to wild-type αB-crystallin and the αB-crystallin mutant R120G, via the intermediate domain of BAG3. Peptides that inhibit this interaction in an in vitro binding assay indicate that two conserved Ile-Pro-Val regions of BAG3 are involved in the interaction with αB-crystallin, which is similar to results showing BAG3 binding to HspB8 and HspB6. BAG3 overexpression increased αB-crystallin R120G solubility and inhibited its intracellular aggregation in HEK293 cells. BAG3 suppressed cell death induced by αB-crystallin R120G overexpression in differentiating C2C12 mouse myoblast cells. Our findings indicate a novel function for BAG3 in inhibiting protein aggregation caused by the genetic mutation of CRYAB responsible for human myofibrillar myopathy. PMID:21423662

Effect of fat type and heat treatment on the microstructure of meat emulsions

DEFF Research Database (Denmark)

Miklos, Rikke; Lametsch, René; Nielsen, Mikkel Schou

2013-01-01

-polymers and stabilize the protein network. Differences in the physicochemical properties of saturated and unsaturated lipids affect the distribution of fat and thereby the functionality and quality of the final product. The objectives were to study the effects of lipid type and heat treatment on changes...... imaging of the tomograms were used to analyse the impact of lipid type on spatial fat distribution, microstructure of the protein network and structural changes caused by heat treatment. The tomograms showed that the fat distribution in the meat emulsions depended on the physicochemical properties......In comminuted meat products the gel-forming abilities of the myofibrillar proteins are of major importance. In meat emulsions fat will be present in globules which are stabilized by a membrane coating made of salt-soluble proteins. These discontinuous fat particles act as fillers or co...

Endogenous proteolytic enzymes--a study of their impact on cod (Gadus morhua) muscle proteins and textural properties in a fermented product.

Science.gov (United States)

Yang, Fang; Rustad, Turid; Xu, Yanshun; Jiang, Qixing; Xia, Wenshui

2015-04-01

The aim of this study was to investigate endogenous proteolytic activities in a cod product and their impact on muscle proteins and textural properties during fermentation and storage. The result of specific proteolytic activities showed that cathepsins, especially cathepsin B, had the highest activities during fermentation and storage. SDS-PAGE indicated more degradation of myofibrillar proteins by cathepsin L than other proteases and that the hydrolysis by cathepsins was pronounced in the last stage of fermentation. Texture analysis showed that cathepsins had a negative impact on gel strength and this impact increased in the last stage of fermentation. However the product still had a firm texture. During storage (4 °C) for one week, no significant changes were seen in the gel strength. In conclusion, cathepsins had more impact on muscle proteins and textural properties than other proteases during fermentation but had little impact on gel strength during storage at 4 °C. Copyright © 2014 Elsevier Ltd. All rights reserved.

The anabolic potential of dietary protein intake on skeletal muscle is prolonged by prior light-load exercise

DEFF Research Database (Denmark)

Bechshøft, Rasmus; Dideriksen, Kasper; Reitelseder, Søren

2013-01-01

Hyperaminoacidemia stimulates myofibrillar fractional synthesis rate (myoFSR) transiently in resting skeletal muscle. We investigated whether light-load resistance exercise can extent this responsiveness....

Comparative Proteomics Identifies Host Immune System Proteins Affected by Infection with Mycobacterium bovis.

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Vladimir López

2016-03-01

Full Text Available Mycobacteria of the Mycobacterium tuberculosis complex (MTBC greatly impact human and animal health worldwide. The mycobacterial life cycle is complex, and the mechanisms resulting in pathogen infection and survival in host cells are not fully understood. Eurasian wild boar (Sus scrofa are natural reservoir hosts for MTBC and a model for mycobacterial infection and tuberculosis (TB. In the wild boar TB model, mycobacterial infection affects the expression of innate and adaptive immune response genes in mandibular lymph nodes and oropharyngeal tonsils, and biomarkers have been proposed as correlates with resistance to natural infection. However, the mechanisms used by mycobacteria to manipulate host immune response are not fully characterized. Our hypothesis is that the immune system proteins under-represented in infected animals, when compared to uninfected controls, are used by mycobacteria to guarantee pathogen infection and transmission. To address this hypothesis, a comparative proteomics approach was used to compare host response between uninfected (TB- and M. bovis-infected young (TB+ and adult animals with different infection status [TB lesions localized in the head (TB+ or affecting multiple organs (TB++]. The results identified host immune system proteins that play an important role in host response to mycobacteria. Calcium binding protein A9, Heme peroxidase, Lactotransferrin, Cathelicidin and Peptidoglycan-recognition protein were under-represented in TB+ animals when compared to uninfected TB- controls, but protein levels were higher as infection progressed in TB++ animals when compared to TB- and/or TB+ adult wild boar. MHCI was the only protein over-represented in TB+ adult wild boar when compared to uninfected TB- controls. The results reported here suggest that M. bovis manipulates host immune response by reducing the production of immune system proteins. However, as infection progresses, wild boar immune response recovers to

Comparative Proteomics Identifies Host Immune System Proteins Affected by Infection with Mycobacterium bovis.

Science.gov (United States)

López, Vladimir; Villar, Margarita; Queirós, João; Vicente, Joaquín; Mateos-Hernández, Lourdes; Díez-Delgado, Iratxe; Contreras, Marinela; Alves, Paulo C; Alberdi, Pilar; Gortázar, Christian; de la Fuente, José

2016-03-01

Mycobacteria of the Mycobacterium tuberculosis complex (MTBC) greatly impact human and animal health worldwide. The mycobacterial life cycle is complex, and the mechanisms resulting in pathogen infection and survival in host cells are not fully understood. Eurasian wild boar (Sus scrofa) are natural reservoir hosts for MTBC and a model for mycobacterial infection and tuberculosis (TB). In the wild boar TB model, mycobacterial infection affects the expression of innate and adaptive immune response genes in mandibular lymph nodes and oropharyngeal tonsils, and biomarkers have been proposed as correlates with resistance to natural infection. However, the mechanisms used by mycobacteria to manipulate host immune response are not fully characterized. Our hypothesis is that the immune system proteins under-represented in infected animals, when compared to uninfected controls, are used by mycobacteria to guarantee pathogen infection and transmission. To address this hypothesis, a comparative proteomics approach was used to compare host response between uninfected (TB-) and M. bovis-infected young (TB+) and adult animals with different infection status [TB lesions localized in the head (TB+) or affecting multiple organs (TB++)]. The results identified host immune system proteins that play an important role in host response to mycobacteria. Calcium binding protein A9, Heme peroxidase, Lactotransferrin, Cathelicidin and Peptidoglycan-recognition protein were under-represented in TB+ animals when compared to uninfected TB- controls, but protein levels were higher as infection progressed in TB++ animals when compared to TB- and/or TB+ adult wild boar. MHCI was the only protein over-represented in TB+ adult wild boar when compared to uninfected TB- controls. The results reported here suggest that M. bovis manipulates host immune response by reducing the production of immune system proteins. However, as infection progresses, wild boar immune response recovers to limit pathogen

Inhibition of Protein Farnesylation Arrests Adipogenesis and Affects PPARγ Expression and Activation in Differentiating Mesenchymal Stem Cells

Science.gov (United States)

Rivas, Daniel; Akter, Rahima; Duque, Gustavo

2007-01-01

Protein farnesylation is required for the activation of multiple proteins involved in cell differentiation and function. In white adipose tissue protein, farnesylation has shown to be essential for the successful differentiation of preadipocytes into adipocytes. We hypothesize that protein farnesylation is required for PPARγ2 expression and activation, and therefore for the differentiation of human mesenchymal stem cells (MSCs) into adipocytes. MSCs were plated and induced to differentiate into adipocytes for three weeks. Differentiating cells were treated with either an inhibitor of farnesylation (FTI-277) or vehicle alone. The effect of inhibition of farnesylation in differentiating adipocytes was determined by oil red O staining. Cell survival was quantified using MTS Formazan. Additionally, nuclear extracts were obtained and prelamin A, chaperon protein HDJ-2, PPARγ, and SREBP-1 were determined by western blot. Finally, DNA binding PPARγ activity was determined using an ELISA-based PPARγ activation quantification method. Treatment with an inhibitor of farnesylation (FTI-277) arrests adipogenesis without affecting cell survival. This effect was concomitant with lower levels of PPARγ expression and activity. Finally, accumulation of prelamin A induced an increased proportion of mature SREBP-1 which is known to affect PPARγ activity. In summary, inhibition of protein farnesylation arrests the adipogenic differentiation of MSCs and affects PPARγ expression and activity. PMID:18274630

Lipo-Protein Emulsion Structure in the Diet Affects Protein Digestion Kinetics, Intestinal Mucosa Parameters and Microbiota Composition.

Science.gov (United States)

Oberli, Marion; Douard, Véronique; Beaumont, Martin; Jaoui, Daphné; Devime, Fabienne; Laurent, Sandy; Chaumontet, Catherine; Mat, Damien; Le Feunteun, Steven; Michon, Camille; Davila, Anne-Marie; Fromentin, Gilles; Tomé, Daniel; Souchon, Isabelle; Leclerc, Marion; Gaudichon, Claire; Blachier, François

2018-01-01

Food structure is a key factor controlling digestion and nutrient absorption. We test the hypothesis that protein emulsion structure in the diet may affect digestive and absorptive processes. Rats (n = 40) are fed for 3 weeks with two diets chemically identical but based on lipid-protein liquid-fine (LFE) or gelled-coarse (GCE) emulsions that differ at the macro- and microstructure levels. After an overnight fasting, they ingest a 15 N-labeled LFE or GCE test meal and are euthanized 0, 15 min, 1 h, and 5 h later. 15 N enrichment in intestinal contents and blood are measured. Gastric emptying, protein digestion kinetics, 15 N absorption, and incorporation in blood protein and urea are faster with LFE than GCE. At 15 min time point, LFE group shows higher increase in GIP portal levels than GCE. Three weeks of dietary adaptation leads to higher expression of cationic amino acid transporters in ileum of LFE compared to GCE. LFE diet raises cecal butyrate and isovalerate proportion relative to GCE, suggesting increased protein fermentation. LFE diet increases fecal Parabacteroides relative abundance but decreases Bifidobacterium, Sutterella, Parasutterella genera, and Clostridium cluster XIV abundance. Protein emulsion structure regulates digestion kinetics and gastrointestinal physiology, and could be targeted to improve food health value. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

The biochemical, textural and sensory properties of king scallop ...

African Journals Online (AJOL)

USER

2010-07-12

Jul 12, 2010 ... fluids and myofibrillar protein denaturation (Ca2+-ATPase activities in actomyosin extracts). ... much prized as food and its adductor muscle is offered to ..... and/or mechanical disruption of mitochondrial membranes.

Ratio of dietary rumen degradable protein to rumen undegradable protein affects nitrogen partitioning but does not affect the bovine milk proteome produced by mid-lactation Holstein dairy cows.

Science.gov (United States)

Tacoma, R; Fields, J; Ebenstein, D B; Lam, Y-W; Greenwood, S L

2017-09-01

Little is known about the bovine milk proteome or whether it can be affected by diet. The objective of this study was to determine if the dietary rumen degradable protein (RDP):rumen undegradable protein (RUP) ratio could alter the bovine milk proteome. Six Holstein cows (parity: 2.5 ± 0.8) in mid lactation were blocked by days in milk (80 ± 43 d in milk) and milk yield (57.5 ± 6.0 kg) and randomly assigned to treatment groups. The experiment was conducted as a double-crossover design consisting of three 21-d periods. Within each period, treatment groups received diets with either (1) a high RDP:RUP ratio (RDP treatment: 62.4:37.6% of crude protein) or (2) a low RDP:RUP ratio (RUP treatment: 51.3:48.7% of crude protein). Both diets were isonitrogenous and isoenergetic (crude protein: 18.5%, net energy for lactation: 1.8 Mcal/kg of dry matter). To confirm N and energy status of cows, dry matter intake was determined daily, rumen fluid samples were collected for volatile fatty acid analysis, blood samples were collected for plasma glucose, β-hydroxybutyrate, urea nitrogen, and fatty acid analysis, and total 24-h urine and fecal samples were collected for N analysis. Milk samples were collected to determine the general milk composition and the protein profile. Milk samples collected for high-abundance protein analysis were subjected to HPLC analysis to determine the content of α-casein, β-casein, and κ-casein, as well as α-lactalbumin and β-lactoglobulin. Samples collected for low-abundance protein analysis were fractionated, enriched using ProteoMiner treatment, and separated using sodium dodecyl sulfate-PAGE. After excision and digestion, the peptides were analyzed using liquid chromatography (LC) tandem mass spectrometry (MS/MS). The LC-MS/MS data were analyzed using PROC GLIMMIX of SAS (version 9.4, SAS Institute Inc., Cary, NC) and adjusted using the MULTTEST procedure. All other parameters were analyzed using PROC MIXED of SAS. No treatment differences

Missense mutation Lys18Asn in dystrophin that triggers X-linked dilated cardiomyopathy decreases protein stability, increases protein unfolding, and perturbs protein structure, but does not affect protein function.

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Surinder M Singh

Full Text Available Genetic mutations in a vital muscle protein dystrophin trigger X-linked dilated cardiomyopathy (XLDCM. However, disease mechanisms at the fundamental protein level are not understood. Such molecular knowledge is essential for developing therapies for XLDCM. Our main objective is to understand the effect of disease-causing mutations on the structure and function of dystrophin. This study is on a missense mutation K18N. The K18N mutation occurs in the N-terminal actin binding domain (N-ABD. We created and expressed the wild-type (WT N-ABD and its K18N mutant, and purified to homogeneity. Reversible folding experiments demonstrated that both mutant and WT did not aggregate upon refolding. Mutation did not affect the protein's overall secondary structure, as indicated by no changes in circular dichroism of the protein. However, the mutant is thermodynamically less stable than the WT (denaturant melts, and unfolds faster than the WT (stopped-flow kinetics. Despite having global secondary structure similar to that of the WT, mutant showed significant local structural changes at many amino acids when compared with the WT (heteronuclear NMR experiments. These structural changes indicate that the effect of mutation is propagated over long distances in the protein structure. Contrary to these structural and stability changes, the mutant had no significant effect on the actin-binding function as evident from co-sedimentation and depolymerization assays. These results summarize that the K18N mutation decreases thermodynamic stability, accelerates unfolding, perturbs protein structure, but does not affect the function. Therefore, K18N is a stability defect rather than a functional defect. Decrease in stability and increase in unfolding decrease the net population of dystrophin molecules available for function, which might trigger XLDCM. Consistently, XLDCM patients have decreased levels of dystrophin in cardiac muscle.

Effect of fat type and heat treatment on the microstructure of meat emulsions

DEFF Research Database (Denmark)

Miklos, Rikke; Lametsch, René; Nielsen, Mikkel Schou

2013-01-01

of the added fat. Use of vegetable oil resulted in homogeneous emulsions with smaller fat globules compared to the use of pork fat. This has previously been shown by the use of light micrographs. However, with the use of phase contrast imaging it was, from the same image, possible to resolve the protein phase......In comminuted meat products the gel-forming abilities of the myofibrillar proteins are of major importance. In meat emulsions fat will be present in globules which are stabilized by a membrane coating made of salt-soluble proteins. These discontinuous fat particles act as fillers or co......-polymers and stabilize the protein network. Differences in the physicochemical properties of saturated and unsaturated lipids affect the distribution of fat and thereby the functionality and quality of the final product. The objectives were to study the effects of lipid type and heat treatment on changes...

Historical Overview of the Effect of -Adrenergic Agonists on Beef Cattle Production

Directory of Open Access Journals (Sweden)

Bradley J. Johnson

2014-05-01

Full Text Available Postnatal muscle hypertrophy of beef cattle is the result of enhanced myofibrillar protein synthesis and reduced protein turnover. Skeletal muscle hypertrophy has been studied in cattle fed β-adrenergic agonists (β-AA, which are receptor-mediated enhancers of protein synthesis and inhibitors of protein degradation. Feeding β-AA to beef cattle increases longissimus muscle cross-sectional area 6% to 40% compared to non-treated cattle. The β-AA have been reported to improve live animal performance, including average daily gain, feed efficiency, hot carcass weight, and dressing percentage. Treatment with β-AA increased mRNA concentration of the β2 or β1-adrenergic receptor and myosin heavy chain IIX in bovine skeletal muscle tissue. This review will examine the effects of skeletal muscle and adipose development with β-AA, and will interpret how the use of β-AA affects performance, body composition, and growth in beef cattle.

Polymorphism of calpastatin gene in Arabic sheep using PCR- RFLP

African Journals Online (AJOL)

STORAGESEVER

2008-08-04

Aug 4, 2008 ... Calpastatin has been known as candidate gene in muscle growth efficiency and ... population, AA, AB, BB genotype have been identified with the 70.27, .... of cimaterol on rabbit growth and myofibrillar protein degradation.

High pressure processing of meat: effects on ultrastructure and protein digestibility.

Science.gov (United States)

Kaur, Lovedeep; Astruc, Thierry; Vénien, Annie; Loison, Olivier; Cui, Jian; Irastorza, Marion; Boland, Mike

2016-05-18

The effects of high pressure processing (HPP, at 175 and 600 MPa) on the ultrastructure and in vitro protein digestion of bovine longissimus dorsi muscle meat were studied. HPP caused a significant change in the visual appearance and texture of the meat subjected to HPP at 600 MPa so that it appeared similar to cooked meat, unlike the meat subjected to HPP at 175 MPa that showed no significant visible change in the colour and texture compared to the raw meat. The muscles were subjected to digestion under simulated gastric conditions for 1 h and then under simulated small-intestinal conditions for a further 2 h. The digests were analysed using gel electrophoresis (SDS-PAGE) and ninhydrin assay for amino N. The effect of the acid conditions of the stomach alone was also investigated. Reduced SDS-PAGE results showed that pepsin-digested (60 min) HPP meats showed fewer proteins or peptides of high molecular weight than the pepsin-digested untreated meat, suggesting more breakdown of the parent proteins in HPP-treated meats. This effect was more pronounced in the muscles treated at 600 MPa. These results are in accordance with microscopy results, which showed greater changes in the myofibrillar structure after simulated gastric digestion of the sample processed at 600 MPa than at 175 MPa. Transmission electron microscopy also showed the presence of protein aggregates in the former sample, resulting probably from protein denaturation of sarcoplasmic proteins, in the subcellular space and between myofibrils; along with cell contraction (similar to that caused by heating) in the former.

Competitive kinetics as a tool to determine rate constants for reduction of ferrylmyoglobin by food components

DEFF Research Database (Denmark)

Jongberg, Sisse; Lund, Marianne Nissen; Pattison, David I.

2016-01-01

Competitive kinetics were applied as a tool to determine apparent rate constants for the reduction of hypervalent haem pigment ferrylmyoglobin (MbFe(IV)=O) by proteins and phenols in aqueous solution of pH 7.4 and I = 1.0 at 25 °C. Reduction of MbFe(IV)=O by a myofibrillar protein isolate (MPI) f...

Standardization of metachromatic staining method of myofibrillar ATPase activity of myosin to skeletal striated muscle of mules and donkeys

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Flora H.F. D'Angelis

2014-09-01

Full Text Available This study aims at standardizing the pre-incubation and incubation pH and temperature used in the metachromatic staining method of myofibrillar ATPase activity of myosin (mATPase used for asses and mules. Twenty four donkeys and 10 mules, seven females and three males, were used in the study. From each animal, fragments from the Gluteus medius muscle were collected and percutaneous muscle biopsy was performed using a 6.0-mm Bergström-type needle. In addition to the metachromatic staining method of mATPase, the technique of nicotinamide adenine dinucleotide tetrazolium reductase (NADH-TR was also performed to confirm the histochemical data. The histochemical result of mATPase for acidic pre-incubation (pH=4.50 and alkaline incubation (pH=10.50, at a temperature of 37ºC, yielded the best differentiation of fibers stained with toluidine blue. Muscle fibers were identified according to the following colors: type I (oxidative, light blue, type IIA (oxidative-glycolytic, intermediate blue and type IIX (glycolytic, dark blue. There are no reports in the literature regarding the characterization and distribution of different types of muscle fibers used by donkeys and mules when performing traction work, cargo transportation, endurance sports (horseback riding and marching competitions. Therefore, this study is the first report on the standardization of the mATPase technique for donkeys and mules.

Effects of varying ruminally undegradable protein supplementation on forage digestion, nitrogen metabolism, and urea kinetics in Nellore cattle fed low-quality tropical forage.

Science.gov (United States)

Batista, E D; Detmann, E; Titgemeyer, E C; Valadares Filho, S C; Valadares, R F D; Prates, L L; Rennó, L N; Paulino, M F

2016-01-01

Effects of supplemental RDP and RUP on nutrient digestion, N metabolism, urea kinetics, and muscle protein degradation were evaluated in Nellore heifers () consuming low-quality signal grass hay (5% CP and 80% NDF, DM basis). Five ruminally and abomasally cannulated Nellore heifers (248 ± 9 kg) were used in a 5 × 5 Latin square. Treatments were the control (no supplement) and RDP supplementation to meet 100% of the RDP requirement plus RUP provision to supply 0, 50, 100, or 150% of the RUP requirement. Supplemental RDP (casein plus NPN) was ruminally dosed twice daily, and RUP supply (casein) was continuously infused abomasally. Jugular infusion of [NN]-urea with measurement of enrichment in urine was used to evaluate urea kinetics. The ratio of urinary 3-methylhistidine to creatinine was used to estimate skeletal muscle protein degradation. Forage NDF intake (2.48 kg/d) was not affected ( ≥ 0.37) by supplementation, but supplementation did increase ruminal NDF digestion ( Urea entry rate and gastrointestinal entry rate of urea were increased by supplementation ( urea entry rate and tended ( = 0.07) to linearly increase gastrointestinal entry rate of urea. Urea use for anabolic purposes tended ( = 0.07) to be increased by supplementation, and RUP provision also tended ( = 0.08) to linearly increase the amount of urea used for anabolism. The fraction of recycled urea N incorporated into microbial N was greater ( urea from the renal tubule than did supplemented heifers. Overall, unsupplemented heifers had greater mobilization of AA from myofibrillar protein, which provided N for urea synthesis and subsequent recycling. Supplemental RUP, when RDP was supplied, not only increased N retention but also supported increased urea N recycling and increased ruminal microbial protein synthesis.

Factors Affecting the Binding of a Recombinant Heavy Metal-Binding Domain (CXXC motif Protein to Heavy Metals

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Kamala Boonyodying

2012-06-01

Full Text Available A number of heavy metal-binding proteins have been used to study bioremediation. CXXC motif, a metal binding domain containing Cys-X-X-Cys motif, has been identified in various organisms. These proteins are capable of binding various types of heavy metals. In this study, heavy metal binding domain (CXXC motif recombinant protein encoded from mcsA gene of S. aureus were cloned and overexpressed in Escherichia coli. The factors involved in the metal-binding activity were determined in order to analyze the potential of recombinant protein for bioremediation. A recombinant protein can be bound to Cd2+, Co2+, Cu2+ and Zn2+. The thermal stability of a recombinant protein was tested, and the results showed that the metal binding activity to Cu2+ and Zn2+ still exist after treating the protein at 85ºC for 30 min. The temperature and pH that affected the metal binding activity was tested and the results showed that recombinant protein was still bound to Cu2+ at 65ºC, whereas a pH of 3-7 did not affect the metal binding E. coli harboring a pRset with a heavy metal-binding domain CXXC motif increased the resistance of heavy metals against CuCl2 and CdCl2. This study shows that metal binding domain (CXXC motif recombinant protein can be effectively bound to various types of heavy metals and may be used as a potential tool for studying bioremediation.

Age- and Activity-Related Differences in the Abundance of Myosin Essential and Regulatory Light Chains in Human Muscle

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James N. Cobley

2016-04-01

Full Text Available Traditional methods for phenotyping skeletal muscle (e.g., immunohistochemistry are labor-intensive and ill-suited to multixplex analysis, i.e., assays must be performed in a series. Addressing these concerns represents a largely unmet research need but more comprehensive parallel analysis of myofibrillar proteins could advance knowledge regarding age- and activity-dependent changes in human muscle. We report a label-free, semi-automated and time efficient LC-MS proteomic workflow for phenotyping the myofibrillar proteome. Application of this workflow in old and young as well as trained and untrained human skeletal muscle yielded several novel observations that were subsequently verified by multiple reaction monitoring (MRM. We report novel data demonstrating that human ageing is associated with lesser myosin light chain 1 content and greater myosin light chain 3 content, consistent with an age-related reduction in type II muscle fibers. We also disambiguate conflicting data regarding myosin regulatory light chain, revealing that age-related changes in this protein more closely reflect physical activity status than ageing per se. This finding reinforces the need to control for physical activity levels when investigating the natural process of ageing. Taken together, our data confirm and extend knowledge regarding age- and activity-related phenotypes. In addition, the MRM transitions described here provide a methodological platform that can be fine-tuned to suite multiple research needs and thus advance myofibrillar phenotyping.

Dietary protein content affects evolution for body size, body fat and viability in Drosophila melanogaster

DEFF Research Database (Denmark)

Kristensen, Torsten N; Overgaard, Johannes; Loeschcke, Volker

2011-01-01

The ability to use different food sources is likely to be under strong selection if organisms are faced with natural variation in macro-nutrient (protein, carbohydrate and lipid) availabilities. Here, we use experimental evolution to study how variable dietary protein content affects adult body...... composition and developmental success in Drosophila melanogaster. We reared flies on either a standard diet or a protein-enriched diet for 17 generations before testing them on both diet types. Flies from lines selected on protein-rich diet produced phenotypes with higher total body mass and relative lipid...... content when compared with those selected on a standard diet, irrespective of which of the two diets they were tested on. However, selection on protein-rich diet incurred a cost as flies reared on this diet had markedly lower developmental success in terms of egg-to-adult viability on both medium types...

A plastome mutation affects processing of both chloroplast and nuclear DNA-encoded plastid proteins.

Science.gov (United States)

Johnson, E M; Schnabelrauch, L S; Sears, B B

1991-01-01

Immunoblotting of a chloroplast mutant (pm7) of Oenothera showed that three proteins, cytochrome f and the 23 kDa and 16 kDa subunits of the oxygen-evolving subcomplex of photosystem II, were larger than the corresponding mature proteins of the wild type and, thus, appear to be improperly processed in pm7. The mutant is also chlorotic and has little or no internal membrane development in the plastids. The improperly processed proteins, and other proteins that are completely missing, represent products of both the plastid and nuclear genomes. To test for linkage of these defects, a green revertant of pm7 was isolated from cultures in which the mutant plastids were maintained in a nuclear background homozygous for the plastome mutator (pm) gene. In this revertant, all proteins analyzed co-reverted to the wild-type condition, indicating that a single mutation in a plastome gene is responsible for the complex phenotype of pm7. These results suggest that the defect in pm7 lies in a gene that affects a processing protease encoded in the chloroplast genome.

In-depth characterisation of the lamb meat proteome from longissimus lumborum

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Tzer-Yang Yu

2015-03-01

Full Text Available Lamb is one of the major red meats consumed globally, both as a key component in the diet of some countries, and as a niche meat product in others. Despite this relatively wide consumption, an in-depth description of the global protein composition of lamb has not been reported. In this study, we investigated the proteome of the 48 h post-mortem lamb longissimus lumborum through separation of the samples into sarcoplasmic, myofibrillar and insoluble fractions, followed by an in-depth shotgun proteomic evaluation and bioinformatic analysis. As a result, 388 ovine-specific proteins were identified and characterised. The 207 proteins found in the sarcoplasmic fraction were dominated by glycolytic enzymes and mitochondrial proteins. This fraction also contained several sarcomeric proteins, e.g., myosin light chains and titin. Some of them might be the degradation products from the post-mortem proteolysis. Actin, myosin and tropomyosin were abundant in the myofibrillar fraction while nebulin and titin were also present. Collagen type I, III and IV were found in the insoluble fraction but there were also sequences from myosin and titin. The present study also confirms the existence of at least 300 predicted protein sequences obtained from the latest issue of the sheep genome (version 3 with high confidence.

DROUGHT AFFECTS PROTEIN AND PHENOLIC CONTENT IN ...

African Journals Online (AJOL)

userpc

ABSTRACT. Bambara groundnut (Vigna subterranea L. Verdc.) is a legume crop, which has long been recognised as a protein-rich and drought-tolerant crop, used extensively in sub-Saharan. Africa. This study evaluates the effect of experimental water deficit stress on total protein concentration, secondary protein structure ...

Inactivation of Tor proteins affects the dynamics of endocytic proteins ...

Indian Academy of Sciences (India)

Tor2 is an activator of the Rom2/Rho1 pathway that regulates -factor internalization. Since the recruitment of endocytic proteins such as actin-binding proteins and the amphiphysins precedes the internalization of -factor, we hypothesized that loss of Tor function leads to an alteration in the dynamics of the endocytic ...

Protein tyrosine nitration in chronic intramuscular parasitism: immunohistochemical evaluation of relationships between nitration, and fiber type-specific responses to infection

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Ted H. Elsasser

2011-05-01

Full Text Available The present study was conducted to determine whether preferential muscle catabolism [psoas major (PM > rectus femoris (RF] observed during the chronic intramuscular stage of Sarcocystis cruzi infection could be associated with the pathological consequences of increased protein tyrosine nitration in fibers characteristically more metabolically active due to higher mitochondrial density. Holstein calves were assigned to control (C, or S. cruzi-infected (I groups, n=5/group. Calves were euthanized on day 63 of infection. Samples of RF and PM were prepared for metabolic fiber typing (MFT: slow oxidative, SO – Type I; fast oxidative glycolytic, FOG - Type IIa; fast glycolytic, FG – Type IIb, fiber area, and immunohistochemical localization of fast myosin heavy chain 2a and 2b, nitrotyrosine (NT, and mitochondrial Complex V ATP-synthase. MFT analysis documented that PM contained twice the number of SO fibers compared to RF (32 v 16%, P<0.002. SO and FOG fibers (Both higher in mitochondrial density than FG fibers in both PM and RF were significantly smaller in area in I calves with mean FG areas not different between C and I. Muscle NT content (Western blot of myofibrillar protein fraction increased with infection; NT was immunohistochemically localized into three distinct patterns in fibers: i sparse fiber staining, ii dense punctuate intrafiber staining, and iii pericystic staining. By image analysis, the greatest punctuate intrafiber pixel density of NT was associated with SO fibers from I calves with the NT colocalizing with mitochondrial Complex V – F1F0 ATP synthase. More fibers were positive for the colocalization in PM than RF (P<0.04. The data are consistent with the concept that fibers rich in mitochondria possessing more inherent oxidative energy capacity generate more nitrated proteins than glycolytic fibers and as such are more affected by the proinflammatory response to infections like Sarcocystosis.

Plasma membrane lipid–protein interactions affect signaling processes in sterol-biosynthesis mutants in Arabidopsis thaliana

Science.gov (United States)

Zauber, Henrik; Burgos, Asdrubal; Garapati, Prashanth; Schulze, Waltraud X.

2014-01-01

The plasma membrane is an important organelle providing structure, signaling and transport as major biological functions. Being composed of lipids and proteins with different physicochemical properties, the biological functions of membranes depend on specific protein–protein and protein–lipid interactions. Interactions of proteins with their specific sterol and lipid environment were shown to be important factors for protein recruitment into sub-compartmental structures of the plasma membrane. System-wide implications of altered endogenous sterol levels for membrane functions in living cells were not studied in higher plant cells. In particular, little is known how alterations in membrane sterol composition affect protein and lipid organization and interaction within membranes. Here, we conducted a comparative analysis of the plasma membrane protein and lipid composition in Arabidopsis sterol-biosynthesis mutants smt1 and ugt80A2;B1. smt1 shows general alterations in sterol composition while ugt80A2;B1 is significantly impaired in sterol glycosylation. By systematically analyzing different cellular fractions and combining proteomic with lipidomic data we were able to reveal contrasting alterations in lipid–protein interactions in both mutants, with resulting differential changes in plasma membrane signaling status. PMID:24672530

Resistance exercise-induced increases in putative anabolic hormones do not enhance muscle protein synthesis or intracellular signalling in young men.

Science.gov (United States)

West, Daniel W D; Kujbida, Gregory W; Moore, Daniel R; Atherton, Philip; Burd, Nicholas A; Padzik, Jan P; De Lisio, Michael; Tang, Jason E; Parise, Gianni; Rennie, Michael J; Baker, Steven K; Phillips, Stuart M

2009-11-01

We aimed to determine whether exercise-induced elevations in systemic concentration of testosterone, growth hormone (GH) and insulin-like growth factor-1 (IGF-1) enhanced post-exercise myofibrillar protein synthesis (MPS) and phosphorylation of signalling proteins important in regulating mRNA translation. Eight young men (20 +/- 1.1 years, BMI = 26 +/- 3.5 kg m(-2)) completed two exercise protocols designed to maintain basal hormone concentrations (low hormone, LH) or elicit increases in endogenous hormones (high hormone, HH). In the LH protocol, participants performed a bout of unilateral resistance exercise with the elbow flexors. The HH protocol consisted of the same elbow flexor exercise with the contralateral arm followed immediately by high-volume leg resistance exercise. Participants consumed 25 g of protein after arm exercise to maximize MPS. Muscle biopsies and blood samples were taken as appropriate. There were no changes in serum testosterone, GH or IGF-1 after the LH protocol, whereas there were marked elevations after HH (testosterone, P anabolic hormones do not enhance fed-state anabolic signalling or MPS following resistance exercise. Local mechanisms are likely to be of predominant importance for the post-exercise increase in MPS.

How does the antagonism between capping and anti-capping proteins affect actin network dynamics?

International Nuclear Information System (INIS)

Hu Longhua; Papoian, Garegin A

2011-01-01

Actin-based cell motility is essential to many biological processes. We built a simplified, three-dimensional computational model and subsequently performed stochastic simulations to study the growth dynamics of lamellipodia-like branched networks. In this work, we shed light on the antagonism between capping and anti-capping proteins in regulating actin dynamics in the filamentous network. We discuss detailed mechanisms by which capping and anti-capping proteins affect the protrusion speed of the actin network and the rate of nucleation of filaments. We computed a phase diagram showing the regimes of motility enhancement and inhibition by these proteins. Our work shows that the effects of capping and anti-capping proteins are mainly transmitted by modulation of the filamentous network density and local availability of monomeric actin. We discovered that the combination of the capping/anti-capping regulatory network with nucleation-promoting proteins introduces robustness and redundancy in cell motility machinery, allowing the cell to easily achieve maximal protrusion speeds under a broader set of conditions. Finally, we discuss distributions of filament lengths under various conditions and speculate on their potential implication for the emergence of filopodia from the lamellipodial network.

Developmental Alterations in Heart Biomechanics and Skeletal Muscle Function in Desmin Mutants Suggest an Early Pathological Root for Desminopathies

NARCIS (Netherlands)

Ramspacher, Caroline; Steed, Emily; Boselli, Francesco; Ferreira, Rita; Faggianelli, Nathalie; Roth, Stéphane; Spiegelhalter, Coralie; Messaddeq, Nadia; Trinh, Le; Liebling, Michael; Chacko, Nikhil; Tessadori, Federico; Bakkers, Jeroen; Laporte, Jocelyn; Hnia, Karim; Vermot, Julien

2015-01-01

Desminopathies belong to a family of muscle disorders called myofibrillar myopathies that are caused by Desmin mutations and lead to protein aggregates in muscle fibers. To date, the initial pathological steps of desminopathies and the impact of desmin aggregates in the genesis of the disease are

Acute moderate elevation of TNF-{alpha} does not affect systemic and skeletal muscle protein turnover in healthy humans

DEFF Research Database (Denmark)

Petersen, Anne Marie; Plomgaard, Peter; Fischer, Christian P

2009-01-01

-alpha infusion (rhTNF-alpha). We hypothesize that TNF-alpha increases human muscle protein breakdown and/or inhibit synthesis. Subjects and Methods: Using a randomized controlled, crossover design post-absorptive healthy young males (n=8) were studied 2 hours under basal conditions followed by 4 hours infusion...... with the phenylalanine 3-compartment model showed similar muscle synthesis, breakdown and net muscle degradation after 2 hours basal and after 4 hours Control or rhTNF-alpha infusion. Conclusion: This study is the first to show in humans that TNF-alpha does not affect systemic and skeletal muscle protein turnover, when......Context: Skeletal muscle wasting has been associated with elevations in circulating inflammatory cytokines, in particular TNF-alpha. Objective: In this study, we investigated whether TNF-alpha affects human systemic and skeletal muscle protein turnover, via a 4 hours recombinant human TNF...

Codon usage regulates protein structure and function by affecting translation elongation speed in Drosophila cells.

Science.gov (United States)

Zhao, Fangzhou; Yu, Chien-Hung; Liu, Yi

2017-08-21

Codon usage biases are found in all eukaryotic and prokaryotic genomes and have been proposed to regulate different aspects of translation process. Codon optimality has been shown to regulate translation elongation speed in fungal systems, but its effect on translation elongation speed in animal systems is not clear. In this study, we used a Drosophila cell-free translation system to directly compare the velocity of mRNA translation elongation. Our results demonstrate that optimal synonymous codons speed up translation elongation while non-optimal codons slow down translation. In addition, codon usage regulates ribosome movement and stalling on mRNA during translation. Finally, we show that codon usage affects protein structure and function in vitro and in Drosophila cells. Together, these results suggest that the effect of codon usage on translation elongation speed is a conserved mechanism from fungi to animals that can affect protein folding in eukaryotic organisms. © The Author(s) 2017. Published by Oxford University Press on behalf of Nucleic Acids Research.

Protein level affects the relative lysine requirement of growing rainbow trout (Oncorhynchus mykiss) fry.

Science.gov (United States)

Bodin, Noelie; Govaerts, Bernadette; Abboudi, Tarik; Detavernier, Christel; De Saeger, Sarah; Larondelle, Yvan; Rollin, Xavier

2009-07-01

The effect of two digestible protein levels (310 and 469 g/kg DM) on the relative lysine (Lys; g Lys/kg DM or g Lys/100 g protein) and the absolute Lys (g Lys intake/kg 0.75 per d) requirements was studied in rainbow trout fry using a dose-response trial. At each protein level, sixteen isoenergetic (22-23 MJ digestible energy/kg DM) diets were tested, involving a full range (2-70 g/kg DM) of sixteen Lys levels. Each diet was given to one group of sixty rainbow trout fry (mean initial body weight 0.78 g) reared at 15 degrees C for 31 feeding d. The Lys requirements were estimated based on the relationships between weight, protein, and Lys gains (g/kg 0.75 per d) and Lys concentration (g/kg DM or g/100 g protein) or Lys intake (g/kg 0.75 per d), using the broken-line model (BLM) and the non-linear four-parameter saturation kinetics model (SKM-4). Both the model and the response criterion chosen markedly impacted the relative Lys requirement. The relative Lys requirement for Lys gain of rainbow trout estimated with the BLM (and SKM-4 at 90 % of the maximum response) increased from 16.8 (19.6) g/kg DM at a low protein level to 23.4 (24.5) g/kg DM at a high protein level. However, the dietary protein content affected neither the absolute Lys requirement nor the relative Lys requirement expressed as g Lys/100 g protein nor the Lys requirement for maintenance (21 mg Lys/kg 0.75 per d).

Proteolysis in salmon ( Salmo salar ) during cold storage : Effects of storage time and smoking process

DEFF Research Database (Denmark)

Lund, K.E.; Nielsen, Henrik Hauch

2001-01-01

Changes in free amino acids (FAAs), small peptides and myofibrillar proteins were investigated in salmon (Salmo salar) muscle stored at OC for up to 23 days and after the stored salmon was smoked. Storage time and smoking process did not increase the formation of FAAs and small peptides indicating...

GH/IGF-I axis and matrix adaptation of the musculotendinous tissue to exercise in humans

DEFF Research Database (Denmark)

Heinemeier, K M; Mackey, Abigail; Doessing, S

2012-01-01

cells (satellite cells), as increased satellite cell numbers are found in human muscle with increased GH/IGF-I levels, despite no change in myofibrillar protein synthesis. Although advanced age is associated with both a reduction in the GH/IGF-I axis activity, and in skeletal muscle mass (sarcopenia...

Communication: Microsecond dynamics of the protein and water affect electron transfer in a bacterial bc1 complex

Science.gov (United States)

Martin, Daniel R.; Matyushov, Dmitry V.

2015-04-01

Cross-membrane electron transport between cofactors localized in proteins of mitochondrial respiration and bacterial photosynthesis is the source of all biological energy. The statistics and dynamics of nuclear fluctuations in these protein/membrane/water heterogeneous systems are critical for their energetic efficiency. The results of 13 μs of atomistic molecular dynamics simulations of the membrane-bound bc1 bacterial complex are analyzed here. The reaction is affected by a broad spectrum of nuclear modes, with the slowest dynamics in the range of time-scales ˜0.1-1.6 μs contributing half of the reaction reorganization energy. Two reorganization energies are required to describe protein electron transfer due to dynamical arrest of protein conformations on the observation window. This mechanistic distinction allows significant lowering of activation barriers for reactions in proteins.

Communication: Microsecond dynamics of the protein and water affect electron transfer in a bacterial bc1 complex

International Nuclear Information System (INIS)

Martin, Daniel R.; Matyushov, Dmitry V.

2015-01-01

Cross-membrane electron transport between cofactors localized in proteins of mitochondrial respiration and bacterial photosynthesis is the source of all biological energy. The statistics and dynamics of nuclear fluctuations in these protein/membrane/water heterogeneous systems are critical for their energetic efficiency. The results of 13 μs of atomistic molecular dynamics simulations of the membrane-bound bc 1 bacterial complex are analyzed here. The reaction is affected by a broad spectrum of nuclear modes, with the slowest dynamics in the range of time-scales ∼0.1-1.6 μs contributing half of the reaction reorganization energy. Two reorganization energies are required to describe protein electron transfer due to dynamical arrest of protein conformations on the observation window. This mechanistic distinction allows significant lowering of activation barriers for reactions in proteins

Dietary carbohydrate deprivation increases 24-hour nitrogen excretion without affecting postabsorptive hepatic or whole body protein metabolism in healthy men

NARCIS (Netherlands)

Bisschop, PH; de Sain-van der Velden, MGM; Stellaard, F; Kuipers, F; Meijer, AJ; Sauerwein, HP; Romijn, JA

Because insulin is an important regulator of protein metabolism, we hypothesized that physiological modulation of insulin secretion, by means of extreme variations in dietary carbohydrate content, affects postabsorptive protein metabolism. Therefore, we studied the effects of three isocaloric diets

Dietary carbohydrate deprivation increases 24-hour nitrogen excretion without affecting postabsorptive hepatic or whole body protein metabolism in healthy men

NARCIS (Netherlands)

Bisschop, P. H.; de Sain-van der Velden, M. G. M.; Stellaard, F.; Kuipers, F.; Meijer, A. J.; Sauerwein, H. P.; Romijn, J. A.

2003-01-01

Because insulin is an important regulator of protein metabolism, we hypothesized that physiological modulation of insulin secretion, by means of extreme variations in dietary carbohydrate content, affects postabsorptive protein metabolism. Therefore, we studied the effects of three isocaloric diets

Does whey protein supplementation affect blood pressure in hypoalbuminemic peritoneal dialysis patients?

Directory of Open Access Journals (Sweden)

Hassan K

2017-08-01

Full Text Available Kamal Hassan,1,2 Fadi Hassan3 1Faculty of Medicine in the Galilee, Bar-Ilan University, Safed, 2Department of Nephrology and Hypertension, Peritoneal Dialysis Unit, 3Department of Internal Medicine E, Galilee Medical Center, Nahariya, Israel Objective: Hypertension and hypoalbuminemia are common risk factors for cardiovascular complications in peritoneal dialysis (PD patients. Data are limited regarding the effects of whey protein consumption on blood pressure in this population. The aim of the present study was to examine if whey protein supplementation for 12 weeks to hypoalbuminemic PD patients affects their blood pressure.Patients and methods: This prospective randomized study included 36 stable PD patients with serum albumin levels <3.8 g/dL. During 12 weeks, 18 patients were instructed to consume 1.2 g/kg/day of protein and an additional whey protein supplement at a dose of 25% of the instructed daily protein (whey protein group. Eighteen patients were instructed to consume protein in the amount of 1.2 g/kg/day and an additional 25%, without whey protein supplementation (control group. Results: Compared to the control group, in the whey protein group, serum albumin levels, oncotic pressure, and dialysate ultrafiltration significantly increased (3.55±0.14 to 4.08±0.15 g/dL, P<0.001; 21.81±2.03 to 24.06±1.54 mmHg, P<0.001; 927.8±120.3 to 1,125.0±125.1 mL/day, P<0.001; respectively and were significantly higher after 12 weeks (4.08±0.15 vs 3.41±0.49 g/dL, P<0.001; 24.06±1.54 vs 22.71±1.77 mmHg, P=0.010; 1,125.0±125.1 vs 930.6±352.8 mL/day, P=0.017; respectively in the whey protein group compared to the control group. Fluid overload, the extracellular to intracellular ratio and mean arterial pressure (MAP significantly decreased (2.46±1.08 to 1.52±0.33, P<0.001; 1.080±0.142 to 0.954±0.124, P<0.001; 102.6±3.80 to 99.83±3.85, P=0.018; respectively and were significantly lower in the whey protein group after 12 weeks (1.52±0

Stress proteins in lymphocytes: Membrane stabilization does not affect the heat shock response

International Nuclear Information System (INIS)

Hughes, C.S.; Repasky, E.A.; Subjeck, J.R.

