scholarly journals The structure of a glycopeptide isolated from the yeast cell wall

1968 ◽  
Vol 109 (3) ◽  
pp. 419-432 ◽  
Author(s):  
R. Sentandreu ◽  
D. H. Northcote
Keyword(s):  
Amino Acids ◽  
Molecular Weight ◽  
Cell Wall ◽  
Amino Acid ◽  
Yeast Cell ◽  
Aspartic Acid ◽  
Yeast Cell Wall ◽  
Low Molecular Weight ◽  
Elimination Reaction ◽  
Sephadex Column

1. Glycopeptides containing mannose were extracted from isolated yeast cell walls by ethylenediamine and purified by treatment with Pronase and fractionation on a Sephadex column. 2. A glycopeptide that appeared homogeneous on electrophoresis and ultracentrifugation had a molecular weight of 76000, and contained a high-molecular-weight mannan and approx. 4% of amino acids. 3. The amino acid composition of the peptide was determined. It was rich in serine and threonine and also contained glucosamine. No cystine and methionine were detected. 4. The glycopeptide underwent a β-elimination reaction when treated with dilute alkali at low temperatures. The reaction resulted in the release of mannose, mannose disaccharides and possibly other low-molecular-weight mannose oligosaccharides. During the β-elimination reaction the dehydro derivatives of serine and threonine were formed. One of the linkages between carbohydrate and amino acids in the glycopeptide is an O-mannosyl bond from mannose and mannose oligosaccharides to serine and threonine. 5. After the β-elimination reaction the bulk of the mannose in the form of the large mannan component was still covalently linked to the peptide. This polysaccharide was therefore attached to the amino acids by a linkage different from the O-mannosyl bonds to serine and threonine that attach the low-molecular-weight sugars. 6. Mannan was prepared from the glycopeptide and from the yeast cell wall by treatment of the fractions with hot solutions of alkali. The mannan contained aspartic acid and glucosamine and some other amino acids. The aspartic acid and glucosamine were present in equimolar amounts; the aspartic acid was the only amino acid present in an amount equivalent to that of glucosamine. Thus there is the possibility of a linkage between the mannan and the peptide via glucosamine and aspartic acid. 7. Mannose 6-phosphate was shown to be part of the mannan structure. Information about the structure of the mannan and the linkage of the glucosamine was obtained by periodate oxidation studies. 8. The glucosamine present in the glycopeptide could not be released by treatment with an enzyme preparation obtained from the gut of Helix pomatia. This enzyme released glucosamine from the intact cell wall. Thus there are probably at least two polymers containing glucosamine in the cell wall. 9. The biosynthesis of the mannan polymer in the yeast cell wall is discussed with regard to the two types of carbohydrate–amino acid linkages found in the glycoprotein.

scholarly journals Yeast cell-wall synthesis

1969 ◽  
Vol 115 (2) ◽  
pp. 231-240 ◽  
Author(s):  
R. Sentandreu ◽  
D. H. Northcote
Keyword(s):  
Molecular Weight ◽  
Cell Wall ◽  
Yeast Cell ◽  
High Molecular Weight ◽  
Peptide Synthesis ◽  
Yeast Cell Wall ◽  
Low Molecular Weight ◽  
Cell Wall Synthesis

1. A study of wall synthesis has been made by following the incorporation of radioactive glucose and threonine into the cytoplasm and wall of yeast. 2. Both glucose and threonine are incorporated into a mannan glycopeptide. The glucose is also synthesized into a structural glucan of the wall. 3. The mannan glycopeptide contains high-molecular-weight mannan and low-molecular-weight mannose and oligosaccharide units composed of mannose. Both types of carbohydrate are attached to the peptide. The extent of radioactive incorporation into these different carbohydrate constituents of the glycopeptide remained constant during a pulse-chase experiment. No evidence of a sequential synthesis of oligosaccharides and high-molecular-weight mannan was obtained. 4. Cycloheximide inhibits the incorporation of threonine into the wall but only partially inhibits the incorporation of glucose. Thus not all the polysaccharide deposited into the wall is dependent on a simultaneous peptide synthesis and incorporation. 5. Protoplasts grown in an iso-osmotic medium secreted a mannan polymer that was probably a glycopeptide.

scholarly journals Characterization of Trypsin Inhibitor in Florunner Peanut Seeds (Arachis hypogaea L.)1

