Abstract
Conditions for a sharp increase in the thermal stability of NADPH oxidase isoforms and production of superoxide radicals in the absence of NADPH
Author(s): Simonyan R.M., Simonyan K.V., Feschyan S.M., Babayan M.A., Simonyan G.M., Isoyan A.S., Simonyan M.A.During storage at 3-4 months in frozen аt -10оС or lyophilized state of the isoforms of NADPH oxidase (Nox) from human donor blood erythrocytes membranes (EM) and from the lung of albino rats cells membranes (LCM), the conformational changes, is conditioned with an increase in the maximal optical absorption was observed. This absorption is typical for the flavin adenine dinucleotide (FAD) in composition of the Nox, with the corresponding increase in the optical spectral index (A365/A530). These indices for the fresh Nox (fNox) from EM and LCM are 3,2±0,01 (p<0,05, n=6) and 3,6±0,03 (p<0,05, n=6), and for the non fresh Nox (nfNox) from EM and LCM are 4,3±0,04 (p<0,05, n=6) and 4,5±0,03 (p<0,05, n=6), correspondingly. nfNox isoforms don't lose solubility and possess the ability for the production of Ð?2- in the absence of NADPH, indicating a higher thermal stability. On the incubation of these nfNox in a boiling water bath for 10-15 min, a decrease in the maximal optical density at 412 nm and 530 nm only for 10-15% is observed. In these conditions, sharp changes in the optical spectral indices for the fNox аnd appreciable lose of the solubility and the absence of the ability for the production of Ð?2- in the presence of NADPH were presented.
It can be concluded that during storage of the NADPH oxidase (Nox) isoforms from EM and LCM at the above-mentioned conditions, the conformational changes, an increase in the index A365A530 and a sharp elevation of the thermal stability and the ability of the superoxide production by these Nox without NADPH were observed.
