scholarly journals On the existence of an unidentified sulphur grouping in the protein molecule. Part I.—On the denaturation of proteins

1923 ◽  
Vol 94 (663) ◽  
pp. 426-441 ◽  
Keyword(s):  
Amino Acid ◽  
Protein Molecule ◽  
Egg White ◽  
Dissociation Product ◽  
Decomposition Products ◽  
Actual Form ◽  
Protein Substance ◽  
Points Of View ◽  
Hydrolysis Of ◽  
Denaturation Of Proteins

The hydrolysis of a protein substance which contains sulphur almost invariably results in the production of cystine among the decomposition products. This amino-acid almost certainly represents the actual form in which the bulk of the sulphur is combined in the molecule of most proteins. Cystine is, indeed, the only sulphur-body so far isolated which can be regarded with certainty as a primary dissociation product of protein. At the same time, there is a certain amount of evidence to suggest that in certain proteins—notably ovalbumin, and also casein—some of the sulphur is present in a form other than cystine. In the research about to be described this question was investigated mainly from two points of view:— (1) An examination was made of certain reactions given by egg white (and its products), attributable to sulphur groupings other than cystine. In the course of this work some light was thrown on the chemistry of denaturation.

scholarly journals Amino Acid Sequence Studies on Bobwhite Quail Egg White Lysozyme

1972 ◽  
Vol 247 (9) ◽  
pp. 2905-2916
Author(s):  
Ellen M. Prager ◽  
Norman Arnheim ◽  
George A. Mross ◽  
Allan C. Wilson
Keyword(s):  
Amino Acid ◽  
Amino Acid Sequence ◽  
Egg White ◽  
Bobwhite Quail ◽  
Egg White Lysozyme

scholarly journals Comparison of the Amino Acid Sequence of Bovine α-Lactalbumin and Hens Egg White Lysozyme

1967 ◽  
Vol 242 (16) ◽  
pp. 3747-3748 ◽  
Author(s):  
Keith Brew ◽  
Thomas C. Vanaman ◽  
Robert L. Hill
Keyword(s):  
Amino Acid ◽  
Amino Acid Sequence ◽  
Egg White ◽  
Egg White Lysozyme

scholarly journals THE ENZYMATIC HYDROLYSIS OF RAW AND HEAT-TREATED EGG WHITE

1935 ◽  
Vol 109 (1) ◽  
pp. 169-175
Author(s):  
Essie White Cohn ◽  
Abraham White
Keyword(s):  
Enzymatic Hydrolysis ◽  
Egg White ◽  
Heat Treated ◽  
Hydrolysis Of

scholarly journals Novel Amino Acid Derivatives of Quinolines as Potential Antibacterial and Fluorophore Agents

2020 ◽  
Vol 88 (4) ◽  
pp. 57
Author(s):  
Oussama Moussaoui ◽  
Rajendra Bhadane ◽  
Riham Sghyar ◽  
El Mestafa El Hadrami ◽  
Soukaina El Amrani ◽  
...  
Keyword(s):  
Amino Acid ◽  
Methyl Esters ◽  
Amino Acid Derivatives ◽  
Bacterial Strains ◽  
Fluorescent Properties ◽  
Topoisomerase Iv ◽  
Microdilution Method ◽  
Hydrolysis Of ◽  
Derivatives Of

A new series of amino acid derivatives of quinolines was synthesized through the hydrolysis of amino acid methyl esters of quinoline carboxamides with alkali hydroxide. The compounds were purified on silica gel by column chromatography and further characterized by TLC, NMR and ESI-TOF mass spectrometry. All compounds were screened for in vitro antimicrobial activity against different bacterial strains using the microdilution method. Most of the synthesized amino acid-quinolines show more potent or equipotent inhibitory action against the tested bacteria than their correspond esters. In addition, many of them exhibit fluorescent properties and could possibly be utilized as fluorophores. Molecular docking and simulation studies of the compounds at putative bacterial target enzymes suggest that the antimicrobial potency of these synthesized analogues could be due to enzyme inhibition via their favorable binding at the fluoroquinolone binding site at the GyrA subunit of DNA gyrase and/or the ParC subunit of topoisomerase-IV.