1988 ◽  
Vol 15 (2) ◽  
pp. 81-84 ◽  
Author(s):  
E. M. Ahmed ◽  
J. A. Applewhite
Keyword(s):  
Molecular Weight ◽  
Amino Acid ◽  
Aspartic Acid ◽  
Arachis Hypogaea ◽  
Trypsin Inhibitor ◽  
Low Molecular Weight ◽  
Arachis Hypogaea L ◽  
Amino Acid Profiles ◽  
Low Levels

Abstract Florunner peanut seeds contained five trypsin isoinhibitors. Amino acid profiles of the trypsin inhibitors fraction showed high levels of aspartic acid, half-cystine and serine and low levels of histidine and tyrosine. The molecular weight of the inhibitor was 8.3 KDa. The presence of multiforms of this inhibitor, its low molecular weight and the high amount of half-cystine indicate that peanut trypsin inhibitor is of the Bowman-Birk type.

Trans-tegumental absorption of L-alanine and L-leucine by a monogenean, Diclidophora merlangi

Parasitology ◽  
1978 ◽  
Vol 76 (1) ◽  
pp. 29-37 ◽  
Author(s):  
D. W. Halton
Keyword(s):  
Amino Acids ◽  
Molecular Weight ◽  
Amino Acid ◽  
Sea Water ◽  
Low Molecular Weight ◽  
Acid Uptake ◽  
Neutral Amino Acids ◽  
Freeze Dried ◽  
Significant Difference

SummaryAn in vitro investigation has been made of the relative roles of the gut and tegument in the absorption of the neutral amino acids L-alanine and L-leucine by a marine fish-gill parasite, Diclidophora merlangi. The use of ligatures to preclude oral ingestion of trace-labelled medium has proved inadequate, invariably damaging the tegument, as revealed by stereoscan electron microscopy, and resulting in artifactual levels of absorption. Three alternative procedures have given consistently reliable data on the route of entry of low molecular weight substrates. (1) Ultrastructural examination of worms previously incubated in electron-dense cationic tracers has shown that, in vitro, there is no oral intake of sea water. (2) The suspending of worms in trace-labelled medium with the mouth out of the medium and comparing amino acid uptake with that of worms totally immersed in medium has revealed no statistically significant difference in the absorption levels. (3) Application of section (freeze-dried) auto-radiography to detect diffusible isotope has demonstrated directly transtegumental absorption of a neutral amino acid. It is concluded from these experiments that Diclidophora has a tegumental transport system for absorbing certain neutral amino acids, and whilst, clearly, the worm is sanguinivorous and digests blood in a well-developed gut, it may also be capable of supplementing this diet with low molecular weight organic nutrient absorbed directly from sea water via the tegument.

Discussion: Amino-acid activation by individual enzymes

1958 ◽  
Vol 149 (936) ◽  
pp. 401-402
Keyword(s):  
Amino Acids ◽  
Molecular Weight ◽  
Amino Acid ◽  
Distribution Pattern ◽  
Mammary Tissue ◽  
Low Molecular Weight ◽  
Major Protein ◽  
Acid Activation ◽  
Amino Acid Activation ◽  
Interesting Paper

I should like to comment on one aspect of Dr Gutfreund’s interesting paper. As he mentioned, we have found evidence that amino acids, after becoming enzymically activated by ATP through the formation of an enzyme-bound amino acyladenylate compound, are transferred to a low molecular weight RNA which, by accident or design, resides in the same crude activating enzyme fraction. It is gratifying that Dr Gutfreund has found a distribution pattern of amino acids on this RNA which roughly agrees with the pattern in the major protein products of mammary tissue. He points out, however, that there is no such correlation when one looks at the pattern of amino-acid activation. Indeed, because of this anomaly, some workers have devised theories of activation involving transacylation steps to account for activation of those amino acids for which an enzyme has not been found. Dr Gutfreund implies that there is much confusion and mystery here, and even suggests that the specificity of activation might be accounted for by soluble RNA , rather than by individual enzymes.

scholarly journals Studies of the limited degradation of mucus glycoproteins. The effect of dilute hydrogen peroxide

1983 ◽  
Vol 211 (2) ◽  
pp. 323-332 ◽  
Author(s):  
J M Creeth ◽  
B Cooper ◽  
A S R Donald ◽  
J R Clamp
Keyword(s):  
Molecular Weight ◽  
Amino Acid ◽  
Aspartic Acid ◽  
Simple Structure ◽  
Peptide Bond ◽  
Low Molecular Weight ◽  
Amino Acid Residues ◽  
Oligosaccharide Moiety ◽  
Small Gain ◽  
Mucus Glycoproteins

