This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Reprints and Permissions Copyright Information Books from ASM Press MicrobeWorld Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Mickelson, M. N. Search for Related Content PubMed PubMed Citation Articles by Mickelson, M. N.

 Previous Article  |  Next Article 

J Bacteriol. 1969 November; 100(2): 895-901
Copyright © 1969 American Society for Microbiology. All Rights Reserved.

Phosphorylation and the Reduced Nicotinamide Adenine Dinucleotide Oxidase Reaction in Streptococcus agalactiae

¹ National Animal Disease Laboratory, Animal Disease and Parasite Research Division, Agricultural Research Service, U.S. Department of Agriculture, Ames, Iowa 50010

ABSTRACT

Cell-free extracts from aerobically grown Streptococcus agalactiae cells possess a reduced nicotinamide adenine dinucleotide (NADH) oxidase which is linked to oxygen. It is inhibited by cyanide, although cytochromes evidently are not involved. Adenosine triphosphate (ATP) formation occurs during the reaction, but 66 to 75% of the total ATP is formed nonoxidatively. The remaining 25 to 35% of the ATP formation is related to the oxidation of NADH. The formation of ATP in the oxidative reaction can be prevented by excluding oxygen or adding cyanide to prevent NADH oxidation. It can also be prevented by adding methylene blue or pyruvate, which bypasses electron transport to oxygen, but does not interfere with NADH oxidation. Potential sources of ATP, such as glycolysis, the pyruvate oxidase reaction, or the oxidative pentose cycle, are not present, and the high nonoxidative ATP formation is ascribed to the adenylate kinase reaction. The reaction requires adenosine diphosphate (ADP) as a phosphate acceptor. NADH oxidation is independent of ADP. Antimycin A, amytal, and 2,4-dinitrophenol decreased, but did not prevent, oxidative formation of ATP. P:O ratios ranged from 0.15 to 0.25. All of the oxidative activity was in the soluble portion of the cell-free extracts.