SEARCH · Search PubMed

Results for “Cysteic Acid”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

SourceResearch connectionFrom yearThrough year

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 235 records · Page 13Linked to original sources

PubMed1986

Changes in food proteins reacted with nitrite at gastric pH.

Casein and egg albumin were reacted with nitrite at pH 3. The reaction mixtures containing nitrite yellowed when the reaction began; after 24 hours of reaction with 7.5 X 10(-3) M nitrite, about 70% of added casein was sedimented as yellow precipitate. There was a considerable loss of lysine, arginine, tyrosine, and tryptophan residues. This was determined from the amino acid compositions of the proteins obtained by the reaction with 2.5 X 10(-2) M nitrite at pH 3 for 48 hours. An amino acid elution pattern of the treated casein showed five peaks due to new amino acids; three of these were provisionally identified to be cysteic acid, methionine sulfone, and 3-nitrotyrosine.

Amino Acids↗

PubMed1978

Structure of immunoglobulin D: evidence for the absence of an extra disulfide bridge in the Fc fragment.

Molecular weight determinations of immunoglobulin D suggest the presence of an extra region of the delta chain. In an attempt to locate this region, an IgDlambda myeloma protein (Gur), was digested with trypsin for 4 min at 56 degrees and the Fc fragment isolated by ion exchange chromatography. N-terminal analysis of this fragment showed a heterogeneity in the site of splitting by trypsin. The Fc was digested with pepsin and trypsin and the cysteine containing peptides isolated by a two dimensional paper high voltage electrophoresis (diagonal map) at pH 3.5. Further purification of these peptides was carried out by HVE at pH 6.5 and 2.1 and their amino acid composition and partial sequence were determined. Only five cysteic acid peptides were obtained, one corresponding to the inter heavy-heavy bridge and the other four, to intra chain bridges. This finding would exclude the possibility of an extra "classical domain" in this region. The position of these peptides in the delta chain has been arranged based on homology with the other classes of immunoglobulins.

Amino Acid Sequence↗

PubMed1996

The neurotransmitter candidature of sulphur-containing excitatory amino acids in the mammalian central nervous system.

While L-glutamate (L-Glu) is considered to be the predominant excitatory amino acid transmitter in the mammalian CNS, other amino acids have come under scrutiny as possible rivals for such a role. These include four sulphur-containing analogues of L-Glu and L-aspartate known as the SAAs. The L-Glu analogues are L-homocysteic acid and L-homocysteine sulphinic acid, while the L-aspartate analogues are L-cysteic acid and L-cysteine sulphinic acid. They are mixed agonists of excitatory amino acid receptors on a variety of neurones and are reported to be present in and released from mammalian CNS tissue. This review serves to summarize the current state of research into the possibility that one or more of these compounds is indeed a transmitter within the mammalian CNS.

Animals↗

PubMed1967

The reaction of iodobenzene-p-sulphonyl chloride (pipsyl chloride) with certain amino acids and peptides, and with insulin.

1. A system of separation using buffered Celite columns is described that enables the pipsyl derivatives of most of the common amino acids to be separated. 2. The reaction of pipsyl chloride with several amino acids not included in previous studies has been investigated. In particular, knowledge of the acid-soluble pipsyl derivatives of arginine, histidine, lysine, tyrosine and cysteic acid has been extended. 3. Reproducible factors have been obtained that enable corrections to be applied for the breakdown of pipsylamino acids on acid hydrolysis. 4. The reaction of pipsyl chloride with peptides has been studied under various conditions. 5. The extent of the reaction between pipsyl chloride and insulin depends on the nature of the solvent-buffer system, and under the best conditions so far found is about 75% complete. 6. In an Appendix, the separation of pipsylamino acids by thin-layer chromatography is described.

Journal Article↗

PubMed1990

Brain G protein gamma subunits contain an all-trans-geranylgeranylcysteine methyl ester at their carboxyl termini.