1987-01-01

Temperatures which have been used to induce heat shock proteins (hsps) have been at the upper physiologic limit or well above this limit. In addition, little attention has been given to the effects of physiologic heat exposures on hsp induction in lymphocytes. The author examined temperatures between 39 0 C and 41 0 C on protein synthesis in the following lymphoid cell lines and cells: BDK, EL-4, JM, DO.11, and in dispersed lymph nodes and thymic tissues. In these studies, 39.5 0 appears to be the threshold for hsp induction (as distinguished by gel electrophoresis). At this temperature the induction of the major hsps at 70 and 89 kDa are observed. Hsp 89 appears to be the most strongly induced in all cells examined. In JM cells, a human cell line, heat shock also induces hsp 68, the non-constitutive hsp at this size. These temperatures do not depress normal levels of protein synthesis. When stearic acid or cholesterol was added to lymphocyte cultures prior to heating (which stabilize membranes), hsp induction appears to occur in a manner indistinguishable from cells heated in normal media. This suggests that membrane fluidity (as influenced by these agents) does not affect or depress the heat shock response in these cells. Finally, the authors observed that 2-deoxyglucose and other inducers of glucose regulated proteins in fibroblasts also induce the major glucose regulated proteins in lymphocytes

High pressure inactivation of relevant target microorganisms in poultry meat products and the evaluation of pressure-induced protein denaturation of marinated poultry under different high pressure treatments

Science.gov (United States)

Schmidgall, Johanna; Hertel, Christian; Bindrich, Ute; Heinz, Volker; Toepfl, Stefan

2011-03-01

In this study, the possibility of extending shelf life of marinated poultry meat products by high pressure processing was evaluated. Relevant spoilage and pathogenic strains were selected and used as target microorganisms (MOs) for challenge experiments. Meat and brine were inoculated with MOs and treated at 450 MPa, 4 °C for 3 min. The results of inactivation show a decreasing pressure tolerance in the series Lactobacillus > Arcobacter > Carnobacterium > Bacillus cereus > Brochothrix thermosphacta > Listeria monocytogenes. Leuconostoc gelidum exhibited the highest pressure tolerance in meat. A protective effect of poultry meat was found for L. sakei and L. gelidum. In parallel, the influence of different marinade formulations (pH, carbonates, citrates) on protein structure changes during a pressure treatment was investigated. Addition of sodium carbonate shows a protection against denaturation of myofibrillar proteins and provides a maximum water-holding capacity. Caustic marinades allowed a higher retention of product characteristics than low-pH marinades.

Deoxynivalenol affects in vitro intestinal epithelial cell barrier integrity through inhibition of protein synthesis

International Nuclear Information System (INIS)

Van De Walle, Jacqueline; Sergent, Therese; Piront, Neil; Toussaint, Olivier; Schneider, Yves-Jacques; Larondelle, Yvan

2010-01-01

Deoxynivalenol (DON), one of the most common mycotoxin contaminants of raw and processed cereal food, adversely affects the gastrointestinal tract. Since DON acts as a protein synthesis inhibitor, the constantly renewing intestinal epithelium could be particularly sensitive to DON. We analyzed the toxicological effects of DON on intestinal epithelial protein synthesis and barrier integrity. Differentiated Caco-2 cells, as a widely used model of the human intestinal barrier, were exposed to realistic intestinal concentrations of DON (50, 500 and 5000 ng/ml) during 24 h. DON caused a concentration-dependent decrease in total protein content associated with a reduction in the incorporation of [ 3 H]-leucine, demonstrating its inhibitory effect on protein synthesis. DON simultaneously increased the paracellular permeability of the monolayer as reflected through a decreased transepithelial electrical resistance associated with an increased paracellular flux of the tracer [ 3 H]-mannitol. A concentration-dependent reduction in the expression level of the tight junction constituent claudin-4 was demonstrated by Western blot, which was not due to diminished transcription, increased degradation, or NF-κB, ERK or JNK activation, and was also observed for a tight junction independent protein, i.e. intestinal alkaline phosphatase. These results demonstrate a dual toxicological effect of DON on differentiated Caco-2 cells consisting in an inhibition of protein synthesis as well as an increase in monolayer permeability, and moreover suggest a possible link between them through diminished synthesis of the tight junction constituent claudin-4.

Denervation in murine fast-twitch muscle: short-term physiological changes and temporal expression profiling.

Science.gov (United States)

Raffaello, Anna; Laveder, Paolo; Romualdi, Chiara; Bean, Camilla; Toniolo, Luana; Germinario, Elena; Megighian, Aram; Danieli-Betto, Daniela; Reggiani, Carlo; Lanfranchi, Gerolamo

2006-03-13

Denervation deeply affects muscle structure and function, the alterations being different in slow and fast muscles. Because the effects of denervation on fast muscles are still controversial, and high-throughput studies on gene expression in denervated muscles are lacking, we studied gene expression during atrophy progression following denervation in mouse tibialis anterior (TA). The sciatic nerve was cut close to trochanter in adult CD1 mice. One, three, seven, and fourteen days after denervation, animals were killed and TA muscles were dissected out and utilized for physiological experiments and gene expression studies. Target cDNAs from TA muscles were hybridized on a dedicated cDNA microarray of muscle genes. Seventy-one genes were found differentially expressed. Microarray results were validated, and the expression of relevant genes not probed on our array was monitored by real-time quantitative PCR (RQ-PCR). Nuclear- and mitochondrial-encoded genes implicated in energy metabolism were consistently downregulated. Among genes implicated in muscle contraction (myofibrillar and sarcoplasmic reticulum), genes typical of fast fibers were downregulated, whereas those typical of slow fibers were upregulated. Electrophoresis and Western blot showed less pronounced changes in myofibrillar protein expression, partially confirming changes in gene expression. Isometric tension of skinned fibers was little affected by denervation, whereas calcium sensitivity decreased. Functional studies in mouse extensor digitorum longus muscle showed prolongation in twitch time parameters and shift to the left in force-frequency curves after denervation. We conclude that, if studied at the mRNA level, fast muscles appear not less responsive than slow muscles to the interruption of neural stimulation.

Lengths of Orthologous Prokaryotic Proteins Are Affected by Evolutionary Factors

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Tatiana Tatarinova

2015-01-01

Full Text Available Proteins of the same functional family (for example, kinases may have significantly different lengths. It is an open question whether such variation in length is random or it appears as a response to some unknown evolutionary driving factors. The main purpose of this paper is to demonstrate existence of factors affecting prokaryotic gene lengths. We believe that the ranking of genomes according to lengths of their genes, followed by the calculation of coefficients of association between genome rank and genome property, is a reasonable approach in revealing such evolutionary driving factors. As we demonstrated earlier, our chosen approach, Bubble-sort, combines stability, accuracy, and computational efficiency as compared to other ranking methods. Application of Bubble Sort to the set of 1390 prokaryotic genomes confirmed that genes of Archaeal species are generally shorter than Bacterial ones. We observed that gene lengths are affected by various factors: within each domain, different phyla have preferences for short or long genes; thermophiles tend to have shorter genes than the soil-dwellers; halophiles tend to have longer genes. We also found that species with overrepresentation of cytosines and guanines in the third position of the codon (GC3 content tend to have longer genes than species with low GC3 content.

Lengths of Orthologous Prokaryotic Proteins Are Affected by Evolutionary Factors.

Science.gov (United States)

Tatarinova, Tatiana; Salih, Bilal; Dien Bard, Jennifer; Cohen, Irit; Bolshoy, Alexander

2015-01-01

Proteins of the same functional family (for example, kinases) may have significantly different lengths. It is an open question whether such variation in length is random or it appears as a response to some unknown evolutionary driving factors. The main purpose of this paper is to demonstrate existence of factors affecting prokaryotic gene lengths. We believe that the ranking of genomes according to lengths of their genes, followed by the calculation of coefficients of association between genome rank and genome property, is a reasonable approach in revealing such evolutionary driving factors. As we demonstrated earlier, our chosen approach, Bubble-sort, combines stability, accuracy, and computational efficiency as compared to other ranking methods. Application of Bubble Sort to the set of 1390 prokaryotic genomes confirmed that genes of Archaeal species are generally shorter than Bacterial ones. We observed that gene lengths are affected by various factors: within each domain, different phyla have preferences for short or long genes; thermophiles tend to have shorter genes than the soil-dwellers; halophiles tend to have longer genes. We also found that species with overrepresentation of cytosines and guanines in the third position of the codon (GC3 content) tend to have longer genes than species with low GC3 content.

MURC, a muscle-restricted coiled-coil protein that modulates the Rho/ROCK pathway, induces cardiac dysfunction and conduction disturbance.

Science.gov (United States)

Ogata, Takehiro; Ueyama, Tomomi; Isodono, Koji; Tagawa, Masashi; Takehara, Naofumi; Kawashima, Tsuneaki; Harada, Koichiro; Takahashi, Tomosaburo; Shioi, Tetsuo; Matsubara, Hiroaki; Oh, Hidemasa

2008-05-01

We identified a novel muscle-restricted putative coiled-coil protein, MURC, which is evolutionarily conserved from frog to human. MURC was localized to the cytoplasm with accumulation in the Z-line of the sarcomere in the murine adult heart. MURC mRNA expression in the heart increased during the developmental process from the embryonic stage to adulthood. In response to pressure overload, MURC mRNA expression increased in the hypertrophied heart. Using the yeast two-hybrid system, we identified the serum deprivation response (SDPR) protein, a phosphatidylserine-binding protein, as a MURC-binding protein. MURC induced activation of the RhoA/ROCK pathway, which modulated serum response factor-mediated atrial natriuretic peptide (ANP) expression and myofibrillar organization. SDPR augmented MURC-induced transactivation of the ANP promoter in cardiomyocytes, and RNA interference of SDPR attenuated the action of MURC on the ANP promoter. Transgenic mice expressing cardiac-specific MURC (Tg-MURC) exhibited cardiac contractile dysfunction and atrioventricular (AV) conduction disturbances with atrial chamber enlargement, reduced thickness of the ventricular wall, and interstitial fibrosis. Spontaneous episodes of atrial fibrillation and AV block were observed in Tg-MURC mice. These findings indicate that MURC modulates RhoA signaling and that MURC plays an important role in the development of cardiac dysfunction and conduction disturbance with increased vulnerability to atrial arrhythmias.

MURC, a Muscle-Restricted Coiled-Coil Protein That Modulates the Rho/ROCK Pathway, Induces Cardiac Dysfunction and Conduction Disturbance▿

Science.gov (United States)

Ogata, Takehiro; Ueyama, Tomomi; Isodono, Koji; Tagawa, Masashi; Takehara, Naofumi; Kawashima, Tsuneaki; Harada, Koichiro; Takahashi, Tomosaburo; Shioi, Tetsuo; Matsubara, Hiroaki; Oh, Hidemasa

2008-01-01

We identified a novel muscle-restricted putative coiled-coil protein, MURC, which is evolutionarily conserved from frog to human. MURC was localized to the cytoplasm with accumulation in the Z-line of the sarcomere in the murine adult heart. MURC mRNA expression in the heart increased during the developmental process from the embryonic stage to adulthood. In response to pressure overload, MURC mRNA expression increased in the hypertrophied heart. Using the yeast two-hybrid system, we identified the serum deprivation response (SDPR) protein, a phosphatidylserine-binding protein, as a MURC-binding protein. MURC induced activation of the RhoA/ROCK pathway, which modulated serum response factor-mediated atrial natriuretic peptide (ANP) expression and myofibrillar organization. SDPR augmented MURC-induced transactivation of the ANP promoter in cardiomyocytes, and RNA interference of SDPR attenuated the action of MURC on the ANP promoter. Transgenic mice expressing cardiac-specific MURC (Tg-MURC) exhibited cardiac contractile dysfunction and atrioventricular (AV) conduction disturbances with atrial chamber enlargement, reduced thickness of the ventricular wall, and interstitial fibrosis. Spontaneous episodes of atrial fibrillation and AV block were observed in Tg-MURC mice. These findings indicate that MURC modulates RhoA signaling and that MURC plays an important role in the development of cardiac dysfunction and conduction disturbance with increased vulnerability to atrial arrhythmias. PMID:18332105

Protein degradation systems in the skeletal muscles of parr and smolt Atlantic salmon Salmo salar L. and brown trout Salmo trutta L.

Science.gov (United States)

Kantserova, Nadezda P; Lysenko, Liudmila A; Veselov, Alexey E; Nemova, Nina N

2017-08-01

Although protein degradation limits the rate of muscle growth in fish, the role of proteolytic systems responsible for degrading myofibrillar proteins in skeletal muscle is not well defined. The study herein aims to evaluate the role of calpains (calcium-activated proteases) and proteasomes (ATP-dependent proteases) in mediating muscle protein turnover at different life stages in wild salmonids. Protease activities were estimated in Atlantic salmon (Salmo salar L.) and brown trout (Salmo trutta L.) parr and smolts from the Indera River (Kola Peninsula, Russia). Calpain and proteasome activities in Atlantic salmon skeletal muscles were lower in smolts as compared with parr. Reduced muscle protein degradation accompanying Atlantic salmon parr-smolt transformation appeared to provide intense muscle growth essential for a minimum threshold size achievement that is required for smoltification. Calpain and proteasome activities in brown trout parr and smolts at age 3+ did not significantly differ. However, calpain activity was higher in smolts brown trout 4+ as compared with parr, while proteasome activity was lower. Results suggest that brown trout smoltification does not correspond with intense muscle growth and is more facultative and plastic in comparison with Atlantic salmon smoltification. Obtained data on muscle protein degradation capacity as well as length-weight parameters of fish reflect differences between salmon and trout in growth and smoltification strategies.

Newly identified protein Imi1 affects mitochondrial integrity and glutathione homeostasis in Saccharomyces cerevisiae.

Science.gov (United States)

Kowalec, Piotr; Grynberg, Marcin; Pająk, Beata; Socha, Anna; Winiarska, Katarzyna; Fronk, Jan; Kurlandzka, Anna

2015-09-01

Glutathione homeostasis is crucial for cell functioning. We describe a novel Imi1 protein of Saccharomyces cerevisiae affecting mitochondrial integrity and involved in controlling glutathione level. Imi1 is cytoplasmic and, except for its N-terminal Flo11 domain, has a distinct solenoid structure. A lack of Imi1 leads to mitochondrial lesions comprising aberrant morphology of cristae and multifarious mtDNA rearrangements and impaired respiration. The mitochondrial malfunctioning is coupled to significantly decrease the level of intracellular reduced glutathione without affecting oxidized glutathione, which decreases the reduced/oxidized glutathione ratio. These defects are accompanied by decreased cadmium sensitivity and increased phytochelatin-2 level. © FEMS 2015. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Protein and carbohydrate composition of larval food affects tolerance tothermal stress and desiccation in adult Drosophila melanogaster

DEFF Research Database (Denmark)

Andersen, Laila H; Kristensen, Torsten N; Loeschcke, Volker

2010-01-01

stress compared to males. Egg production was highest in females that had developed on the protein-enriched medium. However, there was a sex-specific effect of nutrition on egg-to-adult viability, with higher viability for males developing on the sucrose-enriched medium, while female survival was highest......Larval nutrition may affect a range of different life history traits as well as responses to environmental stress in adult insects. Here we test whether raising larvae of fruit flies, Drosophila melanogaster, on two different nutritional regimes affects resistance to cold, heat and desiccation....... In contrast, flies developed on the carbohydrate-enriched growth medium recovered faster from chill coma stress compared to flies developed on a protein-enriched medium. We also found gender differences in stress tolerance, with female flies being more tolerant to chill coma, heat knockdown and desiccation...

Communication: Microsecond dynamics of the protein and water affect electron transfer in a bacterial bc{sub 1} complex

Energy Technology Data Exchange (ETDEWEB)

Martin, Daniel R.; Matyushov, Dmitry V., E-mail: dmitrym@asu.edu [Department of Physics and Department of Chemistry and Biochemistry, Arizona State University, P.O. Box 871504, Tempe, Arizona 85287 (United States)

2015-04-28

Cross-membrane electron transport between cofactors localized in proteins of mitochondrial respiration and bacterial photosynthesis is the source of all biological energy. The statistics and dynamics of nuclear fluctuations in these protein/membrane/water heterogeneous systems are critical for their energetic efficiency. The results of 13 μs of atomistic molecular dynamics simulations of the membrane-bound bc{sub 1} bacterial complex are analyzed here. The reaction is affected by a broad spectrum of nuclear modes, with the slowest dynamics in the range of time-scales ∼0.1-1.6 μs contributing half of the reaction reorganization energy. Two reorganization energies are required to describe protein electron transfer due to dynamical arrest of protein conformations on the observation window. This mechanistic distinction allows significant lowering of activation barriers for reactions in proteins.

Effect of Ginger Extract and Citric Acid on the Tenderness of Duck Breast Muscles

Science.gov (United States)

2015-01-01

The objective of this study was to examine the effect of ginger extract (GE) combined with citric acid on the tenderness of duck breast muscles. Total six marinades were prepared with the combination of citric acid (0 and 0.3 M citric acid) and GE (0, 15, and 30%). Each marinade was sprayed on the surface of duck breasts (15 mL/100 g), and the samples were marinated for 72 h at 4℃. The pH and proteolytic activity of marinades were determined. After 72 h of marination, Warner Bratzler shear force (WBSF), myofibrillar fragmentation index (MFI), pH, cooking loss, moisture content, sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), and protein solubility were evaluated. There was no significant (p>0.05) difference in moisture content or cooking loss among all samples. However, GE marination resulted in a significant (pcitric acid) and WC (with citric acid) conditions were significantly (pcitric acid may be attributed to various mechanisms such as increased MFI and myofibrillar protein solubility. PMID:26877631

Contribution of the microbial and meat endogenous enzymes to the free amino acid and amine contents of dry fermented sausages.

Science.gov (United States)

Hierro, E; de La Hoz, L; Ordóñez, J A

1999-03-01

The role of the starter culture and meat endogenous enzymes on the free amino acid and amine contents of dry fermented sausages was studied. Five batches of sausages were prepared. The control batch was manufactured with aseptic ingredients without microbial inoculation. The other four experimental batches were manufactured with aseptic ingredients inoculated with Lactobacillus plantarum 4045 or Micrococcus-12 or L. plantarum 4045 and Micrococcus-12 or L. plantarum 4045 and Staphylococcus sp. Their effects on pH, a(w), myofibrillar proteins, and free amino acid and amine contents were studied. Sausages inoculated only with L. plantarum 4045 or with this starter combined with a Micrococcaceae had the lowest pH as a result of carbohydrate fermentation. In all batches similar patterns were observed for myofibrillar proteins and free amino acids which could indicate that meat endogenous proteases play an important role in proteolytic phenomena. No changes were observed in the amine fraction, indicating that the strains used as starter cultures did not show amino acid decarboxylase activity.

The Oncogenic Fusion Proteins SET-Nup214 and Sequestosome-1 (SQSTM1)-Nup214 Form Dynamic Nuclear Bodies and Differentially Affect Nuclear Protein and Poly(A)+ RNA Export*

Science.gov (United States)

Port, Sarah A.; Mendes, Adélia; Valkova, Christina; Spillner, Christiane; Fahrenkrog, Birthe; Kaether, Christoph; Kehlenbach, Ralph H.

2016-01-01

Genetic rearrangements are a hallmark of several forms of leukemia and can lead to oncogenic fusion proteins. One example of an affected chromosomal region is the gene coding for Nup214, a nucleoporin that localizes to the cytoplasmic side of the nuclear pore complex (NPC). We investigated two such fusion proteins, SET-Nup214 and SQSTM1 (sequestosome)-Nup214, both containing C-terminal portions of Nup214. SET-Nup214 nuclear bodies containing the nuclear export receptor CRM1 were observed in the leukemia cell lines LOUCY and MEGAL. Overexpression of SET-Nup214 in HeLa cells leads to the formation of similar nuclear bodies that recruit CRM1, export cargo proteins, and certain nucleoporins and concomitantly affect nuclear protein and poly(A)+ RNA export. SQSTM1-Nup214, although mostly cytoplasmic, also forms nuclear bodies and inhibits nuclear protein but not poly(A)+ RNA export. The interaction of the fusion proteins with CRM1 is RanGTP-dependent, as shown in co-immunoprecipitation experiments and binding assays. Further analysis revealed that the Nup214 parts mediate the inhibition of nuclear export, whereas the SET or SQSTM1 part determines the localization of the fusion protein and therefore the extent of the effect. SET-Nup214 nuclear bodies are highly mobile structures, which are in equilibrium with the nucleoplasm in interphase and disassemble during mitosis or upon treatment of cells with the CRM1-inhibitor leptomycin B. Strikingly, we found that nucleoporins can be released from nuclear bodies and reintegrated into existing NPC. Our results point to nuclear bodies as a means of preventing the formation of potentially insoluble and harmful protein aggregates that also may serve as storage compartments for nuclear transport factors. PMID:27613868

The Oncogenic Fusion Proteins SET-Nup214 and Sequestosome-1 (SQSTM1)-Nup214 Form Dynamic Nuclear Bodies and Differentially Affect Nuclear Protein and Poly(A)+ RNA Export.

Science.gov (United States)

Port, Sarah A; Mendes, Adélia; Valkova, Christina; Spillner, Christiane; Fahrenkrog, Birthe; Kaether, Christoph; Kehlenbach, Ralph H

2016-10-28

Genetic rearrangements are a hallmark of several forms of leukemia and can lead to oncogenic fusion proteins. One example of an affected chromosomal region is the gene coding for Nup214, a nucleoporin that localizes to the cytoplasmic side of the nuclear pore complex (NPC). We investigated two such fusion proteins, SET-Nup214 and SQSTM1 (sequestosome)-Nup214, both containing C-terminal portions of Nup214. SET-Nup214 nuclear bodies containing the nuclear export receptor CRM1 were observed in the leukemia cell lines LOUCY and MEGAL. Overexpression of SET-Nup214 in HeLa cells leads to the formation of similar nuclear bodies that recruit CRM1, export cargo proteins, and certain nucleoporins and concomitantly affect nuclear protein and poly(A) + RNA export. SQSTM1-Nup214, although mostly cytoplasmic, also forms nuclear bodies and inhibits nuclear protein but not poly(A) + RNA export. The interaction of the fusion proteins with CRM1 is RanGTP-dependent, as shown in co-immunoprecipitation experiments and binding assays. Further analysis revealed that the Nup214 parts mediate the inhibition of nuclear export, whereas the SET or SQSTM1 part determines the localization of the fusion protein and therefore the extent of the effect. SET-Nup214 nuclear bodies are highly mobile structures, which are in equilibrium with the nucleoplasm in interphase and disassemble during mitosis or upon treatment of cells with the CRM1-inhibitor leptomycin B. Strikingly, we found that nucleoporins can be released from nuclear bodies and reintegrated into existing NPC. Our results point to nuclear bodies as a means of preventing the formation of potentially insoluble and harmful protein aggregates that also may serve as storage compartments for nuclear transport factors. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

Cholesterol Promotes Protein Binding by Affecting Membrane Electrostatics and Solvation Properties.

Science.gov (United States)

Doktorova, Milka; Heberle, Frederick A; Kingston, Richard L; Khelashvili, George; Cuendet, Michel A; Wen, Yi; Katsaras, John; Feigenson, Gerald W; Vogt, Volker M; Dick, Robert A

2017-11-07

Binding of the retroviral structural protein Gag to the cellular plasma membrane is mediated by the protein's matrix (MA) domain. Prominent among MA-PM interactions is electrostatic attraction between the positively charged MA domain and the negatively charged plasma membrane inner leaflet. Previously, we reported that membrane association of HIV-1 Gag, as well as purified Rous sarcoma virus (RSV) MA and Gag, depends strongly on the presence of acidic lipids and is enhanced by cholesterol (Chol). The mechanism underlying this enhancement was unclear. Here, using a broad set of in vitro and in silico techniques we addressed molecular mechanisms of association between RSV MA and model membranes, and investigated how Chol enhances this association. In neutron scattering experiments with liposomes in the presence or absence of Chol, MA preferentially interacted with preexisting POPS-rich clusters formed by nonideal lipid mixing, binding peripherally to the lipid headgroups with minimal perturbation to the bilayer structure. Molecular dynamics simulations showed a stronger MA-bilayer interaction in the presence of Chol, and a large Chol-driven increase in lipid packing and membrane surface charge density. Although in vitro MA-liposome association is influenced by disparate variables, including ionic strength and concentrations of Chol and charged lipids, continuum electrostatic theory revealed an underlying dependence on membrane surface potential. Together, these results conclusively show that Chol affects RSV MA-membrane association by making the electrostatic potential at the membrane surface more negative, while decreasing the penalty for lipid headgroup desolvation. The presented approach can be applied to other viral and nonviral proteins. Copyright © 2017 Biophysical Society. Published by Elsevier Inc. All rights reserved.

Polycomb Protein OsFIE2 Affects Plant Height and Grain Yield in Rice.

Directory of Open Access Journals (Sweden)

Xianbo Liu

Full Text Available Polycomb group (PcG proteins have been shown to affect growth and development in plants. To further elucidate their role in these processes in rice, we isolated and characterized a rice mutant which exhibits dwarfism, reduced seed setting rate, defective floral organ, and small grains. Map-based cloning revealed that abnormal phenotypes were attributed to a mutation of the Fertilization Independent Endosperm 2 (OsFIE2 protein, which belongs to the PcG protein family. So we named the mutant as osfie2-1. Histological analysis revealed that the number of longitudinal cells in the internodes decreased in osfie2-1, and that lateral cell layer of the internodes was markedly thinner than wild-type. In addition, compared to wild-type, the number of large and small vascular bundles decreased in osfie2-1, as well as cell number and cell size in spikelet hulls. OsFIE2 is expressed in most tissues and the coded protein localizes in both nucleus and cytoplasm. Yeast two-hybrid and bimolecular fluorescence complementation assays demonstrated that OsFIE2 interacts with OsiEZ1 which encodes an enhancer of zeste protein previously identified as a histone methylation enzyme. RNA sequencing-based transcriptome profiling and qRT-PCR analysis revealed that some homeotic genes and genes involved in endosperm starch synthesis, cell division/expansion and hormone synthesis and signaling are differentially expressed between osfie2-1 and wild-type. In addition, the contents of IAA, GA3, ABA, JA and SA in osfie2-1 are significantly different from those in wild-type. Taken together, these results indicate that OsFIE2 plays an important role in the regulation of plant height and grain yield in rice.

Ingestion of Casein in a Milk Matrix Modulates Dietary Protein Digestion and Absorption Kinetics but Does Not Modulate Postprandial Muscle Protein Synthesis in Older Men.

Science.gov (United States)

Churchward-Venne, Tyler A; Snijders, Tim; Linkens, Armand M A; Hamer, Henrike M; van Kranenburg, Janneau; van Loon, Luc J C

2015-07-01

The slow digestion and amino acid absorption kinetics of isolated micellar casein have been held responsible for its relatively lower postprandial muscle protein synthetic response compared with rapidly digested proteins such as isolated whey. However, casein is normally consumed within a milk matrix. We hypothesized that protein digestion and absorption kinetics and the subsequent muscle protein synthetic response after micellar casein ingestion are modulated by the milk matrix. The aim of this study was to determine the impact of a milk matrix on casein protein digestion and absorption kinetics and postprandial muscle protein synthesis in older men. In a parallel-group design, 32 healthy older men (aged 71 ± 1 y) received a primed continuous infusion of L-[ring-(2)H5]-phenylalanine, L-[ring-3,5-(2)H2]-tyrosine, and L-[1-(13)C]-leucine, and ingested 25 g intrinsically L-[1-(13)C]-phenylalanine and L-[1-(13)C]-leucine labeled casein dissolved in bovine milk serum (Cas+Serum) or water (Cas). Plasma samples and muscle biopsies were collected in the postabsorptive state and for 300 min in the postprandial period to examine whole-body and skeletal muscle protein metabolism. Casein ingestion increased plasma leucine and phenylalanine concentrations and L-[1-(13)C]-phenylalanine enrichments, with a more rapid rise after Cas vs. Cas+Serum. Nonetheless, dietary protein-derived phenylalanine availability did not differ between Cas+Serum (47 ± 2%, mean ± SEM) and Cas (46 ± 3%) when assessed over the 300-min postprandial period (P = 0.80). The milk matrix did not modulate postprandial myofibrillar protein synthesis rates from 0 to 120 min (0.038 ± 0.005 vs. 0.031 ± 0.007%/h) or from 120 to 300 min (0.052 ± 0.004 vs. 0.067 ± 0.005%/h) after Cas+Serum vs. Cas. Similarly, no treatment differences in muscle protein-bound L-[1-(13)C]-phenylalanine enrichments were observed at 120 min (0.003 ± 0.001 vs. 0.002 ± 0.001) or 300 min (0.015 ± 0.002 vs. 0.016 ± 0.002 mole

Does Cry1Ab protein affect learning performances of the honey bee Apis mellifera L. (Hymenoptera, Apidae)?

Science.gov (United States)

Ramirez-Romero, R; Desneux, N; Decourtye, A; Chaffiol, A; Pham-Delègue, M H

2008-06-01

Genetically modified Bt crops are increasingly used worldwide but side effects and especially sublethal effects on beneficial insects remain poorly studied. Honey bees are beneficial insects for natural and cultivated ecosystems through pollination. The goal of the present study was to assess potential effects of two concentrations of Cry1Ab protein (3 and 5000 ppb) on young adult honey bees. Following a complementary bioassay, our experiments evaluated effects of the Cry1Ab on three major life traits of young adult honey bees: (a) survival of honey bees during sub-chronic exposure to Cry1Ab, (b) feeding behaviour, and (c) learning performance at the time that honey bees become foragers. The latter effect was tested using the proboscis extension reflex (PER) procedure. The same effects were also tested using a chemical pesticide, imidacloprid, as positive reference. The tested concentrations of Cry1Ab protein did not cause lethal effects on honey bees. However, honey bee feeding behaviour was affected when exposed to the highest concentration of Cry1Ab protein, with honey bees taking longer to imbibe the contaminated syrup. Moreover, honey bees exposed to 5000 ppb of Cry1Ab had disturbed learning performances. Honey bees continued to respond to a conditioned odour even in the absence of a food reward. Our results show that transgenic crops expressing Cry1Ab protein at 5000 ppb may affect food consumption or learning processes and thereby may impact honey bee foraging efficiency. The implications of these results are discussed in terms of risks of transgenic Bt crops for honey bees.

Sucrose Sensitivity of Honey Bees Is Differently Affected by Dietary Protein and a Neonicotinoid Pesticide.

Directory of Open Access Journals (Sweden)

Fabien J Démares

Full Text Available Over a decade, declines in honey bee colonies have raised worldwide concerns. Several potentially contributing factors have been investigated, e.g. parasites, diseases, and pesticides. Neonicotinoid pesticides have received much attention due to their intensive use in crop protection, and their adverse effects on many levels of honey bee physiology led the European Union to ban these compounds. Due to their neuronal target, a receptor expressed throughout the insect nervous system, studies have focused mainly on neuroscience and behaviour. Through the Geometric Framework of nutrition, we investigated effects of the neonicotinoid thiamethoxam on survival, food consumption and sucrose sensitivity of honey bees (Apis mellifera. Thiamethoxam did not affect protein and carbohydrate intake, but decreased responses to high concentrations of sucrose. Interestingly, when bees ate fixed unbalanced diets, dietary protein facilitated better sucrose detection. Both thiamethoxam and dietary protein influenced survival. These findings suggest that, in the presence of a pesticide and unbalanced food, honey bee health may be severely challenged. Consequences for foraging efficiency and colony activity, cornerstones of honey bee health, are also discussed.

Casein and soy protein meals differentially affect whole-body and splanchnic protein metabolism in healthy humans.

Science.gov (United States)

Luiking, Yvette C; Deutz, Nicolaas E P; Jäkel, Martin; Soeters, Peter B

2005-05-01

Dietary protein quality is considered to be dependent on the degree and velocity with which protein is digested, absorbed as amino acids, and retained in the gut as newly synthesized protein. Metabolic animal studies suggest that the quality of soy protein is inferior to that of casein protein, but confirmatory studies in humans are lacking. The study objective was to assess the quality of casein and soy protein by comparing their metabolic effects in healthy human subjects. Whole-body protein kinetics, splanchnic leucine extraction, and urea production rates were measured in the postabsorptive state and during 8-h enteral intakes of isonitrogenous [0.42 g protein/(kg body weight . 8 h)] protein-based test meals, which contained either casein (CAPM; n = 12) or soy protein (SOPM; n = 10) in 2 separate groups. Stable isotope techniques were used to study metabolic effects. With enteral food intake, protein metabolism changed from net protein breakdown to net protein synthesis. Net protein synthesis was greater in the CAPM group than in the SOPM group [52 +/- 14 and 17 +/- 14 nmol/(kg fat-free mass (FFM) . min), respectively; P CAPM (P = 0.07). Absolute splanchnic extraction of leucine was higher in the subjects that consumed CAPM [306 +/- 31 nmol/(kg FFM . min)] vs. those that consumed SOPM [235 +/- 29 nmol/(kg FFM . min); P < 0.01]. In conclusion, a significantly larger portion of soy protein is degraded to urea, whereas casein protein likely contributes to splanchnic utilization (probably protein synthesis) to a greater extent. The biological value of soy protein must be considered inferior to that of casein protein in humans.

Implications of white striping and spaghetti meat abnormalities on meat quality and histological features in broilers.

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Baldi, G; Soglia, F; Mazzoni, M; Sirri, F; Canonico, L; Babini, E; Laghi, L; Cavani, C; Petracci, M

2018-01-01

During the past few years, there has been an increasing prevalence of broiler breast muscle abnormalities, such as white striping (WS) and wooden breast conditions. More recently, a new muscular abnormality termed as spaghetti meat (SM) because of the altered structural integrity of the Pectoralis major muscle often associated with WS has emerged. Thus, this study aimed at evaluating the effects of WS and SM conditions, occurring alone or combined within the same P. major muscle, on meat quality traits and muscle histology. In two replications, 96 P. major muscles were classified into four classes: normal (N), WS, SM and WS/SM. The whole fillet was used for weight assessment and morphometric measurements, then each sample was cut in order to separate the superficial layer from the deep one and used to evaluate proximate composition, histological features, nuclear magnetic resonance relaxation times, functional properties and both myofibrillar and sarcoplasmic proteins profile. Fillets affected by WS and SM abnormalities exhibited higher weights and increased thickness and length. SM condition was associated with a relevant decrease in protein content coupled with a significant increase in moisture level, whereas fat content was affected only by the simultaneous presence of WS. Histological evaluations revealed that abnormal samples were characterized by several degenerative aspects that almost completely concerned the superficial layer of the fillets. White striped fillets exhibited necrosis and lysis of fibers, fibrosis, lipidosis, loss of cross striation and vacuolar degeneration. Moreover, SM samples were characterized by poor fiber uniformity and a progressive rarefaction of the endo- and peri-mysial connective tissue, whereas WS/SM fillets showed intermediate histological features. Nuclear magnetic resonance relaxation analysis revealed a higher proportion of extra-myofibrillar water in the superficial section of all the abnormal fillets, especially in SM

Antioxidant properties of salmon (Salmo salar L.) protein fraction hydrolysates revealed following their ex vivo digestion and in vitro hydrolysis.

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Borawska, Justyna; Darewicz, Małgorzata; Pliszka, Monika; Vegarud, Gerd E

2016-06-01

Salmon (Salmo salar L.) myofibryllar protein (MP) and sarcoplasmic protein (SP) were digested with human gastric and duodenal juices and hydrolysed in vitro with commercial pepsin and Corolase PP. The digestion after duodenal juice/Corolase PP caused almost complete breakdown of peptide bonds in MP and SP. The DPPH(•) scavenging activity of proteins decreased during both ex vivo digestion and in vitro hydrolysis. The highest value of DPPH(•) scavenging activity was shown for the gastric digest of SP (8.88 ± 0.87%). The ABTS(+•) scavenging activity of MP and SP increased during digestion/hydrolysis. The duodenal digest of SP was characterised by the highest value of ABTS(+•) scavenging activity (72.7 ± 1.2%). In turn, the highest value of ferric-reducing power was determined for the gastric digest of SP (84.8 ± 0.2%). Salmon antioxidant peptides Phe-Ile-Lys-Lys, His-Leu, Ile-Tyr, Pro-His-Leu, Pro-Trp, Val-Pro-Trp were identified in both ex vivo digested and in vitro hydrolysed MP and SP. An antioxidant peptide, Val-Tyr, was additionally detected in the in vitro hydrolysate of SP. The results indicate the salmon myofibrillar and sarcoplasmic protein fractions as potential sources of antioxidant peptides that could be released in the gastrointestinal tract but their amino acid sequence and quantification vary. © 2015 Society of Chemical Industry. © 2015 Society of Chemical Industry.

Drought affects protein and phenolic content in bambara groundnut ...

African Journals Online (AJOL)

Bambara groundnut (Vigna subterranea L. Verdc.) is a legume crop, which has long been recognised as a protein-rich and drought-tolerant crop, used extensively in sub-Saharan Africa. This study evaluates the effect of experimental water deficit stress on total protein concentration, secondary protein structure and the total ...

Expression of Bax in yeast affects not only the mitochondria but also vacuolar integrity and intracellular protein traffic

DEFF Research Database (Denmark)

Dimitrova, Irina; Toby, Garabet G; Tili, Esmerina

2004-01-01

-transferase (BI-GST) leads to aggregation, but not fusion of the mitochondria. In addition, Bax affects the integrity of yeast vacuoles, resulting in the disintegration and eventual loss of the organelles, and the disruption of intracellular protein traffic. While Bcl-2 coexpression only partially corrects...

Protein turnover in lactating mink (Mustela vison) is not affected by dietary protein supply

DEFF Research Database (Denmark)

Tauson, Anne-Helene; Fink, Rikke; Chwalibog, André

2006-01-01

The mink is a strict carnivore and may therefore serve as a model for the cat. Current recommendations for protein supply for lactating mink are based on production experiments with preweaning kit growth as a measure of dietary adequacy (1,2). Recently, nitrogen balance and substrate oxidation have...... in humans (7), growing pigs (8), and growing rats (9). In adult cats, both protein synthesis and breakdown were lower when feeding a low- than when feeding a high-protein diet [20 vs. 70% of metabolizable energy (ME)5 from protein] (10). The objectives of this study were therefore to develop a ¹5N...

Protein phosphatase 2A mediates JS-K-induced apoptosis by affecting Bcl-2 family proteins in human hepatocellular carcinoma HepG2 cells.

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Liu, Ling; Huang, Zile; Chen, Jingjing; Wang, Jiangang; Wang, Shuying

2018-04-25

Protein phosphatase 2A (PP2A) is an important enzyme within various signal transduction pathways. The present study was investigated PP2A mediates JS-K-induced apoptosis by affecting Bcl-2 family protein. JS-K showed diverse inhibitory effects in five HCC cell lines, especially HepG2 cells. JS-K caused a dose- and time-dependent reduction in cell viability and increased in levels of LDH release. Meanwhile, JS-K- induced apoptosis was characterized by mitochondrial membrane potential reduction, Hoechst 33342 + /PI + dual staining, release of cytochrome c (Cyt c), and activation of cleaved caspase-9/3. Moreover, JS-K-treatment could lead to the activation of protein phosphatase 2A-C (PP2A-C), decrease of anti-apoptotic Bcl-2 family-protein expression including p-Bcl-2 (Ser70), Bcl-2, Bcl-xL, and Mcl-1 as well as the increase of pro-apoptosis Bcl-2 family-protein including Bim, Bad, Bax, and Bak. Furthermore, JS-K caused a marked increase of intracellular NO levels while pre-treatment with Carboxy-PTIO (a NO scavenger) reduced the cytotoxicity effects and the apoptosis rate. Meanwhile, pre-treatment with Carboxy-PTIO attenuated the JS-K-induced up-regulation of PP2A, Cyt c, and cleaved-caspase-9/3 activation. The silencing PP2A-C by siRNA could abolish the activation of PP2A-C, down-regulation of anti-apoptotic Bcl-2 family-protein (p-Bcl-2, Bcl-2, Bcl-xL, and Mcl-1), increase of pro-apoptosis Bcl-2 family-protein (Bim, Bad, Bax, and Bak) and apoptotic-related protein (Cyt c, cleaved caspase-9/3) that were caused by JS-K in HepG2 cells. In addition, pre-treatment with OA (a PP2A inhibitor) also attenuated the above effects induced by JS-K. In summary, NO release from JS-K induces apoptosis through PP2A activation, which contributed to the regulation of Bcl-2 family proteins. © 2018 Wiley Periodicals, Inc.

Regulatory proteins (inhibitors or activators) affect estimates of Msub(r) of enzymes and receptors by radiation inactivation

International Nuclear Information System (INIS)

Potier, M.; Giroux, S.

1985-01-01

The radiation-inactivation method allows the determination of the Msub(r) of enzymes and receptors by monitoring the decay of biological activity as a function of absorbed dose. The presence of regulatory or effector proteins (inhibitors or activators) associated with an enzyme or receptor, or released in the preparation after tissue homogenization, may affect the decay of biological activity. How the activity is affected, however, will depend on the type of inhibition (competitive or non-competitive), the inhibitor or activator concentration, the dissociation constant of the enzyme-effector system, and the effector Msub(r) relative to that of the enzyme. Since little is known on how effector proteins influence radiation inactivation of enzymes and receptors, we have considered a theoretical model in an effort to provide a framework for the interpretation of experimentally obtained data. Our model predicts that competitive and non-competitive inhibitors of enzymes could be distinguished by analysing irradiated samples with various substrate concentrations. Inhibitors will decrease whereas activators will increase the apparent target size of enzymes or receptors. (author)

Pathophysiological changes that affect drug disposition in protein-energy malnourished children

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Oshikoya Kazeem A

2009-12-01

Full Text Available Abstract Protein-energy malnutrition (PEM is a major public health problem affecting a high proportion of infants and older children world-wide and accounts for a high childhood morbidity and mortality in the developing countries. The epidemiology of PEM has been extensively studied globally and management guidelines formulated by the World Health Organization (WHO. A wide spectrum of infections such as measles, malaria, acute respiratory tract infection, intestinal parasitosis, tuberculosis and HIV/AIDS may complicate PEM with two or more infections co-existing. Thus, numerous drugs may be required to treat the patients. In-spite of abundant literature on the epidemiology and management of PEM, focus on metabolism and therapeutic drug monitoring is lacking. A sound knowledge of pathophysiology of PEM and pharmacology of the drugs frequently used for their treatment is required for safe and rational treatment. In this review, we discuss the pathophysiological changes in children with PEM that may affect the disposition of drugs frequently used for their treatment. This review has established abnormal disposition of drugs in children with PEM that may require dosage modification. However, the relevance of these abnormalities to the clinical management of PEM remains inconclusive. At present, there are no good indications for drug dosage modification in PEM; but for drug safety purposes, further studies are required to accurately determine dosages of drugs frequently used for children with PEM.

Intraepithelial and interstitial deposition of pathological prion protein in kidneys of scrapie-affected sheep.

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Ciriaco Ligios

Full Text Available Prions have been documented in extra-neuronal and extra-lymphatic tissues of humans and various ruminants affected by Transmissible Spongiform Encephalopathy (TSE. The presence of prion infectivity detected in cervid and ovine blood tempted us to reason that kidney, the organ filtrating blood derived proteins, may accumulate disease associated PrP(Sc. We collected and screened kidneys of experimentally, naturally scrapie-affected and control sheep for renal deposition of PrP(Sc from distinct, geographically separated flocks. By performing Western blot, PET blot analysis and immunohistochemistry we found intraepithelial (cortex, medulla and papilla and occasional interstitial (papilla deposition of PrP(Sc in kidneys of scrapie-affected sheep. Interestingly, glomerula lacked detectable signals indicative of PrP(Sc. PrP(Sc was also detected in kidneys of subclinical sheep, but to significantly lower degree. Depending on the stage of the disease the incidence of PrP(Sc in kidney varied from approximately 27% (subclinical to 73.6% (clinical in naturally scrapie-affected sheep. Kidneys from flocks without scrapie outbreak were devoid of PrP(Sc. Here we demonstrate unexpectedly frequent deposition of high levels of PrP(Sc in ovine kidneys of various flocks. Renal deposition of PrP(Sc is likely to be a pre-requisite enabling prionuria, a possible co-factor of horizontal prion-transmission in sheep.

