THE PROTEOLYTIC ACTIVITY OF INSULIN

1967 ◽  
Vol 45 (9) ◽  
pp. 1329-1333
Author(s):  
Michel Page ◽  
Claude Godin
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Proteolytic Activity ◽  
Protein Amino Acids

The action of insulin on hemoglobin at pH 7.5 was studied. Four different methods were used to determine the degree of proteolysis. After mixtures of hemoglobin and insulin were incubated for 2 hours, very little amino acid or peptide material was liberated from the proteins. As many amino acids are liberated from hemoglobin when it is incubated alone under the same conditions. It is concluded that autolysis is responsible for the observed increases in non-protein amino acids and that insulin has no proteolytic activity under the conditions used in this study.

scholarly journals BIOSYNTHESIS IN ISOLATED ACETABULARIA CHLOROPLASTS

1972 ◽  
Vol 54 (2) ◽  
pp. 279-294 ◽  
Author(s):  
David C. Shephard ◽  
Wendy B. Levin
Keyword(s):  
Amino Acids ◽  
Protein Synthesis ◽  
Amino Acid ◽  
Technical Problems ◽  
Hydrolyzed Protein ◽  
Protein Amino Acids ◽  
Amino Acid Labeling ◽  
Labeling Pattern

The ability of chloroplasts isolated from Acetabulana mediterranea to synthesize the protein amino acids has been investigated. When this chloroplast isolate was presented with 14CO2 for periods of 6–8 hr, tracer was found in essentially all amino acid species of their hydrolyzed protein Phenylalanine labeling was not detected, probably due to technical problems, and hydroxyproline labeling was not tested for The incorporation of 14CO2 into the amino acids is driven by light and, as indicated by the amount of radioactivity lost during ninhydrin decarboxylation on the chromatograms, the amino acids appear to be uniformly labeled. The amino acid labeling pattern of the isolate is similar to that found in plastids labeled with 14CO2 in vivo. The chloroplast isolate did not utilize detectable amounts of externally supplied amino acids in light or, with added adenosine triphosphate (ATP), in darkness. It is concluded that these chloroplasts are a tight cytoplasmic compartment that is independent in supplying the amino acids used for its own protein synthesis. These results are discussed in terms of the role of contaminants in the observed synthesis, the "normalcy" of Acetabularia chloroplasts, the synthetic pathways for amino acids in plastids, and the implications of these observations for cell compartmentation and chloroplast autonomy.

Inter-annual and seasonal dynamics of amino acid, mineral and vitamin composition of silver belly Leiognathus splendens

2014 ◽  
Vol 95 (4) ◽  
pp. 817-828 ◽  
Author(s):  
Kajal Chakraborty ◽  
Deepu Joseph
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Protein Content ◽  
West Coast ◽  
Sensor Data ◽  
The South ◽  
Post Monsoon ◽  
South West ◽  
South West Coast ◽  
Protein Amino Acids

Silver bellies, Leiognathus splendens were studied for their spatial (south-west and south-east coasts of India), annual (2008–2011) and seasonal (pre-monsoon, monsoon and post-monsoon) variations of protein, amino acids, vitamins and minerals. The monthly mean Sea Viewing Wide Field-of-view Sensor data for the period from January 2008 to December 2011 were taken into account to indicate the distribution of the photosynthetic pigment chlorophyll-a to test the hypothesis that surface productivity might be related to nutritional biochemistry of this species. The four year average total protein content and chlorophyll-a showed good correlation during monsoon on the south-west coast and monsoon/post-monsoon on the south-east coast, suggesting that the protein content is prejudiced by the chlorophyll-a concentration. Amino acid scores observed monsoon maxima along the south-west and south-east coasts. Significant seasonal variations in vitamin content were observed at the study locations with high content of vitamins D3, E, K1 and C on the south-west coast. Na content was maximal during pre-monsoon on the south-west coast, while post-monsoon maxima of Ca and K content were observed. The Fe, Mn and Zn were abundant in the samples collected from the south-west coast. The concentration of Se exhibited maximum values post-monsoon along the south-west and south-east coasts. The present study demonstrated L. splendens as a valuable source of the protein, amino acids, minerals and vitamins, showing that this low-value species is a good source of well balanced proteins with high biological value to be qualified as a preferred healthy food for human consumption.

