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PubMed1966

Isolation and characterization of two antigens of Corynebacterium hofmannii.

Banach, T. M. (University of Manitoba, Winnipeg, Canada), and R. Z. Hawirko. Isolation and characterization of two antigens of Corynebacterium hofmannii. J. Bacteriol. 92:1304-1310. 1966.-A serologically active substance, extracted from sonically treated cells of Corynebacterium hofmannii with hot HCl, produced two precipitin lines by immunodiffusion tests with a hyperimmune homologous serum. Extracts of other species failed to precipitate with the hofmannii antiserum. The active fraction was eluted from a diethylaminoethyl cellulose column in the third adsorption peak at a linear concentration of 0.5 m KCl, and produced two precipitin lines which corresponded in identity to those formed by the acid extract. Separation of the antigens was achieved by rechromatography on a Sephadex G-200 column; the major antigen was designated A; the minor, B. The homogeneity and purity of each antigen was established by immunoelectrophoresis and, in addition, that of antigen A by disc electrophoresis. Biochemical analyses showed that both antigens were composed of a major protein component with polysaccharide and nucleic acid present in an approximate ratio of 17:3:1, respectively. Glutamic acid, aspartic acid, alanine, glycine, valine, and leucine were the main amino acids present. Antigen A contained 17% less protein and 3.5% less carbohydrate than antigen B. The principal sugars of antigen A were identified as arabinose and glucose. The molecular weight, estimated by gradient centrifugation, was 16,500 for antigen A and 21,000 for antigen B.

Amino Acids↗
PubMed1988

Evaluation of substrates for radiometric detection of bacteria in blood cultures.

Various 14C-labeled substrates were evaluated for their potential use in blood culture media. These uniformly labeled compounds were added to hypertonic and anaerobic formulations of modified Columbia broth and compared with analogous BACTEC media with the BACTEC 460. Different bacterial species gave significant growth indices when 2.0 microCi of labeled glucose, glutamic acid, aspartic acid, arginine, or formate was used alone or in combinations in the experimental media. The combination of glucose, glutamic acid, and sodium formate was selected, and simulated blood cultures with representative aerobic, facultative, and anaerobic bacteria and a yeast were compared with BACTEC vials. Under these conditions, the experimental media often became positive several hours earlier than the BACTEC vials and usually produced higher growth indices.

Bacteria↗
PubMed1983

Characterization of lecithin-cholesterol acyltransferase from human plasma. 3. Chemical properties of the enzyme.

The polypeptide molecular weight of lecithin-cholesterol acyltransferase (LCAT) (45000) was obtained by deducting the weight of carbohydrate moiety (25%, w/w) from the total molecular weight of 60000. LCAT was found to have a relatively high content of glutamic acid, aspartic acid, glycine, and leucine residues and four half-cystines. The carbohydrate content was found to be about 25% (w/w): hexoses, 13%; hexosamines, 6.2%; and sialic acid, 5.4%. The total number of 408 amino acid residues per mole and the mean residue weight of 110.3 were found. From fluorescence spectroscopy analysis, 6-7 mol of tryptophan were found per mole of LCAT in 10 mM phosphate (pH 7.4). However, when LCAT was digested by the mixture of chymotrypsin and pronase the tryptophan residues increased to 10-11 mol/mol of LCAT, which agrees well with data obtained previously by ultraviolet absorption spectroscopy. A partial specific volume of 0.707 mL/g was determined by compositional analysis. Human LCAT was found to have a relatively high extinction coefficient (E1%1cm) of 21 at 280 nm and neutral pH. Two residues of cysteine per mole of LCAT were estimated both in the presence or absence of sodium dodecyl sulfate by titration with 5,5'-dithiobis-2-nitrobenzoic acid. The enzyme showed a lower tendency to staining with Coomassie blue R-250 than bovine serum albumin. The enzyme was rapidly inactivated by diisopropyl fluorophosphate (DFP), regardless of whether the free sulfhydryl were blocked or not. The enzyme was also irreversibly inhibited by cysteine above concentrations of 1 mM.(ABSTRACT TRUNCATED AT 250 WORDS)

Amino Acids↗
PubMed1981

Protein deprivation and the brain: effect on enzymes and free amino acids related to glutamate metabolism in rats.