Lipid Bilayer Composition Affects Transmembrane Protein Orientation and Function

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Katie D. Hickey

2011-01-01

Full Text Available Sperm membranes change in structure and composition upon ejaculation to undergo capacitation, a molecular transformation which enables spermatozoa to undergo the acrosome reaction and be capable of fertilization. Changes to the membrane environment including lipid composition, specifically lipid microdomains, may be responsible for enabling capacitation. To study the effect of lipid environment on proteins, liposomes were created using lipids extracted from bull sperm membranes, with or without a protein (Na+ K+-ATPase or -amylase. Protein incorporation, function, and orientation were determined. Fluorescence resonance energy transfer (FRET confirmed protein inclusion in the lipid bilayer, and protein function was confirmed using a colourometric assay of phosphate production from ATP cleavage. In the native lipid liposomes, ATPase was oriented with the subunit facing the outer leaflet, while changing the lipid composition to 50% native lipids and 50% exogenous lipids significantly altered this orientation of Na+ K+-ATPase within the membranes.

Aggregation of polyQ proteins is increased upon yeast aging and affected by Sir2 and Hsf1: novel quantitative biochemical and microscopic assays.

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Aviv Cohen

Full Text Available Aging-related neurodegenerative disorders, such as Parkinson's, Alzheimer's and Huntington's diseases, are characterized by accumulation of protein aggregates in distinct neuronal cells that eventually die. In Huntington's disease, the protein huntingtin forms aggregates, and the age of disease onset is inversely correlated to the length of the protein's poly-glutamine tract. Using quantitative assays to estimate microscopically and capture biochemically protein aggregates, here we study in Saccharomyces cerevisiae aging-related aggregation of GFP-tagged, huntingtin-derived proteins with different polyQ lengths. We find that the short 25Q protein never aggregates whereas the long 103Q version always aggregates. However, the mid-size 47Q protein is soluble in young logarithmically growing yeast but aggregates as the yeast cells enter the stationary phase and age, allowing us to plot an "aggregation timeline". This aging-dependent aggregation was associated with increased cytotoxicity. We also show that two aging-related genes, SIR2 and HSF1, affect aggregation of the polyQ proteins. In Δsir2 strain the aging-dependent aggregation of the 47Q protein is aggravated, while overexpression of the transcription factor Hsf1 attenuates aggregation. Thus, the mid-size 47Q protein and our quantitative aggregation assays provide valuable tools to unravel the roles of genes and environmental conditions that affect aging-related aggregation.

Mutations in the RNA-binding domains of tombusvirus replicase proteins affect RNA recombination in vivo

International Nuclear Information System (INIS)

Panaviene, Zivile; Nagy, Peter D.

2003-01-01

RNA recombination, which is thought to occur due to replicase errors during viral replication, is one of the major driving forces of virus evolution. In this article, we show evidence that the replicase proteins of Cucumber necrosis virus, a tombusvirus, are directly involved in RNA recombination in vivo. Mutations within the RNA-binding domains of the replicase proteins affected the frequency of recombination observed with a prototypical defective-interfering (DI) RNA, a model template for recombination studies. Five of the 17 replicase mutants tested showed delay in the formation of recombinants when compared to the wild-type helper virus. Interestingly, two replicase mutants accelerated recombinant formation and, in addition, these mutants also increased the level of subgenomic RNA synthesis (Virology 308 (2003), 191-205). A trans-complementation system was used to demonstrate that mutation in the p33 replicase protein resulted in altered recombination rate. Isolated recombinants were mostly imprecise (nonhomologous), with the recombination sites clustered around a replication enhancer region and a putative cis-acting element, respectively. These RNA elements might facilitate the proposed template switching events by the tombusvirus replicase. Together with data in the article cited above, results presented here firmly establish that the conserved RNA-binding motif of the replicase proteins is involved in RNA replication, subgenomic RNA synthesis, and RNA recombination

An endogenously produced fragment of cardiac myosin-binding protein C is pathogenic and can lead to heart failure.

Science.gov (United States)

Razzaque, Md Abdur; Gupta, Manish; Osinska, Hanna; Gulick, James; Blaxall, Burns C; Robbins, Jeffrey

2013-08-16

A stable 40-kDa fragment is produced from cardiac myosin-binding protein C when the heart is stressed using a stimulus, such as ischemia-reperfusion injury. Elevated levels of the fragment can be detected in the diseased mouse and human heart, but its ability to interfere with normal cardiac function in the intact animal is unexplored. To understand the potential pathogenicity of the 40-kDa fragment in vivo and to investigate the molecular pathways that could be targeted for potential therapeutic intervention. We generated cardiac myocyte-specific transgenic mice using a Tet-Off inducible system to permit controlled expression of the 40-kDa fragment in cardiomyocytes. When expression of the 40-kDa protein is induced by crossing the responder animals with tetracycline transactivator mice under conditions in which substantial quantities approximating those observed in diseased hearts are reached, the double-transgenic mice subsequently experience development of sarcomere dysgenesis and altered cardiac geometry, and the heart fails between 12 and 17 weeks of age. The induced double-transgenic mice had development of cardiac hypertrophy with myofibrillar disarray and fibrosis, in addition to activation of pathogenic MEK-ERK pathways. Inhibition of MEK-ERK signaling was achieved by injection of the mitogen-activated protein kinase (MAPK)/ERK inhibitor U0126. The drug effectively improved cardiac function, normalized heart size, and increased probability of survival. These results suggest that the 40-kDa cardiac myosin-binding protein C fragment, which is produced at elevated levels during human cardiac disease, is a pathogenic fragment that is sufficient to cause hypertrophic cardiomyopathy and heart failure.

N-cadherin in adult rat cardiomyocytes in culture. II. Spatio-temporal appearance of proteins involved in cell-cell contact and communication. Formation of two distinct N-cadherin/catenin complexes.

Science.gov (United States)

Hertig, C M; Butz, S; Koch, S; Eppenberger-Eberhardt, M; Kemler, R; Eppenberger, H M

1996-01-01

The spatio-temporal appearance and distribution of proteins forming the intercalated disc were investigated in adult rat cardiomyocytes (ARC). The 'redifferentiation model' of ARC involves extensive remodelling of the plasma membrane and of the myofibrillar apparatus. It represents a valuable system to elucidate the formation of cell-cell contact between cardiomyocytes and to assess the mechanisms by which different proteins involved in the cell-cell adhesion process are sorted in a precise manner to the sites of function. Appearance of N-cadherin, the catenins and connexin43 within newly formed adherens and gap junctions was studied. Here first evidence is provided for a formation of two distinct and separable N-cadherin/catenin complexes in cardiomyocytes. Both complexes are composed of N-cadherin and alpha-catenin which bind to either beta-catenin or plakoglobin in a mutually exclusive manner. The two N-cadherin/catenin complexes are assumed to be functionally involved in the formation of cell-cell contacts in ARC; however, the differential appearance and localization of the two types of complexes may also point to a specific role during ARC differentiation. The newly synthesized beta-catenin containing complex is more abundant during the first stages in culture after ARC isolation, while the newly synthesized plakoglobin containing complex progressively accumulates during the morphological changes of ARC. ARC formed a tissue-like pattern in culture whereby the new cell-cell contacts could be dissolved through Ca2+ depletion. Presence of cAMP and replenishment of Ca2+ content in the culture medium not only allowed reformation of cell-cell contacts but also affected the relative protein ratio between the two N-cadherin/catenin complexes, increasing the relative amount of newly synthesized beta-catenin over plakoglobin at a particular stage of ARC differentiation. The clustered N-cadherin/catenin complexes at the plasma membrane appear to be a prerequisite for the

Hepatic expression of the GH/JAK/STAT/IGF pathway, acute-phase response signalling and complement system are affected in mouse offspring by prenatal and early postnatal exposure to maternal high-protein diet.

Science.gov (United States)

Vanselow, Jens; Kucia, Marzena; Langhammer, Martina; Koczan, Dirk; Rehfeldt, Charlotte; Metges, Cornelia C

2011-12-01

Effects of pre- and early postnatal exposure to maternal high-protein diets are not well understood. Transcription profiling was performed in male mouse offspring exposed to maternal high-protein diet during pregnancy and/or lactation to identify affected hepatic molecular pathways. Dams were fed isoenergetic diets with control (20% w/w) or high protein levels (40%). The hepatic expression profiles were evaluated by differential microarray analysis 3 days (d3) and 3 weeks (d21) after birth. Offspring from three different high-protein dietary groups, HP (d3, high-protein diet during pregnancy), HPHP (d21, high-protein diet during pregnancy and lactation) and CHP (d21, control diet during pregnancy and high-protein diet during lactation), were compared with age-matched offspring from dams fed control diet. Offspring body and liver mass of all high-protein groups were decreased. Prenatal high-protein diet affected hepatic expression of genes mapping to the acute response/complement system and the GH/JAK/STAT/IGF signalling pathways. Maternal exposure to high-protein diet during lactation affected hepatic gene expression of the same pathways but additionally affected genes mapping to protein, fatty acid, hexose and pyruvate metabolism. (1) Genes of the acute response/complement system and GH/JAK/STAT/IGF pathways were down-regulated in offspring of dams exposed to high-protein diets during pregnancy and/or lactation. (2) Genes related to nutrient and energy metabolism, however, were only affected when high-protein diet was administered during lactation. (3) Modulation of the GH/JAK/STAT/IGF pathway might be responsible for reduced body and liver masses by maternal high-protein diet.

Two desmin gene mutations associated with myofibrillar myopathies in Polish families.

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Jakub Piotr Fichna

Full Text Available Desmin is a muscle-specific intermediate filament protein which forms a network connecting the sarcomere, T tubules, sarcolemma, nuclear membrane, mitochondria and other organelles. Mutations in the gene coding for desmin (DES cause skeletal myopathies often combined with cardiomyopathy, or isolated cardiomyopathies. The molecular pathomechanisms of the disease remain ambiguous. Here, we describe and comprehensively characterize two DES mutations found in Polish patients with a clinical diagnosis of desminopathy. The study group comprised 16 individuals representing three families. Two mutations were identified: a novel missense mutation (Q348P and a small deletion of nine nucleotides (A357_E359del, previously described by us in the Polish population. A common ancestry of all the families bearing the A357_E359del mutation was confirmed. Both mutations were predicted to be pathogenic using a bioinformatics approach, including molecular dynamics simulations which helped to rationalize abnormal behavior at molecular level. To test the impact of the mutations on DES expression and the intracellular distribution of desmin muscle biopsies were investigated. Elevated desmin levels as well as its atypical localization in muscle fibers were observed. Additional staining for M-cadherin, α-actinin, and myosin heavy chains confirmed severe disruption of myofibrill organization. The abnormalities were more prominent in the Q348P muscle, where both small atrophic fibers as well large fibers with centrally localized nuclei were observed. We propose that the mutations affect desmin structure and cause its aberrant folding and subsequent aggregation, triggering disruption of myofibrils organization.

Two Desmin Gene Mutations Associated with Myofibrillar Myopathies in Polish Families

Science.gov (United States)

Berdynski, Mariusz; Sikorska, Agata; Filipek, Slawomir; Redowicz, Maria Jolanta; Kaminska, Anna; Zekanowski, Cezary

2014-01-01

Desmin is a muscle-specific intermediate filament protein which forms a network connecting the sarcomere, T tubules, sarcolemma, nuclear membrane, mitochondria and other organelles. Mutations in the gene coding for desmin (DES) cause skeletal myopathies often combined with cardiomyopathy, or isolated cardiomyopathies. The molecular pathomechanisms of the disease remain ambiguous. Here, we describe and comprehensively characterize two DES mutations found in Polish patients with a clinical diagnosis of desminopathy. The study group comprised 16 individuals representing three families. Two mutations were identified: a novel missense mutation (Q348P) and a small deletion of nine nucleotides (A357_E359del), previously described by us in the Polish population. A common ancestry of all the families bearing the A357_E359del mutation was confirmed. Both mutations were predicted to be pathogenic using a bioinformatics approach, including molecular dynamics simulations which helped to rationalize abnormal behavior at molecular level. To test the impact of the mutations on DES expression and the intracellular distribution of desmin muscle biopsies were investigated. Elevated desmin levels as well as its atypical localization in muscle fibers were observed. Additional staining for M-cadherin, α-actinin, and myosin heavy chains confirmed severe disruption of myofibrill organization. The abnormalities were more prominent in the Q348P muscle, where both small atrophic fibers as well large fibers with centrally localized nuclei were observed. We propose that the mutations affect desmin structure and cause its aberrant folding and subsequent aggregation, triggering disruption of myofibrils organization. PMID:25541946

Molecular characterization of a long range haplotype affecting protein yield and mastitis susceptibility in Norwegian Red cattle

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Hayes Ben J

2011-08-01

Full Text Available Abstract Background Previous fine mapping studies in Norwegian Red cattle (NRC in the region 86-90.4 Mb on Bos taurus chromosome 6 (BTA6 has revealed a quantitative trait locus (QTL for protein yield (PY around 88 Mb and a QTL for clinical mastitis (CM around 90 Mb. The close proximity of these QTLs may partly explain the unfavorable genetic correlation between these two traits in NRC. A long range haplotype covering this region was introduced into the NRC population through the importation of a Holstein-Friesian bull (1606 Frasse from Sweden in the 1970s. It has been suggested that this haplotype has a favorable effect on milk protein content but an unfavorable effect on mastitis susceptibility. Selective breeding for milk production traits is likely to have increased the frequency of this haplotype in the NRC population. Results Association mapping for PY and CM in NRC was performed using genotypes from 556 SNPs throughout the region 86-97 Mb on BTA6 and daughter-yield-deviations (DYDs from 2601 bulls made available from the Norwegian dairy herd recording system. Highest test scores for PY were found for single-nucleotide polymorphisms (SNPs within and surrounding the genes CSN2 and CSN1S2, coding for the β-casein and αS2-casein proteins. High coverage re-sequencing by high throughput sequencing technology enabled molecular characterization of a long range haplotype from 1606 Frasse encompassing these two genes. Haplotype analysis of a large number of descendants from this bull indicated that the haplotype was not markedly disrupted by recombination in this region. The haplotype was associated with both increased milk protein content and increased susceptibility to mastitis, which might explain parts of the observed genetic correlation between PY and CM in NRC. Plausible causal polymorphisms affecting PY were detected in the promoter region and in the 5'-flanking UTR of CSN1S2. These polymorphisms could affect transcription or translation of

Proteolytic activities in fillets of selected underutilized Australian fish species.

Science.gov (United States)

Ahmed, Z; Donkor, O; Street, W A; Vasiljevic, T

2013-09-01

The hydrolytic activity of major endogenous proteases, responsible for proteolysis of myofibrillar proteins during post-mortem storage, may be an indicator of the textural quality of fish which influences consumer purchasing behaviour and thus market value of the final product. Furthermore, it may also influence the type and bioactive properties of the peptides released during post-mortem proteolysis of myofibrillar proteins. This study compared the activities of cathepsins B, B+L, D, H and calpain-like enzymes in crude muscle extracted from 16 Australian underutilized fish species. Fish species had a significant effect on the activity of these enzymes with barracouta showing the highest cathepsins B, B+L, D and H activities. Activities of cathepsins B and B+L were higher than cathepsin H for all studied species. The more commercially important rock ling and tiger flathead demonstrated higher cathepsin B+L activity, whereas gemfish and eastern school whiting showed higher activity towards cathepsin B. Underutilized fish species showing higher endogenous protease activities may be suitable for fish sauce production, whereas those with lower protease activities for surimi processing. Copyright © 2013 Elsevier Ltd. All rights reserved.

Functional and rheological properties of proteins in frozen turkey breast meat with different ultimate pH.

Science.gov (United States)

Chan, J T Y; Omana, D A; Betti, M

2011-05-01

Functional and rheological properties of proteins from frozen turkey breast meat with different ultimate pH at 24 h postmortem (pH(24)) have been studied. Sixteen breast fillets from Hybrid Tom turkeys were initially selected based on lightness (L*) values for each color group (pale, normal, and dark), with a total of 48 breast fillets. Further selection of 8 breast samples was made within each class of meat according to the pH(24). The average L* and pH values of the samples were within the following range: pale (L* >52; pH ≤5.7), normal (46 meat, respectively. Ultimate pH did not cause major changes in the emulsifying and foaming properties of the extracted sarcoplasmic and myofibrillar proteins. An SDS-PAGE profile of proteins from low and normal pH meat was similar, which revealed that the extent of protein denaturation was the same. Low pH meat had the lowest water-holding capacity compared with normal and high pH meat as shown by the increase in cooking loss, which can be explained by factors other than protein denaturation. Gel strength analysis and folding test revealed that gel-forming ability was better for high pH meat compared with low and normal pH meat.Dynamic viscoelastic behavior showed that myosin denaturation temperature was independent of pH(24). Normal and high pH meat had similar hardness, springiness, and chewiness values as revealed by texture profile analysis. The results from this study indicate that high pH meat had similar or better functional properties than normal pH meat. Therefore, high pH meat is suitable for further processed products, whereas low pH meat may need additional treatment or ingredient formulations to improve its functionality.

Three regulators of G protein signaling differentially affect mating, morphology and virulence in the smut fungus Ustilago maydis.

Science.gov (United States)

Moretti, Marino; Wang, Lei; Grognet, Pierre; Lanver, Daniel; Link, Hannes; Kahmann, Regine

2017-09-01

Regulators of G protein signaling (RGS) proteins modulate heterotrimeric G protein signaling negatively. To broaden an understanding of the roles of RGS proteins in fungal pathogens, we functionally characterized the three RGS protein-encoding genes (rgs1, rgs2 and rgs3) in the phytopathogenic fungus Ustilago maydis. It was found that RGS proteins played distinct roles in the regulation of development and virulence. rgs1 had a minor role in virulence when deleted in a solopathogenic strain. In crosses, rgs1 was dispensable for mating and filamentation, but was required for teliospore production. Haploid rgs2 mutants were affected in cell morphology, growth, mating and were unable to cause disease symptoms in crosses. However, virulence was unaffected when rgs2 was deleted in a solopathogenic strain, suggesting an exclusive involvement in pre-fusion events. These rgs2 phenotypes are likely connected to elevated intracellular cAMP levels. rgs3 mutants were severely attenuated in mating, in their response to pheromone, virulence and formation of mature teliospores. The mating defect could be traced back to reduced expression of the transcription factor rop1. It was speculated that the distinct roles of the three U. maydis RGS proteins were achieved by direct modulation of the Gα subunit-activated signaling pathways as well as through Gα-independent functions. © 2017 John Wiley & Sons Ltd.

Maternal protein restriction affects gene expression and enzyme activity of intestinal disaccharidases in adult rat offspring

International Nuclear Information System (INIS)

Pinheiro, D.F.; Pacheco, P.D.G.; Alvarenga, P.V.; Buratini, J. Jr; Castilho, A.C.S.; Lima, P.F.; Sartori, D.R.S.; Vicentini-Paulino, M.L.M.

2013-01-01

This study investigated the consequences of intrauterine protein restriction on the gastrointestinal tract and particularly on the gene expression and activity of intestinal disaccharidases in the adult offspring. Wistar rat dams were fed isocaloric diets containing 6% protein (restricted, n = 8) or 17% protein (control, n = 8) throughout gestation. Male offspring (n = 5-8 in each group) were evaluated at 3 or 16 weeks of age. Maternal protein restriction during pregnancy produced offspring with growth restriction from birth (5.7 ± 0.1 vs 6.3 ± 0.1 g; mean ± SE) to weaning (42.4 ± 1.3 vs 49.1 ± 1.6 g), although at 16 weeks of age their body weight was similar to control (421.7 ± 8.9 and 428.5 ± 8.5 g). Maternal protein restriction also increased lactase activity in the proximal (0.23 ± 0.02 vs 0.15 ± 0.02), medial (0.30 ± 0.06 vs 0.14 ± 0.01) and distal (0.43 ± 0.07 vs 0.07 ± 0.02 U·g -1 ·min -1 ) small intestine, and mRNA lactase abundance in the proximal intestine (7.96 ± 1.11 vs 2.38 ± 0.47 relative units) of 3-week-old offspring rats. In addition, maternal protein restriction increased sucrase activity (1.20 ± 0.02 vs 0.91 ± 0.02 U·g -1 ·min -1 ) and sucrase mRNA abundance (4.48 ± 0.51 vs 1.95 ± 0.17 relative units) in the duodenum of 16-week-old rats. In conclusion, the present study shows for the first time that intrauterine protein restriction affects gene expression of intestinal enzymes in offspring

Maternal protein restriction affects gene expression and enzyme activity of intestinal disaccharidases in adult rat offspring

Energy Technology Data Exchange (ETDEWEB)

Pinheiro, D.F.; Pacheco, P.D.G.; Alvarenga, P.V.; Buratini, J. Jr; Castilho, A.C.S.; Lima, P.F.; Sartori, D.R.S.; Vicentini-Paulino, M.L.M. [Departamento de Fisiologia, Instituto de Biociências, Universidade Estadual Paulista, Botucatu, SP (Brazil)

2013-03-15

This study investigated the consequences of intrauterine protein restriction on the gastrointestinal tract and particularly on the gene expression and activity of intestinal disaccharidases in the adult offspring. Wistar rat dams were fed isocaloric diets containing 6% protein (restricted, n = 8) or 17% protein (control, n = 8) throughout gestation. Male offspring (n = 5-8 in each group) were evaluated at 3 or 16 weeks of age. Maternal protein restriction during pregnancy produced offspring with growth restriction from birth (5.7 ± 0.1 vs 6.3 ± 0.1 g; mean ± SE) to weaning (42.4 ± 1.3 vs 49.1 ± 1.6 g), although at 16 weeks of age their body weight was similar to control (421.7 ± 8.9 and 428.5 ± 8.5 g). Maternal protein restriction also increased lactase activity in the proximal (0.23 ± 0.02 vs 0.15 ± 0.02), medial (0.30 ± 0.06 vs 0.14 ± 0.01) and distal (0.43 ± 0.07 vs 0.07 ± 0.02 U·g{sup -1}·min{sup -1}) small intestine, and mRNA lactase abundance in the proximal intestine (7.96 ± 1.11 vs 2.38 ± 0.47 relative units) of 3-week-old offspring rats. In addition, maternal protein restriction increased sucrase activity (1.20 ± 0.02 vs 0.91 ± 0.02 U·g{sup -1}·min{sup -1}) and sucrase mRNA abundance (4.48 ± 0.51 vs 1.95 ± 0.17 relative units) in the duodenum of 16-week-old rats. In conclusion, the present study shows for the first time that intrauterine protein restriction affects gene expression of intestinal enzymes in offspring.

Human I-mfa domain proteins specifically interact with KSHV LANA and affect its regulation of Wnt signaling-dependent transcription

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Kusano, Shuichi, E-mail: skusano@m2.kufm.kagoshima-u.ac.jp [Division of Persistent and Oncogenic Viruses, Center for Chronic Viral Diseases, Graduate School of Medical and Dental Sciences, Kagoshima University, 8-35-1 Sakuragaoka, Kagoshima 890-8544 (Japan); Eizuru, Yoshito [Division of Persistent and Oncogenic Viruses, Center for Chronic Viral Diseases, Graduate School of Medical and Dental Sciences, Kagoshima University, 8-35-1 Sakuragaoka, Kagoshima 890-8544 (Japan)

2010-06-04

Kaposi's sarcoma-associated herpes virus (KSHV)-encoded latency-associated nuclear antigen (LANA) protein has been reported to interact with glycogen synthase kinase 3{beta} (GSK-3{beta}) and to negatively regulate its activity, leading to stimulation of GSK-3{beta}-dependent {beta}-catenin degradation. We show here that the I-mfa domain proteins, HIC (human I-mfa domain-containing protein) and I-mfa (inhibitor of MyoD family a), interacted in vivo with LANA through their C-terminal I-mfa domains. This interaction affected the intracellular localization of HIC, inhibited the LANA-dependent transactivation of a {beta}-catenin-regulated reporter construct, and decreased the level of the LANA.GSK-3{beta} complex. These data reveal for the first time that I-mfa domain proteins interact with LANA and negatively regulate LANA-mediated activation of Wnt signaling-dependent transcription by inhibiting the formation of the LANA.GSK-3{beta} complex.

Proteome Changes in biceps femoris Muscle of Iranian One-Humped Camel and Their Effect on Meat Quality Traits

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Mohammad-Javad Varidi

2016-01-01

Full Text Available In this study physicochemical and quality traits of biceps femoris and longissimus thoracis muscles of male and female Iranian one-humped camel were determined during 14 days of refrigeration storage. Analysis of variance of the results showed that only shear force and temperature were affected by the gender (p<0.05. Anatomical location of the muscle influenced the meat properties except for drip loss (p<0.05. Also, except for cooking loss, ageing influenced the physicochemical and quality properties of meat; during 14 days of storage, proteolysis resulted in an increase of L* and b* values, drip loss and myofibrillar fragmentation index, and the decrease of a* value, expressed juice, shear force and sarcomere length. Proteome changes (myofi brillar proteins during storage were investigated. Gel analysis revealed that 19 protein spots were signifi cantly changed during 24, 72 and 168 h post-mortem. Fifteen spots were identified by MALDI-TOF/TOF mass spectrometer. Correlation analysis revealed significant correlations of actin, troponin T, capping protein, heat shock proteins (HSP and desmin with physicochemical and quality properties of meat (p<0.05. Actin might be a potential protein marker for colour, tenderness and water-holding capacity, and HSP27 and desmin are good candidate markers for colour and tenderness, respectively.

Mild hypothermic culture conditions affect residual host cell protein composition post-Protein A chromatography.

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Goey, Cher Hui; Bell, David; Kontoravdi, Cleo

2018-04-01

Host cell proteins (HCPs) are endogenous impurities, and their proteolytic and binding properties can compromise the integrity, and, hence, the stability and efficacy of recombinant therapeutic proteins such as monoclonal antibodies (mAbs). Nonetheless, purification of mAbs currently presents a challenge because they often co-elute with certain HCP species during the capture step of protein A affinity chromatography. A Quality-by-Design (QbD) strategy to overcome this challenge involves identifying residual HCPs and tracing their source to the harvested cell culture fluid (HCCF) and the corresponding cell culture operating parameters. Then, problematic HCPs in HCCF may be reduced by cell engineering or culture process optimization. Here, we present experimental results linking cell culture temperature and post-protein A residual HCP profile. We had previously reported that Chinese hamster ovary cell cultures conducted at standard physiological temperature and with a shift to mild hypothermia on day 5 produced HCCF of comparable product titer and HCP concentration, but with considerably different HCP composition. In this study, we show that differences in HCP variety at harvest cascaded to downstream purification where different residual HCPs were present in the two sets of samples post-protein A purification. To detect low-abundant residual HCPs, we designed a looping liquid chromatography-mass spectrometry method with continuous expansion of a preferred, exclude, and targeted peptide list. Mild hypothermic cultures produced 20% more residual HCP species, especially cell membrane proteins, distinct from the control. Critically, we identified that half of the potentially immunogenic residual HCP species were different between the two sets of samples.

Phenylalanine flux and gastric emptying are not affected by replacement of casein with whey protein in the diet of adult cats consuming frequent small meals.

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Tycholis, Tanya J; Cant, John P; Osborne, Vern R; Shoveller, Anna K

2014-08-12

Decreasing the rate of protein emptying from the stomach may improve efficiency of utilization of dietary amino acids for protein deposition. Some studies in rats and humans have shown casein to be more slowly released from the stomach than whey protein. To test if casein induces a slower rate of gastric emptying in cats than whey protein, L-[1-(13)C]phenylalanine (Phe) was dosed orally into 9 adult cats to estimate gastric emptying and whole-body Phe flux. Concentrations of indispensable amino acids in plasma were not significantly affected by dietary protein source. First-pass splanchnic extraction of Phe was not different between diets and averaged 50% (SEM = 3.8%). The half-time for gastric emptying averaged 9.9 min with casein and 10.3 min with whey protein, and was not significantly different between diets (SEM = 1.7 min). Phenylalanine fluxes were 45.3 and 46.5 μmol/(min · kg) for casein- and whey-based diets, respectively (SEM = 4.7 μmol/(min · kg)). In adult cats fed frequent small meals, the replacement of casein with whey protein in the diet does not affect supply or utilization of amino acids. These two milk proteins appear to be equally capable of meeting the dietary amino acid needs of cats.

Expression of cell cycle proteins according to HPV status in oral squamous cell carcinoma affecting young patients: a pilot study.

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Miranda Galvis, Marisol; Freitas Jardim, Juscelino; Kaminagakura, Estela; Santos-Silva, Alan Roger; Paiva Fonseca, Felipe; Paes Almeida, Oslei; Ajudarte Lopes, Marcio; Lópes Pinto, Clóvis; Kowalski, Luiz Paulo

2018-04-01

Tobacco and alcohol consumption are considered the main risk factors for oral squamous cell carcinoma (OSCC); however, the role of these factors in patients younger than 40 years is controversial, so it has been suggested that genomic instability and high-risk human papillomavirus (HR-HPV) infection may be contributing factors to oral carcinogenesis at a young age. Therefore, the aim of this study was to evaluate the immunoexpression of cell cycle proteins according HPV status in OSCC affecting young patients. A tissue microarray construction based on 34 OSCC samples from young patients (factor receptor, p53, and p16 antibodies. The clinicopathologic features and the immunoexpression of all tested proteins were similar in both groups. Patients with HPV-related OSSC tended to have better cancer-specific survival (CSS; 39% vs 60% 5-y CSS), and overall survival (OS; 29.2% vs 60% 5-year OS). However, this difference was not statistically significant. No significant difference exists in the expression of cell cycle proteins studied between HR-HPV DNA-positive and HR-HPV DNA-negative OSCC affecting young patients. Copyright © 2018 Elsevier Inc. All rights reserved.

A novel family of small proteins that affect plant development

Energy Technology Data Exchange (ETDEWEB)

John Charles Walker

2011-04-29

The DVL genes represent a new group of plant proteins that influence plant growth and development. Overexpression of DVL1, and other members of the DVL family, causes striking phenotypic changes. The DVL proteins share sequence homology in their C-terminal half. Point mutations in the C-terminal domain show it is necessary and deletion studies demonstrate the C-terminal domain is sufficient to confer the overexpression phenotypes. The phenotypes observed, and the conservation of the protein sequence in the plant kingdom, does suggest the DVL proteins have a role in modulating plant growth and development. Our working hypothesis is the DVL proteins function as regulators of cellular signaling pathways that control growth and development.

Effect of white striping on chemical composition and nutritional value of chicken breast meat

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Massimiliano Petracci

2014-03-01

Full Text Available White striping defect (appearance of white striations parallel to muscle fiber on surface of breast is considered an emerging issue in chicken breast meat which is related to increasing growth rate of modern hybrid birds. This study was aimed at evaluating the effect of white striping on chemical composition and nutritional value of chicken breast meat. During three replications, a total of 108 Pectoralis major muscles representing three degrees of white striping (absence=normal; presence classified in 2 levels as moderate or severe were selected to determine proximate composition (moisture, protein, lipid and collagen as well as sarcoplasmic and myofibrillar protein profile by sodium dodecyl sulphatepolyacrylamide gel electrophoresis analysis. The results showed that both severe and moderate white-striped fillets had higher fat content (2.53 vs 1.46 vs 0.78%; P<0.001, lower protein level (20.9 vs 22.2 vs 22.9%; P<0.001, decreased quality of protein as proven by higher collagen content (1.30 vs 1.37 vs 1.43%; P<0.001, and different pattern on myofibrillar and sarcoplasmic fractions when compared to normal fillets. Moreover, severe white-striped fillets exhibited higher energy content (450.7 vs 421.1 kJ/100g; P<0.01 with respect to normal meat. In conclusion, there was a large worsening of nutritional value of chicken breast meat following occurrence of white striping and this might impair consumer attitude towards poultry meat.

Glycosaminoglycan sulphation affects the seeded misfolding of a mutant prion protein.

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Victoria A Lawson

Full Text Available BACKGROUND: The accumulation of protease resistant conformers of the prion protein (PrP(res is a key pathological feature of prion diseases. Polyanions, including RNA and glycosaminoglycans have been identified as factors that contribute to the propagation, transmission and pathogenesis of prion disease. Recent studies have suggested that the contribution of these cofactors to prion propagation may be species specific. METHODOLOGY/PRINCIPAL FINDING: In this study a cell-free assay was used to investigate the molecular basis of polyanion stimulated PrP(res formation using brain tissue or cell line derived murine PrP. Enzymatic depletion of endogenous nucleic acids or heparan sulphate (HS from the PrP(C substrate was found to specifically prevent PrP(res formation seeded by mouse derived PrP(Sc. Modification of the negative charge afforded by the sulphation of glycosaminoglycans increased the ability of a familial PrP mutant to act as a substrate for PrP(res formation, while having no effect on PrP(res formed by wildtype PrP. This difference may be due to the observed differences in the binding of wild type and mutant PrP for glycosaminoglycans. CONCLUSIONS/SIGNIFICANCE: Cofactor requirements for PrP(res formation are host species and prion strain specific and affected by disease associated mutations of the prion protein. This may explain both species and strain dependent propagation characteristics and provide insights into the underlying mechanisms of familial prion disease. It further highlights the challenge of designing effective therapeutics against a disease which effects a range of mammalian species, caused by range of aetiologies and prion strains.

The interaction between endogenous 30S ribosomal subunit protein S11 and Cucumber mosaic virus LS2b protein affects viral replication, infection and gene silencing suppressor activity.

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Ruilin Wang

Full Text Available Cucumber mosaic virus (CMV is a model virus for plant-virus protein interaction and mechanism research because of its wide distribution, high-level of replication and simple genome structure. The 2b protein is a multifunctional protein encoded by CMV that suppresses RNA silencing-based antiviral defense and contributes to CMV virulence in host plants. In this report, 12 host proteins were identified as CMV LS2b binding partners using the yeast two-hybrid screen system from the Arabidopsis thaliana cDNA library. Among the host proteins, 30S ribosomal subunit protein S11 (RPS11 was selected for further studies. The interaction between LS2b and full-length RPS11 was confirmed using the yeast two-hybrid system. Bimolecular fluorescence complementation (BIFC assays observed by confocal laser microscopy and Glutathione S-transferase (GST pull-down assays were used to verify the interaction between endogenous NbRPS11 and viral CMVLS2b both in vivo and in vitro. TRV-based gene silencing vector was used to knockdown NbRPS11 transcription, and immunoblot analysis revealed a decline in infectious viral RNA replication and a decrease in CMV infection in RPS11 down-regulated Nicotiana benthamiana plants. Thus, the knockdown of RPS11 likely inhibited CMV replication and accumulation. The gene silencing suppressor activity of CMV2b protein was reduced by the RPS11 knockdown. This study demonstrated that the function of viral LS2b protein was remarkably affected by the interaction with host RPS11 protein.

Fast hydrogen exchange affects 15N relaxation measurements in intrinsically disordered proteins

International Nuclear Information System (INIS)

Kim, Seho; Wu, Kuen-Phon; Baum, Jean

2013-01-01

Unprotected amide protons can undergo fast hydrogen exchange (HX) with protons from the solvent. Generally, NMR experiments using the out-and-back coherence transfer with amide proton detection are affected by fast HX and result in reduced signal intensity. When one of these experiments, 1 H– 15 N HSQC, is used to measure the 15 N transverse relaxation rate (R 2 ), the measured R 2 rate is convoluted with the HX rate (k HX ) and has higher apparent R 2 values. Since the 15 N R 2 measurement is important for analyzing protein backbone dynamics, the HX effect on the R 2 measurement is investigated and described here by multi-exponential signal decay. We demonstrate these effects by performing 15 N R 2 CPMG experiments on α-synuclein, an intrinsically disordered protein, in which the amide protons are exposed to solvent. We show that the HX effect on R 2 CPMG can be extracted by the derived equation. In conclusion, the HX effect may be pulse sequence specific and results from various sources including the J coupling evolution, the change of steady state water proton magnetization, and the D 2 O content in the sample. To avoid the HX effect on the analysis of relaxation data of unprotected amides, it is suggested that NMR experimental conditions insensitive to the HX should be considered or that intrinsic R 2 CPMG values be obtained by methods described herein.

Multifunctional Thioredoxin-Like Protein from the Gastrointestinal Parasitic Nematodes Strongyloides ratti and Trichuris suis Affects Mucosal Homeostasis

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Dana Ditgen

2016-01-01

Full Text Available The cellular redox state is important for the regulation of multiple functions and is essential for the maintenance of cellular homeostasis and antioxidant defense. In the excretory/secretory (E/S products of Strongyloides ratti and Trichuris suis sequences for thioredoxin (Trx and Trx-like protein (Trx-lp were identified. To characterize the antioxidant Trx-lp and its interaction with the parasite’s mucosal habitat, S. ratti and T. suis Trx-lps were cloned and recombinantly expressed. The primary antioxidative activity was assured by reduction of insulin and IgM. Further analysis applying an in vitro mucosal 3D-cell culture model revealed that the secreted Trx-lps were able to bind to monocytic and intestinal epithelial cells and induce the time-dependent release of cytokines such as TNF-α, IL-22, and TSLP. In addition, the redox proteins also possessed chemotactic activity for monocytic THP-1 cells and fostered epithelial wound healing activity. These results confirm that the parasite-secreted Trx-lps are multifunctional proteins that can affect the host intestinal mucosa.

The adsorption of α-amylase on barley proteins affects the in vitro digestion of starch in barley flour.

Science.gov (United States)

Yu, Wenwen; Zou, Wei; Dhital, Sushil; Wu, Peng; Gidley, Michael J; Fox, Glen P; Gilbert, Robert G

2018-02-15

The conversion of barley starch to sugars is a complex enzymic process. Most previous work concerned the biotechnical aspect of in situ barley enzymes. However, the interactions among the macromolecular substrates and their effects on enzymic catalysis has been little examined. Here, we explore the mechanisms whereby interactions of protein and starch in barley flour affect the kinetics of enzymatic hydrolysis of starch in an in vitro system, using digestion rate data and structural analysis by confocal microscopy. The degradation kinetics of both uncooked barley flour and of purified starches are found to be two-step sequential processes. Barley proteins, especially the water-soluble component, are found to retard the digestion of starch degraded by α-amylase: the enzyme binds with water-insoluble protein and with starch granules, leading to reduced starch hydrolysis. These findings are of potential industrial value in both the brewing and food industries. Copyright © 2017 Elsevier Ltd. All rights reserved.

Amino acid profile of metabolisable protein in lactating dairy cows is affected by dry matter concentration in grass-clover silage

DEFF Research Database (Denmark)

Johansen, Marianne; Lund, Peter; Weisbjerg, Martin Riis

2018-01-01

Our previous study showed that supply of metabolisable protein (MP) to lactating dairy cows increased with increasing dry matter (DM) concentration in grass-clover silage. The aim of this study was to examine how amino acid (AA) profile of MP was affected by silage DM concentration. Eight grass-c...

Three-dimensional models of Mycobacterium tuberculosis proteins Rv1555, Rv1554 and their docking analyses with sildenafil, tadalafil, vardenafil drugs, suggest interference with quinol binding likely to affect protein's function.

Science.gov (United States)

Dash, Pallabini; Bala Divya, M; Guruprasad, Lalitha; Guruprasad, Kunchur

2018-04-18

Earlier based on bioinformatics analyses, we had predicted the Mycobacterium tuberculosis (M.tb) proteins; Rv1555 and Rv1554, among the potential new tuberculosis drug targets. According to the 'TB-drugome' the Rv1555 protein is 'druggable' with sildenafil (Viagra), tadalafil (Cialis) and vardenafil (Levitra) drugs. In the present work, we intended to understand via computer modeling studies, how the above drugs are likely to inhibit the M.tb protein's function. The three-dimensional computer models for M.tb proteins; Rv1555 and Rv1554 constructed on the template of equivalent membrane anchor subunits of the homologous E.coli quinol fumarate reductase respiratory protein complex, followed by drug docking analyses, suggested that the binding of above drugs interferes with quinol binding sites. Also, we experimentally observed the in-vitro growth inhibition of E.coli bacteria containing the homologous M.tb protein sequences with sildenafil and tadalafil drugs. The predicted binding sites of the drugs is likely to affect the above M.tb proteins function as quinol binding is known to be essential for electron transfer function during anaerobic respiration in the homologous E.coli protein complex. Therefore, sildenafil and related drugs currently used in the treatment of male erectile dysfunction targeting the human phosphodiesterase 5 enzyme may be evaluated for their plausible role as repurposed drugs to treat human tuberculosis.

Mutation in cyclophilin B that causes hyperelastosis cutis in American Quarter Horse does not affect peptidylprolyl cis-trans isomerase activity but shows altered cyclophilin B-protein interactions and affects collagen folding.

Science.gov (United States)

Ishikawa, Yoshihiro; Vranka, Janice A; Boudko, Sergei P; Pokidysheva, Elena; Mizuno, Kazunori; Zientek, Keith; Keene, Douglas R; Rashmir-Raven, Ann M; Nagata, Kazuhiro; Winand, Nena J; Bächinger, Hans Peter

2012-06-22

The rate-limiting step of folding of the collagen triple helix is catalyzed by cyclophilin B (CypB). The G6R mutation in cyclophilin B found in the American Quarter Horse leads to autosomal recessive hyperelastosis cutis, also known as hereditary equine regional dermal asthenia. The mutant protein shows small structural changes in the region of the mutation at the side opposite the catalytic domain of CypB. The peptidylprolyl cis-trans isomerase activity of the mutant CypB is normal when analyzed in vitro. However, the biosynthesis of type I collagen in affected horse fibroblasts shows a delay in folding and secretion and a decrease in hydroxylysine and glucosyl-galactosyl hydroxylysine. This leads to changes in the structure of collagen fibrils in tendon, similar to those observed in P3H1 null mice. In contrast to cyclophilin B null mice, where little 3-hydroxylation was found in type I collagen, 3-hydroxylation of type I collagen in affected horses is normal. The mutation disrupts the interaction of cyclophilin B with the P-domain of calreticulin, with lysyl hydroxylase 1, and probably other proteins, such as the formation of the P3H1·CypB·cartilage-associated protein complex, resulting in less effective catalysis of the rate-limiting step in collagen folding in the rough endoplasmic reticulum.

Mutation in Cyclophilin B That Causes Hyperelastosis Cutis in American Quarter Horse Does Not Affect Peptidylprolyl cis-trans Isomerase Activity but Shows Altered Cyclophilin B-Protein Interactions and Affects Collagen Folding*

Science.gov (United States)

Ishikawa, Yoshihiro; Vranka, Janice A.; Boudko, Sergei P.; Pokidysheva, Elena; Mizuno, Kazunori; Zientek, Keith; Keene, Douglas R.; Rashmir-Raven, Ann M.; Nagata, Kazuhiro; Winand, Nena J.; Bächinger, Hans Peter

2012-01-01

The rate-limiting step of folding of the collagen triple helix is catalyzed by cyclophilin B (CypB). The G6R mutation in cyclophilin B found in the American Quarter Horse leads to autosomal recessive hyperelastosis cutis, also known as hereditary equine regional dermal asthenia. The mutant protein shows small structural changes in the region of the mutation at the side opposite the catalytic domain of CypB. The peptidylprolyl cis-trans isomerase activity of the mutant CypB is normal when analyzed in vitro. However, the biosynthesis of type I collagen in affected horse fibroblasts shows a delay in folding and secretion and a decrease in hydroxylysine and glucosyl-galactosyl hydroxylysine. This leads to changes in the structure of collagen fibrils in tendon, similar to those observed in P3H1 null mice. In contrast to cyclophilin B null mice, where little 3-hydroxylation was found in type I collagen, 3-hydroxylation of type I collagen in affected horses is normal. The mutation disrupts the interaction of cyclophilin B with the P-domain of calreticulin, with lysyl hydroxylase 1, and probably other proteins, such as the formation of the P3H1·CypB·cartilage-associated protein complex, resulting in less effective catalysis of the rate-limiting step in collagen folding in the rough endoplasmic reticulum. PMID:22556420

Modulation of mammary gland development in pre-pubertal mice as affected by soya and milk protein supplements.