The Oocytes of the Goby Pomatoschistus minutus. III. Determination of Amino Acid Component

1980 ◽  
Vol 35 (11-12) ◽  
pp. 1094-1095
Author(s):  
Rüdiger Riehl
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Glutamic Acid ◽  
Acid Content ◽  
Amino Acid Content ◽  
Acid Component ◽  
Pomatoschistus Minutus ◽  
Protein Amino Acids ◽  
Amino Acid Component

Abstract The oocytes of the marine goby Pomatoschistus minutus were analyzed for their amino acid content. Most of the amino acids exist as protein, only a little part is free or peptide-bound. Among the protein-bound amino acids, high levels of glutamic acid, proline, alanine, aspartic acid, valine and leucine were detected. These represent more than 60% of the protein amino acids. Among the free acids, glutamic acid, serine and alanine, are dominant. There are no certain proofs of the occurrence of peptide pools in the oocytes of Pomatoschistus minutus.

The relationships between the concentrations of individual amino acids and protein in wheat and barley grain grown at selected locations throughout Manitoba

1996 ◽  
Vol 76 (2) ◽  
pp. 163-169 ◽  
Author(s):  
R. J. Boila ◽  
S. C. Stothers ◽  
L. D. Campbell
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Barley Grain ◽  
Regression Equations ◽  
Acid Protein ◽  
Wide Range ◽  
Indispensable Amino Acids ◽  
Protein Amino Acids ◽  
Barley Protein ◽  
Amino Acid Concentrations

The concentrations of protein and individual amino acids were determined in the grain from three cultivars of wheat and three cultivars of barley, each grown at 12 locations throughout Manitoba over 3 consecutive years. Protein concentration differed (P < 0.05) among the cultivars of wheat but not (P > 0.05) among cultivars of barley. Although the concentrations of several amino acids differed (P < 0.05) among cultivars of wheat or barley the differences among cultivars of each grain were not considered to be critical in relation to the requirements for indispensable amino acids for swine or poultry. The percentage of an ammo acid in the DM of wheat and barley increased (P < 0.05) linearly with an increase in percentage of protein in the grain. The wide range of r2 (0.29 to 0.88) obtained for this amino acid-protein relationship may be due to the different effect of environment (location and year of growth) on the concentration of individual amino acids, compared to protein, among cultivars of wheat or barley. The percentage of total variance due to an interaction between cultivar and environment was low for protein but was several fold higher for individual amino acids. The error in the prediction of amino acid concentrations with regression equations may be no different than the error associated with predicting the mean concentrations of amino acids in the protein of wheat or barley as g (100 g protein)−1, and obtained from tabulations of analyses. However, regression equations for lysine in wheat and barley did account for the significant (P < 0.05) decrease in concentration of lysine in the protein as the percentage of protein in these grains increased. Key words: Grain, wheat, barley, protein, amino acids, Manitoba

scholarly journals Effects of Dietary Crude Protein Levels on Fecal Crude Protein, Amino Acids Flow Amount, Fecal and Ileal Microbial Amino Acids Composition and Amino Acid Digestibility in Growing Pigs

Animals ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 2092
Author(s):  
Zhenguo Yang ◽  
Tianle He ◽  
Gifty Ziema Bumbie ◽  
Hong Hu ◽  
Qingju Chen ◽  
...  
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Essential Amino Acid ◽  
Crude Protein ◽  
Growing Pigs ◽  
Protein Levels ◽  
Low Protein ◽  
Dietary Crude Protein ◽  
Amino Acids Composition ◽  
Protein Amino Acids