We have shown previously that guanine nucleotide-binding protein (G protein) beta gamma complexes purified from bovine brain membranes are methyl esterified on a C-terminal cysteine residue of the gamma polypeptide. In the present study, 3H-methylated G beta gamma complexes cleaved to their constituent amino acids by exhaustive proteolysis were shown to contain radiolabeled material that coeluted with geranylgeranylcysteine methyl ester on reversed-phase HPLC and two TLC systems. Further treatment by performic acid oxidation yielded radiolabeled material that coeluted with L-cysteic acid methyl ester, verifying that the prenyl modification occurs on a C-terminal cysteine residue. Analysis by gas chromatography-coupled mass spectrometry of material released from purified G beta gamma by treatment with Raney nickel positively identified the covalently bound lipid as an all-trans-geranylgeranyl (C20) isoprenoid moiety. To delineate the distribution of this modification among gamma subunits, purified G beta gamma complexes were separated into 5-kDa (gamma 5) and 6-kDa (gamma 6) forms of the gamma polypeptide by reversed-phase HPLC. Gas chromatography-coupled mass spectrometry analyses of Raney nickel-treated purified gamma 5 and gamma 6 subunits showed that both polypeptides were modified by geranylgeranylation. These results demonstrate that at least two forms of brain gamma subunit are posttranslationally modified by geranylgeranylation and carboxyl methylation. These modifications may be important for targeting G beta gamma complexes to membranes.

Animals↗

PubMed1991

Membrane-binding domain of the small G protein G25K contains an S-(all-trans-geranylgeranyl)cysteine methyl ester at its carboxyl terminus.

We showed previously that a 23-kDa guanine nucleotide-binding protein (G protein) purified from bovine brain membranes is carboxyl methylated and that this modification occurs at or near the membrane-binding domain. In the present study, we identified this small G protein as G25K (formerly termed Gp). We demonstrated that proteolytic digests of 3H-methylated G25K contained radiolabeled material that coeluted with synthetic S-(geranylgeranyl)cysteine methyl ester on reversed-phase HPLC. Further treatment by performic acid oxidation yielded radiolabeled material that coeluted with L-cysteic acid methyl ester, verifying that the isoprenoid moiety and carboxyl methyl ester are localized on a C-terminal cysteine residue. Analysis by gas chromatography-coupled mass spectrometry of material released from purified G25K by Raney nickel treatment positively identified the covalently bound lipid as an all-trans-geranylgeranyl (C20) isoprenoid moiety. These results suggest that geranylgeranyl modification and perhaps methyl esterification function in the membrane localization of this small G protein.

Amino Acid Sequence↗

PubMed2003

Plasticity of protein expression during culture of fetal skin cells.

In order to gain insight into the biology of fetal skin during culture, cellular proteins were studied during four culture passages (P00, P01, P04 as well as P10) using high-resolution two-dimensional (2-D) gel electrophoresis and mass spectrometry (MS). Bioinformatic analyses were focused on a region of each gel corresponding to pI between 4 and 8 and M(r) from 8000 to 35 000. In this area, 373 +/- 42 spots were detected (N = 18). Twenty-six spots presented an integrated intensity that increased in the higher passages, whereas five spots showed a progressively lower intensity in subsequent passaging. MS analysis was performed on spots that were unambiguously identified on preparative 2-D gels. Among the 26 spots showing an increased size between P00 and P10, 9 were identified, and corresponded to 3 proteins: (i) peptidyl-prolyl cis-trans isomerase A (P05092; cyclophilin A or cyclosporin A-binding protein), (ii) triosephosphate isomerase (P00938), and (iii) enoyl-CoA hydratase (P30084). Among these nine identified spots, three were absent at P00, but were present at P10. They corresponded to isoforms of peptidyl-prolyl cis-trans isomerase and triosephosphate isomerase, respectively. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) analyses of the acidic isoforms of triosephosphate isomerase showed modifications of cysteine residues to cysteic acid. All these isoforms were clearly present in the skin cells of a 4-year-old child, as well as in skin cells from a 80-year-old man, at P00. These observations probably reflect either an oxidative stress related to cell culture, or, alternatively, maturation, differentiation and the aging of the cells.

Aged↗

PubMed1995

Oxidation of cysteine and methionine residues during acid hydrolysis of proteins in the presence of sodium azide.