6-week-old, female albino rats were fed one of three diets containing 5, 10 and 20% casein for a period of 15 days. Rats fed the low protein diet (5% casein) lost weight (6.3 +/- 0.7 g/week), whereas those on the two higher protein diets gained weight. The concentrations of protein and free amino nitrogen in the brain were significantly lower in those on the low protein diet (5% casein) compared to those on the high protein diet (20% casein). The activities of brain enzymes, glutamine synthetase, glutamine transferase, glutaminase I, glutaminase II and glutamate decarboxylase, and the concentrations of free amino acids, aspartic acid, glutamic acid, glutamine, alanine and GABA were also lower. The prospect for nutritional rehabilitation of rats fed the low protein diet appeared to be excellent and was illustrated by the reversal of the above changes after 15 days on the high protein diet. The diet containing 10% casein was sufficient for the normal production of enzymes and free amino acids related to glutamate metabolism.

Amino Acids↗
PubMed1988

A dog possessing high glutathione (GSH) and K concentrations with an increased Na, K-ATPase activity in its erythrocytes.

We have studied a female mongrel dog found in Kanagawa Prefecture, Japan. This dog was selected and examined thoroughly because she naturally maintained a high glutathione (GSH) concentration in her erythrocytes and did not exhibit any clinical signs or hematologic disorders. Erythrocytes from this animal demonstrated high K and low Na concentrations, as well as accumulation of the amino acids, glutamic acid, aspartic acid and glutamine. The Na, K-ATPase activity was also markedly elevated and the osmotic fragility of the dog's erythrocytes was found to be significantly increased. Crossbreeding of our dog with a normal dog and also with a heterozygous carrier dog revealed that the genetic abnormality possessed by our dog is transmitted as an autosomal recessive trait. All of the clinical data obtained from studying this animal strongly suggest that it possesses a genetic trait similar to that of the HK dogs previously described by Maede.

Animals↗
PubMed1994

Influence of non-fibrous carbohydrate and degradable intake protein on fermentation by ruminal microorganisms in continuous culture.

Four continuous culture fermenters were used in a 4 x 4 Latin square design to evaluate the effects of dietary non-fibrous carbohydrate (NFC) and ruminally degradable intake protein (DIP) on fermentation by ruminal microorganisms. Four diets, arranged in a 2 x 2 factorial, were formulated to contain either 25 or 40% NFC and 50 or 70% of dietary CP as DIP. Dietary DM contained 32% corn silage, 20% alfalfa-grass hay, and 48% concentrate. Solvent-extracted or lignosulfonate-treated soybean meal were used to alter DIP and contributed 40% of dietary CP. Corn or soybean hulls were included at 28% of dietary DM to alter NFC levels. Percentage of true OM digestion was similar (P > .05) among diets but NDF and total nonstructural carbohydrate digestion were inversely related depending on NFC content of the diet. Amylolytic bacterial concentrations (cells/milliliter) were lower (P = .03) in fermenters supplied with 25% NFC diets, resulting in less (P = .0001) total nonstructural carbohydrate digestion. Cellulolytic concentrations were similar (P > .05) among diets despite an increase (P = .002) in NDF digestion with 25% NFC diets. Total viable bacterial concentrations tended to decrease (P = .11) with 50% DIP diets, inducing a decline (P = .03) in total VFA production (millimoles/day). Reduced degradation of CP in 50% DIP diets (P = .008) increased outflow of total amino acid (P = .07) and individual outflows (P < .05) of glutamic acid, aspartic acid, arginine, histidine, and lysine. Few interactions occurred for the parameters measured despite the controlled nature of the fermentation in the current experiment. The preponderance of significant main effects illustrates that ruminal fermentation may not be improved by synchronization of energy and N release but may more likely be limited by either energy or N alone.

Amino Acids↗
PubMed1987

Isolation and amino acid composition of the isotypes of a rat Clara cell specific protein.

A protein of molecular weight about 10,000 (Clara cell protein C) present in lung lavage fluid and specific to Clara cells has been shown to have three isotypes. The isotypes have been individually isolated and purified by a combination of molecular sieving, ion exchange chromatography, column chromatofocusing, and reverse phase chromatography. The protein was monitored by immunoblotting and its purity tested by silver staining of the gel following sodium dodecyl sulfate-polyacrylamide gel electrophoresis. About 33.7% of the 10-kDa protein present in starting rat lavage was recovered in final pure preparation. The 10-kDa Clara cell protein amounted to 0.38% of the total protein in rat lung lavage fluid. The three isotypes were present in a ratio of 1.0:2.8:8.8, the amounts increasing with decreasing pI. None of the isotypes bound to concanavalin A. The amino acid compositions of the three isotypes were similar and were remarkable in that the contents of leucine, glutamic acid, aspartic acid, serine, and proline were high, tyrosine was present in low amounts, and methionine and histidine were absent.

Amino Acids↗
PubMedDate not supplied

Characterization of a unique mucin-like glycoprotein secreted by a human endometrial adenocarcinoma cell line (Ishikawa).