The purpose of this experiment was to evaluate the effects of low protein corn-soybean meal-based diets on fecal CP, amino acid (AA) flow amount, AA digestibility and fecal and ileal microbial AA composition in growing pigs. Eighteen pigs (initial body weight = 30 ± 1.35) were randomly divided into three groups and fed with basal diets with CP levels of 12%, 15% and 18%, respectively. The Lys, Met + Cys, Thr and Trp level in the 12% CP and 15% CP groups is the same as 18% CP group by the addition of four crystalline Lys, Met + Cys, Thr and Trp to the diet. The results showed that with the decrease of dietary CP level from 18% to 12%, the fecal total nitrogen (N), CP and total AA (TAA) flow amount decreased linearly (p < 0.05). Dry matter (DM) digestibility, CP digestibility, TAA digestibility, essential amino acid (EAA) digestibility and non-essential amino acid (NEAA) digestibility increased linearly with the decrease of dietary CP concentration from 18% to 12%. Compared with 18% CP group, the flow amount of Asp, Ser, Glu, Gly, Tyr, Val, Leu and Phe in feces of pigs in the 15% CP group and 12% CP group decreased significantly, while the flow amount of Arg in the 15% CP group was lower than that in the 18% CP group and 12% CP group. The fecal microbial N and AA of the 15% CP group were higher than those of the 18% CP and 12% CP groups. Fecal TAA flow amount decreased linearly with the decrease of the dietary CP levels from 18% to 12%. Fecal TAA and NEAA flow amount also decreased linearly with the decrease of dietary CP level from 18% to 12%. Except for Glu, Gly, Met, Tyr, Thr and Phe, there were significant differences among the three groups in the composition of 17 kinds of AAs in fecal microorganisms. Among the 17 AA compositions of ileal microorganisms, except Tyr and Lys, the other AAs were significantly different among the three groups (p < 0.05)

Amino Acid and Fatty Acid Composition of Tissues of the Dungeness Crab (Cancer magister)

1971 ◽  
Vol 28 (8) ◽  
pp. 1191-1195 ◽  
Author(s):  
W. V. Allen
Keyword(s):  
Skeletal Muscle ◽  
Amino Acids ◽  
Fatty Acids ◽  
Amino Acid ◽  
The Other ◽  
Dungeness Crab ◽  
Cancer Magister ◽  
Storage Organs ◽  
Protein Amino Acids ◽  
Docosahexaenoic Acids

Tissues of the Dungeness crab (Cancer magister Dana) were analyzed for content of total lipid, protein, amino acids, fatty acids, and glucosamine. Ovaries and hepatopancreas were the major lipid storage organs. Gonads (ovaries and testes) and skeletal muscle contained substantially more protein than the other tissues. All tissues except the exoskeleton had balanced amino acid compositions. The exoskeletal protein was deficient in arginine and lysine. Glucosamine was a prominent constituent of the exoskeleton and of the gills and the gastric apparatus. Palmitic, palmitoleic, oleic, eicosapentaenoic, and docosahexaenoic acids were the major fatty acids found in all tissues.

scholarly journals Toxicity of Non-protein Amino Acids to Humans and Domestic Animals

2010 ◽  
Vol 5 (3) ◽  
pp. 1934578X1000500 ◽  
Author(s):  
Peter B. Nunn ◽  
E. Arthur Bell ◽  
Alison A. Watson ◽  
Robert J. Nash
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Medicago Sativa ◽  
Food Chain ◽  
Wild Species ◽  
Lens Culinaris ◽  
Herbal Medicines ◽  
Domestic Animals ◽  
Crop Species ◽  
Protein Amino Acids

Non-protein amino acids are common in plants and are present in widely consumed animal feeds and human foods such as alfalfa ( Medicago sativa), which contains canavanine, and lentil ( Lens culinaris), which contains homoarginine. Some occur in wild species that are inadvertently harvested with crop species. Some nonprotein amino acids and metabolites can be toxic to humans, e.g. Lathyrus species contain a neurotoxic oxalyl-amino acid. Some potential toxins may be passed along a food chain via animal intermediates. The increased interest in herbal medicines in the Western countries will increase exposure to such compounds.