1. The action of dilute H2O2 on a series of ovarian-cyst glycoproteins and glycopolypeptides was investigated. 2. Both native glycoproteins and the glycopolypeptides were carbohydrate-rich, of relatively low molecular weight and of simple structure. 3. At pH 5.6 and 37 degrees C, exposure to H2O2 for a limited time brought about a partial degradation, the molecular weight being decreased by 2-4-fold. 4. Carbohydrate analysis showed very little change in the oligosaccharide moiety, apart from a small decrease in sialic acid in some samples. 5. Amino acid analysis showed minor changes in serine, threonine and proline contents, but almost total loss of histidine. Concomitantly, there was a small gain in aspartic acid. 6. Myosin, examined at both pH 5.7 and 6.7, exhibited generally similar behaviour, there being losses of other amino acid residues as well as histidine: the viscosity was decreased to a low value, and a range of peptides of widely varying size was produced. 7. It is suggested that attack on the histidine residue, with partial conversion into aspartic acid, is accompanied by scission of the histidyl peptide bond.

scholarly journals Studien über Wespengift, I Niedermolekulare Bestandteile des Giftblasenextraktes von Paravespula vulgaris / Studies on Wasp Venom, I Low Molecular Weight Constituents of Venom Sac Extracts from Paravespula vulgaris

1981 ◽  
Vol 36 (6) ◽  
pp. 757-762 ◽  
Author(s):  
Hartmut Klein ◽  
Wittko Francke ◽  
Wilfried A. König
Keyword(s):  
Mass Spectrometry ◽  
Amino Acids ◽  
Fatty Acids ◽  
Molecular Weight ◽  
Gas Chromatography ◽  
Acetic Acid ◽  
Quantitative Analysis ◽  
Amino Acid ◽  
Low Molecular Weight ◽  
Wasp Venom

Abstract Low molecular weight constituents of 3400 venom sacs of Paravespula vulgaris were extracted with water, diluted acetic acid, and methanol. After conversion to volatile derivatives carbohydrates, amino acids, fatty acids, other constituents of phospho lipids, and biogenic amines were identified by gas chromatography and mass spectrometry. Quantitative analysis was achieved for amino acids by amino acid analysis and for glucose by an enzymatic assay. Results are discussed with regard to biosynthesis of wasp toxins and phylogenetic aspects of hymenopteran venoms.

scholarly journals Obtaining and estimating the potential of protein nutraceuticals from highly mineralized collagen-containing beef raw materials

2021 ◽  
Vol 6 (1) ◽  
pp. 10-22
Author(s):  
N. Yu. Mezenova ◽  
S. V. Agafonova ◽  
O. Ya. Mezenova ◽  
L. S. Baidalinova ◽  
T. Grimm
Keyword(s):  
Amino Acids ◽  
Molecular Weight ◽  
Amino Acid ◽  
Raw Materials ◽  
Water Soluble ◽  
Biologically Active ◽  
Low Molecular Weight ◽  
Enzyme Preparations ◽  
Freeze Dried ◽  
Mineralized Collagen

Highly mineralized collagen-containing beef raw materials (tibia, fibula and costal bones) are a source of valuable protein nutraceuticals. They include high molecular weight proteins, oligopeptides and amino acids, which anabolic and physiological potential is used insufficiently. Protein nutraceuticals were obtained by high-temperature hydrolysis of beef raw materials in combination with enzymolysis by proteolytic enzyme preparations Alcalase 2,5 L, Protamex, Protosubtilin G3x. The water-soluble fraction of hydrolysates was studied after its separation and freeze-drying on the content of nitrogenous compounds, fats, minerals, formol-titrated nitrogen, fractional molecular composition. The mathematical dependencies of accumulation of low molecular weight products of protein hydrolysis on enzymolysis duration and doses of different enzyme preparations were obtained. The rational technological scheme of complex processing of beef raw materials with production of protein, fat and mineral-protein additives was proposed. The protein weight fraction in the freeze-dried protein hydrolysates was 69.5–89.6%. All studied protein additives contained peptides with a molecular weight of not more than 100 kDa. The content of low-molecular weight oligopeptides with a molecular weight of less than 10 kDa in the protein additives obtained by enzymatic thermal hydrolysis was more than 90%. The amino acid composition of protein additives produced by different hydrolytic methods was analyzed. Sensory and functional-technological properties of freeze-dried protein compositions were studied. The amino acid potential, high assimilability and physiological activity of protein nutraceuticals from collagen-containing beef raw materials were established. It is recommended to use them in the composition of specialized biologically active additives (BAAs) to food of the osteotropic direction in recipes of specialized and personalized products as a source of amino acids and active peptides.

