Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0027960 (mole)
 21,279 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A new antibiotic named 61-26 active against gram-positive bacteria and some fungi was isolated from a Bacillus strain. The antibiotic is a weakly basic peptide slightly soluble in aqueous alcohols. An approximate empirical formula of C50H93N11O17 and constituent amino acids of aspartic acid (1 mole), serine(2 moles), alanine (2moles), and sum of valine and isoleucine (2 moles) are indicated.
 ...
PMID:Isolation of a new peptide antibiotic complex 61-26. Studies on antibiotics from the geneus Bacillus. V. 111 65

A protease inhibitor specific to trypsin and chymotrypsin was purified from horsegram (Dolichos biflorus) with the inhibition index 0.24 micrograms/micrograms for trypsin and 0.36 micrograms/micrograms for chymotrypsin. In SDS-PAGE, the inhibitor protein was seen as a single band with apparent molecular mass Mr = 15,500. However, on fast protein liquid chromatography (FPLC) or non-denaturating PAGE, the inhibitor resolved into four components revealing the existence of isoinhibitors. Data on amino acid analysis indicate that the isoinhibitors are closely related. The major amino acids in the inhibitor are half cystine (18.9 mole %), aspartic acid (12.7 mole %) and serine (14.3 mole %). The inhibitor was partially stable to 0.1% sodium dodecyl sulphate, 8M urea or 6M guanidine hydrochloride. The inhibitory activity was lost on reduction or carboxamidomethylation or acetylation. Modification of the arginine groups or CNBr cleavage of the protein did not result in significant loss of either tryptic or chymotryptic inhibitory activities. The isoinhibitors separated by FPLC reacted with polyclonal antibody raised in rabbits and had pI values ranging from 4.8-5.1. The horsegram inhibitor thus resembles other Bowman-Birk protease inhibitors.
 ...
PMID:Nature of the tryptic/chymotryptic inhibitor from horsegram (Dolichos biflorus). 181 76

N-Terminal analysis of purified buffalo thyroglobulin by the fluorodinitrobenzene method of Sanger yielded about 1.5 moles of DNP-glutamic acid per mole of buffalo thyroglobulin. No water-soluble DNP-amino acid was detectable as N-terminal. The presence of glutamic acid has been confirmed by Edman degradation and characterization of the PTH-amino acid in different solvent systems, and also after regeneration of free amino acid from PTH-amino acid in butanol-acetic acid-water (4:1:5, v/v) system. This is in contrast to the occurrence of aspartic acid or asparagine as N-terminals for several other mammalian thyroglobulins.
 ...
PMID:N-terminal groups of buffalo thyroglobulin. 235 50

A protein which preferentially binds Z-form duplex DNA has been purified from the cells of Deinococcus radiodurans. The molecular weight of the protein was estimated to be approximately 68,000 by gel filtration and SDS-polyacrylamide gel electrophoresis. Amino acid analysis of the protein indicates that it is not so basic since it contains a lower mole percent of lysine and higher mole percent of aspartic acid than those in histone-like DNA binding protein II (HU) of Escherichia coli. The first fifteen amino acid residues from the N-terminus have been also determined.
 ...
PMID:Isolation of a DNA-binding protein from Deinococcus radiodurans having an affinity for a Z-form polynucleotide. 306 34

Experiments using equilibrium dialysis and fluorescence quenching provided direct evidence that approximately four moles of L-aspartic acid were bound per mole of tetrameric L-asparaginase from Escherichia coli, with a dissociation constant on the order of 60-160 microM. In addition, a set of weaker binding sites with a dissociation constant in the millimolar range were detected. Kinetic studies also revealed that L-aspartic acid inhibited L-asparaginase competitively, with an inhibition constant of 80 microM at micromolar concentrations of L-asparagine; at millimolar concentrations of the amide, an increase in maximal velocity but a decrease in affinity for L-asparagine were observed. L-Aspartic acid at millimolar levels again displayed competitive inhibition. These and other observations suggest that L-aspartic acid binds not only to the active site but also a second site with lower intrinsic affinity for it. The observed "substrate activation" is most likely attributable to the binding of a second molecule of L-asparagine rather than negative cooperativity among the tight sites of the subunits of this tetrameric enzyme. Further support for L-aspartic acid binding to the active site comes from experiments in which the enzyme, when exposed to various group-specific reagents suffered parallel loss of catalytic activity and in its ability to bind L-aspartic acid. Different commercial preparations of Escherichia coli L-asparaginase were found to contain approximately 2-4 moles of L-aspartic acid; these were incompletely removed by dialysis, but could be removed by transamination or decarboxylation. Efficiency of dialysis increased with increasing pH. Taken together, this set of results is consistent with the existence of a covalent beta-aspartyl enzyme intermediate.
 ...
PMID:Interaction between L-aspartic acid and L-asparaginase from Escherichia coli: binding and inhibition studies. 333 41