Science.gov (United States)

Alston-Mills, Brenda; Lepri, J J; Martin, C A

2011-08-01

The objective of the present study was to determine the effects of soya and whey milk protein, α-lactalbumin (α-LA), on mammary gland morphology and the structural support of the gland, in pre-pubertal mice after 7 d of treatment. In Expt 1, weaned (day 21) CD1 mice were given one of the four treatments, three included dietary supplements: (1) control diet, casein, (2) soya, (3) α-LA and (4) subcutaneous injection of 2·5 μg oestradiol benzoate in 20 μl maize oil and fed the control diet. All diets were isoenergetic with equal protein concentrations. All groups that were not treated with oestradiol received the vehicle. Whole-mount analyses were performed to determine longitudinal ductal growth and terminal end bud development. DNA was extracted from the gland and assessed by spectrophotometry (260/280 nm). Tissue extracts for extracellular matrix (ECM) proteins, matrix metalloproteinase-2 (MMP(2)), tissue inhibitor of MMP(2) (TIMP(2)), and serum oestradiol and mammary tissue epidermal growth factors (EGF) were measured by immunoassays. Expt 2 utilised the Her2/neu transgenic strain, with the same protocols. Statistical significance was determined by one-way ANOVA. From Expt 1 and 2, soya and α-LA significantly increased ductal elongation when compared with the oestrogen and control groups. These results were corroborated by data on total DNA and the ratio of MMP(2):TIMP(2). The ratio of MMP(2):TIMP(2) was affected by α-LA. Serum oestradiol was decreased only in the oestradiol-treated groups in both experiments. Soya is known to be oestrogenic and can act on epithelia directly. The mechanism by which α-LA affects glandular development is by modulating the ECM or by promoting the synthesis/activity of EGF.

High-mobility group (HMG) protein HMG-1 and TATA-binding protein-associated factor TAF(II)30 affect estrogen receptor-mediated transcriptional activation.

Science.gov (United States)

Verrier, C S; Roodi, N; Yee, C J; Bailey, L R; Jensen, R A; Bustin, M; Parl, F F

1997-07-01

The estrogen receptor (ER) belongs to a family of ligand-inducible nuclear receptors that exert their effects by binding to cis-acting DNA elements in the regulatory region of target genes. The detailed mechanisms by which ER interacts with the estrogen response element (ERE) and affects transcription still remain to be elucidated. To study the ER-ERE interaction and transcription initiation, we employed purified recombinant ER expressed in both the baculovirus-Sf9 and his-tagged bacterial systems. The effect of high-mobility group (HMG) protein HMG-1 and purified recombinant TATA-binding protein-associated factor TAF(II)30 on ER-ERE binding and transcription initiation were assessed by electrophoretic mobility shift assay and in vitro transcription from an ERE-containing template (pERE2LovTATA), respectively. We find that purified, recombinant ER fails to bind to ERE in spite of high ligand-binding activity and electrophoretic and immunological properties identical to ER in MCF-7 breast cancer cells. HMG-1 interacts with ER and promotes ER-ERE binding in a concentration- and time-dependent manner. The effectiveness of HMG-1 to stimulate ER-ERE binding in the electrophoretic mobility shift assay depends on the sequence flanking the ERE consensus as well as the position of the latter in the oligonucleotide. We find that TAF(II)30 has no effect on ER-ERE binding either alone or in combination with ER and HMG-1. Although HMG-1 promotes ER-ERE binding, it fails to stimulate transcription initiation either in the presence or absence of hormone. In contrast, TAF(II)30, while not affecting ER-ERE binding, stimulates transcription initiation 20-fold in the presence of HMG-1. These results indicate that HMG-1 and TAF(II)30 act in sequence, the former acting to promote ER-ERE binding followed by the latter to stimulate transcription initiation.

Alpha-phellandrene-induced DNA damage and affect DNA repair protein expression in WEHI-3 murine leukemia cells in vitro.

Science.gov (United States)

Lin, Jen-Jyh; Wu, Chih-Chung; Hsu, Shu-Chun; Weng, Shu-Wen; Ma, Yi-Shih; Huang, Yi-Ping; Lin, Jaung-Geng; Chung, Jing-Gung

2015-11-01

Although there are few reports regarding α-phellandrene (α-PA), a natural compound from Schinus molle L. essential oil, there is no report to show that α-PA induced DNA damage and affected DNA repair associated protein expression. Herein, we investigated the effects of α-PA on DNA damage and repair associated protein expression in murine leukemia cells. Flow cytometric assay was used to measure the effects of α-PA on total cell viability and the results indicated that α-PA induced cell death. Comet assay and 4,6-diamidino-2-phenylindole dihydrochloride staining were used for measuring DNA damage and condensation, respectively, and the results indicated that α-PA induced DNA damage and condensation in a concentration-dependent manner. DNA gel electrophoresis was used to examine the DNA damage and the results showed that α-PA induced DNA damage in WEHI-3 cells. Western blotting assay was used to measure the changes of DNA damage and repair associated protein expression and the results indicated that α-PA increased p-p53, p-H2A.X, 14-3-3-σ, and MDC1 protein expression but inhibited the protein of p53, MGMT, DNA-PK, and BRCA-1. © 2014 Wiley Periodicals, Inc.

Altering adsorbed proteins or cellular gene expression in bone-metastatic cancer cells affects PTHrP and Gli2 without altering cell growth

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Jonathan M. Page

2015-09-01

Full Text Available The contents of this data in brief are related to the article titled “Matrix Rigidity Regulates the Transition of Tumor Cells to a Bone-Destructive Phenotype through Integrin β3 and TGF-β Receptor Type II”. In this DIB we will present our supplemental data investigating Integrin expression, attachment of cells to various adhesion molecules, and changes in gene expression in multiple cancer cell lines. Since the interactions of Integrins with adsorbed matrix proteins are thought to affect the ability of cancer cells to interact with their underlying substrates, we examined the expression of Integrin β1, β3, and β5 in response to matrix rigidity. We found that only Iβ3 increased with increasing substrate modulus. While it was shown that fibronectin greatly affects the expression of tumor-produced factors associated with bone destruction (parathyroid hormone-related protein, PTHrP, and Gli2, poly-l-lysine, vitronectin and type I collagen were also analyzed as potential matrix proteins. Each of the proteins was independently adsorbed on both rigid and compliant polyurethane films which were subsequently used to culture cancer cells. Poly-l-lysine, vitronectin and type I collagen all had negligible effects on PTHrP or Gli2 expression, but fibronectin was shown to have a dose dependent effect. Finally, altering the expression of Iβ3 demonstrated that it is required for tumor cells to respond to the rigidity of the matrix, but does not affect other cell growth or viability. Together these data support the data presented in our manuscript to show that the rigidity of bone drives Integrinβ3/TGF-β crosstalk, leading to increased expression of Gli2 and PTHrP.

Effect of confinement and starvation on stress parameters in the American lobster (Homarus americanus

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Edo D'Agaro

2014-12-01

Full Text Available The American lobster (Homarus americanus is one of the most important crustacean resources in North America. In Italy and Europe, this fishery product is available throughout the year and it has a high and increasing commercial demand. American lobsters are traditionally marketed live and stocked, without feed, in temperature controlled recirculating systems for several weeks before being sold in the market places. The current Italian legislation does not fix a maximum length of time for the crustacean confinement and specific welfare requirements. In the present research, a 4-week experiment was carried out using 42 adult H. americanus reared in 4 recirculating aquaculture tanks. After one month of confinement, mean glucose, protein and total haemocyte count levels in the hemolymph of H. americanus were stable and similar (P>0.05 to the values observed at the beginning of the experiment. Results of the proximate analysis of the abdominal muscles of H. americanus showed no significant differences in concentrations of crude protein, lipid and ash during the trial. At the end of the experiment, the sodium dodecyl sulfate-polyacrylamide gel electrophoresis and Western blotting analysis revealed a marked degradation of the muscle myofibrillar proteins. A number of fragments, possibly from myosin, were evident in the range between 50 and 220 kDa between time t0 and t28. Results of this study show that the main hemolymphatic variables and degradation analysis of the muscle myofibrillar proteins can be used as sensitive indicators of the crustacean stress response to confinement and starvation.

Myofibrillar troponin exists in three states and there is signal transduction along skeletal myofibrillar thin filaments.

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Swartz, Darl R; Yang, Zhenyun; Sen, Asok; Tikunova, Svetlana B; Davis, Jonathan P

2006-08-18

Activation of striated muscle contraction is a highly cooperative signal transduction process converting calcium binding by troponin C (TnC) into interactions between thin and thick filaments. Once calcium is bound, transduction involves changes in protein interactions along the thin filament. The process is thought to involve three different states of actin-tropomyosin (Tm) resulting from changes in troponin's (Tn) interaction with actin-Tm: a blocked (B) state preventing myosin interaction, a closed (C) state allowing weak myosin interactions and favored by calcium binding to Tn, and an open or M state allowing strong myosin interactions. This was tested by measuring the apparent rate of Tn dissociation from rigor skeletal myofibrils using labeled Tn exchange. The location and rate of exchange of Tn or its subunits were measured by high-resolution fluorescence microscopy and image analysis. Three different rates of Tn exchange were observed that were dependent on calcium concentration and strong cross-bridge binding that strongly support the three-state model. The rate of Tn dissociation in the non-overlap region was 200-fold faster at pCa 4 (C-state region) than at pCa 9 (B-state region). When Tn contained engineered TnC mutants with weakened regulatory TnI interactions, the apparent exchange rate at pCa 4 in the non-overlap region increased proportionately with TnI-TnC regulatory affinity. This suggests that the mechanism of calcium enhancement of the rate of Tn dissociation is by favoring a TnI-TnC interaction over a TnI-actin-Tm interaction. At pCa 9, the rate of Tn dissociation in the overlap region (M-state region) was 100-fold faster than the non-overlap region (B-state region) suggesting that strong cross-bridges increase the rate of Tn dissociation. At pCa 4, the rate of Tn dissociation was twofold faster in the non-overlap region (C-state region) than the overlap region (M-state region) that likely involved a strong cross-bridge influence on Tn

The acyl-CoA binding protein affects Monascus pigment production in Monascus ruber CICC41233.

Science.gov (United States)

Long, Chuannan; Liu, Mengmeng; Chen, Xia; Wang, Xiaofang; Ai, Mingqiang; Cui, Jingjing; Zeng, Bin

2018-02-01

The present study verified whether acyl-coenzyme A (acyl-CoA)-binding protein (ACBP) affected the production of Monascus pigments (MPs) in Monascus ruber CICC41233 (MrACBP). Phylogenetic analysis revealed that the cloned Mracbp gene, which encoded the MrACBP protein, exhibited the closest match (99% confidence level) to the gene from Penicilliopsis zonata . The MrACBP and maltose-binding protein (MBP) were simultaneously expressed in Escherichia coli Rosetta DE3 in the form of a fusion protein. The microscale thermophoresis binding assay revealed that the purified MBP-MrACBP exhibited a higher affinity for myristoyl-CoA (Kd = 88.16 nM) than for palmitoyl-CoA (Kd = 136.07 nM) and octanoyl-CoA (Kd = 270.9 nM). Further, the Mracbp gene was homologously overexpressed in M. ruber CICC41233, and a positive transformant M. ruber ACBP5 was isolated. The fatty acid myristic acid in M. ruber ACBP5 was lower than that in the parent strain M. ruber CICC41233. However, when compared with the parent strain, the production of total MPs, water-soluble pigment, and ethanol-soluble pigment in M. ruber ACBP5 increased by 11.67, 9.80, and 12.70%, respectively, after 6 days. The relative gene expression level, as determined by a quantitative real-time polymerase chain reaction analysis, of the key genes acbp , pks , mppr1 , fasA , and fasB increased by 4.03-, 3.58-, 1.67-, 2.11-, and 2.62-fold after 6 days. These data demonstrate the binding preference of MrACBP for myristoyl-CoA, and its influence on MPs production.

Nitrite-cured color and phosphate-mediated water binding of pork muscle proteins as affected by calcium in the curing solution.

Science.gov (United States)

Zhao, Jing; Xiong, Youling L

2012-07-01

Calcium is a mineral naturally present in water and may be included into meat products during processing thereby influencing meat quality. Phosphates improve myofibril swelling and meat water-holding capacity (WHC) but can be sensitive to calcium precipitation. In this study, pork shoulder meat was used to investigate the impact of calcium at 0, 250, and 500 ppm and phosphate type [sodium pyrophosphate (PP), tripolyphosphate (TPP), and hexametaphopshate (HMP)] at 10 mM on nitrite-cured protein extract color at various pH levels (5.5, 6.0, and 6.5) and crude myofibril WHC at pH 6.0. Neither calcium nor phosphates present in the curing brines significantly affected the cured color. Increasing the pH tended to promote the formation of metmyoglobin instead of nitrosylmyoglobin. The ability of PP to enhance myofibril WHC was hampered (P meat products. Although not affecting nitrite-cured color, calcium hampers the efficacy of phosphates to promote water binding by muscle proteins, underscoring the importance of water quality for brine-enhanced meat products. © 2012 Institute of Food Technologists®

Factors affecting the separation performance of proteins in capillary electrophoresis.

Science.gov (United States)

Zhu, Yueping; Li, Zhenqing; Wang, Ping; Shen, Lisong; Zhang, Dawei; Yamaguchi, Yoshinori

2018-04-15

Capillary electrophoresis (CE) is an effective tool for protein separation and analysis. Compared with capillary gel electrophoresis (CGE), non-gel sieving capillary electrophoresis (NGSCE) processes the superiority on operation, repeatability and automaticity. Herein, we investigated the effect of polymer molecular weight and concentration, electric field strength, and the effective length of the capillary on the separation performance of proteins, and find that (1) polymer with high molecular weight and concentration favors the separation of proteins, although concentrated polymer hinders its injection into the channel of the capillary due to its high viscosity. (2) The resolution between the adjacent proteins decreases with the increase of electric field strength. (3) When the effective length of the capillary is long, the separation performance improves at the cost of separation time. (4) 1.4% (w/v) hydroxyethyl cellulose (HEC), 100 V/cm voltage and 12 cm effective length offers the best separation for the proteins with molecular weight from 14,400 Da to 97,400 Da. Finally, we employed the optimal electrophoretic conditions to resolve Lysozyme, Ovalbumin, BSA and their mixtures, and found that they were baseline resolved within 15 min. Copyright © 2018 Elsevier B.V. All rights reserved.

Influence of diet on the incorporation of labelled amino acids in muscles of calves

International Nuclear Information System (INIS)

Kumar, P.; Hansen, R.J.; Black, A.L.

1974-01-01

Experiments were conducted to study the influence of diet on the incorporation of labelled amino acids into the semitendinosus and biceps femoris muscles of calves after 48 h administration of isotope through jugular vein. 14 C or 3 H-labelled tyrosine and 14 C or 3 H-histidine were used as tracers. The results suggest that the incorporation into myofibrillar protein fraction of both the muscles was at least two fold greater on good diets as compared to all forage ration. Similar trend was also recorded with the plasma protein fraction at both 24 and 48 h after injection. (author)

Influence of diet on the incorporation of labelled amino acids in muscles of calves

Energy Technology Data Exchange (ETDEWEB)

Kumar, P; Hansen, R J; Black, A L [California Univ., Davis (USA). Dept. of Physiological Sciences

1974-12-01

Experiments were conducted to study the influence of diet on the incorporation of labeled amino acids into the semitendinosus and biceps femoris muscles of calves after 48 h administration of isotope through jugular vein. /sup 14/C or /sup 3/H-labelled tyrosine and /sup 14/C or /sup 3/H-histidine were used as tracers. The results suggest that the incorporation into myofibrillar protein fraction of both the muscles was at least two fold greater on good diets as compared to all forage ration. Similar trend was also recorded with the plasma protein fraction at both 24 and 48 h after injection.

Myopathy With SQSTM1 and TIA1 Variants: Clinical and Pathological Features

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Zhiyv Niu

2018-03-01

Full Text Available ObjectiveThe aim of this study is to identify the molecular defect of three unrelated individuals with late-onset predominant distal myopathy; to describe the spectrum of phenotype resulting from the contributing role of two variants in genes located on two different chromosomes; and to highlight the underappreciated complex forms of genetic myopathies.Patients and methodsClinical and laboratory data of three unrelated probands with predominantly distal weakness manifesting in the sixth-seventh decade of life, and available affected and unaffected family members were reviewed. Next-generation sequencing panel, whole exome sequencing, and targeted analyses of family members were performed to elucidate the genetic etiology of the myopathy.ResultsGenetic analyses detected two contributing variants located on different chromosomes in three unrelated probands: a heterozygous pathogenic mutation in SQSTM1 (c.1175C>T, p.Pro392Leu and a heterozygous variant in TIA1 (c.1070A>G, p.Asn357Ser. The affected fraternal twin of one proband also carries both variants, while the unaffected family members harbor one or none. Two unrelated probands (family 1, II.3, and family 3, II.1 have a distal myopathy with rimmed vacuoles that manifested with index extensor weakness; the other proband (family 2, I.1 has myofibrillar myopathy manifesting with hypercapnic respiratory insufficiency and distal weakness.ConclusionThe findings indicate that all the affected individuals have a myopathy associated with both variants in SQSTM1 and TIA1, respectively, suggesting that the two variants determine the phenotype and likely functionally interact. We speculate that the TIA1 variant is a modifier of the SQSTM1 mutation. We identify the combination of SQSTM1 and TIA1 variants as a novel genetic defect associated with myofibrillar myopathy and suggest to consider sequencing both genes in the molecular investigation of myopathy with rimmed vacuoles and myofibrillar myopathy

Myopathy With SQSTM1 and TIA1 Variants: Clinical and Pathological Features.

Science.gov (United States)

Niu, Zhiyv; Pontifex, Carly Sabine; Berini, Sarah; Hamilton, Leslie E; Naddaf, Elie; Wieben, Eric; Aleff, Ross A; Martens, Kristina; Gruber, Angela; Engel, Andrew G; Pfeffer, Gerald; Milone, Margherita

2018-01-01

The aim of this study is to identify the molecular defect of three unrelated individuals with late-onset predominant distal myopathy; to describe the spectrum of phenotype resulting from the contributing role of two variants in genes located on two different chromosomes; and to highlight the underappreciated complex forms of genetic myopathies. Clinical and laboratory data of three unrelated probands with predominantly distal weakness manifesting in the sixth-seventh decade of life, and available affected and unaffected family members were reviewed. Next-generation sequencing panel, whole exome sequencing, and targeted analyses of family members were performed to elucidate the genetic etiology of the myopathy. Genetic analyses detected two contributing variants located on different chromosomes in three unrelated probands: a heterozygous pathogenic mutation in SQSTM1 (c.1175C>T, p.Pro392Leu) and a heterozygous variant in TIA1 (c.1070A>G, p.Asn357Ser). The affected fraternal twin of one proband also carries both variants, while the unaffected family members harbor one or none. Two unrelated probands (family 1, II.3, and family 3, II.1) have a distal myopathy with rimmed vacuoles that manifested with index extensor weakness; the other proband (family 2, I.1) has myofibrillar myopathy manifesting with hypercapnic respiratory insufficiency and distal weakness. The findings indicate that all the affected individuals have a myopathy associated with both variants in SQSTM1 and TIA1 , respectively, suggesting that the two variants determine the phenotype and likely functionally interact. We speculate that the TIA1 variant is a modifier of the SQSTM1 mutation. We identify the combination of SQSTM1 and TIA1 variants as a novel genetic defect associated with myofibrillar myopathy and suggest to consider sequencing both genes in the molecular investigation of myopathy with rimmed vacuoles and myofibrillar myopathy although additional studies are needed to investigate the

No evidence for involvement of plasma proteins or blood-borne cells in amyloid plaque formation in scrapie-affected mice. An immunohistoperoxidase study

NARCIS (Netherlands)

Eikelenboom, P.; Scott, J. R.; McBride, P. A.; Rozemuller, J. M.; Bruce, M. E.; Fraser, H.

1987-01-01

The present study was designed to investigate blood-brain permeability and the possible involvement of plasma proteins and blood-borne cells in amyloid plaque formation in scrapie-affected mice. No abnormal extravasation of intravenously injected horseradish peroxidase (HRP) was found and with

Effect of irradiated pork on physicochemical properties of meat emulsions

Science.gov (United States)

Choi, Yun-Sang; Sung, Jung-Min; Jeong, Tae-Jun; Hwang, Ko-Eun; Song, Dong-Heon; Ham, Youn-Kyung; Kim, Hyun-Wook; Kim, Young-Boong; Kim, Cheon-Jei

2016-02-01

The effect of pork irradiated with doses up to 10 kGy on meat emulsions formulated with carboxy methyl cellulose (CMC) was investigated. Raw pork was vacuums packaged at a thickness of 2.0 cm and irradiated by X-ray linear accelerator (15 kW, 5 MeV). The emulsion had higher lightness, myofibrillar protein solubility, total protein solubility, and apparent viscosity with increasing doses, whereas cooking loss, total expressible fluid separation, and hardness decreased. There were no significant differences in fat separation, sarcoplasmic protein solubility, springiness, and cohesiveness. Our results indicated that it is treatment by ionizing radiation which causes the effects the physicochemical properties of the final raw meat product.

Growth performance and certain body measurements of ostrich chicks as affected by dietary protein levels during 2-9 weeks of age.

Science.gov (United States)

Mahrose, Kh M; Attia, A I; Ismail, I E; Abou-Kassem, D E; El-Hack, M E Abd

2015-01-01

The present work was conducted to examine the effects of dietary crude protein (CP) levels (18, 21 and 24%) on growth performance (Initial and final body weight, daily body weight gain, feed consumption, feed conversion and protein efficiency ratio) during 2-9 weeks of age and certain body measurements (body height, tibiotarsus length and tibiotarsus girth) at 9 weeks of age. A total of 30 African Black unsexed ostrich chicks were used in the present study in simple randomized design. The results of the present work indicated that initial and final live body weight, body weight gain, feed consumption, feed conversion of ostrich chicks were insignificantly affected by dietary protein level used. Protein efficiency ratio was high in the group of chicks fed diet contained 18% CP. Results obtained indicated that tibiotarsus girth was decreased (P≤0.01) with the increasing dietary protein level, where the highest value of tibiotarsus girth (18.38 cm) was observed in chicks fed 18% dietary protein level. Body height and tibiotarsus length were not significantly different. In conclusion, the results of the present study indicate that ostrich chicks (during 2-9 weeks of age) could grow on diets contain lower levels of CP (18%).

Amino acids and insulin act additively to regulate components of the ubiquitin-proteasome pathway in C2C12 myotubes

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Lomax Michael A

2007-03-01

Full Text Available Abstract Background The ubiquitin-proteasome system is the predominant pathway for myofibrillar proteolysis but a previous study in C2C12 myotubes only observed alterations in lysosome-dependent proteolysis in response to complete starvation of amino acids or leucine from the media. Here, we determined the interaction between insulin and amino acids in the regulation of myotube proteolysis Results Incubation of C2C12 myotubes with 0.2 × physiological amino acids concentration (0.2 × PC AA, relative to 1.0 × PC AA, significantly increased total proteolysis and the expression of 14-kDa E2 ubiquitin conjugating enzyme (p Conclusion In a C2C12 myotube model of myofibrillar protein turnover, amino acid limitation increases proteolysis in a ubiquitin-proteasome-dependent manner. Increasing amino acids or leucine alone, act additively with insulin to down regulate proteolysis and expression of components of ubiquitin-proteasome pathway. The effects of amino acids on proteolysis but not insulin and leucine, are blocked by inhibition of the mTOR signalling pathway.

Fast hydrogen exchange affects {sup 15}N relaxation measurements in intrinsically disordered proteins

Energy Technology Data Exchange (ETDEWEB)

Kim, Seho; Wu, Kuen-Phon; Baum, Jean, E-mail: jean.baum@rutgers.edu [Rutgers University, Department of Chemistry and Chemical Biology (United States)

2013-03-15

Unprotected amide protons can undergo fast hydrogen exchange (HX) with protons from the solvent. Generally, NMR experiments using the out-and-back coherence transfer with amide proton detection are affected by fast HX and result in reduced signal intensity. When one of these experiments, {sup 1}H-{sup 15}N HSQC, is used to measure the {sup 15}N transverse relaxation rate (R{sub 2}), the measured R{sub 2} rate is convoluted with the HX rate (k{sub HX}) and has higher apparent R{sub 2} values. Since the {sup 15}N R{sub 2} measurement is important for analyzing protein backbone dynamics, the HX effect on the R{sub 2} measurement is investigated and described here by multi-exponential signal decay. We demonstrate these effects by performing {sup 15}N R{sub 2}{sup CPMG} experiments on {alpha}-synuclein, an intrinsically disordered protein, in which the amide protons are exposed to solvent. We show that the HX effect on R{sub 2}{sup CPMG} can be extracted by the derived equation. In conclusion, the HX effect may be pulse sequence specific and results from various sources including the J coupling evolution, the change of steady state water proton magnetization, and the D{sub 2}O content in the sample. To avoid the HX effect on the analysis of relaxation data of unprotected amides, it is suggested that NMR experimental conditions insensitive to the HX should be considered or that intrinsic R{sub 2}{sup CPMG} values be obtained by methods described herein.

Using protein design algorithms to understand the molecular basis of disease caused by protein-DNA interactions: the Pax6 example

DEFF Research Database (Denmark)

Alibes, A.; Nadra, A.; De Masi, Federico

2010-01-01

diseases such as aniridia. The validity of FoldX to deal with protein-DNA interactions was demonstrated by showing that high levels of accuracy can be achieved for mutations affecting these interactions. Also we showed that protein-design algorithms can accurately reproduce experimental DNA-binding logos......Quite often a single or a combination of protein mutations is linked to specific diseases. However, distinguishing from sequence information which mutations have real effects in the protein's function is not trivial. Protein design tools are commonly used to explain mutations that affect protein...... stability, or protein-protein interaction, but not for mutations that could affect protein-DNA binding. Here, we used the protein design algorithm FoldX to model all known missense mutations in the paired box domain of Pax6, a highly conserved transcription factor involved in eye development and in several...

Variation in Protein and Calorie Consumption Following Protein Malnutrition in Rattus norvegicus

Science.gov (United States)

Jones, Donna C.; German, Rebecca Z.

2013-01-01

Simple Summary Catch-up growth following malnutrition is likely influenced by available protein and calories. We measured calorie and protein consumption following the removal of protein malnutrition after 40, 60 and 90 days, in laboratory rats. Following the transition in diet, animals self-selected fewer calories, implying elevated protein is sufficient to fuel catch-up growth, eventually resulting in body weights and bone lengths greater or equal to those of control animals. Rats rehabilitated at younger ages, had more drastic alterations in consumption. Variable responses in different ages and sex highlight the plasticity of growth and how nutrition affects body form. This work furthers our understanding of how humans and livestock can recover from protein-restriction malnutrition, which seems to employ different biological responses. Abstract Catch-up growth rates, following protein malnutrition, vary with timing and duration of insult, despite unlimited access to calories. Understanding changing patterns of post-insult consumption, relative rehabilitation timing, can provide insight into the mechanisms driving those differences. We hypothesize that higher catch-up growth rates will be correlated with increased protein consumption, while calorie consumption could remain stable. As catch-up growth rates decrease with age/malnutrition duration, we predict a dose effect in protein consumption with rehabilitation timing. We measured total and protein consumption, body mass, and long bone length, following an increase of dietary protein at 40, 60 and 90 days, with two control groups (chronic reduced protein or standard protein) for 150+ days. Immediately following rehabilitation, rats’ food consumption decreased significantly, implying that elevated protein intake is sufficient to fuel catch-up growth rates that eventually result in body weights and long bone lengths greater or equal to final measures of chronically fed standard (CT) animals. The duration of

Protein restriction does not affect body temperature pattern in female mice.

Science.gov (United States)

Kato, Goro A; Shichijo, Hiroki; Takahashi, Toshihiro; Shinohara, Akio; Morita, Tetsuo; Koshimoto, Chihiro

2017-10-30

Daily torpor is a physiological adaptation in mammals and birds characterized by a controlled reduction of metabolic rate and body temperature during the resting phase of circadian rhythms. In laboratory mice, daily torpor is induced by dietary caloric restriction. However, it is not known which nutrients are related to daily torpor expression. To determine whether dietary protein is a key factor in inducing daily torpor in mice, we fed mice a protein-restricted (PR) diet that included only one-quarter of the amount of protein but the same caloric level as a control (C) diet. We assigned six non-pregnant female ICR mice to each group and recorded their body weights and core body temperatures for 4 weeks. Body weights in the C group increased, but those in the PR group remained steady or decreased. Mice in both groups did not show daily torpor, but most mice in a food-restricted group (n=6) supplied with 80% of the calories given to the C group exhibited decreased body weights and frequently displayed daily torpor. This suggests that protein restriction is not a trigger of daily torpor; torpid animals can conserve their internal energy, but torpor may not play a significant role in conserving internal protein. Thus, opportunistic daily torpor in mice may function in energy conservation rather than protein saving.

Meat and meat products as a source of bioactive peptides

Directory of Open Access Journals (Sweden)

Alfonso Totosaus

2016-12-01

Full Text Available Meat is a high protein content food, with great nutritional and biological value. Meat protein hydrolysis begins with the muscle to meat conversion, during meat ageing. After slaughter, endogen enzymes are responsible of meat softening since myofibrillar anchorage proteins are degraded. Protein hydrolysis continues during food preparation. When meat reaches the stomach, pepsin is the first enzyme to interact. As the food travel trough out gastrointestinal tract, pancreatic enzymes degraded the remained protein and the peptidases made the final proteolysis process. The small proteins or peptides are the absorbed to the circulatory system and distributed to the rest of the body. Bioactive peptides activity of meat and meat products is anti-hypertensive mainly, where histidine, carnosine and anserine are the main peptides identified. Another peptide with anti-oxidant activity is glutathione. The content depends on animal species.

Cardiac myosin binding protein C phosphorylation affects cross-bridge cycle's elementary steps in a site-specific manner.

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Li Wang

Full Text Available Based on our recent finding that cardiac myosin binding protein C (cMyBP-C phosphorylation affects muscle contractility in a site-specific manner, we further studied the force per cross-bridge and the kinetic constants of the elementary steps in the six-state cross-bridge model in cMyBP-C mutated transgenic mice for better understanding of the influence of cMyBP-C phosphorylation on contractile functions. Papillary muscle fibres were dissected from cMyBP-C mutated mice of ADA (Ala273-Asp282-Ala302, DAD (Asp273-Ala282-Asp302, SAS (Ser273-Ala282-Ser302, and t/t (cMyBP-C null genotypes, and the results were compared to transgenic mice expressing wide-type (WT cMyBP-C. Sinusoidal analyses were performed with serial concentrations of ATP, phosphate (Pi, and ADP. Both t/t and DAD mutants significantly reduced active tension, force per cross-bridge, apparent rate constant (2πc, and the rate constant of cross-bridge detachment. In contrast to the weakened ATP binding and enhanced Pi and ADP release steps in t/t mice, DAD mice showed a decreased ADP release without affecting the ATP binding and the Pi release. ADA showed decreased ADP release, and slightly increased ATP binding and cross-bridge detachment steps, whereas SAS diminished the ATP binding step and accelerated the ADP release step. t/t has the broadest effects with changes in most elementary steps of the cross-bridge cycle, DAD mimics t/t to a large extent, and ADA and SAS predominantly affect the nucleotide binding steps. We conclude that the reduced tension production in DAD and t/t is the result of reduced force per cross-bridge, instead of the less number of strongly attached cross-bridges. We further conclude that cMyBP-C is an allosteric activator of myosin to increase cross-bridge force, and its phosphorylation status modulates the force, which is regulated by variety of protein kinases.

Depletion of Arabidopsis SC35 and SC35-like serine/arginine-rich proteins affects the transcription and splicing of a subset of genes.

Science.gov (United States)

Yan, Qingqing; Xia, Xi; Sun, Zhenfei; Fang, Yuda

2017-03-01

Serine/arginine-rich (SR) proteins are important splicing factors which play significant roles in spliceosome assembly and splicing regulation. However, little is known regarding their biological functions in plants. Here, we analyzed the phenotypes of mutants upon depleting different subfamilies of Arabidopsis SR proteins. We found that loss of the functions of SC35 and SC35-like (SCL) proteins cause pleiotropic changes in plant morphology and development, including serrated leaves, late flowering, shorter roots and abnormal silique phyllotaxy. Using RNA-seq, we found that SC35 and SCL proteins play roles in the pre-mRNA splicing. Motif analysis revealed that SC35 and SCL proteins preferentially bind to a specific RNA sequence containing the AGAAGA motif. In addition, the transcriptions of a subset of genes are affected by the deletion of SC35 and SCL proteins which interact with NRPB4, a specific subunit of RNA polymerase II. The splicing of FLOWERING LOCUS C (FLC) intron1 and transcription of FLC were significantly regulated by SC35 and SCL proteins to control Arabidopsis flowering. Therefore, our findings provide mechanistic insight into the functions of plant SC35 and SCL proteins in the regulation of splicing and transcription in a direct or indirect manner to maintain the proper expression of genes and development.

Immunolabelling, histochemistry and in situ hybridisation in human skeletal muscle fibres to detect myosin heavy chain expression at the protein and mRNA level

Science.gov (United States)

SERRANO, A. L.; PÉREZ, MARGARITA; LUCÍA, A.; CHICHARRO, J. L.; QUIROZ-ROTHE, E.; RIVERO, J. L. L.

2001-01-01

The distribution of muscle fibres classified on the basis of their content of different myosin heavy chain (MHC) isoforms was analysed in vastus lateralis muscle biopsies of 15 young men (with an average age of 22 y) by correlating immunohistochemistry with specific anti-MHC monoclonal antibodies, myofibrillar ATPase (mATPase) histochemistry and in situ hybridisation with probes specific for MHC β-slow, MHC-IIA and MHC-IIX. The characterisation of a large number of individual fibres was compared and correlated on a fibre-to-fibre basis. The panel of monoclonal antibodies used in the study allowed classification of human skeletal muscle fibres into 5 categories according to the MHC isoform they express at the protein level, types I, I+IIA, IIA, IIAX and IIX. Hybrid fibres coexpressing two isoforms represented a considerable proportion of the fibre composition (about 14%) and were clearly underestimated by mATPase histochemistry. For a very high percentage of fibres there was a precise correspondence between the MHC protein isoforms and mRNA transcripts. The integrated methods used demonstrate a high degree of precision of the immunohistochemical procedure used for the identification and quantification of human skeletal muscle fibre types. The monoclonal antibody S5-8H2 is particularly useful for identifying hybrid IIAX fibres. This protocol offers new prospects for muscle fibre classification in human experimental studies. PMID:11554510

Protein stability: a crystallographer’s perspective

International Nuclear Information System (INIS)

Deller, Marc C.; Kong, Leopold; Rupp, Bernhard

2016-01-01

An understanding of protein stability is essential for optimizing the expression, purification and crystallization of proteins. In this review, discussion will focus on factors affecting protein stability on a somewhat practical level, particularly from the view of a protein crystallographer. Protein stability is a topic of major interest for the biotechnology, pharmaceutical and food industries, in addition to being a daily consideration for academic researchers studying proteins. An understanding of protein stability is essential for optimizing the expression, purification, formulation, storage and structural studies of proteins. In this review, discussion will focus on factors affecting protein stability, on a somewhat practical level, particularly from the view of a protein crystallographer. The differences between protein conformational stability and protein compositional stability will be discussed, along with a brief introduction to key methods useful for analyzing protein stability. Finally, tactics for addressing protein-stability issues during protein expression, purification and crystallization will be discussed

Protein stability: a crystallographer’s perspective

Energy Technology Data Exchange (ETDEWEB)

Deller, Marc C., E-mail: mdeller@stanford.edu [Stanford University, Shriram Center, 443 Via Ortega, Room 097, MC5082, Stanford, CA 94305-4125 (United States); Kong, Leopold [National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), National Institutes of Health (NIH), Building 8, Room 1A03, 8 Center Drive, Bethesda, MD 20814 (United States); Rupp, Bernhard [k.-k. Hofkristallamt, 91 Audrey Place, Vista, CA 92084 (United States); Medical University of Innsbruck, Schöpfstrasse 41, A-6020 Innsbruck (Austria)

2016-01-26

An understanding of protein stability is essential for optimizing the expression, purification and crystallization of proteins. In this review, discussion will focus on factors affecting protein stability on a somewhat practical level, particularly from the view of a protein crystallographer. Protein stability is a topic of major interest for the biotechnology, pharmaceutical and food industries, in addition to being a daily consideration for academic researchers studying proteins. An understanding of protein stability is essential for optimizing the expression, purification, formulation, storage and structural studies of proteins. In this review, discussion will focus on factors affecting protein stability, on a somewhat practical level, particularly from the view of a protein crystallographer. The differences between protein conformational stability and protein compositional stability will be discussed, along with a brief introduction to key methods useful for analyzing protein stability. Finally, tactics for addressing protein-stability issues during protein expression, purification and crystallization will be discussed.

Progesterone production is affected by unfolded protein response (UPR) signaling during the luteal phase in mice.

Science.gov (United States)

Park, Hyo-Jin; Park, Sun-Ji; Koo, Deog-Bon; Lee, Sang-Rae; Kong, Il-Keun; Ryoo, Jae-Woong; Park, Young-Il; Chang, Kyu-Tae; Lee, Dong-Seok

2014-09-15

We examined whether the three unfolded protein response (UPR) signaling pathways, which are activated in response to endoplasmic reticulum (ER)-stress, are involved in progesterone production in the luteal cells of the corpus luteum (CL) during the mouse estrous cycle. The luteal phase of C57BL/6 female mice (8 weeks old) was divided into two stages: the functional stage (16, 24, and 48 h) and the regression stage (72 and 96 h). Western blotting and reverse transcription (RT)-PCR were performed to analyze UPR protein/gene expression levels in each stage. We investigated whether ER stress affects the progesterone production by using Tm (0.5 μg/g BW) or TUDCA (0.5 μg/g BW) through intra-peritoneal injection. Our results indicate that expressions of Grp78/Bip, p-eIF2α/ATF4, p50ATF6, and p-IRE1/sXBP1 induced by UPR activation were predominantly maintained in functional and early regression stages of the CL. Furthermore, the expression of p-JNK, CHOP, and cleaved caspase3 as ER-stress mediated apoptotic factors increased during the regression stage. Cleaved caspase3 levels increased in the late-regression stage after p-JNK and CHOP expression in the early-regression stage. Additionally, although progesterone secretion and levels of steroidogenic enzymes decreased following intra-peritoneal injection of Tunicamycin, an ER stress inducer, the expression of Grp78/Bip, p50ATF6, and CHOP dramatically increased. These results suggest that the UPR signaling pathways activated in response to ER stress may play important roles in the regulation of the CL function. Furthermore, our findings enhance the understanding of the basic mechanisms affecting the CL life span. Copyright © 2014 Elsevier Inc. All rights reserved.

Membrane biocompatibility does not affect whole body protein metabolism during dialysis

NARCIS (Netherlands)

Veeneman, JM; Kingma, HA; Stellaard, F; de Jong, PE; Reijngoud, DJ; Huisman, RM

2005-01-01

Background: Protein-calorie malnutrition is present in 30-50% of dialysis patients. The lack of biocompatibility of the dialysis membrane, which results in low-grade inflammation, could be responsible for this malnutrition. We investigated whether protein-energy malnutrition could be partly due to

L-Alanylglutamine inhibits signaling proteins that activate protein degradation, but does not affect proteins that activate protein synthesis after an acute resistance exercise.

Science.gov (United States)

Wang, Wanyi; Choi, Ran Hee; Solares, Geoffrey J; Tseng, Hung-Min; Ding, Zhenping; Kim, Kyoungrae; Ivy, John L

2015-07-01

Sustamine™ (SUS) is a dipeptide composed of alanine and glutamine (AlaGln). Glutamine has been suggested to increase muscle protein accretion; however, the underlying molecular mechanisms of glutamine on muscle protein metabolism following resistance exercise have not been fully addressed. In the present study, 2-month-old rats climbed a ladder 10 times with a weight equal to 75 % of their body mass attached at the tail. Rats were then orally administered one of four solutions: placebo (PLA-glycine = 0.52 g/kg), whey protein (WP = 0.4 g/kg), low dose of SUS (LSUS = 0.1 g/kg), or high dose of SUS (HSUS = 0.5 g/kg). An additional group of sedentary (SED) rats was intubated with glycine (0.52 g/kg) at the same time as the ladder-climbing rats. Blood samples were collected immediately after exercise and at either 20 or 40 min after recovery. The flexor hallucis longus (FHL), a muscle used for climbing, was excised at 20 or 40 min post exercise and analyzed for proteins regulating protein synthesis and degradation. All supplements elevated the phosphorylation of FOXO3A above SED at 20 min post exercise, but only the SUS supplements significantly reduced the phosphorylation of AMPK and NF-kB p65. SUS supplements had no effect on mTOR signaling, but WP supplementation yielded a greater phosphorylation of mTOR, p70S6k, and rpS6 compared with PLA at 20 min post exercise. However, by 40 min post exercise, phosphorylation of mTOR and rpS6 in PLA had risen to levels not different than WP. These results suggest that SUS blocks the activation of intracellular signals for MPB, whereas WP accelerates mRNA translation.

Is there an optimal topographical surface in nano-scale affecting protein adsorption and cell behaviors? Part II

Energy Technology Data Exchange (ETDEWEB)

Wang Huajie, E-mail: wanghuajie972001@163.com; Sun Yuanyuan; Cao Ying, E-mail: caoying1130@sina.com; Wang Kui; Yang Lin [Henan Normal University, College of Chemistry and Environmental Science (China); Zhang Yidong; Zheng Zhi [Xuchang University, Institute of Surface Micro and Nano Materials (China)

2012-05-15

Although nano-structured surfaces exhibit superior biological activities to the smooth or micro-structured surfaces, whether there is an optimal topographical surface in nano-scale affecting protein adsorption and cell behaviors is still controversial. In this study, porous aluminum oxide membranes with different pore sizes ranging from 25 to 120 nm were prepared by the anodic oxidation technique. The surface morphology, topography and wettability were analyzed by scanning electron microscope, atomic force microscope and water contact angle measurement, respectively. The results indicated that the synergistic action of the nano-topography structure and hydrophilic/hydrophobic properties resulted in a highest protein adsorption on the aluminum oxide membrane with 80 nm pore size. Additionally, the morphological, metabolic and cell counting methods showed that cells had different sensitivity to porous aluminum oxide membranes with different surface features. Furthermore, this sensitivity was cell type dependent. The optimal pore size of aluminum oxide membranes for cell growth was 80 nm for PC12 cells and 50 nm for NIH 3T3 cells.

How Chain Length and Charge Affect Surfactant Denaturation of Acyl Coenzyme A Binding Protein (ACBP)

DEFF Research Database (Denmark)

Andersen, Kell Kleiner; Otzen, Daniel

2009-01-01

maltoside (DDM). The aim has been to determine how surfactant chain length and micellar charge affect the denaturation mechanism. ACBP denatures in two steps irrespective of surfactant chain length, but with increasing chain length, the potency of the denaturant rises more rapidly than the critical micelle......Using intrinsic tryptophan fluorescence, equilibria and kinetics of unfolding of acyl coenzyme A binding protein (ACBP) have been investigated in sodium alkyl sulfate surfactants of different chain length (8-16 carbon atoms) and with different proportions of the nonionic surfactant dodecyl...... constants increases linearly with denaturant concentration below the cmc but declines at higher concentrations. Both shortening chain length and decreasing micellar charge reduce the overall kinetics of unfolding and makes the dependence of unfolding rate constants on surfactant concentration more complex...

The HSPB8-BAG3 chaperone complex is upregulated in astrocytes in the human brain affected by protein aggregation diseases.

Science.gov (United States)

Seidel, K; Vinet, J; Dunnen, W F A den; Brunt, E R; Meister, M; Boncoraglio, A; Zijlstra, M P; Boddeke, H W G M; Rüb, U; Kampinga, H H; Carra, S

2012-02-01

HSPB8 is a small heat shock protein that forms a complex with the co-chaperone BAG3. Overexpression of the HSPB8-BAG3 complex in cells stimulates autophagy and facilitates the clearance of mutated aggregation-prone proteins, whose accumulation is a hallmark of many neurodegenerative disorders. HSPB8-BAG3 could thus play a protective role in protein aggregation diseases and might be specifically upregulated in response to aggregate-prone protein-mediated toxicity. Here we analysed HSPB8-BAG3 expression levels in post-mortem human brain tissue from patients suffering of the following protein conformation disorders: Alzheimer's disease, Parkinson's disease, Huntington's disease and spinocerebellar ataxia type 3 (SCA3). Western blotting and immunohistochemistry techniques were used to analyse HSPB8 and BAG3 expression levels in fibroblasts from SCA3 patients and post-mortem brain tissues, respectively. In all diseases investigated, we observed a strong upregulation of HSPB8 and a moderate upregulation of BAG3 specifically in astrocytes in the cerebral areas affected by neuronal damage and degeneration. Intriguingly, no significant change in the HSPB8-BAG3 expression levels was observed within neurones, irrespective of their localization or of the presence of proteinaceous aggregates. We propose that the upregulation of HSPB8 and BAG3 may enhance the ability of astrocytes to clear aggregated proteins released from neurones and cellular debris, maintain the local tissue homeostasis and/or participate in the cytoskeletal remodelling that astrocytes undergo during astrogliosis. © 2011 The Authors. Neuropathology and Applied Neurobiology © 2011 British Neuropathological Society.

