scholarly journals Aminopeptidases of pea

1974 ◽  
Vol 141 (1) ◽  
pp. 113-118 ◽  
Author(s):  
T. C. Elleman
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Free Amino ◽  
The Other ◽  
Amide Bond ◽  
Amino Group ◽  
Amide Bonds ◽  
Primary Amino ◽  
Pea Seeds ◽  
Hydrolysis Of

Studies of crude extracts of pea seeds (Pisum sativum, var. Green feast) revealed the presence of three enzymes that hydrolyse the amide bond of aminoacyl β-naphthylamides. They differ in their specificity towards the aminoacyl moiety; one is proline-specific, whereas the other two hydrolyse the β-naphthylamides of primary amino acids. Of the latter, one is highly specific for hydrophobic aminoacyl residues whereas the other has a broader, somewhat complementary specificity, showing preferential hydrolysis of non-hydrophobic aminoacyl residues. These latter two aminoacyl-β-naphthylamidases have been separated and partly characterized with regard to substrate specificity and antagonism by inhibitors. Both are true aminopeptidases, requiring the presence of a free amino group and hydrolysing the amide bonds of amino acid amides, dipeptides and oligopeptides consecutively from the N-terminal end.

scholarly journals The isolation of a product of hydrolysis of the proteins hitherto undescribed

1925 ◽  
Vol 98 (687) ◽  
pp. 58-65 ◽  
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Free Amino Acid ◽  
Convenient Method ◽  
Free Amino ◽  
Barium Carbonate ◽  
Present Communication ◽  
Hydrolysis Products ◽  
Hydrolysis Of

Some time ago, two of the authors of the present communication, in seeking a method for the separation of the amino-acids from the carbohydrates, found that under certain conditions the former could be readily separated in the form of the barium salts of their carbamates, a class of compounds originally described by Siegfried. As these carbamates, on heating with water, are readily decomposed into barium carbonate and the free amino-acid, it was suggested that a convenient method might be evolved, using the formation of these compounds as a basis, for the separation of the hydrolysis products of the proteins.* This suggestion was followed up, and a method was subsequently elaborated and applied to the separation of the hydrolysis products of gelatin by one of the authors in conjunction with Miss H. L. Kingston. Since the publication of the two papers just quoted, the researches on the use of the “carbamate method,” as it may be conveniently called, have been continued, and promise results, which may ultimately lead to a satisfactory separation of most of the hydrolysis products of the proteins when only relatively small amounts of material are available for investigation. During the course of this work the base, which is the chief subject discussed in this paper, was discovered.

scholarly journals Free Amino Acid Enriched Rotifer for Larval Grouper Cromileptes altivelis (Pengkayaan Rotifer dengan Asam Amino Bebas Untuk Larva Kerapu Bebek Cromileptes altivelis)

2015 ◽  
Vol 20 (4) ◽  
pp. 207
Author(s):  
Dedi Jusadi ◽  
Tulas Aprilia ◽  
Muhammad Agus Suprayudi ◽  
Deddy Yaniharto
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Survival Rate ◽  
Free Amino Acid ◽  
Free Amino ◽  
Sea Water ◽  
The Other ◽  
Feeding Period ◽  
Growth And Survival ◽  
First Feeding