Hen egg-white lysozyme (EC 3.2.1.17) was specifically esterified at aspartic acid 52 by the affinity labeling reagent 2',3'-epoxypropyl beta-glycoside of di-(N-acetyl-D-glucosamine) [Eshdat et al. (1973) J. Biol. Chem.248, 5892]. The disulfide bonds of the affinity-labeled enzyme and the aspartic acid 52-ester bond were reduced with dithiothreitol and sodium borohydride, respectively, resulting in the removal of the affinity label. The reduced protein contained 0.9 mole of homoserine and 1 mole less of aspartic acid per mole of protein, as compared to the native enzyme. It was reoxidized by a mixture of reduced and oxidized glutathione to yield a modified protein that possessed one-tenth of the activity of native lysozyme (presumably due to a contamination by regenerated lysozyme formed as a result of hydrolysis of the aspartic acid 52-ester bond during the chemical treatment). The native enzyme, after reduction and reoxidation in the same manner, retained its amino-acid composition, full enzymatic activity, and fluorescence properties. The modified lysozyme, containing homoserine 52, showed the same fluorescence spectrum as the native enzyme. With both proteins, the fluorescence maximum shifted to the blue to a similar extent upon the addition of the saccharide inhibitors tri-(N-acetyl-D-glucosamine) and the cell-wall tetrasaccharide (GlcNAc-MurNAc)(2). The modified enzyme bound these two saccharides with nearly the same binding constants as those found for native lysozyme and for lysozyme that was reduced and reoxidized. Since the side chain of homoserine is similar in size to that of aspartic acid, it is concluded that the loss of enzymatic activity is the direct result of the chemical modification of the carboxyl side chain of aspartic acid 52, thus showing that this amino acid is essential for the catalytic action of the enzyme.
 ...
PMID:Chemical conversion of aspartic acid 52, a catalytic residue in hen egg-white lysozyme, to homoserine. 452 56

1. Inhibition of ox liver glutamate dehydrogenase with N-(N'-acetyl-4[(35)S]-sulphamoylphenyl)maleimide (ASPM) is more specific at pH7.3 than at pH6.9. At pH7.3 inhibition accompanies the incorporation at 1 mole of ASPM residues into about 53000g. of protein. 2. Digestion of the modified protein with chymotrypsin and trypsin yields a unique radioactive peptide. 3. Acid hydrolysis of 1 mole of this peptide yields 1 mole of N(in)-succin-2-yl-lysine. The in-amino group of a lysyl residue is thus the site of modification of the protein. 4. The sequence containing the modified lysyl residue is: [Formula: see text] where Asx respresents either aspartic acid or asparagine.
 ...
PMID:A peptide containing a reactive lysyl group from ox liver glutamate dehydrogenase. 578 69

An abnormal unstable hemoglobin, hemoglobin Philly, was found in three members of a family, each of whom had evidence of a chronic hemolytic state. The presence of the mutant protein was suggested by the rapid appearance of inclusion bodies upon incubation of erythrocytes with brilliant cresyl blue and by the increased heat precipitability of the hemoglobin. However, no abnormal hemoglobin could be demonstrated by electrophoresis or column chromatography. Sulfhydryl titration of the hemolysates with p-mercuribenzoate indicated that there was an average of four reactive sulfhydryl groups per hemoglobin molecule instead of the usual two. The total number of hemoglobin sulfhydryl groups was normal; six groups were measured when denatured globin was reacted with 5,5'-dithiobis[2-nitrobenzoic acid]. This indicated that the increased sulfhydryl reactivity was due to an increased availability to p-mercuribenzoate of the usually unreactive hemoglobin cysteines at beta112 and alpha104. After treatment for (1/2) hr with 4-5 moles of p-mercuribenzoate per mole of hemoglobin, electrophoresis revealed that 30-35% of the hemoglobin had been dissociated into alpha- and beta-chains. Normal hemolysates revealed negligible splitting after 72 hr of similar treatment. The alpha- and beta-chains of hemoglobin Philly were separated from the unsplit hemoglobin A by carboxymethyl cellulose chromatography. Fingerprint and amino acid analyses revealed that tyrosine beta35 was replaced by phenylalanine. In hemoglobin Philly there is loss of the normal hydrogen bond between the tyrosine hydroxyl group and the carboxyl group of aspartic acid alpha126 at the alpha(1)beta(1) contact. This shifts the equilibrium from hemoglobin tetramers toward monomers, exposing the beta112 and alpha104 cysteines. In the cell, precipitation of the unstable monomers may contribute to erythrocyte destruction.
 ...
PMID:Hemoglobin Philly (beta 35 tyrosine phenylalanine): studies in the molecular pathology of hemoglobin. 582 75