Dietary fish protein hydrolysates containing bioactive motifs affect serum and adipose tissue fatty acid compositions, serum lipids, postprandial glucose regulation and growth in obese Zucker fa/fa rats.

Science.gov (United States)

Drotningsvik, Aslaug; Mjøs, Svein A; Pampanin, Daniela M; Slizyte, Rasa; Carvajal, Ana; Remman, Tore; Høgøy, Ingmar; Gudbrandsen, Oddrun A

2016-10-01

The world's fisheries and aquaculture industries produce vast amounts of protein-containing by-products that can be enzymatically hydrolysed to smaller peptides and possibly be used as additives to functional foods and nutraceuticals targeted for patients with obesity-related metabolic disorders. To investigate the effects of fish protein hydrolysates on markers of metabolic disorders, obese Zucker fa/fa rats consumed diets with 75 % of protein from casein/whey (CAS) and 25 % from herring (HER) or salmon (SAL) protein hydrolysate from rest raw material, or 100 % protein from CAS for 4 weeks. The fatty acid compositions were similar in the experimental diets, and none of them contained any long-chain n-3 PUFA. Ratios of lysine:arginine and methionine:glycine were lower in HER and SAL diets when compared with CAS, and taurine was detected only in fish protein hydrolysate diets. Motifs with reported hypocholesterolemic or antidiabetic activities were identified in both fish protein hydrolysates. Rats fed HER diet had lower serum HDL-cholesterol and LDL-cholesterol, and higher serum TAG, MUFA and n-3:n-6 PUFA ratio compared with CAS-fed rats. SAL rats gained more weight and had better postprandial glucose regulation compared with CAS rats. Serum lipids and fatty acids were only marginally affected by SAL, but adipose tissue contained less total SFA and more total n-3 PUFA when compared with CAS. To conclude, diets containing hydrolysed rest raw material from herring or salmon proteins may affect growth, lipid metabolism, postprandial glucose regulation and fatty acid composition in serum and adipose tissue in obese Zucker rats.

Metallothionein 2A affects the cell respiration by suppressing the expression of mitochondrial protein cytochrome c oxidase subunit II.

Science.gov (United States)

Bragina, Olga; Gurjanova, Karina; Krishtal, Jekaterina; Kulp, Maria; Karro, Niina; Tõugu, Vello; Palumaa, Peep

2015-06-01

Metallothioneins (MT) are involved in a broad range of cellular processes and play a major role in protection of cells towards various stressors. Two functions of MTs, namely the maintaining of the homeostasis of transition metal ions and the redox balance, are directly linked to the functioning of mitochondria. Dyshomeostasis of MTs is often related with malfunctioning of mitochondria; however, the mechanism by which MTs affect the mitochondrial respiratory chain is still unknown. We demonstrated that overexpression of MT-2A in HEK cell line decreased the oxidative phosphorylation capacity of the cells. HEK cells overexpressing MT-2A demonstrated reduced oxygen consumption and lower cellular ATP levels. MT-2A did not affect the number of mitochondria, but reduced specifically the level of cytochrome c oxidase subunit II protein, which resulted in lower activity of the complex IV.

Calcium affecting protein expression in longan under simulated acid rain stress.

Science.gov (United States)

Pan, Tengfei; Li, Yongyu; Ma, Cuilan; Qiu, Dongliang

2015-08-01

Longan (Dimocarpus longana Lour. cv. Wulongling) of uniform one-aged seedlings grown in pots were selected to study specific proteins expressed in leaves under simulated acid rain (SiAR) stress and exogenous Ca(2+) regulation. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) results showed that there was a protein band specifically expressed under SiAR of pH 2.5 stress for 15 days with its molecular weight of about 23 kD. A 17 kD protein band specifically expressed after SiAR stress 5 days. Compared with pH 2.5, the pH 3.5 of SiAR made a less influence to protein expression. Two-dimensional electrophoresis (2-DE) results showed that six new specific proteins including C4 (20.2 kD pI 6.0), F (24 kD pI 6.35), B3 (22.3 kD pI 6.35), B4 (23.5 kD pI 6.5), C5 (21.8 kD pI 5.6), and C6 (20.2 kD pI 5.6) specifically expressed. C4 always expressed during SiAR stress. F expressed under the stress of pH 2.5 for 15 days and expressed in all pH SiAR stress for 20 days. The expression of proteins including B3, C5, and C6 was related to pH value and stress intensity of SiAR. The expression of B4 resulted from synergistic effects of SiAR and Ca. The expression of G1 (Mr 19.3 kD, pI 4.5), G2 (Mr 17.8 kD, pI 4.65), G3 (Mr 16.6 kD, pI 4.6), and G4 (Mr 14.7 kD, pI 4.4) enhanced under the treatment of 5 mM ethylene glycol tetraacetic acid (EGTA) and 2 mM chlorpromazine (CPZ). These proteins showed antagonistic effects and might be relative to the Ca-calmodulin (Ca-CaM) system of longan in response to SiAR stress.

Protein binding of glufosinate and factors affecting it revealed by an equilibrium dialysis technique.

Science.gov (United States)

Hori, Y; Koyama, K; Fujisawa, M; Nakajima, M; Shimada, K; Hirose, Y; Kohda, Y; Akuzawa, H

2001-09-01

We investigated the protein binding of glufosinate ammonium (GLF) and several factors affecting this binding using human serum albumin (HSA) and human volunteer serum under various conditions. The mean ratios of the free GLF (RFr-GLF) to 4% HSA were examined in the sera of patients described elsewhere at GLF levels from 1 microg/mL to 500 microg/mL; the range was found to be only from 0.80 to 0.88. Neither the incubation temperature nor buffers containing different chloride ion concentrations had any effect on the RFr-GLF to HSA. Moreover, the addition of heparin, glycoprotein-alpha1-acid (AAG), and sodium azide had no effect on the RFr-GLF. However, pH of the isotonic phosphate buffer and the addition of palmitic or oleic acid were seen to have an effect. In this study, the mean RFr-GLF to healthy human serum was 0.99. This high value was evidenced that GLF was rapidly excreted through the renal route.

Factors affecting yeast growth and protein yield production from ...

African Journals Online (AJOL)

SERVER

2008-02-05

Feb 5, 2008 ... microbial protein which in turn can be used to upgrade both human and animal feeds. Studies to ... In many of the ... These include carbon and energy source .... The Candida sp. used for this study produced discrete colonies ...

Structural and functional affection of the heart in protein energy malnutrition patients on admission and after nutritional recovery.

Science.gov (United States)

El-Sayed, H L; Nassar, M F; Habib, N M; Elmasry, O A; Gomaa, S M

2006-04-01

The pathogenesis of different malnutrition diseases was suggested to affect the heart. This study was designed to detect cardiac affection in protein energy malnutrition (PEM) patients, whether clinically or by electrocardiogram (ECG) and echocardiogram, and to assess the value of the cardiac marker troponin I in patients at risk of myocardial injury with special emphasis on the effect of nutritional rehabilitation. The present study was carried out on 30 PEM infants (16 nonedematous - 14 edematous) and 10 apparently healthy age and sex-matched infants acting as the control group. All studied infants were subjected to full history taking laying stress on dietetic history, thorough clinical and anthropometric measurements. Echocardiography and ECG were also performed. Laboratory investigations were performed including complete blood count, CRP, total proteins, albumin, liver and kidney functions as well as estimation of troponin-I in blood by immulite. Following initial evaluation, all malnourished infants were subjected to nutritional rehabilitation program for approximately 8 weeks, after which the patients were re-evaluated using the same preinterventional parameters. The results of the present study demonstrated that electrical properties of myocardium assessed by ECG showed significant decrease of R wave and QTc interval in patients compared to controls with significant improvement after nutritional rehabilitation. Echocardigraphic changes showed that cardiac mass index was significantly lower in both groups of malnourished cases compared to the controls with significant increase after nutritional rehabilitation. The study showed that the parameters of left ventricular (LV) systolic function which are the ejection fraction, fractional shortening and velocity of circumferential fiber shortening were not significantly reduced in patients compared to the controls. The diastolic function also showed no significant difference in the E wave/A wave (e/a) ratio between

Minor milk constituents are affected by protein concentration and forage digestibility in the feed ration

DEFF Research Database (Denmark)

Larsen, Torben; Alstrup, Lene; Weisbjerg, Martin Riis

2016-01-01

The present study was conducted in order to investigate if selected minor milk components would be indicative for the nutritional situation of the cow. Forty-eight dairy cows were offered a high digestible ration vs. a lower digestible ration combined with 2 protein levels in a 4 × 4 Latin square...... design. Milk glucose, glucose-6-phosphate, cholesterol, triacylglycerides (TAG), uric acid and β-hydroxybutyrate (BHBA) were measured and correlated mutually and towards other milking parameters (yield, h since last milking, days in milk (DIM), urea, etc). The variation range of the suggested variables...... were broad, a fact that may support their utilisation as predictive parameters. The content of milk metabolites was significantly affected by the change in rations as milk glucose, glucose-6-phosphate, uric acid, and the ratio cholesterol: triacylglycerides increased with higher energy intake while...

Chemical-genetic profile analysis in yeast suggests that a previously uncharacterized open reading frame, YBR261C, affects protein synthesis

Directory of Open Access Journals (Sweden)

Eroukova Veronika

2008-12-01

Full Text Available Abstract Background Functional genomics has received considerable attention in the post-genomic era, as it aims to identify function(s for different genes. One way to study gene function is to investigate the alterations in the responses of deletion mutants to different stimuli. Here we investigate the genetic profile of yeast non-essential gene deletion array (yGDA, ~4700 strains for increased sensitivity to paromomycin, which targets the process of protein synthesis. Results As expected, our analysis indicated that the majority of deletion strains (134 with increased sensitivity to paromomycin, are involved in protein biosynthesis. The remaining strains can be divided into smaller functional categories: metabolism (45, cellular component biogenesis and organization (28, DNA maintenance (21, transport (20, others (38 and unknown (39. These may represent minor cellular target sites (side-effects for paromomycin. They may also represent novel links to protein synthesis. One of these strains carries a deletion for a previously uncharacterized ORF, YBR261C, that we term TAE1 for Translation Associated Element 1. Our focused follow-up experiments indicated that deletion of TAE1 alters the ribosomal profile of the mutant cells. Also, gene deletion strain for TAE1 has defects in both translation efficiency and fidelity. Miniaturized synthetic genetic array analysis further indicates that TAE1 genetically interacts with 16 ribosomal protein genes. Phenotypic suppression analysis using TAE1 overexpression also links TAE1 to protein synthesis. Conclusion We show that a previously uncharacterized ORF, YBR261C, affects the process of protein synthesis and reaffirm that large-scale genetic profile analysis can be a useful tool to study novel gene function(s.

Chemical-genetic profile analysis in yeast suggests that a previously uncharacterized open reading frame, YBR261C, affects protein synthesis.

Science.gov (United States)

Alamgir, Md; Eroukova, Veronika; Jessulat, Matthew; Xu, Jianhua; Golshani, Ashkan

2008-12-03

Functional genomics has received considerable attention in the post-genomic era, as it aims to identify function(s) for different genes. One way to study gene function is to investigate the alterations in the responses of deletion mutants to different stimuli. Here we investigate the genetic profile of yeast non-essential gene deletion array (yGDA, approximately 4700 strains) for increased sensitivity to paromomycin, which targets the process of protein synthesis. As expected, our analysis indicated that the majority of deletion strains (134) with increased sensitivity to paromomycin, are involved in protein biosynthesis. The remaining strains can be divided into smaller functional categories: metabolism (45), cellular component biogenesis and organization (28), DNA maintenance (21), transport (20), others (38) and unknown (39). These may represent minor cellular target sites (side-effects) for paromomycin. They may also represent novel links to protein synthesis. One of these strains carries a deletion for a previously uncharacterized ORF, YBR261C, that we term TAE1 for Translation Associated Element 1. Our focused follow-up experiments indicated that deletion of TAE1 alters the ribosomal profile of the mutant cells. Also, gene deletion strain for TAE1 has defects in both translation efficiency and fidelity. Miniaturized synthetic genetic array analysis further indicates that TAE1 genetically interacts with 16 ribosomal protein genes. Phenotypic suppression analysis using TAE1 overexpression also links TAE1 to protein synthesis. We show that a previously uncharacterized ORF, YBR261C, affects the process of protein synthesis and reaffirm that large-scale genetic profile analysis can be a useful tool to study novel gene function(s).

Graphene oxide as a protein matrix: influence on protein biophysical properties.

Science.gov (United States)

Hernández-Cancel, Griselle; Suazo-Dávila, Dámaris; Ojeda-Cruzado, Axel J; García-Torres, Desiree; Cabrera, Carlos R; Griebenow, Kai

2015-10-19

This study provides fundamental information on the influence of graphene oxide (GO) nanosheets and glycans on protein catalytic activity, dynamics, and thermal stability. We provide evidence of protein stabilization by glycans and how this strategy could be implemented when GO nanosheets is used as protein immobilization matrix. A series of bioconjugates was constructed using two different strategies: adsorbing or covalently attaching native and glycosylated bilirubin oxidase (BOD) to GO. Bioconjugate formation was followed by FT-IR, zeta-potential, and X-ray photoelectron spectroscopy measurements. Enzyme kinetic parameters (k(m) and k(cat)) revealed that the substrate binding affinity was not affected by glycosylation and immobilization on GO, but the rate of enzyme catalysis was reduced. Structural analysis by circular dichroism showed that glycosylation did not affect the tertiary or the secondary structure of BOD. However, GO produced slight changes in the secondary structure. To shed light into the biophysical consequence of protein glycosylation and protein immobilization on GO nanosheets, we studied structural protein dynamical changes by FT-IR H/D exchange and thermal inactivation. It was found that glycosylation caused a reduction in structural dynamics that resulted in an increase in thermostability and a decrease in the catalytic activity for both, glycoconjugate and immobilized enzyme. These results establish the usefulness of chemical glycosylation to modulate protein structural dynamics and stability to develop a more stable GO-protein matrix.

Culture medium, gas atmosphere and MAPK inhibition affect regulation of RNA-binding protein targets during mouse preimplantation development.

Science.gov (United States)

Calder, Michele D; Watson, Patricia H; Watson, Andrew J

2011-11-01

During oogenesis, mammalian oocytes accumulate maternal mRNAs that support the embryo until embryonic genome activation. RNA-binding proteins (RBP) may regulate the stability and turnover of maternal and embryonic mRNAs. We hypothesised that varying embryo culture conditions, such as culture medium, oxygen tension and MAPK inhibition, affects regulation of RBPs and their targets during preimplantation development. STAU1, ELAVL1, KHSRP and ZFP36 proteins and mRNAs were detected throughout mouse preimplantation development, whereas Elavl2 mRNA decreased after the two-cell stage. Potential target mRNAs of RBP regulation, Gclc, Slc2a1 and Slc7a1 were detected during mouse preimplantation development. Gclc mRNA was significantly elevated in embryos cultured in Whitten's medium compared with embryos cultured in KSOMaa, and Gclc mRNA was elevated under high-oxygen conditions. Inhibition of the p38 MAPK pathway reduced Slc7a1 mRNA expression while inhibition of ERK increased Slc2a1 mRNA expression. The half-lives of the potential RBP mRNA targets are not regulated in parallel; Slc2a1 mRNA displayed the longest half-life. Our results indicate that mRNAs and proteins encoding five RBPs are present during preimplantation development and more importantly, demonstrate that expression of RBP target mRNAs are regulated by culture medium, gas atmosphere and MAPK pathways.

The RNA binding protein HuR does not interact directly with HIV-1 reverse transcriptase and does not affect reverse transcription in vitro

Directory of Open Access Journals (Sweden)

Gronenborn Angela M

2010-05-01

Full Text Available Abstract Background Lemay et al recently reported that the RNA binding protein HuR directly interacts with the ribonuclease H (RNase H domain of HIV-1 reverse transcriptase (RT and influences the efficiency of viral reverse transcription (Lemay et al., 2008, Retrovirology 5:47. HuR is a member of the embryonic lethal abnormal vision protein family and contains 3 RNA recognition motifs (RRMs that bind AU-rich elements (AREs. To define the structural determinants of the HuR-RT interaction and to elucidate the mechanism(s by which HuR influences HIV-1 reverse transcription activity in vitro, we cloned and purified full-length HuR as well as three additional protein constructs that contained the N-terminal and internal RRMs, the internal and C-terminal RRMs, or the C-terminal RRM only. Results All four HuR proteins were purified and characterized by biophysical methods. They are well structured and exist as monomers in solution. No direct protein-protein interaction between HuR and HIV-1 RT was detected using NMR titrations with 15N labeled HuR variants or the 15N labeled RNase H domain of HIV-1 RT. Furthermore, HuR did not significantly affect the kinetics of HIV-1 reverse transcription in vitro, even on RNA templates that contain AREs. Conclusions Our results suggest that HuR does not impact HIV-1 replication through a direct protein-protein interaction with the viral RT.

Muscle dysfunction in a zebrafish model of Duchenne muscular dystrophy.

Science.gov (United States)

Widrick, Jeffrey J; Alexander, Matthew S; Sanchez, Benjamin; Gibbs, Devin E; Kawahara, Genri; Beggs, Alan H; Kunkel, Louis M

2016-11-01

Sapje zebrafish lack the protein dystrophin and are the smallest vertebrate model of Duchenne muscular dystrophy (DMD). Their small size makes them ideal for large-scale drug discovery screens. However, the extent that sapje mimic the muscle dysfunction of higher vertebrate models of DMD is unclear. We used an optical birefringence assay to differentiate affected dystrophic sapje larvae from their unaffected siblings and then studied trunk muscle contractility at 4-7 days postfertilization. Preparation cross-sectional area (CSA) was similar for affected and unaffected larvae, yet tetanic forces of affected preparations were only 30-60% of normal. ANCOVA indicated that the linear relationship observed between tetanic force and CSA for unaffected preparations was absent in the affected population. Consequently, the average force/CSA of affected larvae was depressed 30-70%. Disproportionate reductions in twitch vs. tetanic force, and a slowing of twitch tension development and relaxation, indicated that the myofibrillar disorganization evident in the birefringence assay could not explain the entire force loss. Single eccentric contractions, in which activated preparations were lengthened 5-10%, resulted in tetanic force deficits in both groups of larvae. However, deficits of affected preparations were three- to fivefold greater at all strains and ages, even after accounting for any recovery. Based on these functional assessments, we conclude that the sapje mutant zebrafish is a phenotypically severe model of DMD. The severe contractile deficits of sapje larvae represent novel physiological endpoints for therapeutic drug screening. Copyright © 2016 the American Physiological Society.

Intrinsically Disordered Segments Affect Protein Half-Life in the Cell and during Evolution

NARCIS (Netherlands)

Lee, R.T.J.G. van der; Lang, B.; Kruse, K.; Gsponer, J.; Groot, N.; Huynen, M.A.; Matouschek, A.; Fuxreiter, M.; Babu, M.M.

2014-01-01

Precise control of protein turnover is essential for cellular homeostasis. The ubiquitin-proteasome system is well established as a major regulator of protein degradation, but an understanding of how inherent structural features influence the lifetimes of proteins is lacking. We report that yeast,

Nicotine reward and affective nicotine withdrawal signs are attenuated in calcium/calmodulin-dependent protein kinase IV knockout mice.

Directory of Open Access Journals (Sweden)

Kia J Jackson

Full Text Available The influx of Ca(2+ through calcium-permeable nicotinic acetylcholine receptors (nAChRs leads to activation of various downstream processes that may be relevant to nicotine-mediated behaviors. The calcium activated protein, calcium/calmodulin-dependent protein kinase IV (CaMKIV phosphorylates the downstream transcription factor cyclic AMP response element binding protein (CREB, which mediates nicotine responses; however the role of CaMKIV in nicotine dependence is unknown. Given the proposed role of CaMKIV in CREB activation, we hypothesized that CaMKIV might be a crucial molecular component in the development of nicotine dependence. Using male CaMKIV genetically modified mice, we found that nicotine reward is attenuated in CaMKIV knockout (-/- mice, but cocaine reward is enhanced in these mice. CaMKIV protein levels were also increased in the nucleus accumbens of C57Bl/6 mice after nicotine reward. In a nicotine withdrawal assessment, anxiety-related behavior, but not somatic signs or the hyperalgesia response are attenuated in CaMKIV -/- mice. To complement our animal studies, we also conducted a human genetic association analysis and found that variants in the CaMKIV gene are associated with a protective effect against nicotine dependence. Taken together, our results support an important role for CaMKIV in nicotine reward, and suggest that CaMKIV has opposing roles in nicotine and cocaine reward. Further, CaMKIV mediates affective, but not physical nicotine withdrawal signs, and has a protective effect against nicotine dependence in human genetic association studies. These findings further indicate the importance of calcium-dependent mechanisms in mediating behaviors associated with drugs of abuse.

Fragile X Mental Retardation Protein Is Required to Maintain Visual Conditioning-Induced Behavioral Plasticity by Limiting Local Protein Synthesis.

Science.gov (United States)

Liu, Han-Hsuan; Cline, Hollis T

2016-07-06

Fragile X mental retardation protein (FMRP) is thought to regulate neuronal plasticity by limiting dendritic protein synthesis, but direct demonstration of a requirement for FMRP control of local protein synthesis during behavioral plasticity is lacking. Here we tested whether FMRP knockdown in Xenopus optic tectum affects local protein synthesis in vivo and whether FMRP knockdown affects protein synthesis-dependent visual avoidance behavioral plasticity. We tagged newly synthesized proteins by incorporation of the noncanonical amino acid azidohomoalanine and visualized them with fluorescent noncanonical amino acid tagging (FUNCAT). Visual conditioning and FMRP knockdown produce similar increases in FUNCAT in tectal neuropil. Induction of visual conditioning-dependent behavioral plasticity occurs normally in FMRP knockdown animals, but plasticity degrades over 24 h. These results indicate that FMRP affects visual conditioning-induced local protein synthesis and is required to maintain the visual conditioning-induced behavioral plasticity. Fragile X syndrome (FXS) is the most common form of inherited intellectual disability. Exaggerated dendritic protein synthesis resulting from loss of fragile X mental retardation protein (FMRP) is thought to underlie cognitive deficits in FXS, but no direct evidence has demonstrated that FMRP-regulated dendritic protein synthesis affects behavioral plasticity in intact animals. Xenopus tadpoles exhibit a visual avoidance behavior that improves with visual conditioning in a protein synthesis-dependent manner. We showed that FMRP knockdown and visual conditioning dramatically increase protein synthesis in neuronal processes. Furthermore, induction of visual conditioning-dependent behavioral plasticity occurs normally after FMRP knockdown, but performance rapidly deteriorated in the absence of FMRP. These studies show that FMRP negatively regulates local protein synthesis and is required to maintain visual conditioning

Interactions of protein content and globulin subunit composition of soybean proteins in relation to tofu gel properties.

Science.gov (United States)

James, Andrew T; Yang, Aijun

2016-03-01

The content and globulin subunit composition of soybean proteins are known to affect tofu quality and food-grade soybeans usually have higher levels of proteins. We studied the tofu quality of soybeans with high (44.8%) or low (39.1%) protein content and with or without the 11S globulin polypeptide, 11SA4. Both protein content and 11SA4 significantly affected tofu gel properties. Soybeans containing more protein had smaller seeds which produced significantly firmer (0.663 vs.0.557 N, pseed size, tofu hardness and water holding capacity and led to significant changes to the profile of storage protein subunits, which may have contributed to the improvement in tofu gel properties. These results suggest that, in combination with higher protein content, certain protein subunits or their polypeptides can also be targeted in selecting soybeans to further improve soy food quality. Copyright © 2015 Elsevier Ltd. All rights reserved.

RNA editing differently affects protein-coding genes in D. melanogaster and H. sapiens.

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Grassi, Luigi; Leoni, Guido; Tramontano, Anna

2015-07-14

When an RNA editing event occurs within a coding sequence it can lead to a different encoded amino acid. The biological significance of these events remains an open question: they can modulate protein functionality, increase the complexity of transcriptomes or arise from a loose specificity of the involved enzymes. We analysed the editing events in coding regions that produce or not a change in the encoded amino acid (nonsynonymous and synonymous events, respectively) in D. melanogaster and in H. sapiens and compared them with the appropriate random models. Interestingly, our results show that the phenomenon has rather different characteristics in the two organisms. For example, we confirm the observation that editing events occur more frequently in non-coding than in coding regions, and report that this effect is much more evident in H. sapiens. Additionally, in this latter organism, editing events tend to affect less conserved residues. The less frequently occurring editing events in Drosophila tend to avoid drastic amino acid changes. Interestingly, we find that, in Drosophila, changes from less frequently used codons to more frequently used ones are favoured, while this is not the case in H. sapiens.

The protein type within a hypocaloric diet affects obesity-related inflammation: the RESMENA project.

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Lopez-Legarrea, Patricia; de la Iglesia, Rocio; Abete, Itziar; Navas-Carretero, Santiago; Martinez, J Alfredo; Zulet, M Angeles

2014-04-01

The aim of this study was to compare the effect of two energy-restricted, differing with regard to protein content, on the inflammation state of obese individuals with features of metabolic syndrome. Ninety-six participants completed an 8-wk randomized intervention trial that compared the RESMENA diet (-30% energy, with 30% energy from protein) with a control diet (-30% energy, with 15% energy from protein) that was based on American Heart Association criteria. The mean body weight losses were 7.09 ± 0.82 kg and 6.73 ± 0.71 kg, respectively, with no differences seen between the groups. The endpoint inflammation score-which was based on high-sensitivity C-reactive protein, interleukin-6, tumor necrosis factor-α, and plasminogen activator inhibitor-1 levels-was significantly lower (P = 0.012) in the low-protein group (6.81 ± 2.32 versus 7.94 ± 1.94). The linear regression analyses revealed that total protein intake was positively associated with inflammation (P = 0.007) as well as with animal protein (P = 0.025) and meat protein (P = 0.015), but neither vegetable- nor fish-derived proteins were found to influence inflammatory status. Our results suggest that the type of protein consumed (more than the total protein consumed) within an energy-restricted diet influences the inflammation status associated with obesity-related comorbidities. Copyright © 2014 Elsevier Inc. All rights reserved.

Human skeletal muscle: transition between fast and slow fibre types.

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Neunhäuserer, Daniel; Zebedin, Michaela; Obermoser, Magdalena; Moser, Gerhard; Tauber, Mark; Niebauer, Josef; Resch, Herbert; Galler, Stefan

2011-05-01

Human skeletal muscles consist of different fibre types: slow fibres (slow twitch or type I) containing the myosin heavy chain isoform (MHC)-I and fast fibres (fast twitch or type II) containing MHC-IIa (type IIA) or MHC-IId (type IID). The following order of decreasing kinetics is known: type IID > type IIA > type I. This order is especially based on the kinetics of stretch activation, which is the most discriminative property among fibre types. In this study we tested if hybrid fibres containing both MHC-IIa and MHC-I (type C fibres) provide a transition in kinetics between fast (type IIA) and slow fibres (type I). Our data of stretch activation kinetics suggest that type C fibres, with different ratios of MHC-IIa and MHC-I, do not provide a continuous transition. Instead, a specialized group of slow fibres, which we called "transition fibres", seems to provide a transition. Apart of their kinetics of stretch activation, which is most close to that of type IIA, the transition fibres are characterized by large cross-sectional areas and low maximal tensions. The molecular cause for the mechanical properties of the transition fibres is unknown. It is possible that the transition fibres contain an unknown slow MHC isoform, which cannot be separated by biochemical methods. Alternatively, or in addition, isoforms of myofibrillar proteins, other than MHC, and posttranslational modifications of myofibrillar proteins could play a role regarding the characteristics of the transition fibres.

Suppression of DNA-dependent protein kinase sensitize cells to radiation without affecting DSB repair

International Nuclear Information System (INIS)

Gustafsson, Ann-Sofie; Abramenkovs, Andris; Stenerlöw, Bo

2014-01-01

Highlights: • We reduced the level of DNA-PKcs with siRNA and examined cells after γ-irradiation. • Low DNA-PKcs levels lead to radiosensitivity but did not affect repair of DSB. • Low DNA-PKcs levels may block progression of mitosis. • DNA-PKcs role in mitotic progression is independent of its role in DSB repair. • We suggest different mechanisms by which loss of DNA-PKcs function sensitize cells. - Abstract: Efficient and correct repair of DNA double-strand break (DSB) is critical for cell survival. Defects in the DNA repair may lead to cell death, genomic instability and development of cancer. The catalytic subunit of DNA-dependent protein kinase (DNA-PKcs) is an essential component of the non-homologous end joining (NHEJ) which is the major DSB repair pathway in mammalian cells. In the present study, by using siRNA against DNA-PKcs in four human cell lines, we examined how low levels of DNA-PKcs affected cellular response to ionizing radiation. Decrease of DNA-PKcs levels by 80–95%, induced by siRNA treatment, lead to extreme radiosensitivity, similar to that seen in cells completely lacking DNA-PKcs and low levels of DNA-PKcs promoted cell accumulation in G2/M phase after irradiation and blocked progression of mitosis. Surprisingly, low levels of DNA-PKcs did not affect the repair capacity and the removal of 53BP1 or γ-H2AX foci and rejoining of DSB appeared normal. This was in strong contrast to cells completely lacking DNA-PKcs and cells treated with the DNA-PKcs inhibitor NU7441, in which DSB repair were severely compromised. This suggests that there are different mechanisms by which loss of DNA-PKcs functions can sensitize cells to ionizing radiation. Further, foci of phosphorylated DNA-PKcs (T2609 and S2056) co-localized with DSB and this was independent of the amount of DNA-PKcs but foci of DNA-PKcs was only seen in siRNA-treated cells. Our study emphasizes on the critical role of DNA-PKcs for maintaining survival after radiation exposure

Suppression of DNA-dependent protein kinase sensitize cells to radiation without affecting DSB repair

Energy Technology Data Exchange (ETDEWEB)

Gustafsson, Ann-Sofie, E-mail: ann-sofie.gustafsson@bms.uu.se; Abramenkovs, Andris; Stenerlöw, Bo

2014-11-15

Highlights: • We reduced the level of DNA-PKcs with siRNA and examined cells after γ-irradiation. • Low DNA-PKcs levels lead to radiosensitivity but did not affect repair of DSB. • Low DNA-PKcs levels may block progression of mitosis. • DNA-PKcs role in mitotic progression is independent of its role in DSB repair. • We suggest different mechanisms by which loss of DNA-PKcs function sensitize cells. - Abstract: Efficient and correct repair of DNA double-strand break (DSB) is critical for cell survival. Defects in the DNA repair may lead to cell death, genomic instability and development of cancer. The catalytic subunit of DNA-dependent protein kinase (DNA-PKcs) is an essential component of the non-homologous end joining (NHEJ) which is the major DSB repair pathway in mammalian cells. In the present study, by using siRNA against DNA-PKcs in four human cell lines, we examined how low levels of DNA-PKcs affected cellular response to ionizing radiation. Decrease of DNA-PKcs levels by 80–95%, induced by siRNA treatment, lead to extreme radiosensitivity, similar to that seen in cells completely lacking DNA-PKcs and low levels of DNA-PKcs promoted cell accumulation in G2/M phase after irradiation and blocked progression of mitosis. Surprisingly, low levels of DNA-PKcs did not affect the repair capacity and the removal of 53BP1 or γ-H2AX foci and rejoining of DSB appeared normal. This was in strong contrast to cells completely lacking DNA-PKcs and cells treated with the DNA-PKcs inhibitor NU7441, in which DSB repair were severely compromised. This suggests that there are different mechanisms by which loss of DNA-PKcs functions can sensitize cells to ionizing radiation. Further, foci of phosphorylated DNA-PKcs (T2609 and S2056) co-localized with DSB and this was independent of the amount of DNA-PKcs but foci of DNA-PKcs was only seen in siRNA-treated cells. Our study emphasizes on the critical role of DNA-PKcs for maintaining survival after radiation exposure

Alternative S2 Hinge Regions of the Myosin Rod Affect Myofibrillar Structure and Myosin Kinetics

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Miller, Mark S.; Dambacher, Corey M.; Knowles, Aileen F.; Braddock, Joan M.; Farman, Gerrie P.; Irving, Thomas C.; Swank, Douglas M.; Bernstein, Sanford I.; Maughan, David W.; (RPI); (IIT); (SDSU); (Vermont)

2009-07-01

The subfragment 2/light meromyosin 'hinge' region has been proposed to significantly contribute to muscle contraction force and/or speed. Transgenic replacement of the endogenous fast muscle isovariant hinge A (exon 15a) in Drosophila melanogaster indirect flight muscle with the slow muscle hinge B (exon 15b) allows examination of the structural and functional changes when only this region of the myosin molecule is different. Hinge B was previously shown to increase myosin rod length, increase A-band and sarcomere length, and decrease flight performance compared to hinge A. We applied additional measures to these transgenic lines to further evaluate the consequences of modifying this hinge region. Structurally, the longer A-band and sarcomere lengths found in the hinge B myofibrils appear to be due to the longitudinal addition of myosin heads. Functionally, hinge B, although a significant distance from the myosin catalytic domain, alters myosin kinetics in a manner consistent with this region increasing myosin rod length. These structural and functional changes combine to decrease whole fly wing-beat frequency and flight performance. Our results indicate that this hinge region plays an important role in determining myosin kinetics and in regulating thick and thin filament lengths as well as sarcomere length.

Rift Valley fever virus NSs protein functions and the similarity to other bunyavirus NSs proteins.

Science.gov (United States)

Ly, Hoai J; Ikegami, Tetsuro

2016-07-02

Rift Valley fever is a mosquito-borne zoonotic disease that affects both ruminants and humans. The nonstructural (NS) protein, which is a major virulence factor for Rift Valley fever virus (RVFV), is encoded on the S-segment. Through the cullin 1-Skp1-Fbox E3 ligase complex, the NSs protein promotes the degradation of at least two host proteins, the TFIIH p62 and the PKR proteins. NSs protein bridges the Fbox protein with subsequent substrates, and facilitates the transfer of ubiquitin. The SAP30-YY1 complex also bridges the NSs protein with chromatin DNA, affecting cohesion and segregation of chromatin DNA as well as the activation of interferon-β promoter. The presence of NSs filaments in the nucleus induces DNA damage responses and causes cell-cycle arrest, p53 activation, and apoptosis. Despite the fact that NSs proteins have poor amino acid similarity among bunyaviruses, the strategy utilized to hijack host cells are similar. This review will provide and summarize an update of recent findings pertaining to the biological functions of the NSs protein of RVFV as well as the differences from those of other bunyaviruses.

The 96th Amino Acid of the Coat Protein of Cucumber Green Mottle Mosaic Virus Affects Virus Infectivity

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Zhenwei Zhang

2017-12-01

Full Text Available Cucumber green mottle mosaic virus (CGMMV is one of the most devastating viruses infecting members of the family Cucurbitaceae. The assembly initiation site of CGMMV is located in the coding region of the coat protein, which is not only involved in virion assembly but is also a key factor determining the long-distance movement of the virus. To understand the effect of assembly initiation site and the adjacent region on CGMMV infectivity, we created a GTT deletion mutation in the GAGGTTG assembly initiation site of the infectious clone of CGMMV, which we termed V97 (deletion mutation at residue 97 of coat protein, followed by the construction of the V94A and T104A mutants. We observed that these three mutations caused mosaic after Agrobacterium-mediated transformation in Nicotiana benthamiana, albeit with a significant delay compared to the wild type clone. The mutants also had a common spontaneous E96K mutation in the coat protein. These results indicated that the initial assembly site and the sequence of the adjacent region affected the infectivity of the virus and that E96 might play an essential role in this process. We constructed two single point mutants—E96A and E96K—and three double mutants—V94A-E96K, V97-E96K and T104A-E96K—to further understand the role of E96 in CGMMV pathogenesis. After inoculation in N. benthamiana, E96A showed delayed systemic symptoms, but the E96K and three double mutants exhibited typical symptoms of mosaic at seven days post-infection. Then, sap from CGMMV-infected N. benthamiana leaves was mechanically inoculated on watermelon plants. We confirmed that E96 affected CGMMV infection using double antibody sandwich-enzyme-linked immunosorbent assay (DAS-ELISA, reverse transcription-polymerase chain reaction (RT-PCR, and sequencing, which further confirmed the successful infection of the related mutants, and that E96K can compensate the effect of the V94, V97, and T104 mutations on virus infectivity. In

Factors affecting antioxidant activity of soybean meal and caseine protein hydrolysates

International Nuclear Information System (INIS)

Korczak, J.

1998-01-01

Antioxidative activity of protein hydrolysates was dependent on the raw material, condition of hydrolysis and lipid substrate used in model systems. Soybean meal hydrolysate was more active in lard and in linoleic acid emulsion than caseine hydrolysate, whereas caseine was more active in vegetable oils. Antioxidant activity of evaluated protein hydrolysates in all lipid systems, with or without oxidation catalysts, suggests them as natural food additives for lipid stabilization, thus for improvement of its nutritional value and sensory properties

A putative ATP/GTP binding protein affects Leishmania mexicana growth in insect vectors and vertebrate hosts

Science.gov (United States)

Hlaváčová, Jana; Zimmer, Sara L.; Butenko, Anzhelika; Podešvová, Lucie; Leštinová, Tereza; Lukeš, Julius; Kostygov, Alexei; Votýpka, Jan; Volf, Petr

2017-01-01

Background Leishmania virulence factors responsible for the complicated epidemiology of the various leishmaniases remain mainly unidentified. This study is a characterization of a gene previously identified as upregulated in two of three overlapping datasets containing putative factors important for Leishmania’s ability to establish mammalian intracellular infection and to colonize the gut of an insect vector. Methodology/Principal findings The investigated gene encodes ATP/GTP binding motif-containing protein related to Leishmania development 1 (ALD1), a cytosolic protein that contains a cryptic ATP/GTP binding P-loop. We compared differentiation, growth rates, and infective abilities of wild-type and ALD1 null mutant cell lines of L. mexicana. Loss of ALD1 results in retarded growth kinetics but not defects in differentiation in axenic culture. Similarly, when mice and the sand fly vector were infected with the ALD1 null mutant, the primary difference in infection and colonization phenotype relative to wild type was an inability to achieve maximal host pathogenicity. While ability of the ALD1 null mutant cells to infect macrophages in vitro was not affected, replication within macrophages was clearly curtailed. Conclusions/Significance L. mexicana ALD1, encoding a protein with no assigned functional domains or motifs, was identified utilizing multiple comparative analyses with the related and often experimentally overlooked monoxenous flagellates. We found that it plays a role in Leishmania infection and colonization in vitro and in vivo. Results suggest that ALD1 functions in L. mexicana’s general metabolic network, rather than function in specific aspect of virulence as anticipated from the compared datasets. This result validates our comparative genomics approach for finding relevant factors, yet highlights the importance of quality laboratory-based analysis of genes tagged by these methods. PMID:28742133

Categorizing Biases in High-Confidence High-Throughput Protein-Protein Interaction Data Sets*

Science.gov (United States)

Yu, Xueping; Ivanic, Joseph; Memišević, Vesna; Wallqvist, Anders; Reifman, Jaques

2011-01-01

We characterized and evaluated the functional attributes of three yeast high-confidence protein-protein interaction data sets derived from affinity purification/mass spectrometry, protein-fragment complementation assay, and yeast two-hybrid experiments. The interacting proteins retrieved from these data sets formed distinct, partially overlapping sets with different protein-protein interaction characteristics. These differences were primarily a function of the deployed experimental technologies used to recover these interactions. This affected the total coverage of interactions and was especially evident in the recovery of interactions among different functional classes of proteins. We found that the interaction data obtained by the yeast two-hybrid method was the least biased toward any particular functional characterization. In contrast, interacting proteins in the affinity purification/mass spectrometry and protein-fragment complementation assay data sets were over- and under-represented among distinct and different functional categories. We delineated how these differences affected protein complex organization in the network of interactions, in particular for strongly interacting complexes (e.g. RNA and protein synthesis) versus weak and transient interacting complexes (e.g. protein transport). We quantified methodological differences in detecting protein interactions from larger protein complexes, in the correlation of protein abundance among interacting proteins, and in their connectivity of essential proteins. In the latter case, we showed that minimizing inherent methodology biases removed many of the ambiguous conclusions about protein essentiality and protein connectivity. We used these findings to rationalize how biological insights obtained by analyzing data sets originating from different sources sometimes do not agree or may even contradict each other. An important corollary of this work was that discrepancies in biological insights did not

Human Polycomb group EED protein negatively affects HIV-1 assembly and release

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Darlix Jean-Luc

2007-06-01

Full Text Available Abstract Background The human EED protein, a member of the superfamily of Polycomb group (PcG proteins with WD-40 repeats, has been found to interact with three HIV-1 components, namely the structural Gag matrix protein (MA, the integrase enzyme (IN and the Nef protein. The aim of the present study was to analyze the possible biological role of EED in HIV-1 replication, using the HIV-1-based vector HIV-Luc and EED protein expressed by DNA transfection of 293T cells. Results During the early phase of HIV-1 infection, a slight negative effect on virus infectivity occurred in EED-expressing cells, which appeared to be dependent on EED-MA interaction. At late times post infection, EED caused an important reduction of virus production, from 20- to 25-fold as determined by CAp24 immunoassay, to 10- to 80-fold based on genomic RNA levels, and this decrease was not due to a reduction of Gag protein synthesis. Coexpression of WTNef, or the non-N-myristoylated mutant NefG2A, restored virus yields to levels obtained in the absence of exogenous EED protein. This effect was not observed with mutant NefΔ57 mimicking the Nef core, or with the lipid raft-retargeted fusion protein LAT-Nef. LATAA-Nef, a mutant defective in the lipid raft addressing function, had the same anti-EED effect as WTNef. Cell fractionation and confocal imaging showed that, in the absence of Nef, EED mainly localized in membrane domains different from the lipid rafts. Upon co-expression with WTNef, NefG2A or LATAA-Nef, but not with NefΔ57 or LAT-Nef, EED was found to relocate into an insoluble fraction along with Nef protein. Electron microscopy of HIV-Luc producer cells overexpressing EED showed significant less virus budding at the cell surface compared to control cells, and ectopic assembly and clustering of nuclear pore complexes within the cytoplasm. Conclusion Our data suggested that EED exerted an antiviral activity at the late stage of HIV-1 replication, which included genomic

The relationship between protein synthesis and protein degradation in object recognition memory.

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Furini, Cristiane R G; Myskiw, Jociane de C; Schmidt, Bianca E; Zinn, Carolina G; Peixoto, Patricia B; Pereira, Luiza D; Izquierdo, Ivan

2015-11-01

For decades there has been a consensus that de novo protein synthesis is necessary for long-term memory. A second round of protein synthesis has been described for both extinction and reconsolidation following an unreinforced test session. Recently, it was shown that consolidation and reconsolidation depend not only on protein synthesis but also on protein degradation by the ubiquitin-proteasome system (UPS), a major mechanism responsible for protein turnover. However, the involvement of UPS on consolidation and reconsolidation of object recognition memory remains unknown. Here we investigate in the CA1 region of the dorsal hippocampus the involvement of UPS-mediated protein degradation in consolidation and reconsolidation of object recognition memory. Animals with infusion cannulae stereotaxically implanted in the CA1 region of the dorsal hippocampus, were exposed to an object recognition task. The UPS inhibitor β-Lactacystin did not affect the consolidation and the reconsolidation of object recognition memory at doses known to affect other forms of memory (inhibitory avoidance, spatial learning in a water maze) while the protein synthesis inhibitor anisomycin impaired the consolidation and the reconsolidation of the object recognition memory. However, β-Lactacystin was able to reverse the impairment caused by anisomycin on the reconsolidation process in the CA1 region of the hippocampus. Therefore, it is possible to postulate a direct link between protein degradation and protein synthesis during the reconsolidation of the object recognition memory. Copyright © 2015 Elsevier B.V. All rights reserved.

Zinc finger protein rotund deficiency affects development of the thoracic leg in Bombyx mori.

Science.gov (United States)

Zhou, Chun-Yan; Zha, Xing-Fu; Liu, Hua-Wei; Xia, Qing-You

2017-06-01

The insect limb develops from the imaginal disc or larval leg during metamorphosis. The molecular mechanisms involved in the development from the larval to the adult leg are poorly understood. Herein, we cloned the full length of a zinc finger gene rotund from Bombyx mori (Bmrn), which contained a 1419 bp open reading frame, and encoded a 473 amino acid protein. Reverse transcription polymerase chain reaction and Western blot analyses demonstrated that Bmrn was expressed at higher levels in the epidermis than in other tissues tested, and it showed a very high expression level during metamorphosis. Knock-down of Bmrn produced defects in the tarsus and pretarsus, including the fusion and reduction of tarsomeres, and the developmental arrest of pretarsus. Our data showed that Bmrn is involved in the formation of the tarsus and pretarsus, whereas its homologous gene in Drosophila has been shown to affect three tarsal segments (t2-t4), suggesting that the remodeling of the leg has involved changes in the patterning of gene regulation during evolution. © 2016 Institute of Zoology, Chinese Academy of Sciences.