Pembenihan ikan kerapu dihadapkan pada rendahnya sintasan, terutama fase awal hidupnya. Rendahnya sintasan diduga berhubungan dengan belum berkembangnya organ pencernaan larva dan tidak tersedianya pakan yang siap diserap tubuh. Pemberian asam amino bebas seperti taurin dan glutamin melalui rotifer diharapkan dapat meningkatan ketersediaan nutrien yang dapat diserap dengan cepat oleh larva, sehingga sintasan larva tinggi dan dapat tumbuh lebih cepat. Penelitian bertujuan mengukur pengaruh glutamin atau taurin terhadap sintasan dan pertumbuhan larva kerapu bebek Cromileptes altivelis. Larva umur 1 hari (10 ekor.L-1) dipelihara dalam bak fiberglass volume 500 L yang diisi air laut sampai 330 L. Larva diberi pakan rotifer diperkaya 0,5 g glutamin, 0,5 g taurin, atau tanpa glutamin dan taurin. Larva dipelihara selama 16 hari dengan pemberian pakan 2 kali  per hari. Satu jam setelah pemberian pakan dilakukan pengamatan terhadap jumlah rotifer dalam saluran pencernaan larva ikan. Hasil penelitian menunjukkan jumlah rotifer dalam saluran pencernaan larva meningkat seiring dengan bertambahnya umur. Namun, jumlah rata-rata rotifer yang dikonsumsi larva pada perlakuan 0,5 g glutamin atau 0,5 g taurin lebih banyak dibanding perlakuan tanpa taurin dan glutamin. Larva yang diberi rotifer hasil pengkayaan dengan 0,5 g glutamin atau 0,5 g taurin memiliki sintasan yang tidak berbeda (P>0,05), masing-masing 19,2±2,25%, dan 24,5±1,20%, dan secara signifikan lebih banyak dibanding larva di perlakuan tanpa glutamin dan taurin yang nilainya 13,0±1,70%. Larva yang diberi rotifer hasil pengkayaan dengan 0,5 g taurin secara signifikan lebih panjang (5,5±0,18 mm) dari ikan di perlakuan 0,5 g glutamin (5,3±0,12 mm). Demikian juga, larva di perlakuan glutamin lebih panjang dari pelakuan tanpa glutamin dan taurin (5,0±0,16 mm). Pengkayaan rotifer menggunakan asam amino bebas taurin atau glutamin dapat meningkatkan sintasan dan pertumbuhan larva kerapu bebek. Namun, taurin lebih baik dibanding glutamin karena memberi efek ke pertumbuhan ikan yang lebih cepat. Kata kunci: taurin, glutamin, kerapu bebek, Cromileptes altivelis. The hatchery production of grouper faced to the problem of low surival rate, especially during the first feeding period. During this period, the digestive organ of larvae was underdeveloped, and the nutrient in live food was not readily absorbed by larvae. Feeding on free amino acids, such as taurine or glutamine, enriched rotifer would be enhanced the nutrient readily absorbed thereby resulting to the improvement of growth and survival rate of larvae. A duplicate experiment was conducted to evaluate the effect of rotifer enriched with free amino acid of glutamine or taurine, on the growth and survival rate of larval grouper Cromileptes altivelis. One day old larvae were cultured in 500 l fiberglass containing 330 l of sea water with a density of 10 ind.L-1. Larvae were fed on rotifer enriched with either 0.5 g glutamine, 0.5 g taurine, or without glutamine nor taurine. Larvae were fed on rotifer twice a day at 08.00 and 14.00, and cultured for 16 days. One h after feeding, rotifer content in the gut of larvae were observed. Results showed that larvae fed on rotifer enriched with 0.5 g taurine or 0.5 g glutamie had higher rotifer content in the gut than that in the other group. Larvae fed on rotifer enriched with 0.5 g glutamine or 0.5 g taurine had the same survival rate (P>0.05), 19.2±2.25% and 24.5±1.20%, respectively; these values were significantly higher than that in the other group which was 13.0±1.70%.  The total length of larvae fed on rotifer enriched with 0.5 g taurine (5.5±0.18 mm) significantly was the biggest compared than others; while those fed on rotifer enriched with 0.5 g glutamine (5.3±0.12 mm) was bigger than fish fed on rotifer without glutamine nor taurine (5.0±0.16 mm). Thus, it can be concluded that survival rate and growth of larvae were improved when feeding on rotifer enriched with taurine or glutamine. Nevertheless, taurine was more efective than glutamine due to its effect resulted the highest growth performance of larval grouper. Keywords: taurine, glutamine, grouper, Cromileptes altivelis

scholarly journals Splanchnic-bed transfers of amino acids in sheep blood and plasma, as monitored through use of a multiple U-13C-labelled amino acid mixture

1996 ◽  
Vol 75 (2) ◽  
pp. 217-235 ◽  
Author(s):  
G. E. Lobley ◽  
A. Connell ◽  
D. K. Revell ◽  
B. J. Bequette ◽  
D. S. Brown ◽  
...  
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Free Amino Acids ◽  
Free Amino ◽  
Essential Amino Acids ◽  
Whole Body ◽  
Gas Chromatography Mass Spectrometry ◽  
Acid Mixture ◽  
Body Protein ◽  
Hydrolysis Of