Cell walls were isolated by mechanical disruption of mid-log phase cells of Bacillus stearothermophilus NCA 1503-4R grown in Trypticase-yeast extract-fructose medium at 55 C. The cell walls were purified by treatment with sodium dodecyl sulfate (SDS) and incubation with deoxyribonuclease and trypsin. The cell wall peptidoglycan contained glucosamine, muramic acid, alpha, epsilon-diaminopimelic acid, and glutamic acid. Low amounts of glycine, galactosamine, serine, aspartic acid, lysine, and valine were also present. The relative mole ratios of glutamic acid-alpha, epsilon-diaminopimelic acid-glycine-alanine were 1.00:1.26:0.08:1.55. The cell walls were free from ribonucleic acid and deoxyribonucleic acid and contained less than 0.2% chloroform-methanol extractable lipid and 0.09 mumole of phosphorus per mg of cell wall. Teichoic acid was not detected in the cell walls of this organism. Cell walls isolated without treatment with SDS contained 7.5% chloroform-methanol extractable lipid, 0.24 mumole of phosphorus per mg of cell wall, and relatively high concentrations of all amino acids. These results suggest that the extracted lipid is not a cell wall component per se, but a contaminant from the lipoprotein cell membrane.
 ...
PMID:Chemical composition of the cell walls of Bacillus stearothermophilus. 603 16

A new apolipoprotein E (apo E) phenotype has been demonstrated in a Finnish hypertriglyceridemic subject (R.M.). At the time of this study, R.M.'s plasma triglyceride and cholesterol levels were 1,021 and 230 mg/dl, respectively. The subject's apo E isoelectric focusing pattern was characterized by two major bands, one in the E3 position and the other in the E1 position. Normally the E1 position is occupied by sialylated derivatives of apo E4, E3, or E2. The E1 band of subject R.M. is not a sialylated form, however, because it was not affected by neuraminidase digestion. The identity of the E1 variant as a genetically determined structure was established by amino acid and partial sequence analyses, confirming that the variant is an example of a previously uncharacterized apo E phenotype, E3/1. Both cysteamine modification and amino acid analysis demonstrated that this variant contains two cysteine residues per mole. Sequence analysis of two cyanogen bromide fragments and one tryptic fragment of the apo E3/1 showed that it differs from E2(Arg158----Cys) at residue 127, where an aspartic acid residue is substituted for glycine. This single amino acid interchange is sufficient to account for the one-charge difference observed on isoelectric focusing gels between E2(Arg158----Cys) and the E1 variant. The variant has been designated E1 (Gly127----Asp, Arg158----Cys). When compared with apo E3, the E1 variant demonstrated reduced ability to compete with 125I-LDL for binding to LDL (apo B,E) receptors on cultured fibroblasts (approximately 4% of the amount of binding of apo E3). This defective binding is similar to that of E2-(Arg158----Cys). Therefore, the binding defect of the variant is probably due to the presence of cysteine at residue 158, rather than aspartic acid at residue 127. In contrast, the apo E3 isoform from this subject demonstrated normal binding activity, indicating that it has a normal structure. In family studies, the vertical transmission of the apo E1 variant has been established. It is not yet clear, however, if the hypertriglyceridemia observed in the proband is associated with the presence of the E1(Gly127----Asp, Arg158----Cys) variant.
 ...
PMID:A novel electrophoretic variant of human apolipoprotein E. Identification and characterization of apolipoprotein E1. 632 33


<< Previous 1 2 3 4 5 Next >>