Amino acid changes within the E protein hinge region that affect dengue virus type 2 infectivity and fusion

International Nuclear Information System (INIS)

Butrapet, Siritorn; Childers, Thomas; Moss, Kelley J.; Erb, Steven M.; Luy, Betty E.; Calvert, Amanda E.; Blair, Carol D.; Roehrig, John T.; Huang, Claire Y.-H.

2011-01-01

Fifteen mutant dengue viruses were engineered and used to identify AAs in the molecular hinge of the envelope protein that are critical to viral infection. Substitutions at Q52, A54, or E133 reduced infectivity in mammalian cells and altered the pH threshold of fusion. Mutations at F193, G266, I270, or G281 affected viral replication in mammalian and mosquito cells, but only I270W had reduced fusion activity. T280Y affected the pH threshold for fusion and reduced replication in C6/36 cells. Three different mutations at L135 were lethal in mammalian cells. Among them, L135G abrogated fusion and reduced replication in C6/36 cells, but only slightly reduced the mosquito infection rate. Conversely, L135W replicated well in C6/36 cells, but had the lowest mosquito infection rate. Possible interactions between hinge residues 52 and 277, or among 53, 135, 170, 186, 265, and 276 required for hinge function were discovered by sequence analysis to identify compensatory mutations.

Body Position Modulates Gastric Emptying and Affects the Post-Prandial Rise in Plasma Amino Acid Concentrations Following Protein Ingestion in Humans

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Andrew M. Holwerda

2016-04-01

Full Text Available Dietary protein digestion and amino acid absorption kinetics determine the post-prandial muscle protein synthetic response. Body position may affect gastrointestinal function and modulate the post-prandial rise in plasma amino acid availability. We aimed to assess the impact of body position on gastric emptying rate and the post-prandial rise in plasma amino acid concentrations following ingestion of a single, meal-like amount of protein. In a randomized, cross-over design, eight healthy males (25 ± 2 years, 23.9 ± 0.8 kg·m−2 ingested 22 g protein and 1.5 g paracetamol (acetaminophen in an upright seated position (control and in a −20° head-down tilted position (inversion. Blood samples were collected during a 240-min post-prandial period and analyzed for paracetamol and plasma amino acid concentrations to assess gastric emptying rate and post-prandial amino acid availability, respectively. Peak plasma leucine concentrations were lower in the inversion compared with the control treatment (177 ± 15 vs. 236 ± 15 mmol·L−1, p < 0.05, which was accompanied by a lower plasma essential amino acid (EAA response over 240 min (31,956 ± 6441 vs. 50,351 ± 4015 AU; p < 0.05. Peak plasma paracetamol concentrations were lower in the inversion vs. control treatment (5.8 ± 1.1 vs. 10.0 ± 0.6 mg·L−1, p < 0.05. Gastric emptying rate and post-prandial plasma amino acid availability are significantly decreased after protein ingestion in a head-down tilted position. Therefore, upright body positioning should be considered when aiming to augment post-prandial muscle protein accretion in both health and disease.

Utilizing protein-lean coproducts from corn containing recombinant pharmaceutical proteins for ethanol production.

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Paraman, Ilankovan; Moeller, Lorena; Scott, M Paul; Wang, Kan; Glatz, Charles E; Johnson, Lawrence A

2010-10-13

Protein-lean fractions of corn (maize) containing recombinant (r) pharmaceutical proteins were evaluated as a potential feedstock to produce fuel ethanol. The levels of residual r-proteins in the coproduct, distillers dry grains with solubles (DDGS), were determined. Transgenic corn lines containing recombinant green fluorescence protein (r-GFP) and a recombinant subunit vaccine of Escherichia coli enterotoxin (r-LTB), primarily expressed in endosperm, and another two corn lines containing recombinant human collagen (r-CIα1) and r-GFP, primarily expressed in germ, were used as model systems. The kernels were either ground and used for fermentation or dry fractionated to recover germ-rich fractions prior to grinding for fermentation. The finished beers of whole ground kernels and r-protein-spent endosperm solids contained 127-139 and 138-155 g/L ethanol concentrations, respectively. The ethanol levels did not differ among transgenic and normal corn feedstocks, indicating the residual r-proteins did not negatively affect ethanol production. r-Protein extraction and germ removal also did not negatively affect fermentation of the remaining mass. Most r-proteins were inactivated during the mashing process used to prepare corn for fermentation. No functionally active r-GFP or r-LTB proteins were found after fermentation of the r-protein-spent solids; however, a small quantity of residual r-CIα1 was detected in DDGS, indicating that the safety of DDGS produced from transgenic grain for r-protein production needs to be evaluated for each event. Protease treatment during fermentation completely hydrolyzed the residual r-CIα1, and no residual r-proteins were detectable in DDGS.

Biophysics of protein evolution and evolutionary protein biophysics

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Sikosek, Tobias; Chan, Hue Sun

2014-01-01

The study of molecular evolution at the level of protein-coding genes often entails comparing large datasets of sequences to infer their evolutionary relationships. Despite the importance of a protein's structure and conformational dynamics to its function and thus its fitness, common phylogenetic methods embody minimal biophysical knowledge of proteins. To underscore the biophysical constraints on natural selection, we survey effects of protein mutations, highlighting the physical basis for marginal stability of natural globular proteins and how requirement for kinetic stability and avoidance of misfolding and misinteractions might have affected protein evolution. The biophysical underpinnings of these effects have been addressed by models with an explicit coarse-grained spatial representation of the polypeptide chain. Sequence–structure mappings based on such models are powerful conceptual tools that rationalize mutational robustness, evolvability, epistasis, promiscuous function performed by ‘hidden’ conformational states, resolution of adaptive conflicts and conformational switches in the evolution from one protein fold to another. Recently, protein biophysics has been applied to derive more accurate evolutionary accounts of sequence data. Methods have also been developed to exploit sequence-based evolutionary information to predict biophysical behaviours of proteins. The success of these approaches demonstrates a deep synergy between the fields of protein biophysics and protein evolution. PMID:25165599

Comparative decline of the protein profiles of nebulin in response to denervation in skeletal muscle

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Wei, Jih-Hua [Department of Internal Medicine, Min-Sheng General Hospital, Taoyuan, Taiwan (China); Chang, Nen-Chung [Division of Cardiology, Department of Internal Medicine, College of Medicine, Taipei Medical University Hospital, Taipei, Taiwan (China); Chen, Sy-Ping [Department of Nursing, Chang Gung University of Science and Technology, Taoyuan, Taiwan (China); Geraldine, Pitchairaj [Department of Animal Science, School of Life Sciences, Bharathidasan University, Tiruchirappalli, Tamil Nadu (India); Jayakumar, Thanasekaran, E-mail: tjaya_2002@yahoo.co.in [Department of Pharmacology and Graduate Institute of Medical Sciences, College of Medicine, Taipei Medical University, Taipei, Taiwan (China); Fong, Tsorng-Harn, E-mail: thfong@tmu.edu.tw [Department of Anatomy and Cell Biology, College of Medicine, Taipei Medical University, Taipei, Taiwan (China)

2015-10-09

The sliding filament model of the sarcomere was developed more than half a century ago. This model, consisting only of thin and thick filaments, has been efficacious in elucidating many, but not all, features of skeletal muscle. Work during the 1980s revealed the existence of two additional filaments: the giant filamentous proteins titin and nebulin. Nebulin, a giant myofibrillar protein, acts as a protein ruler to maintain the lattice arrays of thin filaments and plays a role in signal transduction and contractile regulation. However, the change of nebulin and its effect on thin filaments in denervation-induced atrophic muscle remains unclear. The purpose of this study is to examine the content and pattern of nebulin, myosin heavy chain (MHC), actin, and titin in innervated and denervated tibialis anterior (TA) muscles of rats using sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), densitometry and electron microscopic (EM) analyses. The results revealed that denervation induced muscle atrophy is accompanied by decreased nebulin content in a time-dependent manner. For instant, the levels of nebulin in denervated muscles were markedly (P < 0.05) decreased, about 24.6% and 40.2% in comparison with innervated muscle after denervation of 28 and 56 days, respectively. The nebulin/MHC, nebulin/actin, and nebulin/titin ratios were decreased, suggesting a concomitant reduction of nebulin in denervated muscle. Moreover, a western blotting assay proved that nebulin declined faster than titin on 28 and 56 days of denervated muscle. In addition, EM study revealed that the disturbed arrangements of myofilaments and a disorganized contractile apparatus were also observed in denervated muscle. Overall, the present study provides evidence that nebulin is more sensitive to the effect of denervation than MHC, actin, and titin. Nebulin decline indeed resulted in disintegrate of thin filaments and shortening of sarcomeres. - Highlights: • We successfully

Protein Turnover and Cellular Stress in Mildly and Severely Affected Muscles from Patients with Limb Girdle Muscular Dystrophy Type 2I

DEFF Research Database (Denmark)

Hauerslev, Simon; Sveen, Marie-Louise; Vissing, John

2013-01-01

Patients with Limb girdle muscular dystrophy type 2I (LGMD2I) are characterized by progressive muscle weakness and wasting primarily in the proximal muscles, while distal muscles often are spared. Our aim was to investigate if wasting could be caused by impaired regeneration in the proximal...... by using the developmental markers embryonic myosin heavy chain (eMHC) and neural cell adhesion molecule (NCAM) and also assessing satellite cell activation status by myogenin positivity. Severe muscle histopathology was occasionally observed in the proximal muscles of patients with LGMD2I whereas distal...... highly increased in severely affected muscles compared to mildly affected muscles. Our results indicate that alterations in the protein turnover and myostatin levels could progressively impair the muscle mass maintenance and/or regeneration resulting in gradual muscular atrophy....

The DnaJ-like zinc finger domain protein PSA2 affects light acclimation and chloroplast development in Arabidopsis thaliana

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Yan-Wen eWang

2016-03-01

Full Text Available The biosynthesis of chlorophylls and carotenoids and the assembly of thylakoid membranes are critical for the photoautotrophic growth of plants. Different factors are involved in these two processes. In recent years, members of the DnaJ-like zinc finger domain proteins have been found to take part in the biogenesis and/or the maintenance of plastids. One member of this family of proteins, PSA2, was recently found to localize to the thylakoid lumen and regulate the accumulation of photosystem I. In this study, we report that the silencing of PSA2 in Arabidopsis thaliana resulted in variegated leaves and retarded growth. Although both chlorophylls and total carotenoids decreased in the psa2 mutant, violaxanthin and zeaxanthin accumulated in the mutant seedlings grown under growth condition. Lower levels of non-photochemical quenching and electron transport rate were also found in the psa2 mutant seedlings under growth condition compared with those of the wild-type plants, indicating an impaired capability to acclimate to normal light irradiance when PSA2 was silenced. Moreover, we also observed an abnormal assembly of grana thylakoids and poorly developed stroma thylakoids in psa2 chloroplasts. Taken together, our results demonstrate that PSA2 is a member of the DnaJ-like zinc finger domain protein family that affects light acclimation and chloroplast development.

Protein tyrosine nitration in the cell cycle

International Nuclear Information System (INIS)

Jia, Min; Mateoiu, Claudia; Souchelnytskyi, Serhiy

2011-01-01

Highlights: → Enrichment of 3-nitrotyrosine containing proteins from cells synchronized in different phases of the cell cycle. → Identification of 76 tyrosine nitrated proteins that change expression during the cell cycle. → Nineteen identified proteins were previously described as regulators of cell proliferation. -- Abstract: Nitration of tyrosine residues in proteins is associated with cell response to oxidative/nitrosative stress. Tyrosine nitration is relatively low abundant post-translational modification that may affect protein functions. Little is known about the extent of protein tyrosine nitration in cells during progression through the cell cycle. Here we report identification of proteins enriched for tyrosine nitration in cells synchronized in G0/G1, S or G2/M phases of the cell cycle. We identified 27 proteins in cells synchronized in G0/G1 phase, 37 proteins in S phase synchronized cells, and 12 proteins related to G2/M phase. Nineteen of the identified proteins were previously described as regulators of cell proliferation. Thus, our data indicate which tyrosine nitrated proteins may affect regulation of the cell cycle.

Protein turnover and cellular stress in mildly and severely affected muscles from patients with limb girdle muscular dystrophy type 2I.

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Simon Hauerslev

Full Text Available Patients with Limb girdle muscular dystrophy type 2I (LGMD2I are characterized by progressive muscle weakness and wasting primarily in the proximal muscles, while distal muscles often are spared. Our aim was to investigate if wasting could be caused by impaired regeneration in the proximal compared to distal muscles. Biopsies were simultaneously obtained from proximal and distal muscles of the same patients with LGMD2I (n = 4 and healthy subjects (n = 4. The level of past muscle regeneration was evaluated by counting internally nucleated fibers and determining actively regenerating fibers by using the developmental markers embryonic myosin heavy chain (eMHC and neural cell adhesion molecule (NCAM and also assessing satellite cell activation status by myogenin positivity. Severe muscle histopathology was occasionally observed in the proximal muscles of patients with LGMD2I whereas distal muscles were always relatively spared. No difference was found in the regeneration markers internally nucleated fibers, actively regenerating fibers or activation status of satellite cells between proximal and distal muscles. Protein turnover, both synthesis and breakdown, as well as cellular stress were highly increased in severely affected muscles compared to mildly affected muscles. Our results indicate that alterations in the protein turnover and myostatin levels could progressively impair the muscle mass maintenance and/or regeneration resulting in gradual muscular atrophy.

Grape powder consumption affects the expression of neurodegeneration-related brain proteins in rats chronically fed a high-fructose-high-fat diet.

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Liao, Hsiang; Chou, Liang-Mao; Chien, Yi-Wen; Wu, Chi-Hao; Chang, Jung-Su; Lin, Ching-I; Lin, Shyh-Hsiang

2017-05-01

Abnormal glucose metabolism in the brain is recognized to be associated with cognitive decline. Because grapes are rich in polyphenols that produce antioxidative and blood sugar-lowering effects, we investigated how grape consumption affects the expression and/or phosphorylation of neurodegeneration-related brain proteins in aged rats fed a high-fructose-high-fat (HFHF) diet. Wistar rats were maintained on the HFHF diet from the age of 8 weeks to 66 weeks, and then on an HFHF diet containing either 3% or 6% grape powder as an intervention for 12 weeks. Western blotting was performed to measure the expression/phosphorylation levels of several cortical and hippocampal proteins, including amyloid precursor protein (APP), tau, phosphatidylinositol-3-kinase (PI3K), extracellular signal-regulated kinase (ERK), receptor for advanced glycation end products (RAGEs), erythroid 2-related factor 2 (Nrf2) and brain-derived neurotrophic factor (BDNF). Inclusion of up to 6% grape powder in the diet markedly reduced RAGE expression and tau hyperphosphorylation, but upregulated the expression of Nrf2 and BDNF, as well as the phosphorylation of PI3K and ERK, in the brain tissues of aged rats fed the HFHF diet. Thus, grape powder consumption produced beneficial effects in HFHF-diet-fed rats, exhibiting the potential to ameliorate changes in neurodegeneration-related proteins in the brain. Copyright © 2017 Elsevier Inc. All rights reserved.

Dynamic factors affecting gaseous ligand binding in an artificial oxygen transport protein.

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Zhang, Lei; Andersen, Eskil M E; Khajo, Abdelahad; Magliozzo, Richard S; Koder, Ronald L

2013-01-22

We report the functional analysis of an artificial hexacoordinate oxygen transport protein, HP7, which operates via a mechanism similar to that of human neuroglobin and cytoglobin: the destabilization of one of two heme-ligating histidine residues. In the case of HP7, this is the result of the coupling of histidine side chain ligation with the burial of three charged glutamate residues on the same helix. Here we compare gaseous ligand binding, including rates, affinities, and oxyferrous state lifetimes, of both heme binding sites in HP7. We find that despite the identical sequence of helices in both binding sites, there are differences in oxygen affinity and oxyferrous state lifetime that may be the result of differences in the freedom of motion imposed by the candelabra fold on the two sites of the protein. We further examine the effect of mutational removal of the buried glutamates on function. Heme iron in the ferrous state of this mutant is rapidly oxidized when exposed to oxygen. Compared to that of HP7, the distal histidine affinity is increased by a 22-fold decrease in the histidine ligand off rate. Electron paramagnetic resonance comparison of these ferric hemoproteins demonstrates that the mutation increases the level of disorder at the heme binding site. Nuclear magnetic resonance-detected deuterium exchange demonstrates that the mutation greatly increases the degree of penetration of water into the protein core. The inability of the mutant protein to bind oxygen may be due to an increased level of water penetration, the large decrease in binding rate caused by the increase in distal histidine affinity, or a combination of the two factors. Together, these data underline the importance of the control of protein dynamics in the design of functional artificial proteins.

Magnolol Affects Cellular Proliferation, Polyamine Biosynthesis and Catabolism-Linked Protein Expression and Associated Cellular Signaling Pathways in Human Prostate Cancer Cells in vitro

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Brendan T. McKeown

2015-01-01

Full Text Available Background: Prostate cancer is the most commonly diagnosed form of cancer in men in Canada and the United States. Both genetic and environmental factors contribute to the development and progression of many cancers, including prostate cancer. Context and purpose of this study: This study investigated the effects of magnolol, a compound found in the roots and bark of the magnolia tree Magnolia officinalis, on cellular proliferation and proliferation-linked activities of PC3 human prostate cancer cells in vitro. Results: PC3 cells exposed to magnolol at a concentration of 80 μM for 6 hours exhibited decreased protein expression of ornithine decarboxylase, a key regulator in polyamine biosynthesis, as well as affecting the expression of other proteins involved in polyamine biosynthesis and catabolism. Furthermore, protein expression of the R2 subunit of ribonucleotide reductase, a key regulatory protein associated with DNA synthesis, was significantly decreased. Finally, the MAPK (mitogen-activated protein kinase, PI3K (phosphatidylinositol 3-kinase, NFκB (nuclear factor of kappa-light-chain-enhancer of activated B cells and AP-1 (activator protein 1 cellular signaling pathways were assayed to determine which, if any, of these pathways magnolol exposure would alter. Protein expressions of p-JNK-1 and c-jun were significantly increased while p-p38, JNK-1/2, PI3Kp85, p-PI3Kp85, p-Akt, NFκBp65, p-IκBα and IκBα protein expressions were significantly decreased. Conclusions: These alterations further support the anti-proliferative effects of magnolol on PC3 human prostate cancer cells in vitro and suggest that magnolol may have potential as a novel anti-prostate cancer agent.

Energy and Protein Supplementation Does Not Affect Protein and Amino Acid Kinetics or Pregnancy Outcomes in Underweight Indian Women.

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Dwarkanath, Pratibha; Hsu, Jean W; Tang, Grace J; Anand, Pauline; Thomas, Tinku; Thomas, Annamma; Sheela, C N; Kurpad, Anura V; Jahoor, Farook

2016-02-01

In India, the prevalence of low birth weight is high in women with a low body mass index (BMI), suggesting that underweight women are not capable of providing adequate energy and protein for fetal growth. Furthermore, as pregnancy progresses, there is increased need to provide methyl groups for methylation reactions associated with the synthesis of new proteins and, unlike normal-BMI American women, low-BMI Indian women are unable to increase methionine transmethylation and remethylation rates as pregnancy progresses from trimester 1 to 3. This also negatively influences birth weight. The aim was to determine the effect of dietary supplementation with energy and protein from 12 ± 1 wk of gestation to time of delivery compared with no supplement on pregnancy outcomes, protein kinetics, and the fluxes of the methyl group donors serine and glycine. Protein kinetics and serine and glycine fluxes were measured by using standard stable isotope tracer methods in the fasting and postprandial states in 24 pregnant women aged 22.9 ± 0.7 y with low BMIs [BMI (in kg/m(2)) ≤18.5] at 12 ± 1 wk (trimester 1) and 30 ± 1 wk (trimester 3) of gestation. After the first measurement, subjects were randomly assigned to either receive the supplement (300 kcal/d, 15 g protein/d) or no supplement. Supplementation had no significant effect on any variable of pregnancy outcome, and except for fasting state decreases in leucine flux (125 ± 7.14 compared with 113 ± 5.06 μmol ⋅ kg(-1) ⋅ h(-1); P = 0.04) and nonoxidative disposal (110 ± 6.97 compared with 101 ± 3.69 μmol ⋅ kg(-1) ⋅ h(-1); P = 0.02) from trimesters 1 to 3, it had no effect on any other leucine kinetic variable or urea, glycine, and serine fluxes. We conclude that in Indian women with a low BMI, supplementation with energy and protein from week 12 of pregnancy to time of delivery does not improve pregnancy outcome, whole-body protein kinetics, or serine and glycine fluxes. © 2016 American Society for Nutrition.

NB protein does not affect influenza B virus replication in vitro and is not required for replication in or transmission between ferrets

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Elderfield, Ruth A.; Koutsakos, Marios; Frise, Rebecca; Bradley, Konrad; Ashcroft, Jonathan; Miah, Shanhjahan; Lackenby, Angie

2016-01-01

The influenza B virus encodes a unique protein, NB, a membrane protein whose function in the replication cycle is not, as yet, understood. We engineered a recombinant influenza B virus lacking NB expression, with no concomitant difference in expression or activity of viral neuraminidase (NA) protein, an important caveat since NA is encoded on the same segment and initiated from a start codon just 4 nt downstream of NB. Replication of the virus lacking NB was not different to wild-type virus with full-length NB in clonal immortalized or complex primary cell cultures. In the mouse model, virus lacking NB induced slightly lower IFN-α levels in infected lungs, but this did not affect virus titres or weight loss. In ferrets infected with a mixture of viruses that did or did not express NB, there was no fitness advantage for the virus that retained NB. Moreover, virus lacking NB protein was transmitted following respiratory droplet exposure of sentinel animals. These data suggest no role for NB in supporting replication or transmission in vivo in this animal model. The role of NB and the nature of selection to retain it in all natural influenza B viruses remain unclear. PMID:26703440

potential for quality protein maize for reducing protein- energy

African Journals Online (AJOL)

ACSS

social systems hampering QPM promotion and adoption and to identify ... affects growth and development. Protein- energy ... to purchase QPM seed leading to PEU reduction. Education ..... decision support framework “targetCSA”. Agricultural ...

Effect of acute heat stress and slaughter processing on poultry meat quality and postmortem carbohydrate metabolism.

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Wang, R H; Liang, R R; Lin, H; Zhu, L X; Zhang, Y M; Mao, Y W; Dong, P C; Niu, L B; Zhang, M H; Luo, X

2017-03-01

This study investigated the effects of acute heat stress and slaughter processing on poultry meat quality and carbohydrate metabolism. Broilers (200) were randomly divided into 2 groups receiving heat stress (HS; 36°C for one h), compared to a non-stressed control (C). At slaughter, each group was further divided into 2 groups for slaughter processing (L = laboratory; F = commercial factory). L group breasts were removed immediately after bleeding without carcass scalding or defeathering, and stored at 4°C. F group broilers were scalded (60°C, 45 s) after bleeding and defeathering. Then the breasts were removed and cooled in ice water until the core temperature was ≤4°C. Rates of Pectoralis core temperature and pH decline were changed by slaughter processing, but only HS affected ultimate pH in group L. HS muscles had higher L* values (P  0.05). Sarcoplasmic protein solubility was higher in F processed birds (P < 0.05). HS decreased the solubility of myofibrillar and total protein in the L-slaughtered birds. Thus, HS caused a higher frequency of accelerated muscle glycolysis than controls. Factory processing (chilling) could not completely eliminate the effects of accelerated glycolysis caused by pre-slaughter HS. © 2016 Poultry Science Association Inc.

Combined vitamin B-12 and balanced protein-energy supplementation affect homocysteine remethylation in the methionine cycle in pregnant south Indian women of low vitamin B-12 status

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Low-quality dietary protein intake and vitamin B-12 deficiency could interact to decrease methionine transmethylation and remethylation rates during pregnancy, and may affect epigenetic modifications of the fetal genome. The objective of this randomized, partially open-labeled intervention trial was...

Dietary protein sources differentially affect microbiota, mTOR activity and transcription of mTOR signaling pathways in the small intestine.

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Soumya K Kar

Full Text Available Dietary protein sources can have profound effects on host-microbe interactions in the gut that are critically important for immune resilience. However more knowledge is needed to assess the impact of different protein sources on gut and animal health. Thirty-six wildtype male C57BL/6J mice of 35 d age (n = 6/group; mean ± SEM body weight 21.9 ± 0.25 g were randomly assigned to groups fed for four weeks with semi synthetic diets prepared with one of the following protein sources containing (300 g/kg as fed basis: soybean meal (SBM, casein, partially delactosed whey powder, spray dried plasma protein, wheat gluten meal and yellow meal worm. At the end of the experiment, mice were sacrificed to collect ileal tissue to acquire gene expression data, and mammalian (mechanistic target of rapamycin (mTOR activity, ileal digesta to study changes in microbiota and serum to measure cytokines and chemokines. By genome-wide transcriptome analysis, we identified fourteen high level regulatory genes that are strongly affected in SBM-fed mice compared to the other experimental groups. They mostly related to the mTOR pathway. In addition, an increased (P < 0.05 concentration of granulocyte colony-stimulating factor was observed in serum of SBM-fed mice compared to other dietary groups. Moreover, by 16S rRNA sequencing, we observed that SBM-fed mice had higher (P < 0.05 abundances of Bacteroidales family S24-7, compared to the other dietary groups. We showed that measurements of genome-wide expression and microbiota composition in the mouse ileum reveal divergent responses to diets containing different protein sources, in particular for a diet based on SBM.

Mutations Affecting G-Protein Subunit α11 in Hypercalcemia and Hypocalcemia

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Babinsky, Valerie N.; Head, Rosie A.; Cranston, Treena; Rust, Nigel; Hobbs, Maurine R.; Heath, Hunter; Thakker, Rajesh V.

2013-01-01

BACKGROUND Familial hypocalciuric hypercalcemia is a genetically heterogeneous disorder with three variants: types 1, 2, and 3. Type 1 is due to loss-of-function mutations of the calcium-sensing receptor, a guanine nucleotide–binding protein (G-protein)–coupled receptor that signals through the G-protein subunit α11 (Gα11). Type 3 is associated with adaptor-related protein complex 2, sigma 1 subunit (AP2S1) mutations, which result in altered calcium-sensing receptor endocytosis. We hypothesized that type 2 is due to mutations effecting Gα11 loss of function, since Gα11 is involved in calcium-sensing receptor signaling, and its gene (GNA11) and the type 2 locus are colocalized on chromosome 19p13.3. We also postulated that mutations effecting Gα11 gain of function, like the mutations effecting calcium-sensing receptor gain of function that cause autosomal dominant hypocalcemia type 1, may lead to hypocalcemia. METHODS We performed GNA11 mutational analysis in a kindred with familial hypocalciuric hypercalcemia type 2 and in nine unrelated patients with familial hypocalciuric hypercalcemia who did not have mutations in the gene encoding the calcium-sensing receptor (CASR) or AP2S1. We also performed this analysis in eight unrelated patients with hypocalcemia who did not have CASR mutations. In addition, we studied the effects of GNA11 mutations on Gα11 protein structure and calcium-sensing receptor signaling in human embryonic kidney 293 (HEK293) cells. RESULTS The kindred with familial hypocalciuric hypercalcemia type 2 had an in-frame deletion of a conserved Gα11 isoleucine (Ile200del), and one of the nine unrelated patients with familial hypocalciuric hypercalcemia had a missense GNA11 mutation (Leu135Gln). Missense GNA11 mutations (Arg181Gln and Phe341Leu) were detected in two unrelated patients with hypocalcemia; they were therefore identified as having autosomal dominant hypocalcemia type 2. All four GNA11 mutations predicted disrupted protein

Application potential of ATR-FT/IR molecular spectroscopy in animal nutrition: revelation of protein molecular structures of canola meal and presscake, as affected by heat-processing methods, in relationship with their protein digestive behavior and utilization for dairy cattle.

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Theodoridou, Katerina; Yu, Peiqiang

2013-06-12

Protein quality relies not only on total protein but also on protein inherent structures. The most commonly occurring protein secondary structures (α-helix and β-sheet) may influence protein quality, nutrient utilization, and digestive behavior. The objectives of this study were to reveal the protein molecular structures of canola meal (yellow and brown) and presscake as affected by the heat-processing methods and to investigate the relationship between structure changes and protein rumen degradations kinetics, estimated protein intestinal digestibility, degraded protein balance, and metabolizable protein. Heat-processing conditions resulted in a higher value for α-helix and β-sheet for brown canola presscake compared to brown canola meal. The multivariate molecular spectral analyses (PCA, CLA) showed that there were significant molecular structural differences in the protein amide I and II fingerprint region (ca. 1700-1480 cm(-1)) between the brown canola meal and presscake. The in situ degradation parameters, amide I and II, and α-helix to β-sheet ratio (R_a_β) were positively correlated with the degradable fraction and the degradation rate. Modeling results showed that α-helix was positively correlated with the truly absorbed rumen synthesized microbial protein in the small intestine when using both the Dutch DVE/OEB system and the NRC-2001 model. Concerning the protein profiles, R_a_β was a better predictor for crude protein (79%) and for neutral detergent insoluble crude protein (68%). In conclusion, ATR-FT/IR molecular spectroscopy may be used to rapidly characterize feed structures at the molecular level and also as a potential predictor of feed functionality, digestive behavior, and nutrient utilization of canola feed.

Presence or absence of carbohydrates and the proportion of fat in a high-protein diet affect appetite suppression but not energy expenditure in normal-weight human subjects fed in energy balance.

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Veldhorst, Margriet A B; Westerterp, Klaas R; van Vught, Anneke J A H; Westerterp-Plantenga, Margriet S

2010-11-01

Two types of relatively high-protein diets, with a normal or low proportion of carbohydrates, have been shown effective for weight loss. The objective was to assess the significance of the presence or absence of carbohydrates and the proportion of fat in high-protein diets for affecting appetite suppression, energy expenditure, and fat oxidation in normal-weight subjects in energy balance. Subjects (aged 23 (sd 3) years and BMI 22·0 (sd 1·9) kg/m2) were stratified in two groups. Each was offered two diets in a randomised cross-over design: group 1 (n 22) - normal protein (NP; 10, 60 and 30 % energy (En%) from protein, carbohydrate and fat), high protein (HP; 30, 40 and 30 En%); group 2 (n 23) - normal protein (NP-g; 10, 60 and 30 En%), high protein, carbohydrate-free (HP-0C; 30, 0 and 70 En%) for 2 d; NP-g and HP-0C were preceded by glycogen-lowering exercise (day 1). Appetite was measured throughout day 2 using visual analogue scales (VAS). Energy expenditure (EE) and substrate oxidation (respiratory quotient; RQ) were measured in a respiration chamber (08.00 hours on day 2 until 07.30 hours on day 3). Fasting plasma β-hydroxybutyrate (BHB) concentration was measured (day 3). NP-g and NP did not differ in hunger, EE, RQ and BHB. HP-0C and HP v. NP-g and NP, respectively, were lower in hunger (P fat oxidation were higher on a high-protein diet without than with carbohydrates exchanged for fat. Energy expenditure was not affected by the carbohydrate content of a high-protein diet.

Data for in-depth characterisation of the lamb meat proteome from longissimus lumborum

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Tzer-Yang Yu

2015-06-01

Full Text Available This Data article provides Supplementary data related to the research article titled “In-depth characterisation of the lamb meat proteome from longissimus lumborum” by Yu et al. [1]. This research article reports the proteome catalogue of the 48 h post-mortem lamb longissimus lumborum. A list of 388 ovine-specific proteins were identified and characterised after separating the samples into sarcoplasmic, myofibrillar and insoluble fractions, followed by an in-depth shotgun proteomic evaluation and bioinformatic analysis. The detailed list of identified proteins, the annotated MS/MS spectra corresponding to the proteins identified by a single peptide-spectrum match, the raw Gene Ontology annotation data and other miscellaneous files, as will be described below, were contained in this Data article. We hope the data presented here will contribute to the current knowledge of the global protein composition of lamb skeletal muscle/meat.

Effects of soy sauce on physicochemical and textural properties of tumbled chicken breast.

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Kim, H W; Hwang, K E; Song, D H; Kim, Y J; Lim, Y B; Choi, J H; Choi, Y S; Kim, H Y; Kim, C J

2014-03-01

The objective of this study was to evaluate the effects of soy sauce on the physicochemical and textural properties of tumbled chicken breasts. Chicken breasts marinated with distilled water (Con), 4% NaCl solution, 4% NaCl and lactic acid solution (pH 4.9), and soy sauce solution (4% salt concentration and pH 4.9) were vacuum tumbled at 3°C for 60 min. The chicken breast marinated with soy sauce solution showed lower lightness and higher redness and yellowness due to the color of the soy sauce. The acidic marinades led to a decrease in pH value of tumbled chicken breast. The acidic marinades increased collagen solubility of sample compared with 4% NaCl solution, resulting in decreased shear force. Water-holding capacity, marination and cooking yields, and solubility of myofibrillar proteins were mainly affected by the presence of salt in the marinade, rather than by pH alternation. Our results suggested that soy sauce marination can improve the tenderness of tumbled chicken breast.

Toxicologic and Analytical Studies with T-2 and Related Trichothecene Mycotoxins

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1985-08-20

damaged myocytes, hypercontraction bands with myofibrillar, lysis or marked distension of sarcoplasmic reticulum with myofibrillar ly Is. * ’was...the increased activity of AST in both groups may suggest toxic or ischemic damage ’to visceral or muscular tissues. In the low dose group, systemic...pig. If there is a sudden change In the respiratory requirements, th? air accessory hose (Figure 3) can be used to rapidly add air to the distensible

N-linked glycans do not affect plasma membrane localization of multidrug resistance protein 4 (MRP4) but selectively alter its prostaglandin E2 transport activity.

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Miah, M Fahad; Conseil, Gwenaëlle; Cole, Susan P C

2016-01-22

Multidrug resistance protein 4 (MRP4) is a member of subfamily C of the ATP-binding cassette superfamily of membrane transport proteins. MRP4 mediates the ATP-dependent efflux of many endogenous and exogenous solutes across the plasma membrane, and in polarized cells, it localizes to the apical or basolateral plasma membrane depending on the tissue type. MRP4 is a 170 kDa glycoprotein and here we show that MRP4 is simultaneously N-glycosylated at Asn746 and Asn754. Furthermore, confocal immunofluorescence studies showed that N-glycans do not affect MRP4's apical membrane localization in polarized LLC-PK1 cells or basolateral membrane localization in polarized MDCKI cells. However, vesicular transport assays showed that N-glycans differentially affect MRP4's ability to transport prostaglandin E2, but not estradiol glucuronide. Together these data indicate that N-glycosylation at Asn746 and Asn754 is not essential for plasma membrane localization of MRP4 but cause substrate-selective effects on its transport activity. Copyright © 2015 Elsevier Inc. All rights reserved.

The protein precursors of peptides that affect the mechanics of connective tissue and/or muscle in the echinoderm Apostichopus japonicus.

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Maurice R Elphick

Full Text Available Peptides that cause muscle relaxation or contraction or that modulate electrically-induced muscle contraction have been discovered in the sea cucumber Apostichopus japonicus (Phylum Echinodermata; Class Holothuroidea. By analysing transcriptome sequence data, here the protein precursors of six of these myoactive peptides (the SALMFamides Sticho-MFamide-1 and -2, NGIWYamide, stichopin, GN-19 and GLRFA have been identified, providing novel insights on neuropeptide and endocrine-type signalling systems in echinoderms. The A. japonicus SALMFamide precursor comprises eight putative neuropeptides including both L-type and F-type SALMFamides, which contrasts with previous findings from the sea urchin Strongylocentrotus purpuratus where L-type and F-type SALMFamides are encoded by different genes. The NGIWYamide precursor contains five copies of NGIWYamide but, unlike other NG peptide-type neuropeptide precursors in deuterostomian invertebrates, the NGIWYamide precursor does not have a C-terminal neurophysin domain, indicating loss of this character in holothurians. NGIWYamide was originally discovered as a muscle contractant, but it also causes stiffening of mutable connective tissue in the body wall of A. japonicus, whilst holokinins (PLGYMFR and derivative peptides cause softening of the body wall. However, the mechanisms by which these peptides affect the stiffness of body wall connective tissue are unknown. Interestingly, analysis of the A. japonicus transcriptome reveals that the only protein containing the holokinin sequence PLGYMFR is an alpha-5 type collagen. This suggests that proteolysis of collagen may generate peptides (holokinins that affect body wall stiffness in sea cucumbers, providing a novel perspective on mechanisms of mutable connective tissue in echinoderms.

Heating and reduction affect the reaction with tannins of wine protein fractions differing in hydrophobicity.

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Marangon, Matteo; Vincenzi, Simone; Lucchetta, Marco; Curioni, Andrea

2010-02-15

During the storage, bottled white wines can manifest haziness due to the insolubilisation of the grape proteins that may 'survive' in the fermentation process. Although the exact mechanism of this occurrence is not fully understood, proteins and tannins are considered two of the key factors involved in wine hazing, since their aggregation leads to the formation of insoluble particles. To better understand this complex interaction, proteins and tannins from the same unfined Pinot grigio wine were separated. Wine proteins were then fractionated by hydrophobic interaction chromatography (HIC). A significant correlation between hydrophobicity of the wine protein fractions and the haze formed after reacting with wine tannins was found, with the most reactive fractions revealing (by SDS-PAGE and RP-HPLC analyses) the predominant presence of thaumatin-like proteins. Moreover, the effects of both protein heating and disulfide bonds reduction (with dithiotreithol) on haze formation in the presence of tannins were assessed. These treatments generally resulted in an improved reactivity with tannins, and this phenomenon was related to both the surface hydrophobicity and composition of the protein fractions. Therefore, haze formation in wines seems to be related to hydrophobic interactions occurring among proteins and tannins. These interactions should occur on hydrophobic tannin-binding sites, whose exposition on the proteins can depend on both protein heating and reduction. Copyright 2009 Elsevier B.V. All rights reserved.

Addition of Aegilops U and M Chromosomes Affects Protein and Dietary Fiber Content of Wholemeal Wheat Flour

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Marianna Rakszegi

2017-09-01

Full Text Available Cereal grain fiber is an important health-promoting component in the human diet. One option to improve dietary fiber content and composition in wheat is to introduce genes from its wild relatives Aegilops biuncialis and Aegilops geniculata. This study showed that the addition of chromosomes 2Ug, 4Ug, 5Ug, 7Ug, 2Mg, 5Mg, and 7Mg of Ae. geniculata and 3Ub, 2Mb, 3Mb, and 7Mb of Ae. biuncialis into bread wheat increased the seed protein content. Chromosomes 1Ug and 1Mg increased the proportion of polymeric glutenin proteins, while the addition of chromosomes 1Ub and 6Ub led to its decrease. Both Aegilops species had higher proportions of β-glucan compared to arabinoxylan (AX than wheat lines, and elevated β-glucan content was also observed in wheat chromosome addition lines 5U, 7U, and 7M. The AX content in wheat was increased by the addition of chromosomes 5Ug, 7Ug, and 1Ub while water-soluble AX was increased by the addition of chromosomes 5U, 5M, and 7M, and to a lesser extent by chromosomes 3, 4, 6Ug, and 2Mb. Chromosomes 5Ug and 7Mb also affected the structure of wheat AX, as shown by the pattern of oligosaccharides released by digestion with endoxylanase. These results will help to map genomic regions responsible for edible fiber content in Aegilops and will contribute to the efficient transfer of wild alleles in introgression breeding programs to obtain wheat varieties with improved health benefits.Key Message: Addition of Aegilops U- and M-genome chromosomes 5 and 7 improves seed protein and fiber content and composition in wheat.

Specific alterations in complement protein activity of little brown myotis (Myotis lucifugus hibernating in white-nose syndrome affected sites.

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Marianne S Moore

Full Text Available White-nose syndrome (WNS is the most devastating condition ever reported for hibernating bats, causing widespread mortality in the northeastern United States. The syndrome is characterized by cutaneous lesions caused by a recently identified psychrophilic and keratinophylic fungus (Geomyces destructans, depleted fat reserves, atypical behavior, and damage to wings; however, the proximate cause of mortality is still uncertain. To assess relative levels of immunocompetence in bats hibernating in WNS-affected sites compared with levels in unaffected bats, we describe blood plasma complement protein activity in hibernating little brown myotis (Myotis lucifugus based on microbicidal competence assays using Escherichia coli, Staphylococcus aureus and Candida albicans. Blood plasma from bats collected during mid-hibernation at WNS-affected sites had higher bactericidal ability against E. coli and S. aureus, but lower fungicidal ability against C. albicans when compared with blood plasma from bats collected at unaffected sites. Within affected sites during mid-hibernation, we observed no difference in microbicidal ability between bats displaying obvious fungal infections compared to those without. Bactericidal ability against E. coli decreased significantly as hibernation progressed in bats collected from an affected site. Bactericidal ability against E. coli and fungicidal ability against C. albicans were positively correlated with body mass index (BMI during late hibernation. We also compared complement activity against the three microbes within individuals and found that the ability of blood plasma from hibernating M. lucifugus to lyse microbial cells differed as follows: E. coli>S. aureus>C. albicans. Overall, bats affected by WNS experience both relatively elevated and reduced innate immune responses depending on the microbe tested, although the cause of observed immunological changes remains unknown. Additionally, considerable trade-offs may exist

Specific alterations in complement protein activity of little brown myotis (Myotis lucifugus) hibernating in white-nose syndrome affected sites.

Science.gov (United States)

Moore, Marianne S; Reichard, Jonathan D; Murtha, Timothy D; Zahedi, Bita; Fallier, Renee M; Kunz, Thomas H

2011-01-01

White-nose syndrome (WNS) is the most devastating condition ever reported for hibernating bats, causing widespread mortality in the northeastern United States. The syndrome is characterized by cutaneous lesions caused by a recently identified psychrophilic and keratinophylic fungus (Geomyces destructans), depleted fat reserves, atypical behavior, and damage to wings; however, the proximate cause of mortality is still uncertain. To assess relative levels of immunocompetence in bats hibernating in WNS-affected sites compared with levels in unaffected bats, we describe blood plasma complement protein activity in hibernating little brown myotis (Myotis lucifugus) based on microbicidal competence assays using Escherichia coli, Staphylococcus aureus and Candida albicans. Blood plasma from bats collected during mid-hibernation at WNS-affected sites had higher bactericidal ability against E. coli and S. aureus, but lower fungicidal ability against C. albicans when compared with blood plasma from bats collected at unaffected sites. Within affected sites during mid-hibernation, we observed no difference in microbicidal ability between bats displaying obvious fungal infections compared to those without. Bactericidal ability against E. coli decreased significantly as hibernation progressed in bats collected from an affected site. Bactericidal ability against E. coli and fungicidal ability against C. albicans were positively correlated with body mass index (BMI) during late hibernation. We also compared complement activity against the three microbes within individuals and found that the ability of blood plasma from hibernating M. lucifugus to lyse microbial cells differed as follows: E. coli>S. aureus>C. albicans. Overall, bats affected by WNS experience both relatively elevated and reduced innate immune responses depending on the microbe tested, although the cause of observed immunological changes remains unknown. Additionally, considerable trade-offs may exist between energy

Estimation of Serum Triglycerides, Serum Cholesterol, Total Protein, IgG Levels in Chronic Periodontitis Affected Elderly Patients: A Cross-Sectional Study.

Science.gov (United States)

Saravanan, A V; Ravishankar, P L; Kumar, Pradeep; Rajapandian, K; Kalaivani, V; Rajula, M Prem Blaisie

2017-01-01

The present study was conducted to evaluate the serum triglycerides, serum cholesterol, total protein, and IgG levels in elderly patients who were affected by periodontal disease. This study was conducted at the Rajah Muthiah Dental College and Hospital in the periodontics division. The study was conducted for a period of 3 months. This study is a prospective analytical study. Sixty individuals who were systemically healthy in the age group of 50 and above were included in this study. Control and experimental groups of 30 participants each were included. Plaque index, gingival index, probing pocket depth, and clinical attachment loss were recorded. Biochemical parameters such as serum cholesterol, serum triglycerides, total protein, and IgG levels were also evaluated and correlated with the periodontal parameters. Data was analyzed using SPSS version 16.0 (IBM Corp., Armonk, NY). The relationship between periodontal status and the biochemical parameters such as serum cholesterol, serum triglycerides, total protein, and IgG levels were evaluated by Student's t-test. There was no significant difference in the plaque and gingival scores between the experimental and control group. It was observed that serum cholesterol level and total protein level was lower in participants suffering from chronic periodontitis. Triglycerides level was significantly elevated in the experimental group. IgG, a level which is not significant, concluded that there is no difference in control and experimental group. It was concluded from the results obtained from the study that there is an association between serum triglycerides, serum cholesterol, total protein, and periodontal disease. However, further longitudinal and well-controlled studies are required to evaluate the relationship between these biochemical parameters and periodontal disease.