A human endometrial adenocarcinoma cell line (Ishikawa) has been shown to incorporate [3H]glucosamine and to secrete a radiolabeled high molecular weight compound which is excluded from a Sepharose CL-2B column. The excluded material was resistant to hyaluronidase, chondroitinase ABC, and heparinase. These findings rule out the possibility of this material being a proteoglycan. The susceptibility of this material to digestion with pronase, neuraminidase, and alkaline borohydride treatment strongly suggests that the excluded material is an O-glycosidic glycoprotein. The glycoprotein secreted by Ishikawa cells (ICGP) did not react immunologically with antibodies against either lactoferrin or fibronectin, but did react with an antibody made against tracheal mucin. Conversely, immunoblot analysis revealed that an antibody made against ICGP did not recognize hyaluronic acid, chondroitin, heparin, nasal turbinate mucin, bovine submaxillary gland mucin, lactoferrin, or fibronectin, but did recognize tracheal mucin. Analysis of ICGP amino acid and carbohydrate composition showed that it is rich in serine, threonine, glutamic acid, aspartic acid, and N-acetylneuraminic acid. In this respect, ICGP differs from other mucins, even though it is immunologically similar to respiratory mucin; hence we may consider ICGP to be a mucin-like glycoprotein. Secretion of ICGP can be modulated by Ca(2+)-ionophore and other mucus secretagogues, such as platelet activating factor, carbachol, and monocyte/macrophage mucus secretagogue, all mediators of lung inflammation. Ishikawa cells and anti-ICGP antibody may be used in studies on in vitro regulation of mucin-like glycoprotein synthesis and secretion in the respiratory tract as well as in the endometrium.

Adenocarcinoma↗
PubMed1996

Immunity in the connective tissue diseases. The humoral side of the coin.

Clinicians who care for patients with various connective tissue diseases frequently employ measurements of autoantibodies such as rheumatoid factors (RFs), anti-Sm antibodies, or anti-neutrophil cytoplasmic antibodies (cANCA) as a method to follow patients. Although the primary specificity of RFs appears to be directed against the Fc portion (C gamma 3 and C gamma 2 domains) of IgG, epitope mapping studies have now also demonstrated that many RFs also react with linear regions on beta 2-microglobulin and Class I HLA molecules. Cross reacting regions of IgG, beta 2m, and HLA Class I frequently show immunodominant tyrosines, trytophanes, valines, leucines, glutamic acids, aspartic acids, and threonines. Immunodominant linear epitopes on Sm antigen may be limited to regions expressing the PPPGMRPP or PPPGIRGP motifs. A number of linear regions of Proteinase 3 reacting with IgG antibodies in the sera of patients with Wegener's granulomatosis have now been identified. However, affinity purified rabbit antibodies to two of these major PR3 antigenic sties (ATVQLPQ and RVGAHDP) linked to Sepharose to form affinity columns, absorbed equal amounts of a mixture of many serum proteins from both Wegener's patients and normal controls. Continued study of this interface between autoantibody production, disease, and normal immune modulation is necessary.

Amino Acid Sequence↗
PubMed1985

Isolation and purification of a small peptide with activity of increasing E-receptor expression from calf thymus.

A small peptide of molecular mass lower than 1,000 daltons was isolated and purified from a crude extract of calf thymus. It has been demonstrated to have the activity of increasing E-rosette formation and E-receptor expression of human and porcine T-lymphocytes with three different in vitro assays. Amino acid composition analysis showed that this peptide consists of glutamic acid, aspartic acid and glycine residues at a molecular ratio of 3:3:2. A hypothesis of a multi-factoral and multi-staged mechanism of regulation of thymocyte differentiation and maturation in the thymus is proposed.

Animals↗
PubMed1979

Purification and characterization of a trypsin inhibitor from rice bran.

A trypsin inhibitor was isolated and purified from the bran of rice, Oryza sativa, by extraction with 1% sodium chloride, heat treatment, ammonium sulfate precipitation, ion-exchange chromatography on a CM-Sephadex C-25 and gel filtration on a Sephadex G-75. The final preparation was homogeneous by electrophoretic analysis. Rice bran trypsin inhibitor (RBTI) had a molecular weight of about 14,500 and an isoelectric point of 8.07. The amino acids, acid composition was characterized by high contents of basic amino acids, aspartic acid, glutamic acid, proline and cystine. BRTI inhibited bovine trypsin at an inhibitor-enzyme molar ratio of 1:1.6. It displayed, however, nobility to inhibit alpha-chymotrypsin, pepsin, papain and subtilisin BPN'.