SOURCES OF CARBON FOR THE SYNTHESIS OF PROTEIN AMINO ACIDS IN ATTACHED PHOTOSYNTHESIZING WHEAT LEAVES

1963 ◽  
Vol 41 (7) ◽  
pp. 985-994 ◽  
Author(s):  
J. A. Hellebust ◽  
R. G. S. Bidwell
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Glutamic Acid ◽  
Protein Turnover ◽  
Soluble Sugars ◽  
Protein Nitrogen ◽  
Considerable Portion ◽  
Protein Amino Acids ◽  
Specific Activities ◽  
Wheat Leaves

Attached, rapidly growing wheat leaves were allowed to photoassimilate C14O2 and C12O2 alternately. Samples of leaves were collected after each period of photosynthesis and were analyzed for amounts and total activities of soluble sugars and amino acids, and protein amino acids. The leaves were also analyzed for protein nitrogen and amounts and total activities of respired carbon. Samples of roots were also collected and the amounts, total activities, and specific activities of their soluble compounds were determined. It was possible to calculate from these data the proportions of carbon entering some protein amino acids which came either from soluble amino acid pools or by a direct route from photosynthate, bypassing the soluble pools. More than half of the carbon entering protein-bound serine and glycine was derived from newly assimilated CO2, while protein glutamic acid, aspartic acid, and alanine derived more of their carbon from the soluble amino acid pools. Analysis of the data from roots indicated that a considerable portion of the carbon translocated from the leaves was derived from newly assimilated CO2. There was some indication that protein turnover took place, but it was concluded that proteins could not have contributed significantly as substrates for respiration in these leaves.

scholarly journals The localization of proteolytic activity in rat liver mitochondria and its relation to mitochondrial swelling and aging

1969 ◽  
Vol 111 (5) ◽  
pp. 763-776 ◽  
Author(s):  
K. G. M. M. Alberti ◽  
W. Bartley
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Proteolytic Activity ◽  
Rat Liver ◽  
Acid Production ◽  
Liver Mitochondria ◽  
Ground Substance ◽  
Rat Liver Mitochondria ◽  
Amino Acid Production ◽  
Freezing And Thawing

1. On storage of rat liver mitochondria at 0°, water content, total amino acid content and leakage of protein all rose steadily over a 72hr. period. The initial ratio of intramitochondrial to extramitochondrial amino acid concentration lay between 18 and 24. Initially this rose, but it then fell to 1·9 at the end of storage. The concentration gradient between internal and external amino acids was relatively constant throughout the period. These processes were accentuated at 22° and 40°, the concentration gradient reaching 70μmoles/ml., water content rising to 8·3mg./mg. dry wt. and protein leakage reaching 42% of total mitochondrial protein. ‘Swelling agents’ produced no correlated changes in amino acid production and swelling. 2. Added glutamate was not concentrated within the pellet of whole or disrupted mitochondria. Endogenous amino acids were distributed evenly between the pellet and the supernatant of disrupted mitochondria. It is concluded that amino acids are produced within mitochondria and that adsorption and uptake from the medium do not contribute significantly to amino acids in the pellet. 3. β-Glycerophosphate, a lysosome protectant, increased amino acid production by rat liver mitochondria. Treatment with Triton X-100 and disruption by freezing and thawing showed that 56% of proteolytic activity was ‘free’ in whole mitochondria, whereas only 11% of acid phosphatase activity, a lysosomal enzyme, was ‘free’. 4. ‘Light’ mitochondria contained 30% more neutral proteolytic activity but 300% more acid phosphatase activity than ‘heavy’ mitochondria. 5. Electron micrographs of mitochondrial preparations showed less than one particle in 500 that could be identified as a lysosome. Treatment with Triton X-100 disrupted the structure of roughly 50% of the mitochondria; the rest appeared to retain their membrane, cristae and ground substance. Freezing and thawing caused gross swelling and loss of ground substance and rupture of external membranes. 6. Of the recovered proteolytic activity, 81% at pH7·4 and 70% at pH5·8 were found in the high-speed supernatant of broken mitochondria. A further fivefold increase in specific activity was found in the first protein fraction obtained by Sephadex G-50 gel filtration. 7. Between 60 and 80% of proteolytic activity was found in the 40–60%-saturated ammonium sulphate precipitate. Almost all of the soluble-fraction proteolytic activity could be recovered in a pH5·0 supernatant. 8. The results give no support to the view that mitochondrial neutral proteolytic activity reflects lysosomal content. 9. The possible role of intramitochondrial amino acid production and the proteolysis of internal barriers in passive swelling of mitochondria is discussed.

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