Gene Prioritization by Integrated Analysis of Protein Structural and Network Topological Properties for the Protein-Protein Interaction Network of Neurological Disorders

Directory of Open Access Journals (Sweden)

Yashna Paul

2016-01-01

Full Text Available Neurological disorders are known to show similar phenotypic manifestations like anxiety, depression, and cognitive impairment. There is a need to identify shared genetic markers and molecular pathways in these diseases, which lead to such comorbid conditions. Our study aims to prioritize novel genetic markers that might increase the susceptibility of patients affected with one neurological disorder to other diseases with similar manifestations. Identification of pathways involving common candidate markers will help in the development of improved diagnosis and treatments strategies for patients affected with neurological disorders. This systems biology study for the first time integratively uses 3D-structural protein interface descriptors and network topological properties that characterize proteins in a neurological protein interaction network, to aid the identification of genes that are previously not known to be shared between these diseases. Results of protein prioritization by machine learning have identified known as well as new genetic markers which might have direct or indirect involvement in several neurological disorders. Important gene hubs have also been identified that provide an evidence for shared molecular pathways in the neurological disease network.

Co-operative intra-protein structural response due to protein-protein complexation revealed through thermodynamic quantification: study of MDM2-p53 binding.

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Samanta, Sudipta; Mukherjee, Sanchita

2017-10-01

The p53 protein activation protects the organism from propagation of cells with damaged DNA having oncogenic mutations. In normal cells, activity of p53 is controlled by interaction with MDM2. The well understood p53-MDM2 interaction facilitates design of ligands that could potentially disrupt or prevent the complexation owing to its emergence as an important objective for cancer therapy. However, thermodynamic quantification of the p53-peptide induced structural changes of the MDM2-protein remains an area to be explored. This study attempts to understand the conformational free energy and entropy costs due to this complex formation from the histograms of dihedral angles generated from molecular dynamics simulations. Residue-specific quantification illustrates that, hydrophobic residues of the protein contribute maximum to the conformational thermodynamic changes. Thermodynamic quantification of structural changes of the protein unfold the fact that, p53 binding provides a source of inter-element cooperativity among the protein secondary structural elements, where the highest affected structural elements (α2 and α4) found at the binding site of the protein affects faraway structural elements (β1 and Loop1) of the protein. The communication perhaps involves water mediated hydrogen bonded network formation. Further, we infer that in inhibitory F19A mutation of P53, though Phe19 is important in the recognition process, it has less prominent contribution in the stability of the complex. Collectively, this study provides vivid microscopic understanding of the interaction within the protein complex along with exploring mutation sites, which will contribute further to engineer the protein function and binding affinity.

Co-operative intra-protein structural response due to protein-protein complexation revealed through thermodynamic quantification: study of MDM2-p53 binding

Science.gov (United States)

Samanta, Sudipta; Mukherjee, Sanchita

2017-10-01

The p53 protein activation protects the organism from propagation of cells with damaged DNA having oncogenic mutations. In normal cells, activity of p53 is controlled by interaction with MDM2. The well understood p53-MDM2 interaction facilitates design of ligands that could potentially disrupt or prevent the complexation owing to its emergence as an important objective for cancer therapy. However, thermodynamic quantification of the p53-peptide induced structural changes of the MDM2-protein remains an area to be explored. This study attempts to understand the conformational free energy and entropy costs due to this complex formation from the histograms of dihedral angles generated from molecular dynamics simulations. Residue-specific quantification illustrates that, hydrophobic residues of the protein contribute maximum to the conformational thermodynamic changes. Thermodynamic quantification of structural changes of the protein unfold the fact that, p53 binding provides a source of inter-element cooperativity among the protein secondary structural elements, where the highest affected structural elements (α2 and α4) found at the binding site of the protein affects faraway structural elements (β1 and Loop1) of the protein. The communication perhaps involves water mediated hydrogen bonded network formation. Further, we infer that in inhibitory F19A mutation of P53, though Phe19 is important in the recognition process, it has less prominent contribution in the stability of the complex. Collectively, this study provides vivid microscopic understanding of the interaction within the protein complex along with exploring mutation sites, which will contribute further to engineer the protein function and binding affinity.

Quality, functionality, and shelf life of fermented meat and meat products: A review.

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Kumar, Pavan; Chatli, M K; Verma, Akhilesh K; Mehta, Nitin; Malav, O P; Kumar, Devendra; Sharma, Neelesh

2017-09-02

Fermentation of meat is a traditional preservation method used widely for improving quality and shelf life of fermented meat products. Fermentation of meat causes a number of physical, biochemical, and microbial changes, which eventually impart functional properties, sensory characteristics, and nutritional aspects to these products and inhibit the growth of various pathogenic and spoilage microorganisms. These changes include acidification (carbohydrate catabolism), solubilization and gelation of myofibrillar and sarcoplasmic proteins of muscle, degradation of proteins and lipids, reduction of nitrate into nitrite, formation of nitrosomyoglobin, and dehydration. Dry-fermented sausages are increasingly being used as carrier of probiotics. The production of biogenic amines during fermentation can be controlled by selecting proper starter cultures and other preventive measures such as quality of raw materials, hygienic measures, temperature, etc.

GH and IGF-I levels are positively associated with musculotendinous collagen expression: Experiments in acromegalic and GHD patients

DEFF Research Database (Denmark)

Doessing, Simon; Holm, Lars; Heinemeier, Katja

2010-01-01

OBJECTIVE: Disproportionate growth of musculoskeletal tissue is a major cause of morbidity in both acromegalic (ACRO) and GH-deficient (GHD) patients. GH/IGF1 is likely to play an important role in the regulation of tendon and muscle collagen. We hypothesized that the local production of collagen...... is associated with the level of GH/IGF1.DESIGN AND METHODS: As primary outcomes, collagen mRNA expression and collagen protein fractional synthesis rate (FSR) were determined locally in skeletal muscle and tendon in nine ACRO and nine GHD patients. Moreover, muscle myofibrillar protein synthesis and tendon...... collagen morphology were determined.RESULTS AND CONCLUSIONS: Muscle collagen I and III mRNA expression was higher in ACRO patients versus GHD patients (PIGF1Ea and IGF1Ec...

Quantifying the molecular origins of opposite solvent effects on protein-protein interactions.

Directory of Open Access Journals (Sweden)

Vincent Vagenende

Full Text Available Although the nature of solvent-protein interactions is generally weak and non-specific, addition of cosolvents such as denaturants and osmolytes strengthens protein-protein interactions for some proteins, whereas it weakens protein-protein interactions for others. This is exemplified by the puzzling observation that addition of glycerol oppositely affects the association constants of two antibodies, D1.3 and D44.1, with lysozyme. To resolve this conundrum, we develop a methodology based on the thermodynamic principles of preferential interaction theory and the quantitative characterization of local protein solvation from molecular dynamics simulations. We find that changes of preferential solvent interactions at the protein-protein interface quantitatively account for the opposite effects of glycerol on the antibody-antigen association constants. Detailed characterization of local protein solvation in the free and associated protein states reveals how opposite solvent effects on protein-protein interactions depend on the extent of dewetting of the protein-protein contact region and on structural changes that alter cooperative solvent-protein interactions at the periphery of the protein-protein interface. These results demonstrate the direct relationship between macroscopic solvent effects on protein-protein interactions and atom-scale solvent-protein interactions, and establish a general methodology for predicting and understanding solvent effects on protein-protein interactions in diverse biological environments.

Peroxisome protein import: a complex journey.

Science.gov (United States)

Baker, Alison; Lanyon-Hogg, Thomas; Warriner, Stuart L

2016-06-15

The import of proteins into peroxisomes possesses many unusual features such as the ability to import folded proteins, and a surprising diversity of targeting signals with differing affinities that can be recognized by the same receptor. As understanding of the structure and function of many components of the protein import machinery has grown, an increasingly complex network of factors affecting each step of the import pathway has emerged. Structural studies have revealed the presence of additional interactions between cargo proteins and the PEX5 receptor that affect import potential, with a subtle network of cargo-induced conformational changes in PEX5 being involved in the import process. Biochemical studies have also indicated an interdependence of receptor-cargo import with release of unloaded receptor from the peroxisome. Here, we provide an update on recent literature concerning mechanisms of protein import into peroxisomes. © 2016 The Author(s).

Stage of lactation and corresponding diets affect in situ protein degradation by dairy cows.

Science.gov (United States)

Schadt, I; Mertens, D R; Van Soest, P J; Azzaro, G; Licitra, G

2014-12-01

The influence of stage of lactation and corresponding diets on rates of protein degradation (kd) is largely unstudied. Study objectives were to measure and compare in situ ruminal kd of crude protein (CP) and estimate rumen CP escape (rumen-undegradable protein; RUP) of selected feeds by cows at 3 stages of lactation fed corresponding diets, and to determine the incubation times needed in an enzymatic in vitro procedure, using 0.2 units of Streptomyces griseus protease per percent of true CP, that predicted in situ RUP. Residue CP was measured after in situ fermentation for 4, 8, 12, 24, 36, 48, and 72 h of 5 protein sources and 3 total mixed rations, which were fed to the in situ cows. Two nonlactating (dry) cows and 2 cows each at 190 (mid) and 90 (peak) days of lactation were used. Each pair of cows was offered free-choice diets that differed in composition to meet their corresponding nutrient requirements. Diets had decreasing proportions of forages and contained (dry matter basis) 11.9, 15.1 and 16.4% CP and 54.3, 40.3 and 35.3% neutral detergent fiber, for dry, mid, and peak TMR (TMR1, TMR2, and TMR3), respectively. Intakes were 10.3, 21.4, and 23.8kg of dry matter/d, respectively. Kinetic CP fractions (extractable, potentially degradable, undegradable, or slowly degradable) were unaffected by treatment. Lag time and kd varied among feeds. The kd was faster for all feeds (0.136/h) when incubated in dry-TMR1 cows compared with mid-TMR2 (0.097/h) or peak-TMR3 (0.098/h) cows, and no differences in lag time were detected. Calculated RUP, using estimated passage rates for each cow based on intake, differed between dry-TMR1 (0.382) and mid-TMR2 (0.559) or peak-TMR3 (0.626) cows, with a tendency for mid-TMR2 to be different from peak-TMR3. Using the average kd and lag time obtained from dry-TMR1 to calculate RUP for mid-TMR2 and peak-TMR3 cows using their passage rates reduced RUP values by 6.3 and 9.5 percentage units, respectively. Except for that of herring meal

High Dietary Protein Intake and Protein-Related Acid Load on Bone Health.

Science.gov (United States)

Cao, Jay J

2017-12-01

Consumption of high-protein diets is increasingly popular due to the benefits of protein on preserving lean mass and controlling appetite and satiety. The paper is to review recent clinical research assessing dietary protein on calcium metabolism and bone health. Epidemiological studies show that long-term, high-protein intake is positively associated with bone mineral density and reduced risk of bone fracture incidence. Short-term interventional studies demonstrate that a high-protein diet does not negatively affect calcium homeostasis. Existing evidence supports that the negative effects of the acid load of protein on urinary calcium excretion are offset by the beneficial skeletal effects of high-protein intake. Future research should focus on the role and the degree of contribution of other dietary and physiological factors, such as intake of fruits and vegetables, in reducing the acid load and further enhancing the anabolic effects of protein on the musculoskeletal system.

Monitoring and control of protein production in fungi

DEFF Research Database (Denmark)

Schalén, Martin

: • How is protein production affected on a single cell level due to environmental stress factors? • How can we improve heterologous protein production in filamentous fungi, and how does production in Aspergillus nidulans compare to protein production in the industrially exploited Aspergillus niger...... stress elements on the production of heterologous proteins in S. cerevisiae is investigated. A fluorescent reporter strain, producing an intracellular protein linked to tagRFP from the glycolytic PGK1 promoter is constructed. This strain is used to monitor the level of production in each cell when...... exposed to environmental stress. The cells are grown in shake flasks as well as bioreactors and protein levels are analyzed by flow cytometry. It is demonstrated that the fluorescent reporter can be used to study the effects on stress elements on a population basis. Production of the protein was affected...

Assembly of presynaptic filaments. Factors affecting the assembly of RecA protein onto single-stranded DNA

DEFF Research Database (Denmark)

Thresher, RJ; Christiansen, Gunna; Griffith, JD

1988-01-01

We have previously shown that the assembly of RecA protein onto single-stranded DNA (ssDNA) facilitated by SSB protein occurs in three steps: (1) rapid binding of SSB protein to the ssDNA; (2) nucleation of RecA protein onto this template; and (3) co-operative polymerization of additional Rec......M in the presence of 12 mM-Mg2+), and relatively low concentrations of SSB protein (1 monomer per 18 nucleotides). Assembly was depressed threefold when SSB protein was added to one monomer per nine nucleotides. These effects appeared to be exerted at the nucleation step. Following nucleation, RecA protein...... assembled onto ssDNA at net rates that varied from 250 to 900 RecA protein monomers per minute, with the rate inversely related to the concentration of SSB protein. Combined sucrose sedimentation and electron microscope analysis established that SSB protein was displaced from the ssDNA during RecA protein...

Prion protein polymorphisms affect chronic wasting disease progression.

Directory of Open Access Journals (Sweden)

Chad J Johnson

Full Text Available Analysis of the PRNP gene in cervids naturally infected with chronic wasting disease (CWD suggested that PRNP polymorphisms affect the susceptibility of deer to infection. To test this effect, we orally inoculated 12 white-tailed deer with CWD agent. Three different PRNP alleles, wild-type (wt; glutamine at amino acid 95 and glycine at 96, Q95H (glutamine to histidine at amino acid position 95 and G96S (glycine to serine at position 96 were represented in the study cohort with 5 wt/wt, 3 wt/G96S, and 1 each wt/Q95H and Q95H/G96S. Two animals were lost to follow-up due to intercurrent disease. The inoculum was prepared from Wisconsin hunter-harvested homozygous wt/wt animals. All infected deer presented with clinical signs of CWD; the orally infected wt/wt had an average survival period of 693 days post inoculation (dpi and G96S/wt deer had an average survival period of 956 dpi. The Q95H/wt and Q95H/G96S deer succumbed to CWD at 1,508 and 1,596 dpi respectively. These data show that polymorphisms in the PRNP gene affect CWD incubation period. Deer heterozygous for the PRNP alleles had extended incubation periods with the Q95H allele having the greatest effect.

Protein stability: a crystallographer’s perspective

Science.gov (United States)

Deller, Marc C.; Kong, Leopold; Rupp, Bernhard

2016-01-01

Protein stability is a topic of major interest for the biotechnology, pharmaceutical and food industries, in addition to being a daily consideration for academic researchers studying proteins. An understanding of protein stability is essential for optimizing the expression, purification, formulation, storage and structural studies of proteins. In this review, discussion will focus on factors affecting protein stability, on a somewhat practical level, particularly from the view of a protein crystallographer. The differences between protein conformational stability and protein compositional stability will be discussed, along with a brief introduction to key methods useful for analyzing protein stability. Finally, tactics for addressing protein-stability issues during protein expression, purification and crystallization will be discussed. PMID:26841758

Digestion and microbial protein synthesis in sheep as affected by ...

African Journals Online (AJOL)

Useni , Alain

enzyme (EFE) on the in vitro gas production (GP) and ANKOM digestion systems on the mixture of milled ... determine the EFE effect on the DM, CP and NDF digestion of a mixture of lucerne hay and wheat straw .... and the microbial protein synthesis (MPS) measured as purine derivates (RNA equivalent in µg/DM g) on.

Estimation of Serum Triglycerides, Serum Cholesterol, Total Protein, IgG Levels in Chronic Periodontitis Affected Elderly Patients: A Cross-Sectional Study

Science.gov (United States)

Saravanan, A. V.; Ravishankar, P. L.; Kumar, Pradeep; Rajapandian, K.; Kalaivani, V.; Rajula, M. Prem Blaisie

2017-01-01

Aim: The present study was conducted to evaluate the serum triglycerides, serum cholesterol, total protein, and IgG levels in elderly patients who were affected by periodontal disease. Materials and Methods: This study was conducted at the Rajah Muthiah Dental College and Hospital in the periodontics division. The study was conducted for a period of 3 months. This study is a prospective analytical study. Sixty individuals who were systemically healthy in the age group of 50 and above were included in this study. Control and experimental groups of 30 participants each were included. Plaque index, gingival index, probing pocket depth, and clinical attachment loss were recorded. Biochemical parameters such as serum cholesterol, serum triglycerides, total protein, and IgG levels were also evaluated and correlated with the periodontal parameters. Data was analyzed using SPSS version 16.0 (IBM Corp., Armonk, NY). The relationship between periodontal status and the biochemical parameters such as serum cholesterol, serum triglycerides, total protein, and IgG levels were evaluated by Student's t-test. Results: There was no significant difference in the plaque and gingival scores between the experimental and control group. It was observed that serum cholesterol level and total protein level was lower in participants suffering from chronic periodontitis. Triglycerides level was significantly elevated in the experimental group. IgG, a level which is not significant, concluded that there is no difference in control and experimental group. Conclusion: It was concluded from the results obtained from the study that there is an association between serum triglycerides, serum cholesterol, total protein, and periodontal disease. However, further longitudinal and well-controlled studies are required to evaluate the relationship between these biochemical parameters and periodontal disease. PMID:28462181

Hematological alterations in protein malnutrition.

Science.gov (United States)

Santos, Ed W; Oliveira, Dalila C; Silva, Graziela B; Tsujita, Maristela; Beltran, Jackeline O; Hastreiter, Araceli; Fock, Ricardo A; Borelli, Primavera

2017-11-01

Protein malnutrition is one of the most serious nutritional problems worldwide, affecting 794 million people and costing up to $3.5 trillion annually in the global economy. Protein malnutrition primarily affects children, the elderly, and hospitalized patients. Different degrees of protein deficiency lead to a broad spectrum of signs and symptoms of protein malnutrition, especially in organs in which the hematopoietic system is characterized by a high rate of protein turnover and, consequently, a high rate of protein renewal and cellular proliferation. Here, the current scientific information about protein malnutrition and its effects on the hematopoietic process is reviewed. The production of hematopoietic cells is described, with special attention given to the hematopoietic microenvironment and the development of stem cells. Advances in the study of hematopoiesis in protein malnutrition are also summarized. Studies of protein malnutrition in vitro, in animal models, and in humans demonstrate several alterations that impair hematopoiesis, such as structural changes in the extracellular matrix, the hematopoietic stem cell niche, the spleen, the thymus, and bone marrow stromal cells; changes in mesenchymal and hematopoietic stem cells; increased autophagy; G0/G1 cell-cycle arrest of progenitor hematopoietic cells; and functional alterations in leukocytes. Structural and cellular changes of the hematopoietic microenvironment in protein malnutrition contribute to bone marrow atrophy and nonestablishment of hematopoietic stem cells, resulting in impaired homeostasis and an impaired immune response. © The Author(s) 2017. Published by Oxford University Press on behalf of the International Life Sciences Institute. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

A high protein diet during pregnancy affects hepatic gene expression of energy sensing pathways along ontogenesis in a porcine model.

Directory of Open Access Journals (Sweden)

Michael Oster

Full Text Available In rodent models and in humans the impact of gestational diets on the offspring's phenotype was shown experimentally and epidemiologically. The underlying programming of fetal development was shown to be associated with an increased risk of degenerative diseases in adulthood, including the metabolic syndrome. There are clues that diet-dependent modifications of the metabolism during fetal life can persist until adulthood. This leads to the hypothesis that the offspring's transcriptomes show short-term and long-term changes depending on the maternal diet. To this end pregnant German landrace gilts were fed either a high protein diet (HP, 30% CP or an adequate protein diet (AP, 12% CP throughout pregnancy. Hepatic transcriptome profiles of the offspring were analyzed at prenatal (94 dpc and postnatal stages (1, 28, 188 dpn. Depending on the gestational dietary exposure, mRNA expression levels of genes related to energy metabolism, N-metabolism, growth factor signaling pathways, lipid metabolism, nucleic acid metabolism and stress/immune response were affected either in a short-term or in a long-term manner. Gene expression profiles at fetal stage 94 dpc were almost unchanged between the diets. The gestational HP diet affected the hepatic expression profiles at prenatal and postnatal stages. The effects encompassed a modulation of the genome in terms of an altered responsiveness of energy and nutrient sensing pathways. Differential expression of genes related to energy production and nutrient utilization contribute to the maintenance of development and growth performance within physiological norms, however the modulation of these pathways may be accompanied by a predisposition for metabolic disturbances up to adult stages.

A study of muscular tissue of animal origin by reflection-spectroscopy methods

Science.gov (United States)

Plotnikova, L. V.; Nechiporenko, A. P.; Orekhova, S. M.; Plotnikov, P. P.; Ishevskii, A. L.

2017-06-01

A comparative analysis of the spectral characteristics of the surface of muscular tissue of animal origin (pork) and its main components has been performed by the methods of diffuse reflection electronic spectroscopy (DRES) and frustrated total internal reflection IR spectroscopy. The experiments have shown that the application of the DRES method makes it possible to detect more pronounced changes in the surface optical characteristics of muscular tissue and obtain electronic spectra containing information about the component composition of its main parts under successive extraction of sarcoplasmic materials, myofibrillar proteins of the actomyosin complex, and stroma mucopolysaccharides.

Effects of protein supplements on muscle damage, soreness and recovery of muscle function and physical performance: a systematic review.

Science.gov (United States)

Pasiakos, Stefan M; Lieberman, Harris R; McLellan, Tom M

2014-05-01

demonstrating ingestion of a protein supplement following a bout of exercise attenuates muscle soreness and/or lowers markers of muscle damage. However, beneficial effects such as reduced muscle soreness and markers of muscle damage become more evident when supplemental protein is consumed after daily training sessions. Furthermore, the data suggest potential ergogenic effects associated with protein supplementation are greatest if participants are in negative nitrogen and/or energy balance. Small sample numbers and lack of dietary control limited the effectiveness of several investigations. In addition, studies did not measure the effects of protein supplementation on direct indices of muscle damage such as myofibrillar disruption and various measures of protein signaling indicative of a change in rates of protein synthesis and degradation. As a result, the interpretation of the data was often limited. Overwhelmingly, studies have consistently demonstrated the acute benefits of protein supplementation on post-exercise muscle anabolism, which, in theory, may facilitate the recovery of muscle function and performance. However, to date, when protein supplements are provided, acute changes in post-exercise protein synthesis and anabolic intracellular signaling have not resulted in measureable reductions in muscle damage and enhanced recovery of muscle function. Limitations in study designs together with the large variability in surrogate markers of muscle damage reduced the strength of the evidence-base.

Induction of protein X in Escherichia coli

International Nuclear Information System (INIS)

Little, J.W.; Hanawalt, P.C.

1977-01-01

The authors have examined some of the treatments that might induce protein X and they have, in particular, tested the hypothesis that DNA degradation products play an essential role in the induction process. UV irradiation, nalidixic acid treatment, or thymine starvation result in protein X synthesis in wild type strains. However, UV irradiation, unlike nalidixic acid, also induced protein X in recB strains, in which little DNA degradation occurs. The presence of DNA fragments resulting from hostcontrolled restriction of phage lambda DNA did not affect protein X synthesis. It was concluded that no causal relationship exists bewteen the production of DNA fragments and induction of protein X. The presence of the plasmid R 46, which confers enhanced mutagenesis and UV resistance on its host, did not affect protein X synthesis. Growth in the presence of 5-bromouracil, which does not result in production of degradation fragments, resulted eventually in a low rate of protein X synthesis. In dnaA mutants, deficient in the initiation of new rounds of replication, UV irradiation induced protein X, again unlike nalidixic acid. Thus, the inhibition of active replication forks is not an essential requirement for protein X induction. (orig./MG) [de

The Networks of Genes Encoding Palmitoylated Proteins in Axonal and Synaptic Compartments Are Affected in PPT1 Overexpressing Neuronal-Like Cells

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Francesco Pezzini

2017-08-01

Full Text Available CLN1 disease (OMIM #256730 is an early childhood ceroid-lipofuscinosis associated with mutated CLN1, whose product Palmitoyl-Protein Thioesterase 1 (PPT1 is a lysosomal enzyme involved in the removal of palmitate residues from S-acylated proteins. In neurons, PPT1 expression is also linked to synaptic compartments. The aim of this study was to unravel molecular signatures connected to CLN1. We utilized SH-SY5Y neuroblastoma cells overexpressing wild type CLN1 (SH-p.wtCLN1 and five selected CLN1 patients’ mutations. The cellular distribution of wtPPT1 was consistent with regular processing of endogenous protein, partially detected inside Lysosomal Associated Membrane Protein 2 (LAMP2 positive vesicles, while the mutants displayed more diffuse cytoplasmic pattern. Transcriptomic profiling revealed 802 differentially expressed genes (DEGs in SH-p.wtCLN1 (as compared to empty-vector transfected cells, whereas the number of DEGs detected in the two mutants (p.L222P and p.M57Nfs*45 was significantly lower. Bioinformatic scrutiny linked DEGs with neurite formation and neuronal transmission. Specifically, neuritogenesis and proliferation of neuronal processes were predicted to be hampered in the wtCLN1 overexpressing cell line, and these findings were corroborated by morphological investigations. Palmitoylation survey identified 113 palmitoylated protein-encoding genes in SH-p.wtCLN1, including 25 ones simultaneously assigned to axonal growth and synaptic compartments. A remarkable decrease in the expression of palmitoylated proteins, functionally related to axonal elongation (GAP43, CRMP1 and NEFM and of the synaptic marker SNAP25, specifically in SH-p.wtCLN1 cells was confirmed by immunoblotting. Subsequent, bioinformatic network survey of DEGs assigned to the synaptic annotations linked 81 DEGs, including 23 ones encoding for palmitoylated proteins. Results obtained in this experimental setting outlined two affected functional modules (connected to

Kinetics of protein unfolding at interfaces

International Nuclear Information System (INIS)

Yano, Yohko F

2012-01-01

The conformation of protein molecules is determined by a balance of various forces, including van der Waals attraction, electrostatic interaction, hydrogen bonding, and conformational entropy. When protein molecules encounter an interface, they are often adsorbed on the interface. The conformation of an adsorbed protein molecule strongly depends on the interaction between the protein and the interface. Recent time-resolved investigations have revealed that protein conformation changes during the adsorption process due to the protein-protein interaction increasing with increasing interface coverage. External conditions also affect the protein conformation. This review considers recent dynamic observations of protein adsorption at various interfaces and their implications for the kinetics of protein unfolding at interfaces. (topical review)

The glycosylation status of the murine hepatitis coronavirus M protein affects the interferogenic capacity of the virus in vitro and its ability to replicate in the liver but not the brain

International Nuclear Information System (INIS)

Haan, Cornelis A.M. de; Wit, Marel de; Kuo, Lili; Montalto-Morrison, Cynthia; Haagmans, Bart L.; Weiss, Susan R.; Masters, Paul S.; Rottier, Peter J.M.

2003-01-01

The coronavirus M protein, the most abundant coronaviral envelope component, is invariably glycosylated, which provides the virion with a diffuse, hydrophilic cover on its outer surface. Remarkably, while the group 1 and group 3 coronaviruses all have M proteins with N-linked sugars, the M proteins of the group 2 coronaviruses [e.g., mouse hepatitis virus (MHV)] are O-glycosylated. The conservation of the N- and O-glycosylation motifs suggests that each of these types of carbohydrate modifications is beneficial to their respective virus. Since glycosylation of the M protein is not required for virus assembly, the oligosaccharides are likely to be involved in the virus-host interaction. In order to investigate the role of the M protein glycosylation in the host, two genetically modified MHVs were generated by using targeted RNA recombination. The recombinant viruses carried M proteins that were either N-glycosylated or not glycosylated at all, and these were compared with the parental, O-glycosylated, virus. The M protein glycosylation state did not influence the tissue culture growth characteristics of the recombinant viruses. However, it affected their interferogenic capacity as measured using fixed, virus-infected cells. Viruses containing M proteins with N-linked sugars induced type I interferons to higher levels than viruses carrying M proteins with O-linked sugars. MHV with unglycosylated M proteins appeared to be a poor interferon inducer. In mice, the recombinant viruses differed in their ability to replicate in the liver, but not in the brain, whereas their in vivo interferogenic capacity did not appear to be affected by their glycosylation status. Strikingly, their abilities to replicate in the liver correlated with their in vitro interferogenic capacity. This apparent correlation might be explained by the functioning of lectins, such as the mannose receptor, which are abundantly expressed in the liver but also play a role in the induction of interferon

Dairy Proteins and Energy Balance

DEFF Research Database (Denmark)

Bendtsen, Line Quist

High protein diets affect energy balance beneficially through decreased hunger, enhanced satiety and increased energy expenditure. Dairy products are a major source of protein. Dairy proteins are comprised of two classes, casein (80%) and whey proteins (20%), which are both of high quality......, but casein is absorbed slowly and whey is absorbed rapidly. The present PhD study investigated the effects of total dairy proteins, whey, and casein, on energy balance and the mechanisms behind any differences in the effects of the specific proteins. The results do not support the hypothesis that dairy...... proteins, whey or casein are more beneficial than other protein sources in the regulation of energy balance, and suggest that dairy proteins, whey or casein seem to play only a minor role, if any, in the prevention and treatment of obesity....

The effects of Capn1 gene inactivation on skeletal muscle growth, development, and atrophy, and the compensatory role of other proteolytic systems.

Science.gov (United States)

Kemp, C M; Oliver, W T; Wheeler, T L; Chishti, A H; Koohmaraie, M

2013-07-01

Myofibrillar protein turnover is a key component of muscle growth and degeneration, requiring proteolytic enzymes to degrade the skeletal muscle proteins. The objective of this study was to investigate the role of the calpain proteolytic system in muscle growth development using μ-calpain knockout (KO) mice in comparison with control wild-type (WT) mice, and evaluate the subsequent effects of silencing this gene on other proteolytic systems. No differences in muscle development between genotypes were observed during the early stages of growth due to the up regulation of other proteolytic systems. The KO mice showed significantly greater m-calpain protein abundance (P proteolytic systems to ensure muscle protein homeostasis in vivo. Furthermore, these data contribute to the existing evidence of the importance of the calpain system's involvement in muscle growth, development, and atrophy. Collectively, these data suggest that there are opportunities to target the calpain system to promote the growth and/or restoration of skeletal muscle mass.

Non-cytotoxic Concentration of Cisplatin Decreases Neuroplasticity-Related Proteins and Neurite Outgrowth Without Affecting the Expression of NGF in PC12 Cells.

Science.gov (United States)

Ferreira, Rafaela Scalco; Dos Santos, Neife Aparecida Guinaim; Martins, Nádia Maria; Fernandes, Laís Silva; Dos Santos, Antonio Cardozo

2016-11-01

Cisplatin is the most effective and neurotoxic platinum chemotherapeutic agent. It induces a peripheral neuropathy characterized by distal axonal degeneration that might progress to degeneration of cell bodies and apoptosis. Most symptoms occur nearby distal axonal branches and axonal degeneration might induce peripheral neuropathy regardless neuronal apoptosis. The toxic mechanism of cisplatin has been mainly associated with DNA damage, but cisplatin might also affect neurite outgrowth. Nevertheless, the neurotoxic mechanism of cisplatin remains unclear. We investigated the early effects of cisplatin on axonal plasticity by using non-cytotoxic concentrations of cisplatin and PC12 cells as a model of neurite outgrowth and differentiation. PC12 cells express NGF-receptors (trkA) and respond to NGF by forming neurites, branches and synaptic vesicles. For comparison, we used a neuronal model (SH-SY5Y cells) that does not express trkA nor responds to NGF. Cisplatin did not change NGF expression in PC12 cells and decreased neurite outgrowth in both models, suggesting a NGF/trkA independent mechanism. It also reduced axonal growth (GAP-43) and synaptic (synapsin I and synaptophysin) proteins in PC12 cells, without inducing mitochondrial damage or apoptosis. Therefore, cisplatin might affect axonal plasticity before DNA damage, NGF/trkA down-regulation, mitochondrial damage or neuronal apoptosis. This is the first study to show that neuroplasticity-related proteins might be early targets of the neurotoxic action of cisplatin and their role on cisplatin-induced peripheral neuropathy should be investigated in vivo.

Navy Bean Flour Particle Size and Protein Content Affect Cake Baking and Batter Quality(1).

Science.gov (United States)

Singh, Mukti; Byars, Jeffrey A; Liu, Sean X

2015-06-01

Whole navy bean flour and its fine and coarse particle size fractions were used to completely replace wheat flour in cakes. Replacement of wheat flour with whole bean flour significantly increased the protein content. The protein content was adjusted to 3 levels with navy bean starch. The effect of navy bean flour and its fractions at 3 levels of protein on cake batter rheology and cake quality was studied and compared with wheat flour samples. Batters prepared from navy bean flour and its fractions had higher viscosity than the cake flour. Reducing the protein content by addition of starch significantly lowered the viscosity of cake batters. The whole navy bean flour and coarse bean fraction cakes were softer than cakes made with wheat flour but had reduced springiness. Principal component analysis showed a clear discrimination of cakes according to protein. It also showed that low protein navy bean flour cakes were similar to wheat flour cakes. Navy bean flour with protein content adjusted to the level of cake (wheat) flour has potential as a healthy alternative in gluten-free cakes. Published 2015. This article is a U.S. Government work and is in the public domain in the USA.

Protein raftophilicity. How bioinformatics can help membranologists

DEFF Research Database (Denmark)

Nielsen, Henrik; Sperotto, Maria Maddalena

)-based bioinformatics approach. The ANN was trained to recognize feature-based patterns in proteins that are considered to be associated with lipid rafts. The trained ANN was then used to predict protein raftophilicity. We found that, in the case of α-helical membrane proteins, their hydrophobic length does not affect...

Ion pairs in non-redundant protein structures

Indian Academy of Sciences (India)

Ion pairs contribute to several functions including the activity of catalytic triads, fusion of viral membranes, stability in thermophilic proteins and solvent–protein interactions. Furthermore, they have the ability to affect the stability of protein structures and are also a part of the forces that act to hold monomers together.

Proteome Analysis of Human Sebaceous Follicle Infundibula Extracted from Healthy and Acne-Affected Skin

Science.gov (United States)

Bek-Thomsen, Malene; Lomholt, Hans B.; Scavenius, Carsten; Enghild, Jan J.; Brüggemann, Holger

2014-01-01

Acne vulgaris is a very common disease of the pilosebaceous unit of the human skin. The pathological processes of acne are not fully understood. To gain further insight sebaceous follicular casts were extracted from 18 healthy and 20 acne-affected individuals by cyanoacrylate-gel biopsies and further processed for mass spectrometry analysis, aiming at a proteomic analysis of the sebaceous follicular casts. Human as well as bacterial proteins were identified. Human proteins enriched in acne and normal samples were detected, respectively. Normal follicular casts are enriched in proteins such as prohibitins and peroxiredoxins which are involved in the protection from various stresses, including reactive oxygen species. By contrast, follicular casts extracted from acne-affected skin contained proteins involved in inflammation, wound healing and tissue remodeling. Among the most distinguishing proteins were myeloperoxidase, lactotransferrin, neutrophil elastase inhibitor and surprisingly, vimentin. The most significant biological process among all acne-enriched proteins was ‘response to a bacterium’. Identified bacterial proteins were exclusively from Propionibacterium acnes. The most abundant P. acnes proteins were surface-exposed dermatan sulphate adhesins, CAMP factors, and a so far uncharacterized lipase in follicular casts extracted from normal as well as acne-affected skin. This is a first proteomic study that identified human proteins together with proteins of the skin microbiota in sebaceous follicular casts. PMID:25238151

Occurrence of protein disulfide bonds in different domains of life: a comparison of proteins from the Protein Data Bank.

Science.gov (United States)

Bošnjak, I; Bojović, V; Šegvić-Bubić, T; Bielen, A

2014-03-01

Disulfide bonds (SS bonds) are important post-translational modifications of proteins. They stabilize a three-dimensional (3D) structure (structural SS bonds) and also have the catalytic or regulatory functions (redox-active SS bonds). Although SS bonds are present in all groups of organisms, no comparative analyses of their frequency in proteins from different domains of life have been made to date. Using the Protein Data Bank, the number and subcellular locations of SS bonds in Archaea, Bacteria and Eukarya have been compared. Approximately three times higher frequency of proteins with SS bonds in eukaryotic secretory organelles (e.g. endoplasmic reticulum) than in bacterial periplasmic/secretory pathways was calculated. Protein length also affects the SS bond frequency: the average number of SS bonds is positively correlated with the length for longer proteins (>200 amino acids), while for the shorter and less stable proteins (proteins (250-350 amino acids) indicated a high number of SS bonds only in Archaea which could be explained by the need for additional protein stabilization in hyperthermophiles. The results emphasize higher capacity for the SS bond formation and isomerization in Eukarya when compared with Archaea and Bacteria.

The missing piece in the puzzle: Prediction of aggregation via the protein-protein interaction parameter A∗2.

Science.gov (United States)

Koepf, Ellen; Schroeder, Rudolf; Brezesinski, Gerald; Friess, Wolfgang

2018-07-01

The tendency of protein pharmaceuticals to form aggregates is a major challenge during formulation development, as aggregation affects quality and safety of the product. In particular, the formation of large native-like particles in the context of liquid-air interfacial stress is a well-known but not fully understood problem. Focusing on the two most fundamental criteria of protein formulation affecting protein-protein interaction, the impact of pH and ionic strength on the interaction parameter A ∗ 2 and its link to aggregation upon mechanical stress was investigated. A ∗ 2 of two monoclonal antibodies (mABs) and a polyclonal IgG was determined using dynamic light scattering and was correlated to the number of particles formed upon shaking in vials analyzed by visual inspection, turbidity analysis, light obscuration and micro-flow imaging. A good correlation between aggregation induced by interfacial stress and formulation pH was given. It could be shown that A ∗ 2 was highest for mAB 1 and lowest for IgG, what was in good accordance with the number of particles formed. Shaking of IgG resulted in overall higher numbers of particles compared to the two mABs. A ∗ 2 decreased and particle numbers increased with increasing pH. Different to pH, ionic strength only slightly affected A ∗ 2 . Nevertheless, at high ionic (100 mM) strength the samples exhibited more pronounced particle formation, particularly of large particles >25 µm, which was most pronounced at high pH. Protein solutions were identified to form continuous films with an inhomogeneous protein distribution at the liquid-air interface. These areas of agglomerated, native-like protein material can be transferred into the bulk solution by compression-decompression of the interface. Whether or not those clusters lead to the appearance of large protein aggregates or fall apart depends on the attractive or repulsive forces between protein molecules. Thus, protein aggregation due to interfacial

Interaction betwen Lead and Bone Protein to Affect Bone Calcium Level Using UV-Vis Spectroscopy

Science.gov (United States)

Noor, Z.; Azharuddin, A.; Aflanie, I.; Kania, N.; Suhartono, E.

2018-05-01

This present study aim to evaluate the interactions between lead (Pb) and with bone protein by UV-Vis approach. In addition, this prsent study also aim to investigate the effect of Pb on bone calcium (Ca) level. The present study was a true experimental study design to examine the impact of Pb exposure in bone of male rats (Rattus novergicus). The study involved 5 groups, P1 was the control group, while the other (P2-P5) were the case group with exposure of Pb in different concentration within 4 weeks. At the end of the exposure, the interaction between Pb and protein was determined using UV-Vis spectrophotometric method, and the Ca level was determined using permanganometric method. The results shows that that there is an interaction between Pb and bone protein. The result also shows that the value of the binding constant of Protein-Pb is 32.71. It means Pb have an high affinity to bind with bone protein, which promote a further reaction to induced the release of bone Ca from the bone protein. In conclusion, this present study found an obvious relationship between Pb and bone protein which promote a further reaction to increase the releasing of bone calcium.

HIV protein sequence hotspots for crosstalk with host hub proteins.

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Mahdi Sarmady

Full Text Available HIV proteins target host hub proteins for transient binding interactions. The presence of viral proteins in the infected cell results in out-competition of host proteins in their interaction with hub proteins, drastically affecting cell physiology. Functional genomics and interactome datasets can be used to quantify the sequence hotspots on the HIV proteome mediating interactions with host hub proteins. In this study, we used the HIV and human interactome databases to identify HIV targeted host hub proteins and their host binding partners (H2. We developed a high throughput computational procedure utilizing motif discovery algorithms on sets of protein sequences, including sequences of HIV and H2 proteins. We identified as HIV sequence hotspots those linear motifs that are highly conserved on HIV sequences and at the same time have a statistically enriched presence on the sequences of H2 proteins. The HIV protein motifs discovered in this study are expressed by subsets of H2 host proteins potentially outcompeted by HIV proteins. A large subset of these motifs is involved in cleavage, nuclear localization, phosphorylation, and transcription factor binding events. Many such motifs are clustered on an HIV sequence in the form of hotspots. The sequential positions of these hotspots are consistent with the curated literature on phenotype altering residue mutations, as well as with existing binding site data. The hotspot map produced in this study is the first global portrayal of HIV motifs involved in altering the host protein network at highly connected hub nodes.

A comparative study of functional properties of normal and wooden breast broiler chicken meat with NaCl addition.

Science.gov (United States)

Xing, Tong; Zhao, Xue; Han, Minyi; Cai, Linlin; Deng, Shaolin; Zhou, Guanghong; Xu, Xinglian

2017-09-01

The selection of broilers for augmented growth rate and breast has brought about wooden-breast (WB) muscle abnormalities, which caused substantial economic losses. The objective of this study was to compare water holding capacity, water mobility and distribution, salt-soluble protein (SSP) content, and protein profiles of normal and WB chicken meat with different additions of NaCl. Thirty WB and 30 normal chicken breasts were selected from a deboning line of a major Chinese processing plant at 2 to 3 h post mortem. Two different meat batters were formulated to 150 mg/g meat protein and different NaCl contents (0%, 1%, 2%, 3%, and 4%). Results indicated that as NaCl contents increased, the cooking loss of meat batters decreased (P meat showed different protein profiles, with myosin heavy chain exhibiting a higher intensity at ≥3% salt level. Low-field nuclear magnetic resonance (LF-NMR)revealed an increased T22 and higher P22 in raw WB meat compared to normal meat (P meat batters, WB meat batters had reduced T21 and lower immobilized water proportions at low NaCl contents (meat gels. Meat gels prepared from WB had a lower proportion of water within the myofibrillar protein matrix and a greater proportion of exuded bulk water at NaCl contents meat, meat batters and gels, water distribution and mobility of WB exhibited significant differences compared to normal meat. The addition of NaCl affected water mobility and distributions in meat batters, with a level of 3% NaCl eliminating the differences between processed normal and WB meat products. © 2017 Poultry Science Association Inc.

Exploring the diversity of protein modifications: special bacterial phosphorylation systems

DEFF Research Database (Denmark)

Mijakovic, Ivan; Grangeasse, Christophe; Turgay, Kürşad

2016-01-01

Protein modifications not only affect protein homeostasis but can also establish new cellular protein functions and are important components of complex cellular signal sensing and transduction networks. Among these post-translational modifications, protein phosphorylation represents the one that ...

Sensitizing properties of proteins

DEFF Research Database (Denmark)

Poulsen, Lars K.; Ladics, Gregory S; McClain, Scott

2014-01-01

The scope of allergy risk is diverse considering the myriad ways in which protein allergenicity is affected by physiochemical characteristics of proteins. The complexity created by the matrices of foods and the variability of the human immune system add additional challenges to understanding...... the relationship between sensitization potential and allergy disease. To address these and other issues, an April 2012 international symposium was held in Prague, Czech Republic, to review and discuss the state-of-the-science of sensitizing properties of protein allergens. The symposium, organized by the Protein...... Allergenicity Technical Committee of the International Life Sciences Institute's Health and Environmental Sciences Institute, featured presentations on current methods, test systems, research trends, and unanswered questions in the field of protein sensitization. A diverse group of over 70 interdisciplinary...

Modifications to the translational apparatus which affect the regulation of protein synthesis in sea urchin embryos

International Nuclear Information System (INIS)

Scalise, F.W.

1988-01-01

Protein synthesis can be regulated at a number of cellular levels. I have examined how modifications to specific components of the protein synthetic machinery are involved in regulating the efficiency of initiation of translation during early sea urchin embryogenesis. It is demonstrated that Ca 2+ concentrations exceeding 500 uM cause the inhibition of protein synthesis in cell-free translation lysates prepared from sea urchin embryos. Specific changes in the state of phosphorylation of at least 8 proteins occur during this Ca 2+ -mediated repression of translation. Analysis of these proteins has indicated that, unlike mammalian systems, there is no detectable level of Ca 2+ -dependent phosphorylation of the αsubunit eIF-2. Two of the proteins which do become phosphorylated in response to Ca 2+ are calmodulin and an isoelectric form of sea urchin eIF-4D. In addition, 2 proteins which share similarities with kinases involved in the regulation of protein synthesis in mammalian cells, also become phosphorylated. I have investigated the consequences of changes in eIF-4D during sea urchin embryogenesis because it has been proposed that a polyamine-mediated conversion of lysine to hypusine in this factor may enhance translational activity. It is demonstrated that [ 3 H] spermidine-derived radioactivity is incorporated into a number of proteins when sea urchin embryos are labeled in vivo, and that the pattern of individual proteins that become labeled changes over the course of the first 30 hr of development

Soy protein modification: A review

Directory of Open Access Journals (Sweden)

Barać Miroljub B.