Amino Acids↗
PubMed2003

A single polymorphic residue within the peptide-binding cleft of MHC class I molecules determines spectrum of tapasin dependence.

Different HLA class I alleles display a distinctive dependence on tapasin for surface expression and Ag presentation. In this study, we show that the tapasin dependence of HLA class I alleles correlates to the nature of the amino acid residues present at the naturally polymorphic position 114. The tapasin dependence of HLA class I alleles bearing different residues at position 114 decreases in the order of acidity, with high tapasin dependence for acidic amino acids (aspartic acid and glutamic acid), moderate dependence for neutral amino acids (asparagine and glutamine), and low dependence for basic amino acids (histidine and arginine). A glutamic acid to histidine substitution at position 114 allows the otherwise tapasin-dependent HLA-B4402 alleles to load high-affinity peptides independently of tapasin and to have surface expression levels comparable to the levels seen in the presence of tapasin. The opposite substitution, histidine to glutamic acid at position 114, is sufficient to change the HLA-B2705 allele from the tapasin-independent to the tapasin-dependent phenotype. Furthermore, analysis of point mutants at position 114 reveals that tapasin plays a principal role in transforming the peptide-binding groove into a high-affinity, peptide-receptive conformation. The natural polymorphisms in HLA class I H chains that selectively affect tapasin-dependent peptide loading provide insights into the functional interaction of tapasin with MHC class I molecules.

Alleles↗
PubMed1977

Biosynthesis of streptolidine moiety of streptothricins by Streptomyces noursei JA 3890b.

The incorporation of uniformly 14C-labeled compounds into the streptothricin-type antibiotic nourseothricin was studied with a strain of Streptomyces noursei JA 3890b. 6.5% of radioactivity from U-14C-L-arginine was incorporated into the antibiotic, while glutamic acid, aspartic acid, alanine, proline, glycine and leucine displayed much lower incorporations. Furhtermore, 95% of the activity incorporated from arginine was located in the streptolidine moiety supporting the suggestion that this subunit of streptothricin antibiotics is formed via the dehydroarginine pathway.

Amino Acids↗
PubMed1998

[Amino acid composition evaluation of Pleurotus spp. cultivated in banana leaves].

The protein quality of edible mushrooms besides being species/strain specific, could also vary with the growth substrate. The aim of this work was to determine the amino acid composition of the protein from edible mushrooms--Pleurotus sp. "Florida" (L1), P. ostreatoroseus (L2) and P. sajor-caju (L3), cultivated on banana leaves (BL) single and, mixed with sugar cane bagasse (BLSCB). Total amino acids, cystine and tryptophan were evaluated; the chemical score index and PDCAAS--"protein digestibility-correct amino acid scoring" were calculated. From both substrates, the studied species contain all essential amino acids; in decreasing order, the amino acids in great amounts were glutamic acid, aspartic acid, leucine and lysine. The L1 chemical score was 90.4, with limitation in sulfur and aromatic amino acids when from BL substrate; and, from BLSC substrate the chemical score was 88.7 with limitation in aromatics only. The L2 and L3 was 100, 0, independent of cultivation substrate. The calculated PDCAAS value, considering 90% of recommended digestibility, varied between 80.0-96%. The L1 proteins were limiting in sulfur and aromatic amino acids and had the lowest value of PDCAAS (approximately 80.0) in both substrates; the L3 proteins were limiting in aromatic, sulfur and tryptophan, dependent of cultivation substrate; the L2 proteins had the greatest value of PDCAAS (approximately 96%) and were limiting in aromatic and/or sulfur amino acids, dependent of cultivation substrate. Considering the conditions of this study, the protein of the studied species is incomplete, although of high biological value, comparable to meet.

Amino Acids↗
PubMed1979

[Balanced parenteral and oral feeding of underweight newborn infants].

The oral feeding of 50 newborns with low birth weight was combined with infusions of two different amino acid solutions (mother milk-adapted and requirement-adapted), parenteral lipids and glucose. All infants showed a rapid weight gain, the N-balance became positive, hypoglycemic or hyperosmotic reactions were missing. Amino acid imbalances could not be seen, values of glutamic acid, aspartic acid and asparagine differed in both groups just as proline. In management of infants with low birth weight the supplemental application of these amino acid solutions, lipids and glucose has advantages.

Administration, Oral↗
PubMedDate not supplied

[Changes in the amino acid levels in hydrolysates of bacteria adhering to the rumen in sheep during feeding with high and low nitrogen diets].