Antioxidant and Hypolipidemic Potential of Peptides from Broccoli Stems and Leaves

2018 ◽  
Vol 18 (1) ◽  
pp. 16-20
Author(s):  
Chen Hua ◽  
Xia Li-Shan ◽  
Zhang Xu-Dong
Keyword(s):  
Amino Acids ◽  
Molecular Weight ◽  
Antioxidant Activity ◽  
Amino Acid ◽  
Nutritive Value ◽  
Reduced Glutathione ◽  
Low Molecular Weight ◽  
Weight Analysis ◽  
Stems And Leaves ◽  
Scavenging Rates

To isolate bioactive broccoli peptides, crude proteins were flocculated from heated juice of broccoli stems and leaves and then hydrolyzed by proteases. Different proteases yielded different peptides with a significant effect on the bio-activities of broccoli peptides. Antioxidant activity of the broccoli peptides was investigated by measuring their DPPH (1,1-diphenyl-2-picrylhydrazyl) radicals scavenging action in comparison to native antioxidants, reduced glutathione (GSH) and soybean peptides. Broccoli peptides (obtained by Neutrase® hydrolysis) at 5.0 mg/mL exhibited 72.8% of radicals scavenging rates, resembling GSH at 1.0 mg/mL (72.1%), and was 2.8 times than that of soybean peptides at 5.0 mg/mL (25.7%). Subsequently, the hypolipidemic activities were measured by oral gastric gavage of broccoli peptides in hyperlipemic golden hamster. Treatment with broccoli peptides (obtained by papain hydrolysis) significantly decreased the serum TC and LDL-C levels (P < 0.01) in experimental rats. The constitution of amino acid and the distribution of molecular weight analysis showed broccoli peptides contained sixteen amino acids and a great percentage of low molecular weight peptides (<1 kDa, 77.67%). By analyzing the amino acid compositions and bio-activities, our results indicate the high nutritive value and possible applications of broccoli peptides for human health.

Synthesis and evaluation of chiral β-amino acid-based low-molecular-weight organogelators possessing a methyl/trifluoromethyl side chain

2019 ◽  
Vol 43 (7) ◽  
pp. 2882-2887 ◽  
Author(s):  
Koichi Kodama ◽  
Ryuta Kawamata ◽  
Takuji Hirose
Keyword(s):  
Amino Acids ◽  
Molecular Weight ◽  
Amino Acid ◽  
Supramolecular Structures ◽  
Side Chain ◽  
Low Molecular Weight ◽  
Side Chains ◽  
Low Molecular Weight Organogelators

Impacts of side-chains and chirality of organogelators derived from β-amino acids are described with their supramolecular structures.

CHARACTERIZATION OF THE PIGMENT OF MICROCOCCUS VIOLAGABRIELLAE

1964 ◽  
Vol 10 (5) ◽  
pp. 659-675 ◽  
Author(s):  
J. N. Campbell ◽  
J. L. Nichols ◽  
Sheila A. Berry
Keyword(s):  
Amino Acids ◽  
Molecular Weight ◽  
Amino Acid ◽  
Cross Reactivity ◽  
Low Molecular Weight ◽  
Terminal Amino Acid ◽  
Iron Chelate ◽  
Peptide Moiety ◽  
Terminal Amino

Production of the red insoluble pigment by Micrococcus violagabriellae was studied. Pigmentation was found to require oxygen and high levels of iron and to be stimulated by tryptophan alone among the amino acids. The pigment was isolated, purified, and analyzed chemically and spectrophotometrically. It was found to be similar to pulcherrimin from Candida pulcherrima. Immunological cross reactivity and analysis of derivatives confirmed the similarity between the bacterial and yeast pigments. From these data it is postulated that the pigment is an iron chelate of pulcherriminic acid with an associated low molecular weight peptide moiety with glycine as the sole N-terminal amino acid. The pigment appears to differ from that of C. pulcherrima solely with respect to this peptide and in the mode of aggregation of the molecule.

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