ChemInform Abstract: Perfect Enantioselective Hydrolysis of Amino Acid Esters by Modified . alpha.-Chymotrypsin.

ChemInform ◽  
2010 ◽  
Vol 26 (21) ◽  
pp. no-no
Author(s):  
R. UEOKA ◽  
J. OKAI ◽  
K. SHIMADA ◽  
D. SEGAWA ◽  
T. NAKATA ◽  
...  
Keyword(s):  
Amino Acid ◽  
Enantioselective Hydrolysis ◽  
Amino Acid Esters ◽  
Hydrolysis Of ◽  
Acid Esters

scholarly journals GES-2, a Class A β-Lactamase fromPseudomonas aeruginosa with Increased Hydrolysis of Imipenem

2001 ◽  
Vol 45 (9) ◽  
pp. 2598-2603 ◽  
Author(s):  
Laurent Poirel ◽  
Gerhard F. Weldhagen ◽  
Thierry Naas ◽  
Christophe De Champs ◽  
Michael G. Dove ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Pseudomonas Aeruginosa ◽  
Amino Acid ◽  
Amino Acid Change ◽  
Blood Cultures ◽  
Class A ◽  
Omega Loop ◽  
Cephalosporin Resistance ◽  
Lactamase Gene ◽  
Hydrolysis Of

ABSTRACT Pseudomonas aeruginosa GW-1 was isolated in 2000 in South Africa from blood cultures of a 38-year-old female who developed nosocomial pneumonia. This isolate harbored a self-transferable ca. 100-kb plasmid that conferred an expanded-spectrum cephalosporin resistance profile associated with an intermediate susceptibility to imipenem. A β-lactamase gene, bla GES-2, was cloned from whole-cell DNA of P. aeruginosa GW-1 and expressed in Escherichia coli. GES-2, with a pI value of 5.8, hydrolyzed expanded-spectrum cephalosporins, and its substrate profile was extended to include imipenem compared to that of GES-1, identified previously in Klebsiella pneumoniae. GES-2 activity was less inhibited by clavulanic acid, tazobactam and imipenem than GES-1. The GES-2 amino acid sequence differs from that of GES-1 by a glycine-to-asparagine substitution in position 170 located in the omega loop of Ambler class A enzymes. This amino acid change may explain the extension of the substrate profile of the plasmid-encoded β-lactamase GES-2.

A kinetic study of the acid autoxidation of tryptophan

1972 ◽  
Vol 25 (10) ◽  
pp. 2139 ◽  
Author(s):  
M Stewart ◽  
CH Nicholls
Keyword(s):  
Free Radical ◽  
Amino Acid ◽  
Kinetic Study ◽  
Acid Hydrolysis ◽  
Soda Glass ◽  
Glass Containers ◽  
Hydrolysis Of

The decomposition of tryptophan in aqueous HC1 at 100�C has been shown to proceed by a free-radical autoxidation mechanism. The acid functions by protonating the amino acid at either the 1- or 3-positions prior to autoxidation and so 1-methyltryptophan is also decomposed under these conditions. Impurities present in the soda glass containers used are shown to be responsible for the initiation of the reaction. The decomposition of tryptophan during the acid hydrolysis of proteins is considered in the light of these results.