AbstractThe response in whole-body and splanchnic tissue mass and isotope amino acid transfers in both plasma and blood has been studied in sheep offered 800 g lucerne (Medicago sutiva) pellets/d. Amino acid mass transfers were quantified over a 4 h period,by arterio-venous procedures, across the portal-drained viscera (PDV) and liver on day 5 of an intravenous infusion of either vehicle or the methylated products, choline (0.5 g/d) plus creatine (10 g/d). Isotopic movements were monitored over the same period during a 10 h infusion of a mixture of U-13C-labelled amino acids obtained from hydrolysis of labelled algal cells. Sixteen amino acids were monitored by gas chromatography-mass spectrometry, with thirteen of these analysed within a single chromatographic analysis. Except for methionine, which is discussed in a previous paper, no significant effects of choline plus creatine infusion were observed on any of the variables reported. Whole-body protein irreversible-loss rates ranged from 158 to 245 g/d for the essential amino acids, based on the relative enrichments (dilution of the U-13C molecules by those unlabelled) of free amino acids in arterial plasma, and 206-519 g/d, when blood free amino acid relative enrichments were used for the calculations. Closer agreement was obtained between lysine, threonine, phenylalanine and the branched-chain amino acids. Plasma relative enrichments always exceeded those in blood (P < 0.001), possibly due to hydrolysis of peptides or degradation of protein within the erythrocyte or slow equilibration between plasma and the erythrocyte. Net absorbed amino acids across the PDV were carried predominantly in the plasma. Little evidence was obtained of any major and general involvement of the erythrocytes in the transport of free amino acids from the liver. Net isotope movements also supported these findings. Estimates of protein synthesis rates across the PDV tissues from [U-13C] leucine kinetics showed good agreement with previous values obtained with single-labelled leucine. Variable rates were obtained between the essential amino acids, probably due to different intracellular dilutions. Isotope dilution across the liver was small and could be attributed predominantly to uni-directional transfer from extracellular sources into the hepatocytes and this probably dominates the turnover of the intracellular hepatic amino acid pools.

scholarly journals The sites of hydrolysis of dipeptides containing leucine and glycine by rat jejunum in vitro

1969 ◽  
Vol 114 (4) ◽  
pp. 855-861 ◽  
Author(s):  
E. B. Fern ◽  
R. C. Hider ◽  
D. R. London
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
The Other ◽  
Peptidase Activity ◽  
Rat Jejunum ◽  
Effective Inhibitor ◽  
Inhibitory Effects ◽  
Molar Basis ◽  
Hydrolysis Of

1. The effect of peptides containing leucine and glycine on accumulation of leucine and glycine by everted jejunal rings was studied. 2. It was shown that, on a molar basis, leucyl-leucine is a more effective inhibitor of uptake of [14C]leucine than is either leucylglycine or glycyl-leucine. These latter dipeptides behave alike. 3. The concentration of the dipeptides and their constituent amino acids in both the incubation medium and the tissue has been followed in these experiments by amino acid analysis. No leucine-containing peptides were observed in the tissue. 4. The inhibitory effects of the mixed dipeptides are altered by pH changes in an analogous way to the alterations in peptidase activity. 5. The experimental results indicate that leucine-containing peptides are hydrolysed before the transport step. 6. Glycylglycine, on the other hand, has only a small effect on the accumulation of glycine, although large amounts of the peptide accumulate unchanged in the tissue. This suggests that glycylglycine is taken up by a different mechanism to that for the leucine dipeptides.

Free Amino Acids in the Haemocytes and Plasma of the Larva of Calliphora Vicina

1974 ◽  
Vol 61 (2) ◽  
pp. 463-472
Author(s):  
P. D. EVANS ◽  
A. C. CROSSLEY
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Free Amino Acid ◽  
Free Amino ◽  
The Other ◽  
Calliphora Vicina ◽  
Total Free Amino Acid ◽  
Insect Haemocytes ◽  
Homeostatic Function ◽  
Amino Acid Concentrations

Free amino acid concentrations have been measured in haemolymph samples taken from 3rd instar larvae of the blowfly, Calliphora vicina, at various stages prior to pupariation. The amino acids found in the haemocyte fraction only accounted for 6% of the total free amino acid concentration of the haemolymph. However, a high percentage of the dicarboxylic amino acids, glutamate and aspartate, 62% and 69% respectively, appeared to be sequestered in the haemocyte fraction at 72 h prior to pupariation. The percentage of the other individual amino acids found in the haemocyte fraction represented less than 10% of their amount in whole haemolymph. It is proposed that these results, together with the increase in the haemocyte levels of glutamate observed after injecting larvae with saline containing glutamate, are one of the first indications of a homeostatic function of insect haemocytes with respect to haemolypmh amino acids.