2004-01-01

Full Text Available Soy protein products such as flour, concentrates and isolates are used in food formulation because of their functionality, nutritional value and low cost. To obtain their optimal nutritive and functional properties as well as desirable flavor different treatments are used. Soybean proteins can be modified by physical, chemical and enzymatic treatments. Different thermal treatments are most commonly used, while the most appropriate way of modifying soy proteins from the standpoint of safety is their limited proteolysis. These treatments cause physical and chemical changes that affect their functional properties. This review discusses three principal methods used for modification of soy protein products, their effects on dominant soy protein properties and some biologically active compounds.

Identification and characterization of proteins involved in nuclear organization using Drosophila GFP protein trap lines.

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Margaret Rohrbaugh

Full Text Available Strains from a collection of Drosophila GFP protein trap lines express GFP in the normal tissues where the endogenous protein is present. This collection can be used to screen for proteins distributed in the nucleus in a non-uniform pattern.We analyzed four lines that show peripheral or punctate nuclear staining. One of these lines affects an uncharacterized gene named CG11138. The CG11138 protein shows a punctate distribution in the nuclear periphery similar to that of Drosophila insulator proteins but does not co-localize with known insulators. Interestingly, mutations in Lamin proteins result in alterations in CG11138 localization, suggesting that this protein may be a novel component of the nuclear lamina. A second line affects the Decondensation factor 31 (Df31 gene, which encodes a protein with a unique nuclear distribution that appears to segment the nucleus into four different compartments. The X-chromosome of males is confined to one of these compartments. We also find that Drosophila Nucleoplasmin (dNlp is present in regions of active transcription. Heat shock leads to loss of dNlp from previously transcribed regions of polytene chromosome without redistribution to the heat shock genes. Analysis of Stonewall (Stwl, a protein previously found to be necessary for the maintenance of germline stem cells, shows that Stwl is present in a punctate pattern in the nucleus that partially overlaps with that of known insulator proteins. Finally we show that Stwl, dNlp, and Df31 form part of a highly interactive network. The properties of other components of this network may help understand the role of these proteins in nuclear biology.These results establish screening of GFP protein trap alleles as a strategy to identify factors with novel cellular functions. Information gained from the analysis of CG11138 Stwl, dNlp, and Df31 sets the stage for future studies of these proteins.

Evaluation of factors that affect analytic variability of urine protein-to-creatinine ratio determination in dogs.

Science.gov (United States)

Rossi, Gabriele; Giori, Luca; Campagnola, Simona; Zatelli, Andrea; Zini, Eric; Paltrinieri, Saverio

2012-06-01

To determine whether preanalytic and analytic factors affect evaluation of the urinary protein-to-creatinine (UPC) ratio in dogs. 50 canine urine samples. The UPC ratio was measured to assess the intra-assay imprecision (20 measurements within a single session), the influence of predilution (1:10, 1:20, and 1:100) for urine creatinine concentration measurement, and the effect of storage at room temperature (approx 20°C), 4°C, and -20°C. The coefficient of variation at room temperature determined with the 1:20 predilution was samples with a low protein concentration or low urine specific gravity. This variability could result in misclassification of samples with UPC ratios close to the thresholds defined by the International Renal Interest Society to classify dogs as nonproteinuric (0.2), borderline proteinuric (0.21 to 0.50), or proteinuric (> 0.51). A proportional bias was found in samples prediluted 1:10, compared with samples prediluted 1:20 or 1:100. At room temperature, the UPC ratio did not significantly increase after 2 and 4 hours. After 12 hours at room temperature and at 4°C, the UPC ratio significantly increased. The UPC ratio did not significantly change during 3 months of storage at -20°C. The intra-assay precision of the UPC ratio was sufficiently low to avoid misclassification of samples, except for values close to 0.2 or 0.5. The optimal predilution ratio for urine creatinine concentration measurement was 1:20. A 1:100 predilution is recommended in samples with a urine specific gravity > 1.030. The UPC ratio must be measured as soon as samples are collected. Alternatively, samples should be immediately frozen to increase their stability and minimize the risk of misclassification of proteinuria.

Roles for the coat protein telokin-like domain and the scaffolding protein amino-terminus

Science.gov (United States)

Suhanovsky, Margaret M.; Teschke, Carolyn M.

2011-01-01

Assembly of icosahedral capsids of proper size and symmetry is not understood. Residue F170 in bacteriophage P22 coat protein is critical for conformational switching during assembly. Substitutions at this site cause assembly of tubes of hexamerically arranged coat protein. Intragenic suppressors of the ts phenotype of F170A and F170K coat protein mutants were isolated. Suppressors were repeatedly found in the coat protein telokin-like domain at position 285, which caused coat protein to assemble into petite procapsids and capsids. Petite capsid assembly strongly correlated to the side chain volume of the substituted amino acid. We hypothesize that larger side chains at position 285 torque the telokin-like domain, changing flexibility of the subunit and intercapsomer contacts. Thus, a single amino acid substitution in coat protein is sufficient to change capsid size. In addition, the products of assembly of the variant coat proteins were affected by the size of the internal scaffolding protein. PMID:21784500

The effects of non-synonymous single nucleotide polymorphisms (nsSNPs) on protein-protein interactions.

Science.gov (United States)

Yates, Christopher M; Sternberg, Michael J E

2013-11-01

Non-synonymous single nucleotide polymorphisms (nsSNPs) are single base changes leading to a change to the amino acid sequence of the encoded protein. Many of these variants are associated with disease, so nsSNPs have been well studied, with studies looking at the effects of nsSNPs on individual proteins, for example, on stability and enzyme active sites. In recent years, the impact of nsSNPs upon protein-protein interactions has also been investigated, giving a greater insight into the mechanisms by which nsSNPs can lead to disease. In this review, we summarize these studies, looking at the various mechanisms by which nsSNPs can affect protein-protein interactions. We focus on structural changes that can impair interaction, changes to disorder, gain of interaction, and post-translational modifications before looking at some examples of nsSNPs at human-pathogen protein-protein interfaces and the analysis of nsSNPs from a network perspective. © 2013.

Defective Proteasome Delivery of Polyubiquitinated Proteins by Ubiquilin-2 Proteins Containing ALS Mutations.

Directory of Open Access Journals (Sweden)

Lydia Chang

Full Text Available Ubiquilin proteins facilitate delivery of ubiquitinated proteins to the proteasome for degradation. Interest in the proteins has been heightened by the discovery that gene mutations in UBQLN2 cause dominant inheritance of amyotrophic lateral sclerosis (ALS. However, the mechanisms by which the mutations cause ALS are not known. Here we report on the underlying defect of ubiquilin-2 proteins containing ALS-linked mutations in affecting proteasome-mediated degradation. We found that overexpression of ubiquilin-2 proteins containing any one of five different ALS mutations slow degradation of Myc, a prototypic proteasome substrate. Examination of coprecipitating proteins indicated that the mutant proteins are generally capable of binding polyubiquitinated proteins, but defective in binding the proteasome. GST-pulldown studies revealed that many of the mutants bind weaker to the S5a subunit of the proteasome, compared with wild type (WT ubiquilin-2 protein. The results suggest the mutant proteins are unable to deliver their captured cargo to the proteasome for degradation, which presumably leads to toxicity. Quantification of cell death is consistent with this idea. Measurement of protein turnover further indicated the mutant proteins have longer half-lives than WT ubiquilin-2. Our studies provide novel insight into the mechanism by which ALS-linked mutations in UBQLN2 interfere with protein degradation.

Navy bean flour particle size and protein content affect cake baking and batter quality

Science.gov (United States)

There is a great demand for wheat alternatives in foods, particularly baked goods, as gluten sensitivity increases. Baked goods such as cakes have wheat flour as a major ingredient, which is rich in gluten protein. Bean proteins do not have gluten, and are a good source of soluble fiber, B-vitamins,...

Protein Phosphorylation and Mineral Binding Affect the Secondary Structure of the Leucine-Rich Amelogenin Peptide

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Hajime Yamazaki

2017-06-01

Full Text Available Previously, we have shown that serine-16 phosphorylation in native full-length porcine amelogenin (P173 and the Leucine-Rich Amelogenin Peptide (LRAP(+P, an alternative amelogenin splice product, affects protein assembly and mineralization in vitro. Notably, P173 and LRAP(+P stabilize amorphous calcium phosphate (ACP and inhibit hydroxyapatite (HA formation, while non-phosphorylated counterparts (rP172, LRAP(−P guide the growth of ordered bundles of HA crystals. Based on these findings, we hypothesize that the phosphorylation of full-length amelogenin and LRAP induces conformational changes that critically affect its capacity to interact with forming calcium phosphate mineral phases. To test this hypothesis, we have utilized Fourier transform infrared spectroscopy (FTIR to determine the secondary structure of LRAP(−P and LRAP(+P in the absence/presence of calcium and selected mineral phases relevant to amelogenesis; i.e., hydroxyapatite (HA: an enamel crystal prototype and (ACP: an enamel crystal precursor phase. Aqueous solutions of LRAP(−P or LRAP(+P were prepared with or without 7.5 mM of CaCl2 at pH 7.4. FTIR spectra of each solution were obtained using attenuated total reflectance, and amide-I peaks were analyzed to provide secondary structure information. Secondary structures of LRAP(+P and LRAP(−P were similarly assessed following incubation with suspensions of HA and pyrophosphate-stabilized ACP. Amide I spectra of LRAP(−P and LRAP(+P were found to be distinct from each other in all cases. Spectra analyses showed that LRAP(−P is comprised mostly of random coil and β-sheet, while LRAP(+P exhibits more β-sheet and α-helix with little random coil. With added Ca, the random coil content increased in LRAP(−P, while LRAP(+P exhibited a decrease in α-helix components. Incubation of LRAP(−P with HA or ACP resulted in comparable increases in β-sheet structure. Notably, however, LRAP(+P secondary structure was more affected by

Production of bacterial protein from sugar cane bagasse pith

Energy Technology Data Exchange (ETDEWEB)

Molina, O E; Callieri, D A.S.; Perotti de Galvez, N

1980-01-01

Bacterial protein was produced during the fermentation of sugar cane bagasse pith (BP) by a mixture of cellulolytic bacteria, one of them being a species of Cellulomonas. If the BP were treated with 1% NaOH prior to fermentation, the liquor could be used twice more without affecting the yield of bacterial protein. After that, the liquor became too dark and impaired the subsequent washing of BP. If the concentration of N (as NaN0/sub 3/) in the fermentation medium were raised, the conversion factor to protein was lowered, but the amount of protein formed per L per h and the ratio of protein to BP became higher. The evolution of pH, the dry matter content, cellulolytic activity, and protein yield were all affected by the type of N source used. The yield of bacterial protein can probably be increased by automatically controlling the pH and dissolved O levels of the culture.

Poxviral Ankyrin Proteins

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Michael H. Herbert

2015-02-01

Full Text Available Multiple repeats of the ankyrin motif (ANK are ubiquitous throughout the kingdoms of life but are absent from most viruses. The main exception to this is the poxvirus family, and specifically the chordopoxviruses, with ANK repeat proteins present in all but three species from separate genera. The poxviral ANK repeat proteins belong to distinct orthologue groups spread over different species, and align well with the phylogeny of their genera. This distribution throughout the chordopoxviruses indicates these proteins were present in an ancestral vertebrate poxvirus, and have since undergone numerous duplication events. Most poxviral ANK repeat proteins contain an unusual topology of multiple ANK motifs starting at the N-terminus with a C-terminal poxviral homologue of the cellular F-box enabling interaction with the cellular SCF ubiquitin ligase complex. The subtle variations between ANK repeat proteins of individual poxviruses suggest an array of different substrates may be bound by these protein-protein interaction domains and, via the F-box, potentially directed to cellular ubiquitination pathways and possible degradation. Known interaction partners of several of these proteins indicate that the NF-κB coordinated anti-viral response is a key target, whilst some poxviral ANK repeat domains also have an F-box independent affect on viral host-range.

Redox agents and N-ethylmaleimide affect protein polymerization during laboratory scale dry pasta production and cooking.

Science.gov (United States)

Bruneel, Charlotte; Buggenhout, Joke; Lagrain, Bert; Brijs, Kristof; Delcour, Jan A

2016-04-01

Durum wheat (Triticum durum Desf.) semolina gluten proteins consist of monomeric gliadin and polymeric glutenin and determine the quality of pasta products made therefrom. During pasta drying, glutenin starts polymerizing already below 60 °C (65% relative humidity (RH)), whereas gliadin only is incorporated in the protein network at temperatures exceeding 68 °C (68% RH) through thiol (SH)/disulfide (SS) exchange reactions. Removal of free SH groups in glutenin by adding 2.3 μmol KBrO3 or KIO3 per g dry matter semolina protein (g protein) or 13.8 μmol N-ethylmaleimide/g protein reduces gliadin-glutenin cross-linking during pasta drying and/or cooking and yields cooked pasta of high quality. Introducing free SH groups by adding 13.8 μmol glutathione/g protein increases gliadin-glutenin cross-linking during pasta processing, resulting in cooked pasta of lower quality. We hypothesize that too much gliadin incorporation in the glutenin network during pasta processing tightens the protein network and results in lower cooking quality. Copyright © 2015 Elsevier Ltd. All rights reserved.

Low-load high volume resistance exercise stimulates muscle protein synthesis more than high-load low volume resistance exercise in young men.

Directory of Open Access Journals (Sweden)

Nicholas A Burd

Full Text Available BACKGROUND: We aimed to determine the effect of resistance exercise intensity (%1 repetition maximum-1RM and volume on muscle protein synthesis, anabolic signaling, and myogenic gene expression. METHODOLOGY/PRINCIPAL FINDINGS: Fifteen men (21+/-1 years; BMI=24.1+/-0.8 kg/m2 performed 4 sets of unilateral leg extension exercise at different exercise loads and/or volumes: 90% of repetition maximum (1RM until volitional failure (90FAIL, 30% 1RM work-matched to 90%FAIL (30WM, or 30% 1RM performed until volitional failure (30FAIL. Infusion of [ring-13C6] phenylalanine with biopsies was used to measure rates of mixed (MIX, myofibrillar (MYO, and sarcoplasmic (SARC protein synthesis at rest, and 4 h and 24 h after exercise. Exercise at 30WM induced a significant increase above rest in MIX (121% and MYO (87% protein synthesis at 4 h post-exercise and but at 24 h in the MIX only. The increase in the rate of protein synthesis in MIX and MYO at 4 h post-exercise with 90FAIL and 30FAIL was greater than 30WM, with no difference between these conditions; however, MYO remained elevated (199% above rest at 24 h only in 30FAIL. There was a significant increase in AktSer473 at 24h in all conditions (P=0.023 and mTORSer2448 phosphorylation at 4 h post-exercise (P=0.025. Phosporylation of Erk1/2Tyr202/204, p70S6KThr389, and 4E-BP1Thr37/46 increased significantly (P<0.05 only in the 30FAIL condition at 4 h post-exercise, whereas, 4E-BP1Thr37/46 phosphorylation was greater 24 h after exercise than at rest in both 90FAIL (237% and 30FAIL (312% conditions. Pax7 mRNA expression increased at 24 h post-exercise (P=0.02 regardless of condition. The mRNA expression of MyoD and myogenin were consistently elevated in the 30FAIL condition. CONCLUSIONS/SIGNIFICANCE: These results suggest that low-load high volume resistance exercise is more effective in inducing acute muscle anabolism than high-load low volume or work matched resistance exercise modes.

BioMagResBank (BMRB) as a partner in the Worldwide Protein Data Bank (wwPDB): new policies affecting biomolecular NMR depositions

International Nuclear Information System (INIS)

Markley, John L.; Ulrich, Eldon L.; Berman, Helen M.; Henrick, Kim; Nakamura, Haruki; Akutsu, Hideo

2008-01-01

We describe the role of the BioMagResBank (BMRB) within the Worldwide Protein Data Bank (wwPDB) and recent policies affecting the deposition of biomolecular NMR data. All PDB depositions of structures based on NMR data must now be accompanied by experimental restraints. A scheme has been devised that allows depositors to specify a representative structure and to define residues within that structure found experimentally to be largely unstructured. The BMRB now accepts coordinate sets representing three-dimensional structural models based on experimental NMR data of molecules of biological interest that fall outside the guidelines of the Protein Data Bank (i.e., the molecule is a peptide with 23 or fewer residues, a polynucleotide with 3 or fewer residues, a polysaccharide with 3 or fewer sugar residues, or a natural product), provided that the coordinates are accompanied by representation of the covalent structure of the molecule (atom connectivity), assigned NMR chemical shifts, and the structural restraints used in generating model. The BMRB now contains an archive of NMR data for metabolites and other small molecules found in biological systems

A protein kinase binds the C-terminal domain of the readthrough protein of Turnip yellows virus and regulates virus accumulation.

Science.gov (United States)

Rodriguez-Medina, Caren; Boissinot, Sylvaine; Chapuis, Sophie; Gereige, Dalya; Rastegar, Maryam; Erdinger, Monique; Revers, Frédéric; Ziegler-Graff, Véronique; Brault, Véronique

2015-12-01

Turnip yellows virus (TuYV), a phloem-limited virus, encodes a 74kDa protein known as the readthrough protein (RT) involved in virus movement. We show here that a TuYV mutant deleted of the C-terminal part of the RT protein (TuYV-∆RTCter) was affected in long-distance trafficking in a host-specific manner. By using the C-terminal domain of the RT protein as a bait in a yeast two-hybrid screen of a phloem cDNA library from Arabidopsis thaliana we identified the calcineurin B-like protein-interacting protein kinase-7 (AtCIPK7). Transient expression of a GFP:CIPK7 fusion protein in virus-inoculated Nicotiana benthamiana leaves led to local increase of wild-type TuYV accumulation, but not that of TuYV-∆RTCter. Surprisingly, elevated virus titer in inoculated leaves did not result in higher TuYV accumulation in systemic leaves, which indicates that virus long-distance movement was not affected. Since GFP:CIPK7 was localized in or near plasmodesmata, CIPK7 could negatively regulate TuYV export from infected cells. Copyright © 2015 Elsevier Inc. All rights reserved.

Thyroid hormone affects secretory activity and uncoupling protein-3 expression in rat harderian gland.

Science.gov (United States)

Chieffi Baccari, Gabriella; Monteforte, Rossella; de Lange, Pieter; Raucci, Franca; Farina, Paola; Lanni, Antonia

2004-07-01

The effects of T(3) administration on the rat Harderian gland were examined at morphological, biochemical, and molecular levels. T(3) induced hypertrophy of the two cell types (A and B) present in the glandular epithelium. In type A cells, the hypertrophy was mainly due to an increase in the size of the lipid compartment. The acinar lumina were filled with lipoproteic substances, and the cells often showed an olocrine secretory pattern. In type B cells, the hypertrophy largely consisted of a marked proliferation of mitochondria endowed with tightly packed cristae, the mitochondrial number being nearly doubled (from 62 to 101/100 microm(2)). Although the average area of individual mitochondria decreased by about 50%, the total area of the mitochondrial compartment increased by about 80% (from 11 to 19/100 microm(2)). This could be ascribed to T(3)-induced mitochondrial proliferation. The morphological and morphometric data correlated well with our biochemical results, which indicated that mitochondrial respiratory activity is increased in hyperthyroid rats. T(3), by influencing the metabolic function of the mitochondrial compartment, induces lipogenesis and the release of secretory product by type A cells. Mitochondrial uncoupling proteins 2 and 3 were expressed at both mRNA and protein levels in the euthyroid rat Harderian gland. T(3) treatment increased the mRNA levels of both uncoupling protein 2 (UCP2) and UCP3, but the protein level only of UCP3. A possible role for these proteins in the Harderian gland is discussed.

Protein O-Mannosyltransferases Affect Sensory Axon Wiring and Dynamic Chirality of Body Posture in the Drosophila Embryo.

Science.gov (United States)

Baker, Ryan; Nakamura, Naosuke; Chandel, Ishita; Howell, Brooke; Lyalin, Dmitry; Panin, Vladislav M

2018-02-14

Genetic defects in protein O-mannosyltransferase 1 (POMT1) and POMT2 underlie severe muscular dystrophies. POMT genes are evolutionarily conserved in metazoan organisms. In Drosophila , both male and female POMT mutants show a clockwise rotation of adult abdominal segments, suggesting a chirality of underlying pathogenic mechanisms. Here we described and analyzed a similar phenotype in POMT mutant embryos that shows left-handed body torsion. Our experiments demonstrated that coordinated muscle contraction waves are associated with asymmetric embryo rolling, unveiling a new chirality marker in Drosophila development. Using genetic and live-imaging approaches, we revealed that the torsion phenotype results from differential rolling and aberrant patterning of peristaltic waves of muscle contractions. Our results demonstrated that peripheral sensory neurons are required for normal contractions that prevent the accumulation of torsion. We found that POMT mutants show abnormal axonal connections of sensory neurons. POMT transgenic expression limited to sensory neurons significantly rescued the torsion phenotype, axonal connectivity defects, and abnormal contractions in POMT mutant embryos. Together, our data suggested that protein O-mannosylation is required for normal sensory feedback to control coordinated muscle contractions and body posture. This mechanism may shed light on analogous functions of POMT genes in mammals and help to elucidate the etiology of neurological defects in muscular dystrophies. SIGNIFICANCE STATEMENT Protein O-mannosyltransferases (POMTs) are evolutionarily conserved in metazoans. Mutations in POMTs cause severe muscular dystrophies associated with pronounced neurological defects. However, neurological functions of POMTs remain poorly understood. We demonstrated that POMT mutations in Drosophila result in abnormal muscle contractions and cause embryo torsion. Our experiments uncovered a chirality of embryo movements and a unique POMT -dependent

Hepatitis C virus infection protein network.

Science.gov (United States)

de Chassey, B; Navratil, V; Tafforeau, L; Hiet, M S; Aublin-Gex, A; Agaugué, S; Meiffren, G; Pradezynski, F; Faria, B F; Chantier, T; Le Breton, M; Pellet, J; Davoust, N; Mangeot, P E; Chaboud, A; Penin, F; Jacob, Y; Vidalain, P O; Vidal, M; André, P; Rabourdin-Combe, C; Lotteau, V

2008-01-01

A proteome-wide mapping of interactions between hepatitis C virus (HCV) and human proteins was performed to provide a comprehensive view of the cellular infection. A total of 314 protein-protein interactions between HCV and human proteins was identified by yeast two-hybrid and 170 by literature mining. Integration of this data set into a reconstructed human interactome showed that cellular proteins interacting with HCV are enriched in highly central and interconnected proteins. A global analysis on the basis of functional annotation highlighted the enrichment of cellular pathways targeted by HCV. A network of proteins associated with frequent clinical disorders of chronically infected patients was constructed by connecting the insulin, Jak/STAT and TGFbeta pathways with cellular proteins targeted by HCV. CORE protein appeared as a major perturbator of this network. Focal adhesion was identified as a new function affected by HCV, mainly by NS3 and NS5A proteins.

The challenging environment on board the International Space Station affects endothelial cell function by triggering oxidative stress through thioredoxin interacting protein overexpression: the ESA-SPHINX experiment.

Science.gov (United States)

Versari, Silvia; Longinotti, Giulia; Barenghi, Livia; Maier, Jeanette Anne Marie; Bradamante, Silvia

2013-11-01

Exposure to microgravity generates alterations that are similar to those involved in age-related diseases, such as cardiovascular deconditioning, bone loss, muscle atrophy, and immune response impairment. Endothelial dysfunction is the common denominator. To shed light on the underlying mechanism, we participated in the Progress 40P mission with Spaceflight of Human Umbilical Vein Endothelial Cells (HUVECs): an Integrated Experiment (SPHINX), which consisted of 12 in-flight and 12 ground-based control modules and lasted 10 d. Postflight microarray analysis revealed 1023 significantly modulated genes, the majority of which are involved in cell adhesion, oxidative phosphorylation, stress responses, cell cycle, and apoptosis. Thioredoxin-interacting protein was the most up-regulated (33-fold), heat-shock proteins 70 and 90 the most down-regulated (5.6-fold). Ion channels (TPCN1, KCNG2, KCNJ14, KCNG1, KCNT1, TRPM1, CLCN4, CLCA2), mitochondrial oxidative phosphorylation, and focal adhesion were widely affected. Cytokine detection in the culture media indicated significant increased secretion of interleukin-1α and interleukin-1β. Nitric oxide was found not modulated. Our data suggest that in cultured HUVECs, microgravity affects the same molecular machinery responsible for sensing alterations of flow and generates a prooxidative environment that activates inflammatory responses, alters endothelial behavior, and promotes senescence.

Influence of Bleaching on Flavor of 34% Whey Protein Concentrate and Residual Benzoic Acid Concentration in Dried Whey Proteins

Science.gov (United States)

Previous studies have shown that bleaching negatively affects the flavor of 70% whey protein concentrate (WPC70), but bleaching effects on lower-protein products have not been established. Benzoyl peroxide (BP), a whey bleaching agent, degrades to benzoic acid (BA) and may elevate BA concentrations...

Antioxidant Treatment and Induction of Autophagy Cooperate to Reduce Desmin Aggregation in a Cellular Model of Desminopathy.

Directory of Open Access Journals (Sweden)

Eva Cabet

Full Text Available Desminopathies, a subgroup of myofibrillar myopathies (MFMs, the progressive muscular diseases characterized by the accumulation of granulofilamentous desmin-positive aggregates, result from mutations in the desmin gene (DES, encoding a muscle-specific intermediate filament. Desminopathies often lead to severe disability and premature death from cardiac and/or respiratory failure; no specific treatment is currently available. To identify drug-targetable pathophysiological pathways, we performed pharmacological studies in C2C12 myoblastic cells expressing mutant DES. We found that inhibition of the Rac1 pathway (a G protein signaling pathway involved in diverse cellular processes, antioxidant treatment, and stimulation of macroautophagy reduced protein aggregation by up to 75% in this model. Further, a combination of two or three of these treatments was more effective than any of them alone. These results pave the way towards the development of the first treatments for desminopathies and are potentially applicable to other muscle or brain diseases associated with abnormal protein aggregation.

Protein synthesis in x-irradiated rabbit lens

International Nuclear Information System (INIS)

Garadi, R.; Foltyn, A.R.; Giblin, F.J.; Reddy, V.N.

1984-01-01

The present study deals with the incorporation of 35 S methionine into lens crystallins as a function of time after x-irradiation. Crystallin synthesis is first affected approximately 4 weeks following x-irradiation. This coincides with the time period at which the ratio of the two cations in the lens is affected, as shown in earlier studies. A greater decrease in 35 S-methionine incorporation into crystallins is observed between 5-7 weeks following x-irradiation in good agreement with a cation imbalance at these time intervals. These studies also revealed for the first time that the change in cation distribution can affect not only crystallin synthesis, but also the synthesis of certain polypeptides of lens membranes. No alteration in protein synthesis could be detected in lens epithelium even after 7 weeks following irradiation. In addition to the effect of Na+ and K+ levels on protein synthesis, an impaired transport of amino acids into the x-rayed lens was also found to be a factor in the observed reduction in synthesis of the crystallin, cytoskeletal and membrane proteins of the fiber cells. It is concluded that Na+/K+ ratio as well as the availability of amino acids in the lens are important factors in protein synthesis of x-ray cataracts

Dependence of myosin-ATPase on structure bound creatine kinase in cardiac myfibrils from rainbow trout and freshwater turtle

DEFF Research Database (Denmark)

Haagensen, L.; Jensen, D.H.; Gesser, Hans

2008-01-01

The influence of myofibrillar creatine kinase on the myosin-ATPase activity was examined in cardiac ventricular myofibrils isolated from rainbow trout (Oncorhynchus mykiss) and freshwater turtle (Trachemys scripta). The ATPase rate was assessed by recording the rephosphorylation of ADP by the pyr......The influence of myofibrillar creatine kinase on the myosin-ATPase activity was examined in cardiac ventricular myofibrils isolated from rainbow trout (Oncorhynchus mykiss) and freshwater turtle (Trachemys scripta). The ATPase rate was assessed by recording the rephosphorylation of ADP...... by the pyruvate kinase reaction alone or together with the amount of creatine formed, when myofibrillar bound creatine kinase was activated with phosphocreatine. The steady-state concentration of ADP in the solution was varied through the activity of pyruvate kinase added to the solution. For rainbow trout...... myofibrils at a high pyruvate kinase activity, creatine kinase competed for ADP but did not influence the total ATPase activity. When the ADP concentration was elevated within the physiological range by lowering the pyruvate kinase activity, creatine kinase competed efficiently and increased the ATPase...

Interaction of Berberine derivative with protein POT1 affect telomere function in cancer cells

Energy Technology Data Exchange (ETDEWEB)

Xiao, Nannan; Chen, Siqi; Ma, Yan; Qiu, Jun; Tan, Jia-Heng; Ou, Tian-Miao; Gu, Lian-Quan; Huang, Zhi-Shu [School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou University City, Waihuan East Road 132, Guangzhou 510006 (China); Li, Ding, E-mail: liding@mail.sysu.edu.cn [School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou University City, Waihuan East Road 132, Guangzhou 510006 (China)

2012-03-16

Highlights: Black-Right-Pointing-Pointer The protein POT1 plays an important role in telomere protection. Black-Right-Pointing-Pointer Functional POT1 was overexpressed in Escherichia coli for the first time, and purified. Black-Right-Pointing-Pointer Compound Sysu-00692 was found to be the first POT1-binding ligand. Black-Right-Pointing-Pointer Sysu-00692 could interfere with the binding activity of POT1 in vivo. Black-Right-Pointing-Pointer Sysu-00692 had inhibition on telomerase and cell proliferation. -- Abstract: The protein POT1 plays an important role in telomere protection, which is related with telomere elongation and cell immortality. The protein has been recognized as a promising drug target for cancer treatment. In the present study, we cloned, overexpressed in Escherichia coli for the first time, and purified recombinant human POT1. The protein was proved to be active through filter binding assay, FRET and CD experiments. In the initial screening for protein binding ligands using SPR, compound Sysu-00692 was found to bind well with the POT1, which was confirmed with EMSA. Its in vivo activity study showed that compound Sysu-00692 could interfere with the binding between human POT1 and the telomeric DNA through chromatin immunoprecipitation. Besides, the compound showed mild inhibition on telomerase and cell proliferation. As we know, compound Sysu-00692 is the first reported POT1-binding ligand, which could serve as a lead compound for further improvement. This work offered a potentially new approach for drug design for the treatment of cancers.

Shotgun proteomic analytical approach for studying proteins adsorbed onto liposome surface

KAUST Repository

Capriotti, Anna Laura; Caracciolo, Giulio; Cavaliere, Chiara; Crescenzi, Carlo; Pozzi, Daniela; Laganà , Aldo

2011-01-01

The knowledge about the interaction between plasma proteins and nanocarriers employed for in vivo delivery is fundamental to understand their biodistribution. Protein adsorption onto nanoparticle surface (protein corona) is strongly affected

Lactation Affects Isolated Mitochondria and Its Fatty Acid Composition but Has No Effect on Tissue Protein Oxidation, Lipid Peroxidation or DNA-Damage in Laboratory Mice

Directory of Open Access Journals (Sweden)

Teresa G. Valencak

2016-01-01

Full Text Available Linking peak energy metabolism to lifespan and aging remains a major question especially when focusing on lactation in females. We studied, if and how lactation affects in vitro mitochondrial oxygen consumption and mitochondrial fatty acid composition. In addition, we assessed DNA damage, lipid peroxidation and protein carbonyls to extrapolate on oxidative stress in mothers. As model system we used C57BL/6NCrl mice and exposed lactating females to two ambient temperatures (15 °C and 22 °C while they nursed their offspring until weaning. We found that state II and state IV respiration rates of liver mitochondria were significantly higher in the lactating animals than in non-lactating mice. Fatty acid composition of isolated liver and heart mitochondria differed between lactating and non-lactating mice with higher n-6, and lower n-3 polyunsaturated fatty acids in the lactating females. Surprisingly, lactation did not affect protein carbonyls, lipid peroxidation and DNA damage, nor did moderate cold exposure of 15 °C. We conclude that lactation increases rates of mitochondrial uncoupling and alters mitochondrial fatty acid composition thus supporting the “uncoupling to survive” hypothesis. Regarding oxidative stress, we found no impact of lactation and lower ambient temperature and contribute to growing evidence that there is no linear relationship between oxidative damage and lactation.

Proteins Play Important Role in Intercellular Adhesion Affecting on Fruit Textural Quality

DEFF Research Database (Denmark)

Bahadur Adhikari, Khem; Shomer, Ilan

2012-01-01

Fruit textural quality is becoming a major quality parameter for export, postharvest preservation, handling and processing. The main determinant of textural quality is intercellular adhesion (ICA) as attributed by the cell wall (CW) and its components. The importance of CW protein in ICA strength......Fruit textural quality is becoming a major quality parameter for export, postharvest preservation, handling and processing. The main determinant of textural quality is intercellular adhesion (ICA) as attributed by the cell wall (CW) and its components. The importance of CW protein in ICA...... strengthening was exempli ed in Medjoul date (Phoenix dactylifera L.) fruit, as a model. Fruit mesocarp sensitively responded to culture environment which was assayed in vitro at pH 3.5( pKa) in presence of organic acid molecules. The max penetration force, as a measure of ICA strength, of p...

Multi-protein assemblies underlie the mesoscale organization of the plasma membrane

Science.gov (United States)

Saka, Sinem K.; Honigmann, Alf; Eggeling, Christian; Hell, Stefan W.; Lang, Thorsten; Rizzoli, Silvio O.

2014-01-01

Most proteins have uneven distributions in the plasma membrane. Broadly speaking, this may be caused by mechanisms specific to each protein, or may be a consequence of a general pattern that affects the distribution of all membrane proteins. The latter hypothesis has been difficult to test in the past. Here, we introduce several approaches based on click chemistry, through which we study the distribution of membrane proteins in living cells, as well as in membrane sheets. We found that the plasma membrane proteins form multi-protein assemblies that are long lived (minutes), and in which protein diffusion is restricted. The formation of the assemblies is dependent on cholesterol. They are separated and anchored by the actin cytoskeleton. Specific proteins are preferentially located in different regions of the assemblies, from their cores to their edges. We conclude that the assemblies constitute a basic mesoscale feature of the membrane, which affects the patterning of most membrane proteins, and possibly also their activity. PMID:25060237

Making muscles "stronger": exercise, nutrition, drugs.

Science.gov (United States)

Aagaard, P

2004-06-01

As described in this review, maximal muscle strength is strongly influenced by resistive-types of exercise, which induce adaptive changes in both neuromuscular function and muscle morphology. Further, timed intake of protein in conjunction with resistance training elicit greater strength and muscle size gains than resistance training alone. Creatine supplementation amplifies the hypertrophic response to resistance training, although some individuals may not respond positively. Locally produced muscle growth factors are upregulated during creatine supplementation, which contributes to increase the responsiveness of muscle cells to intensive training stimuli. Usage of anabolic steroids boosts muscle hypertrophy beyond inherent genetical limits, not only by increasing the DNA transcription rate for myofibrillar proteins but also by increasing the nucleus-to-cytoplasm ratio due to accelerated activation of myogenic satellite cells. However, severe tissue damaging effects exist with anabolic steroids, some of which are irreversible.

Labelling of proteins with radioiodine and their application

International Nuclear Information System (INIS)

Franek, M.; Hampl, J.; Rodak, L.; Hruska, K.; Prochazka, Z.

1975-01-01

Various techniques of labelling proteins and peptides with radioactive iodine are reviewed. Particular attention is focused on the mechanism of iodination of tyrosine used as a model substance for radioiodination of proteins. Particular consideration is given to recent techniques attaining high specific radioactivity without side effects on the protein molecule and to factors affecting the rate of iodination and its character (buffers, polarity of the reaction environment, molecule type, etc.). The suitability is shown of radioiodinated proteins in the studies of protein metabolism and in the radioimmunoanalytical determination of substances of both the protein and non-protein nature. The possibility of further application of radioiodinated protein is discussed. (author)

Dimerization in the Grb7 Protein

OpenAIRE

Peterson, Tabitha A.; Benallie, Renee L.; Bradford, Andrew M.; Pias, Sally C.; Yazzie, Jaron.; Lor, Siamee N.; Haulsee, Zachary M.; Park, Chad K.; Johnson, Dennis L.; Rohrschneider, Larry R.; Spuches, Anne.; Lyons, Barbara A.

2012-01-01

In previous studies, we showed that the tyrosine phosphorylation state of growth factor receptor–bound protein 7 (Grb7) affects its ability to bind to the transcription regulator FHL2 and the cortactin-interacting protein, human HS-1-associated protein-1. Here, we present results describing the importance of dimerization in the Grb7–Src homology 2 (SH2) domain in terms of its structural integrity and the ability to bind phosphorylated tyrosine peptide ligands. A tyrosine phosphorylation-mimic...

Nutrient Fortification of Human Donor Milk Affects Intestinal Function and Protein Metabolism in Preterm Pigs

DEFF Research Database (Denmark)

Sun, Jing; Li, Yanqi; Nguyen, Duc Ninh

2018-01-01

(BC) may be an alternative nutrient fortifier, considering its high content of protein and milk bioactive factors. Objective: We investigated whether BC was superior to an FF product based on processed bovine milk and vegetable oil to fortify donor human milk (DHM) for preterm pigs, used as a model......) and DHM with or without FF or BC fortification (+4.6 g protein ⋅ kg-1 ⋅ d-1). Results: DPM-fed pigs showed higher growth (10-fold), protein synthesis (+15-30%), villus heights, lactase and peptidase activities (+30%), and reduced intestinal cytokines (-50%) relative to DHM pigs (all P ....05). Fortification increased protein synthesis (+20-30%), but with higher weight gain and lower urea and cortisol concentrations for DHM+BC compared with DHM+FF pigs (2- to 3-fold differences, all P ≤ 0.06). DHM+FF pigs showed more diarrhea and reduced lactase and peptidase activities, hexose uptake, and villus...

Force spectroscopy studies on protein-ligand interactions: a single protein mechanics perspective.

Science.gov (United States)

Hu, Xiaotang; Li, Hongbin

2014-10-01

Protein-ligand interactions are ubiquitous and play important roles in almost every biological process. The direct elucidation of the thermodynamic, structural and functional consequences of protein-ligand interactions is thus of critical importance to decipher the mechanism underlying these biological processes. A toolbox containing a variety of powerful techniques has been developed to quantitatively study protein-ligand interactions in vitro as well as in living systems. The development of atomic force microscopy-based single molecule force spectroscopy techniques has expanded this toolbox and made it possible to directly probe the mechanical consequence of ligand binding on proteins. Many recent experiments have revealed how ligand binding affects the mechanical stability and mechanical unfolding dynamics of proteins, and provided mechanistic understanding on these effects. The enhancement effect of mechanical stability by ligand binding has been used to help tune the mechanical stability of proteins in a rational manner and develop novel functional binding assays for protein-ligand interactions. Single molecule force spectroscopy studies have started to shed new lights on the structural and functional consequence of ligand binding on proteins that bear force under their biological settings. Copyright © 2014 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.

Effect of radiation treatment on protein quality and vitamin content of animal feeds

International Nuclear Information System (INIS)

Eggum, B.O.

1979-01-01

This paper reports the effects of autoclaving and irradiation on the protein quality and vitamin content of various nutrients of laboratory animal diets. The protein quality and its amino acid composition was not significantly affected by a radiation dose as high as 7.0 Mrad, whereas the protein quality of autoclaved diet (102 0 C for 5 minutes) was significantly affected. Vitamin B 1 , B 0 and α-tocopherol appeared to be affected by irradiation, whereas autoclaving reduced the levels of vitamins A, B 1 and E. (author)

Using Protein Dimers to Maximize the Protein Hybridization Efficiency with Multisite DNA Origami Scaffolds

Science.gov (United States)

Verma, Vikash; Mallik, Leena; Hariadi, Rizal F.; Sivaramakrishnan, Sivaraj; Skiniotis, Georgios; Joglekar, Ajit P.

2015-01-01

DNA origami provides a versatile platform for conducting ‘architecture-function’ analysis to determine how the nanoscale organization of multiple copies of a protein component within a multi-protein machine affects its overall function. Such analysis requires that the copy number of protein molecules bound to the origami scaffold exactly matches the desired number, and that it is uniform over an entire scaffold population. This requirement is challenging to satisfy for origami scaffolds with many protein hybridization sites, because it requires the successful completion of multiple, independent hybridization reactions. Here, we show that a cleavable dimerization domain on the hybridizing protein can be used to multiplex hybridization reactions on an origami scaffold. This strategy yields nearly 100% hybridization efficiency on a 6-site scaffold even when using low protein concentration and short incubation time. It can also be developed further to enable reliable patterning of a large number of molecules on DNA origami for architecture-function analysis. PMID:26348722

Using Protein Dimers to Maximize the Protein Hybridization Efficiency with Multisite DNA Origami Scaffolds.

Directory of Open Access Journals (Sweden)

Vikash Verma

Full Text Available DNA origami provides a versatile platform for conducting 'architecture-function' analysis to determine how the nanoscale organization of multiple copies of a protein component within a multi-protein machine affects its overall function. Such analysis requires that the copy number of protein molecules bound to the origami scaffold exactly matches the desired number, and that it is uniform over an entire scaffold population. This requirement is challenging to satisfy for origami scaffolds with many protein hybridization sites, because it requires the successful completion of multiple, independent hybridization reactions. Here, we show that a cleavable dimerization domain on the hybridizing protein can be used to multiplex hybridization reactions on an origami scaffold. This strategy yields nearly 100% hybridization efficiency on a 6-site scaffold even when using low protein concentration and short incubation time. It can also be developed further to enable reliable patterning of a large number of molecules on DNA origami for architecture-function analysis.

Protein phosphorylation in isolated hepatocytes of septic and endotoxemic rats

International Nuclear Information System (INIS)

Deaciuc, I.V.; Spitzer, J.A.

1989-01-01

The purpose of this study was to investigate possible alterations induced by sepsis and endotoxicosis in the late phase of Ca2+-dependent signaling in rat liver. Hepatocytes isolated from septic or chronically endotoxin (ET)-treated rats were labeled with [32P]H3PO4 and stimulated with various agents. Proteins were resolved by one-dimensional polyacrylamide gel electrophoresis and autoradiographed. Vasopressin (VP)- and phenylephrine (PE)-induced responses were attenuated in both septic and ET-treated rats for cytosolic and membrane proteins compared with their respective controls. Glucagon and 12-O-myristate phorbol-13-acetate (TPA) affected only the phosphorylation of membrane proteins. Glucagon-induced changes in the phosphorylation of membrane proteins were affected by both sepsis and endotoxicosis, whereas TPA-stimulated phosphorylation was lowered only in endotoxicosis. Response to the Ca2+ ionophore A23187 was depressed in septic rats for cytosolic proteins. The phosphorylation of two cytosolic proteins, i.e., 93 and 61 kDa (previously identified as glycogen phosphorylase and pyruvate kinase, respectively), in response to VP, PE, and A23187 was severely impaired by endotoxicosis and sepsis. TPA did not affect the phosphorylation state of these two proteins. The results show that sepsis and endotoxicosis produce perturbations of the phosphorylation step in Ca2+ transmembrane signaling. Such changes can explain alterations of glycogenolysis and gluconeogenesis associated with sepsis and endotoxicosis

Enhanced Bio-hydrogen Production from Protein Wastewater by Altering Protein Structure and Amino Acids Acidification Type

Science.gov (United States)

Xiao, Naidong; Chen, Yinguang; Chen, Aihui; Feng, Leiyu

2014-01-01

Enhanced bio-hydrogen production from protein wastewater by altering protein structure and amino acids acidification type via pH control was investigated. The hydrogen production reached 205.2 mL/g-protein when protein wastewater was pretreated at pH 12 and then fermented at pH 10. The mechanism studies showed that pH 12 pretreatment significantly enhanced protein bio-hydrolysis during the subsequent fermentation stage as it caused the unfolding of protein, damaged the protein hydrogen bonding networks, and destroyed the disulfide bridges, which increased the susceptibility of protein to protease. Moreover, pH 10 fermentation produced more acetic but less propionic acid during the anaerobic fermentation of amino acids, which was consistent with the theory of fermentation type affecting hydrogen production. Further analyses of the critical enzymes, genes, and microorganisms indicated that the activity and abundance of hydrogen producing bacteria in the pH 10 fermentation reactor were greater than those in the control. PMID:24495932