Sub-critical water hydrolysis of hog hair for amino acid production

2010 ◽  
Vol 101 (7) ◽  
pp. 2472-2476 ◽  
Author(s):  
M.B. Esteban ◽  
A.J. García ◽  
P. Ramos ◽  
M.C. Márquez
Keyword(s):  
Amino Acid ◽  
Acid Production ◽  
Amino Acid Production ◽  
Water Hydrolysis ◽  
Hydrolysis Of

scholarly journals Molecular Cloning and Characterization of Bifidobacterium bifidum 1,2-α-l-Fucosidase (AfcA), a Novel Inverting Glycosidase (Glycoside Hydrolase Family 95)

2004 ◽  
Vol 186 (15) ◽  
pp. 4885-4893 ◽  
Author(s):  
Takane Katayama ◽  
Akiko Sakuma ◽  
Takatoshi Kimura ◽  
Yutaka Makimura ◽  
Jun Hiratake ◽  
...  
Keyword(s):  
Amino Acid ◽  
Genomic Library ◽  
Bifidobacterium Bifidum ◽  
Glycoside Hydrolases ◽  
Glycoside Hydrolase Family ◽  
Amino Acid Residues ◽  
Gene Encoding ◽  
Sugar Chain ◽  
Hydrolysis Of

ABSTRACT A genomic library of Bifidobacterium bifidum constructed in Escherichia coli was screened for the ability to hydrolyze the α-(1→2) linkage of 2′-fucosyllactose, and a gene encoding 1,2-α-l-fucosidase (AfcA) was isolated. The afcA gene was found to comprise 1,959 amino acid residues with a predicted molecular mass of 205 kDa and containing a signal peptide and a membrane anchor at the N and C termini, respectively. A domain responsible for fucosidase activity (the Fuc domain; amino acid residues 577 to 1474) was localized by deletion analysis and then purified as a hexahistidine-tagged protein. The recombinant Fuc domain specifically hydrolyzed the terminal α-(1→2)-fucosidic linkages of various oligosaccharides and a sugar chain of a glycoprotein. The stereochemical course of the hydrolysis of 2′-fucosyllactose was determined to be inversion by using 1H nuclear magnetic resonance. The primary structure of the Fuc domain exhibited no similarity to those of any glycoside hydrolases (GHs) but showed high similarity to those of several hypothetical proteins in a database. Thus, it was revealed that the AfcA protein constitutes a novel inverting GH family (GH family 95).

scholarly journals Chicken Intestinal Alkaline Phosphatase

1960 ◽  
Vol 43 (6) ◽  
pp. 1149-1169 ◽  
Author(s):  
M. Kunitz
Keyword(s):  
Alkaline Phosphatase ◽  
Zinc Ions ◽  
Magnesium Ions ◽  
Intestinal Alkaline Phosphatase ◽  
Reversible Inactivation ◽  
Higher Temperature ◽  
Kinetics Of ◽  
Hydrolysis Of ◽  
Zn Ions ◽  
Denaturation Of Proteins

Purified chicken intestinal alkaline phosphatase is active at pH 8 to 9, but becomes rapidly inactivated with change of pH to 6 or less. Also, a solution of the inactivated enzyme at pH 4.5 rapidly regains its activity at pH 8. In the range of pH 6 to 8 a solution of purified alkaline phosphatase consists of a mixture of active and inactive enzyme in equilibrium with each other. The rate of inactivation at lower pH and of reactivation at higher pH increases with increase in temperature. Also, the activity at equilibrium in the range of pH 6 to 8 increases with temperature so that a solution equilibrated at higher temperature loses part of its activity on cooling, and vice versa, a rise in temperature shifts the equilibrium toward higher activity. The kinetics of inactivation of the enzyme at lower pH and the reactivation at higher pH is that of a unimolecular reaction. The thermodynamic values for the heat and entropy of the reversible inactivation and reactivation of the enzyme are considerably lower than those observed for the reversible denaturation of proteins. The inactivated enzyme at pH 4 to 6 is rapidly reactivated on addition of Zn ions even at pH 4 to 6. However, zinc ions are unable to replace magnesium ions as cocatalysts for the enzymatic hydrolysis of organic phosphates by alkaline phosphatase.

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