The Journal of Biochemistry
Online ISSN : 1756-2651
Print ISSN : 0021-924X
CLASSIFICATION OF CATALASE-POISONS BASED ON OBSERVATIONS OF THEIR INTERACTION WITH CATALASE. II
Y. OGURAY. TONOMURAS. HINOH. TAMIYA
著者情報
ジャーナル フリー

1950 年 37 巻 2 号 p. 179-204

詳細
抄録

1) Interactions between two poisons in their action upon catalase were studied both by kinetic and spectrophotom;tric methods. Based on the results obtained, poisons of catalase were divided into four types, i.e. Cyanide, Azide, Phenol and Hydrogen Ion Types. To each of these groups belong the following substances:
Cyanide Type: cyanide, chloride, fluoride and sulfide.
Azide Type: azide and hydroxylamine. Phenol Type: phenol, resorcinol, hydroquinone, cresols, chloro-phenols and nitrophenols.
Hydrogen Ion Type, of which hydrogen ion represents the only member thus far found.
The study of the mutual action of the substances belonging to the first mentioned three groups formed the subject of the present report.
2) Poisons belonging to the same group “compete” with each other for a definite active center of the catalase molecule; accord-ingly, two poisons, G1 apd G2, belonging to the same group cannot share one catalase molecule (E) at the same time. This was shown, not only by kinetic method but also spectrophotometrically-in the case of-substances of Cyanide and Azide Types-by the fact that on adding G1 and G2 in sufficient quantities, catalase solution shows only the mixed spectra of EG1 and EG2, the ratio of which depends upon the relative concentrations of G1 and G2 and their relative affinities toward E.
3) Poisons belonging to different groups are linked to different active centers in the catalase molecule, a conclusion which has partly been drawn in cur previous paper in which we inferred that the poisons of Phenol Type attach to the protein moiety, while those of Cyanide and Azide Types combine with protohemins of the catalase' molecule. Owing to the difference of the site of attachment, poisons belonging to different groups may be expected to link to one catalase molecule at the same time, forming a triple complex of the type EG1G2. This expectation was borne out not only by various kinetic experiments, but also-for the substances of Cyanide and Azide Types-spectrophotometrically by the discovery of a characteristic spectrum of EG1G2 which was essentially different from either that of EG1 or of EG2.
4) By analyses of various quantitative data, it was shown that the affinity of G1 to EG2 is not always the same as that between G1 and E; in other words, poisons belonging to different types can exert certain mutual influences in their combination with catalase molecule. The substances of the three categories dealt with in this paper were found to act upon each other more or less “repulsively”, i.e. G1 requires more energy to combine with EG2 than to combine with E. The data to be reported later will show that the hydrogen ion, when attached to catalase molecule, act “attractively” on phenols, but quite “indifferently” upon substances belonging to the Cyanide and Azide Types.
5) On the available data it may be concluded that the catalase molecule has at least four active or sensitive centers, each having affinities to the poisons or respective types mentioned above.
This investigation forms a part of study of the Research Commitee of Heavy Metal Catalysis of the National Research Council and was supported by a grant donated to one of the authers (Tamiya) by the Ministry of Education.

著者関連情報
© The Japanese Biochemical Society
前の記事 次の記事
feedback
Top