Data/hora: 13/06/2024 07:30:19

Biblioteca(s): | Embrapa Caprinos e Ovinos.
Data corrente: | 01/08/1992
Data da última atualização: | 12/04/2024
Autoria: | ZGLICZYNSKI, J. M.; SELVARAJ, R. J.; PAUL, B. B.; STELMASZYWSKA, T.; POSKITT, P. K. F.; SBARRA, A. J.
Título: | Chlorination by the mycloperoxidase-H2O2-Cl-antimicrobial system at acid and neutral pH.
Ano de publicação: | 1977
Fonte/Imprenta: | Proceedings Society Experimental Biology Medical, v. 154, n. 3, p. 418-422, 1977.
DOI: | https://doi.org/10.3181/00379727-154-39
Idioma: | Inglês
Conteúdo: | The oxidation of Cl- ion by H2O2 yielding Cl+ is catalyzed by myelope-roxidase (MPO) prepared from human PMN. Both H2O2 and CI- in this reaction serve as substrates. Affinity (apparent) studies between MPO and CI- and MPO and H2O2 were carried out. Both (apparent) affinities vary according to pH. The higher the pH, the less the affinity for Cl-. In contrast, the affinity between MPO and H2O2 increases with pH. The dissociation constant of the MPO-CI- enzyme substrate complex is affected by the second substrate, H2O2. The effect of H2O2 on the MPO-C1- affinity is competitive. Likewise, the MPO-H2O2 affinity is decreased with increasing Cl- concentration. This influence is also competitive. From these interactions, it may be concluded that the optimal pH for chlori-nation is dependent on the [H2O2]/[C1-] ratio. The relationship of pH, H2O2, and CI- concentrations may be expressed by the following formula: pH = log [CI-] x560/ [H2O2]. Using the formula, it can be shown that optimal chlorination may occur between pH 4.0 and 7.4. We wish to thank Paul Wallace and Gerry Heatley for technical assistance, Roberta Lemon for preparing the manuscript, and George Daynes for photography. This investigation was supported by Grant CA-1567 awarded by the National Cancer Institute, DHEW, and USPHS Grant HD-1805, NIH.
Thesagro: | Imunologia; Microbiologia.
Thesaurus Nal: | Immunology; Microbiology.
Categoria do assunto: | X Pesquisa, Tecnologia e Engenharia
Registro original: | Embrapa Caprinos e Ovinos (CNPC)
Exemplares: | CNPC - (7883-1) - ADD - AP - PP - SP 00650 -  - SP 00650 - DIS