AN ANTIVIRAL SUBSTANCE FROM PENICILLIUM CYANEO-FULVUM BIOURGE: III. STUDIES ON THE NATURE OF THE ANTIVIRAL SUBSTANCE

1967 ◽  
Vol 13 (11) ◽  
pp. 1481-1488
Author(s):  
Delfa Syeklocha ◽  
Patricia M. Cooke ◽  
J. W. Stevenson
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Positive Charge ◽  
Reducing Sugar ◽  
The Other ◽  
Two Dimensional ◽  
Carbohydrate Complex ◽  
Amido Black ◽  
Antiviral Substance ◽  
Hydrolysis Of

An attempt has been made to determine the nature of an antiviral substance derived from Penicillium cyaneo-fulvum. Although the material was available only in semipurified state, horizontal electrophoresis showed just two components present, one with a positive charge and the other with a negative one. Both stained with mucicarmine and Amido black. After hydrolysis of the preparation, 13 amino acids were identified by two-dimensional chromatography. Preliminary studies indicate that the semipurified material contains 21–25% reducing sugar. The effect of a variety of enzymes on the activity of the preparation has been studied. The results indicate that the antiviral substance may be an amino acid – carbohydrate complex.

Succinimidyl esters of fatty acids for amino acid acylations

1976 ◽  
Vol 54 (5) ◽  
pp. 733-737 ◽  
Author(s):  
Alenka Paquet
Keyword(s):  
Amino Acids ◽  
Fatty Acids ◽  
Amino Acid ◽  
Free Amino ◽  
Side Chain ◽  
Amino Acid Esters ◽  
Amino Group ◽  
Acyl Chlorides ◽  
Hydroxysuccinimide Esters ◽  
Acid Esters

Fatty acid N-hydroxysuccinimide esters have been prepared from the thallium(I) salt of N-hydroxysuccinimide and the corresponding acyl chlorides in essentially quantitative yields. These active esters were used for acylation of amino acid esters in organic solvents, or of free amino acids in aqueous medium. The title compounds were found to be selective towards the side chain amino group of lysine. An efficient preparation of ε-N-benzyloxycarbonyl-L-lysine using benzyl succinimidyl carbonate is described.

Amino Acid Metabolism in Plants. II. Transamination Reactions of Free Protein Amino Acids in Cell-Free Extracts of Cotyledons and Growing Tissues of Bushbean Seedlings (Phaseolus vulgaris L.)

1972 ◽  
Vol 50 (5) ◽  
pp. 538-542 ◽  
Author(s):  
J. C. Forest ◽  
F. Wightman
Keyword(s):  
Amino Acids ◽  
Protein Synthesis ◽  
Amino Acid ◽  
Amino Acid Metabolism ◽  
Acid Metabolism ◽  
The Other ◽  
Amino Group ◽  
Phaseolus Vulgaris L ◽  
Keto Acids ◽  
Protein Amino Acids

The different transaminase reactions for 22 protein amino acids were investigated in extracts of cotyledons and growing tissues of 8-day-old bushbean seedlings when either α-ketoglutarate, oxaloacetate, pyruvate, or glyoxylate was used as amino group acceptor. The results indicate that both cotyledons and growing tissues exhibited a similar pattern of transaminase activities with respect to the amino acids normally required for protein synthesis. It was found that with the exception of proline, hydroxyproline, and cystine which did not appear to be transaminated, and of serine and threonine which were transaminated only when pyruvate or glyoxylate was provided as the amino group acceptor, all the other 17 amino acids were transaminated to different extents when each of the four keto acids tested was supplied as the amino group acceptor. Glutamic acid, aspartic acid, and alanine were, by far, the best amino group donors and α-ketoglutarate was generally found to be the best amino acceptor. Consideration is given to the number and substrate specificity of the aminotransferases catalyzing the reactions demonstrated in this study.