The effects of low and high nitrogen diets on amino acid levels were studied in hydrolyzates of ruminal bacteria adhered to four topographically different anatomic parts of the ruminal wall (dorsal, ventral and caudal parts as well as reticulum) in 18 sheep + of the Slovak Merino breed divided into three experimental groups. The epimural bacteria of the dorsal and ventral parts of the ovine rumen revealed the most sensitive reaction to the varying amounts of nitrogen ingested with the diet. In hydrolyzates of ruminal bacteria adhered to the dorsal and ventral epithelium, 15 and 14 amino acids were changing (Figs. 1, 2). In hydrolyzates of epimural bacteria, a sensitive reaction was observed in the following amino acids: alanine, histidine, thyroxin, arginine and proline (Tabs. I-IV). In all topographical and anatomical parts of the rumen, both alanine and histidine levels in hydrolyzates of epimural ruminal bacteria significantly increased with the diet with high-nitrogen content fed, but was falling in sheep fed with low-nitrogen diet. Changes in alanine concentrations may be explained by the fact that alanine forms a part of the mechanism for short-time storage of ammonia in bacterial cells (Bartos, 1987). The fact that alanine is in its lack deaminated to pyruvate (Havassy, 1976) is explained by significant fall in alanine contained in hydrolyzates of bacterial proteins when fed low nitrogen diets. Significant fall in alanine in shortage of amino acid bound nitrogen can be explained by the fact that under these conditions, the alanine skeleton is being incorporated in to 80% of amino acids synthetized de novo by ruminal bacteria (Syväoja and Kreula, 1980). When sheep flock was fed the high-nitrogen diet, thyroxin and proline levels were significantly reduced in hydrolyzates of epimural bacteria from all parts of the rumen, while low-nitrogen diet significantly increased the concentrations of both given amino acids in comparison with the control. Bartos (1987) gives in his study the table containing weight representation of different amino acids in proteins of bacteria of the ruminal content compiled on the basis of data of several authors. These data principally correspond to the results of our measurements in hydrolyzates of epimural bacteria. The highest weight representation of amino acids in hydrolyzates of epimural bacteria was found for glutamic acid, aspartic acid and arginine, while the lowest ones were detected for thyroxin, proline and phenylalanine.(ABSTRACT TRUNCATED AT 400 WORDS)

Amino Acids↗
PubMed1990

Elucidation of discontinuous linear determinants in peptides.

Synthetic peptides, made by the method of simultaneous multiple peptide synthesis, were coupled to the protein carrier keyhole limpet hemocyanin and used to raise mAb. Omission and substitution analogs of the original peptides were tested by ELISA to characterize their reactivity with the respective mAb. Linear antigenic determinants were located for 18 different peptides by using omission analogs. The length of the antigenic determinants ranged from 2 to 8 residues, with an average of 6 residues. The three aromatic amino acids, phenylalanine, tryptophan, and tyrosine, the charged hydrophilic amino acids, aspartic acid and lysine, and the neutral amino acid alanine were found to occur most often in the determinant region of the peptides tested, whereas asparagine, cysteine, and histidine occurred the least often. Alanine substitution analogs provided more information than omission analogs by enabling the determination of which side chain groups of the antigenic determinant residues were not critical for binding to the mAb. Detailed, "fingerprint" information about the interaction of the peptide, GASPYPNLSNQQT, and its mAb was obtained by synthesizing a complete series of analogs with individual substitutions for each position of the antigenic determinant, PYPNLS, with the 19 other amino acids. These results suggest that, at the amino acid level, all antigenic determinants of synthetic peptides defined by mAb can be considered discontinuous linear determinants.

Amino Acid Sequence↗
PubMed1991

Chemical analysis and amino acid content of temperature-sensitive mutants of Saccharomyces cerevisiae.

Temperature-sensitive (ts) mutants of Saccharomyces cerevisiae Y-196 were isolated by using UV irradiation and/or EMS treatment. They grew normally at permissive temperature (30 degrees C), but could not grow at restrictive temperature (38 degrees C). From chemical composition analysis, it was found that ts mutants AMY-159, and AMY-88 had the highest protein and RNA contents, respectively. When the cells were cultivated at 30 degrees C to stationary phase and then shifted to 38 degrees C for 4 hr, protein contents of wild-type and most of the ts mutants increased but RNA contents decreased. Glutamic acid, aspartic acid and lysine were the three major amino acids of protein in all isolates tested at both temperatures. When the ts mutants AMY-136, AMY-161, and AMY-157 were cultured at 38 degrees C for 4 hr, methionine contents increased Amino acid scores of ts mutants AMY-15 and AMY-88 increased when they were shifted to 38 degrees C for 2 to 4 doubling times. The amounts of amino acids produced in some ts mutants were higher than that of wild-type.

Amino Acids↗