Sodium azide is widely used as bacteriostatic agent during downstream processing of proteins. Amino acid composition analysis of protein samples, subjected to hydrolysis with hydrochloric acid in a buffer containing sodium azide, revealed the presence of cysteic acid, methionine sulfoxide, and methionine sulfone in addition to the expected reaction products. Hydrolysis with methanesulfonic acid in the presence of sodium azide resulted in detection of only methionine sulfoxide in addition to the expected products. When the proteins were hydrolyzed in a buffer containing no sodium azide or after its removal by dialysis, no oxidation products were detected (except for minor amounts of methionine sulfoxide). The generation of the particular oxidation products was affected by the concentration of sodium azide in the protein solution. Therefore, presence of sodium azide in protein samples intended for amino acid composition analysis may lead to wrong conclusions concerning oxidation of cysteine and methionine residues.

Amino Acids↗

PubMed2002

The reactivity and oxidation pathway of cysteine 232 in recombinant human alpha 1-antitrypsin.

Oxidative damage to the sulfur-containing amino acids, methionine and cysteine, is a major concern in biotechnology and medicine. alpha1-Antitrypsin, which is a metastable and conformationally flexible protein that belongs to the serpin family of protease inhibitors, contains nine methionines and a single cysteine in its primary sequence. Although it is known that methionine oxidation in the protein active site results in a loss of biological activity, there is little specific knowledge regarding the reactivity of its unpaired thiol, Cys-232. In this study, the thiol-modifying reagent NBD-Cl (7-chloro-4-nitrobenz-2-oxa-1,3-diazole) was used to label peroxide-modified alpha1-antitrypsin and demonstrate that the Cys-232 in vitro oxidation pathway begins with a stable sulfenic acid intermediate and is followed by the formation of sulfinic and cysteic acid in successive steps. pH-dependent reactivity with hydrogen peroxide showed that Cys-232 has a pK(a) of 6.86 +/- 0.05, a value that is more than 1.5 pH units lower than that of a typical protein thiol. pH-induced conformational changes in the region surrounding Cys-232 were also examined and indicate that mildly acidic conditions induce a conformation that enhances Cys-232 reactivity. In summary, this work provides new insights into alpha1-antitrypsin reactivity in oxidizing environments and shows that a unique structural environment renders its unpaired thiol, Cys-232, its most reactive amino acid.

Cysteine↗

PubMed1961

Utilization of sulfur compounds by Streptococcus bovis.

Prescott, J. M. (A. &. M. College of Texas, College Station). Utilization of sulfur compounds by Streptococcus bovis. J. Bacteriol. 82:724-728. 1961.-Two strains of Streptococcus bovis utilize a variety of compounds as their only source of sulfur, yet exert a definite selectivity in their nutritional requirements for this element. Among sulfur-containing amino acids and related compounds, cystine and cysteine support excellent growth, but cysteic acid and cysteine sulfinic acid do not; methionine is completely inactive as an only sulfur source, but growth is provided by lanthionine, djenkolic acid, allo-cystathionine, homocystine, homocysteine, and glutathione. Several organic sulfur compounds other than amino acids are effective sulfur sources, among which are thioglycolate, thiomalate, thiourea, and thiouracil. In contrast, thiodiglycolate, thiodiglycol, and (phenylthio) acetic acid fail to support growth. Of the inorganic sulfur sources tested, sulfide and thiosulfate are utilized, but sulfite and sulfate are not; it thus appears that the state of oxidation is a critical factor in the utilization of sulfur by these strains of S. bovis. A complex amino acid mixture, without sulfur-containing amino acids, produces more rapid and reproducible growth than either arginine or ammonium acetate when used as a nitrogen source for testing the sulfur compounds. Growth rates are frequently better when the sulfur sources are autoclaved than when they are sterilized by filtration, although the qualitative responses to the compounds are generally similar.

Alanine↗

PubMed1992

Influence of casein and soy flour proteins on aminoacid content in the liver of experimental animals.

