The kinetics of radical decay in crystalline amino acids. 7. Monohydrates

SummaryVarious investigators have separated the coagulation products formed when fibrinogen is clotted with thrombin and identified fibrinopeptides A and B. Two other peaks are observed in the chromatogram of the products of coagulation, but these have mostly been dismissed by other workers. They have been identified by us as amino acids, smaller peptides and amorphous material (37). We have re-chromatographed these peaks and identified several amino acids. In a closed system of fibrinogen and thrombin, the only reaction products should be fibrin and peptide A and peptide B. This reasoning has come about because thrombin has been reported to be specific for the glycyl-arginyl peptide bond. It is suggested that thrombin also breaks other peptide linkages and the Peptide A and Peptide B are attacked by thrombin to yield proteolytic products. Thrombin is therefore probably not specific for the glycyl-arginyl bond but will react on other linkages as well.If the aforementioned is correct then the fibrinopeptides A and B would cause an inhibition with the coagulation mechanism itself. We have shown that an inhibition does occur. We suggest that there is an autoinhibition to the clotting mechanism that might be a control mechanism in the human body.The experiment was designed for coagulation to occur under controlled conditions of temperature and time. Purified reactants were used. We assembled an apparatus to record visually the speed of the initial reaction, the rate of the reaction, and the density of the final clot formed after a specific time.The figures we derived made available to us data whereby we could calculate and plot the information to show the mechanism and suggest that such an inhibition does exist and also further suggest that it might be competitive.In order to prove true competitive inhibition it is necessary to fulfill the criteria of the Lineweaver-Burk plot. This has been done. We have also satisfied other criteria of Dixon (29) and Bergman (31) that suggest true competitive inhibition.

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Kinetics and mechanism of oxidation of DL-α-alanine by permanganate ion in acid perchlorate media

Canadian Journal of Chemistry ◽

10.1139/v91-292 ◽

1991 ◽

Vol 69 (12) ◽

pp. 2018-2023 ◽

Cited By ~ 30

Author(s):

Refat M. Hassan

Keyword(s):

Amino Acids ◽

Ionic Strength ◽

Acid Solution ◽

Second Order ◽

Perchloric Acid Solution ◽

Oxidation Reduction ◽

Initial Stage ◽

Aqueous Perchloric Acid ◽

Mechanism Of Oxidation ◽

Kinetics Of

The kinetics of permanganate oxidation of DL-α-alanine in aqueous perchloric acid solution at a constant ionic strength of 2.0 mol dm−3 has been investigated spectrophotometrically. The reaction was found to show second-order kinetics overall with respect to each of the reactants in the slow initial stage; the second-order kinetics are not, however, maintained throughout the relatively fast final stage of reaction. The added salts lead to the prediction that Mn(III) and (or) Mn(IV) play a very important role in the reaction kinetics. A tentative mechanism consistent with the kinetics is discussed. Key words: kinetics, oxidation, reduction, amino acids, permanganate.

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SOME ASPECTS OF THE STRUCTURE OF HEMOGLOBIN

Canadian Journal of Biochemistry ◽

10.1139/o64-087 ◽

1964 ◽

Vol 42 (6) ◽

pp. 755-762 ◽

Cited By ~ 26

Author(s):

David B. Smith

Keyword(s):

Amino Acids ◽

Amino Acid ◽

Amino Acid Sequence ◽

Partial Amino Acid Sequence ◽

Heme Pocket ◽

Terminal Amino ◽

Polypeptide Chains ◽

Kinetics Of ◽

Β Chain

An outline of present ideas concerning the arrangement, folding, and chemistry of the polypeptide chains of hemoglobin is given with some references to present know ledge of myoglobin.New material includes a partial amino acid sequence of the β-chain of horse hemoglobin, details concerning the amino acids lining the heme pocket of horse hemoglobin, and the effects of carboxypeptidases A and B on horse oxy- and horse deoxy-hemoglobin. The kinetics of the latter reactions are not simple. The C-terminal amino acids are released more rapidly from the oxygenated form.

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Identification in skeletal muscle of a distinct extracellular pool of amino acids, and its role in protein synthesis

Biochemical Journal ◽

10.1042/bj1210817 ◽

1971 ◽

Vol 121 (5) ◽

pp. 817-827 ◽

Cited By ~ 74

Author(s):

R. C. Hider ◽

E. B. Fern ◽

D. R. London

Keyword(s):

Skeletal Muscle ◽

Amino Acids ◽

Protein Synthesis ◽

Amino Acid ◽

Incubation Medium ◽

Extensor Digitorum Longus ◽

Extensor Digitorum ◽

Longus Muscle ◽

Kinetics Of

1. The kinetics of radioactive labelling of extra- and intra-cellular amino acid pools and protein of the extensor digitorum longus muscle were studied after incubations with radioactive amino acids in vitro. 2. The results indicated that an extracellular pool could be defined, the contents of which were different from those of the incubation medium. 3. It was concluded that amino acids from the extracellular pool, as defined in this study, were incorporated directly into protein.

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