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Activation of a NADPH Oxidase From Horse Polymorphonuclear Leukocytes in a Cell‐ Free System
Author(s) -
Heyneman R.A.,
Vercauteren R.E.
Publication year - 1984
Publication title -
journal of leukocyte biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.819
H-Index - 191
eISSN - 1938-3673
pISSN - 0741-5400
DOI - 10.1002/jlb.36.6.751
Subject(s) - superoxide , nadph oxidase , chronic granulomatous disease , cytosol , respiratory burst , biology , biochemistry , oxidase test , oxygen , enzyme , reactive oxygen species , chemistry , immunology , organic chemistry
A postnuclear cell fraction from resting horse polymorphonuclear (PMN) leukocytes incubated with fatty acid‐salt ions such as oleate or linoleate generated a NADPH‐dependent oxygen consumption and superoxide production. Oxidative activity was negligible or absent in the postnuclear fraction from mononuclear leukocytes, p‐chloromercuribenzene sulfonic acid‐treated granulocytes, and granulocytes from a patient with chronic granulomatous disease. Although consistently associated with the membrane fraction from resting PMN leukocytes, the superoxide‐generating activity was shown to be dependent on a thus far unknown cytosolic constituent. The apparent K m 's for NADPH and NADH (66 and 1,600 µ M, respectively), the pH optimum for the reaction (7.0), the cyanide insensitivity, and transient nature of the reaction together with the stoichiometric relationship between oxygen uptake and NADPH oxidation led to the conclusion that in the presence of cytosol a cell‐free latent respiratory burst oxidase can be converted into an active enzyme by interaction with oleate micelles.