We have observed a significantly increased content of fats and decreased content of proteins in the liver of experimental rats fed a diet supplemented with 25% casein proteins in comparison with the application of de-fatted soy flour. Casein proteins have a higher content of methionine in relation to cystine than baked soy flour. But the soy diet in contrast to the casein diet has a high content of free aminoacids which are not present in casein at all: aspartic acid, asparagine, alpha-aminoadipic acid, methionine, norleucine, lysine, phenylalanine, beta-alanine, ethanolamine, histidine, proline, gamma-aminobutyric acid, taurine. Differences in free valine, alanine, arginine, glycine, ornithine and cysteic acid are also significant. The content of free aminoacids in the liver of experimental animals fed a soy diet is high in the content of cystine, cystathionine, ornithine, beta-aminoisobutyric acid, beta-alanine, gamma-aminobutyric acid, leucine. We have also found accumulation of methionine, glycine, alpha-aminobutyric acid, taurine and citrulline in free aminoacids from the liver of animals fed a casein diet. Citrulline and glycine in free aminoacids from the liver of animals fed a soy protein supplement were not recorded. Our investigations have shown that the application of a soy diet enriched with cystine acts protectively on methionine and that methionine is preferentially utilized for protein synthesis. The catabolic pathway of methionine prevails in animals on a casein diet.

Alanine↗

PubMed1996

Hypotrichosis, hair structure defects, hypercysteine hair and glucosuria: a new genetic syndrome?

Structural hair changes may be the expression of a genetic disorder affecting hair growth, part of a congenital syndrome with accompanying hair malformations, or a marker for an underlying metabolic disorder. We report a 22-month-old Turkish girl and her 10-month-old brother, whose scalp hair became fragile and sparse at about 6-7 months of age. Glucosuria, without diabetes or kidney disease, was detected 3-4 months later. Clinical examination revealed normal physical and mental development, and an analysis of plucked hairs showed dysplastic and broken hair shafts. Polarizing microscopy and scanning electron microscopic studies revealed torsion, and irregularities and impressions of the hair shaft, as seen in pili torti, trichorrhexis nodosa and pseudomonilethrix. Analysis of the amino-acid composition of the hair demonstrated a significant reduction of sulphonic cysteic acid and an elevated cysteine and lanthionine content in the girl, and elevated lanthionine levels in her brother. Electrophoretic analysis of the girl's hair proteins revealed a normal composition but a high extractability of hair proteins. The triad of hypotrichosis, structural hair-shaft defects and abnormal amino-acid composition, accompanied by glucosuria without diabetes, may represent a new genetic syndrome.

Amino Acids↗

PubMed1979

Determination of D-penicillamine in serum and urine of patients with rheumatoid arthritis.

A chromatographic auto-analyser method is described for the determination of total D-penicillamine in biological fluids. After oxidation with performic acid, D-penicillaminic acid is separated from other ninhydrin-positive acidic amino acids by anion-exchange chromatography. Total cysteine/cystine is simultaneously determined as cysteic acid, which makes the method equally suitable for patients with cystinuria. The detection limit in serum and urine is 2 microM D-penicillamine, which is more than sufficient for clinical application. The metabolite S-methyl-D-penicillamine is oxidized by performic acid to a sulphone, which can be determined after separation by cation-exchange chromatography.

Amino Acids↗

PubMed1981

Glutamate-stimulated phosphorylation of a specific protein in P2 fractions of rat cerebral cortex.

Incubation of P2 fractions from rat cerebral cortex with 32Pi in the presence of L-glutamate caused an increased phosphorylation of a protein with apparent molecular weight of 43,000 (P43) as demonstrated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and autoradiography. This glutamate-stimulated phosphorylation of P43 was already detectable 10 s after the addition of glutamate and was dependent on the concentrations of glutamate in the incubation medium. Other excitatory amino acids such as D-glutamate, L-aspartate, D,L-cysteic acid, L-cysteinesulfinic acid, and D,L-alpha-aminoadipic acid did not stimulate the phosphorylation of P43. In contrast, alpha-ketoglutarate and succinate stimulated the phosphorylation of this protein. Glutamate-stimulated phosphorylation of P43 seemed not to be mediated by either cAMP or cGMP and was inhibited by the presence of Ca2+ in the incubation medium. Experiments performed with metabolic inhibitors indicated that glutamate-stimulated protein phosphorylation is localized in mitochondria. This conclusion is supported by the occurrence of glutamate-stimulated phosphorylation of P43 in mitochondrial fractions from several peripheral tissues. The present results are consistent with the hypothesis that P43 is a component of the pyruvate dehydrogenase complex of mitochondria.