LYTIC ENZYMES OF SORANGIUM SP.: A COMPARISON OF THE PROTEOLYTIC PROPERTIES OF THE α- AND β-LYTIC PROTEASES

1965 ◽  
Vol 43 (12) ◽  
pp. 1961-1970 ◽  
Author(s):  
D. R. Whitaker ◽  
C. Roy ◽  
C. S. Tsai ◽  
L. Jurášek
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Methyl Ester ◽  
Esterase Activity ◽  
The Other ◽  
Carboxyl Group ◽  
Lytic Enzymes ◽  
Amidase Activity ◽  
A Chain ◽  
Hydrolysis Of

The proteolytic properties of the α- and β-lytic proteases of a species of Sorangium were compared. Neither enzyme showed evidence of aminopeptidase, carboxypeptidase, or amidase activity in tests with a series of peptides and substituted amino acids at pH 5.2, 7.2, and 9.0. Neither enzyme showed evidence of esterase activity towards N-benzoyl-L-arginine methyl ester at pH 6.8. Hydrolysis of the A chain of oxidized insulin at pH 9 slows down markedly when the α-enzyme has cleaved the chain once; the initial fast cleavage can take place at linkages between residues 9 and 10, 10 and 11, and 12 and 13; more slowly cleaved linkages are between residues 3 and 4, and 8 and 9. Hydrolysis of the B chain by the α-enzyme at pH 9 is still faster and slows down when the chain has been cleaved twice. One fast cleavage is at the linkage between residues 18 and 19; the other can take place at the linkages between residues 12 and 13, and 14 and 15; more slowly cleaved linkages are between residues 8 and 9, 9 and 10, and 15 and 16. Under the conditions tested, the β-enzyme does not hydrolyze the A chain appreciably at pH 9. It cleaves the B chain rapidly at the linkage between residues 23 and 24 and more slowly at linkages between residues 18 and 19. The linkages split by both enzymes are those which involve the carboxyl group of a neutral amino acid.

scholarly journals N-Lipidated Amino Acids and Peptides Immobilized on Cellulose Able to Split Amide Bonds

Materials ◽  
2019 ◽  
Vol 12 (4) ◽  
pp. 578 ◽  
Author(s):  
Justyna Fraczyk ◽  
Zbigniew Kamiński
Keyword(s):  
Amino Acids ◽  
Reaction Rate ◽  
Amide Bond ◽  
Amide Bonds ◽  
Two Stages ◽  
Hydrolysis Of ◽  
Preliminary Phase ◽  
Very High ◽  
High Reaction Rate

N-lipidated short peptides and amino acids immobilized on the cellulose were used ascatalysts cleaved amide bonds under biomimetic conditions. In order to select catalytically mostactive derivatives a library of 156 N-lipidated amino acids, dipeptides and tripeptides immobilizedon cellulose was obtained. The library was synthesized from serine, histidine and glutamic acidpeptides N-acylated with heptanoic, octanoic, hexadecanoic and (E)-octadec-9-enoic acids.Catalytic efficiency was monitored by spectrophotometric determination of p-nitroaniline formedby the hydrolysis of a 0.1 M solution of Z-Leu-NP. The most active 8 structures contained tripeptidefragment with 1-3 serine residues. It has been found that incorporation of metal ions into catalyticpockets increase the activity of the synzymes. The structures of the 17 most active catalysts selectedfrom the library of complexes obtained with Cu2+ ion varied from 16 derivatives complexed withZn2+ ion. For all of them, a very high reaction rate during the preliminary phase of measurementswas followed by a substantial slowdown after 1 h. The catalytic activity gradually diminished aftersubsequent re-use. HPLC analysis of amide bond splitting confirmed that substrate consumptionproceeded in two stages. In the preliminary stage 24–40% of the substrate was rapidly hydrolysedfollowed by the substantially lower reaction rate. Nevertheless, using the most competentsynzymes product of hydrolysis was formed with a yield of 60–83% after 48h under mild andstrictly biomimetic conditions.

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