Animals↗

PubMed1991

The protein HC chromophore is linked to the cysteine residue at position 34 of the polypeptide chain by a reduction-resistant bond and causes the charge heterogeneity of protein HC.

Protein HC, an extremely charge-heterogeneous lipocalin, carries a yellow-brown fluorescent chromophore of unknown structure covalently bound at an unidentified site of its polypeptide chain. Two chromophore-carrying peptides with 60% of the chromophore material (defined as material absorbing light at 330 nm) were isolated from pepsin-digested native human protein HC by reversed-phase high performance liquid chromatography. Sequence analysis of these peptides indicated that the chromophore was bound to the cysteine residue at position 34 of the protein HC polypeptide chain. Sequence analysis of a native chromophore-tripeptide complex, isolated from pronase digests of the pepsin-produced peptides, identified the sequence Thr33-X34-Pro35, corroborating the position of the chromophore linkage. Quantitative amino acid analysis of the hydrolyzed, performic acid-oxidized, chromophore-tripeptide complex demonstrated approximately equal amounts of threonine, cysteic acid, and proline in the complex. Reduction and carboxymethylation of the native chromophore-tripeptide complex did not remove the chromophore from the peptide. The absorption spectrum of the chromophore-tripeptide complex was similar to that of native protein HC, implying that all of the heterogeneity of protein HC resides in its chromophore.

Alkylation↗

PubMed1999

Cysteic- and homocysteic acid-S-(aminoiminomethyl) amides: a new class of modified arginines useful in peptide synthesis.

A novel, practical synthesis of the title compounds and their derivatives are described. The protecting groups for amino, guanidino and carboxylic functions of substituted amides of cysteic and homocysteic acid were selected with the aim of making the amino acid derivatives synthons for peptide synthesis both in solution and by the solid phase method. Studying the structure-activity relationship some new kyotorphin, [Leu] kyotorphin and MIF-1 analogues, containing the unusual amino acid cysteic acid-S-(aminoiminomethyl) amide (sArg) in position two, have been prepared. It is a very promising compound, a structural analogue of arginine and an efficient antagonist in its metabolism.

Amides↗

PubMedDate not supplied

Cysteic and cysteine sulphinic acid decarboxylase activity in rat tissues during postnatal growth.

1) Cysteic and cysteine sulphinate decarboxylase activities have been determined in rat retina, brain, liver, kidney, lung and spleen during postnatal growth. 2) The two enzymic activities increase as function of age in retina, brain and liver. 3) In contrast the cysteic and cysteine sulphinate decarboxylase activities decrease with age in kidney, lung and spleen. 4) The rate of decarboxylation of cysteine sulphinate is higher than cysteic acid and the ratio of the two decarboxylating activities for each tissue is constant; this uniformity may exclude the existence of two separate enzymes.

Aging↗

PubMed1995

Primary substrate specificity of recombinant human stratum corneum chymotryptic enzyme.

Stratum corneum chymotryptic enzyme (SCCE) is a new human serine proteinase expressed by keratinocytes in the epidermis. Its function may be to catalyze the degradation of intercellular cohesive structures in the cornified layer of the skin in the continuous sheeding of cells from the skin surface. In this work the primary substrate specificity of recombinant SCCE was determined with oxidized bovine insulin B chain as substrate. Cleavage products were separated with high performance liquid chromatography and analyzed by amino acid sequence analysis and mass spectrometry. Cleavage sites were localized to Leu 6-cysteic acid 7, Tyr 16-Leu 17, Phe 25-Tyr 26, and Tyr 26-Thr 27 in insulin B chain. It is concluded that SCCE belongs to the family of serine endoproteinases specific for amino acid residues with aromatic side chains in the P1 position.

Amino Acid Sequence↗