Me. Vazquezmemije et al., ISOLATION AND COMPARATIVE-STUDIES OF MITOCHONDRIAL F1-ATPASE FROM RATTESTIS AND BEEF-HEART, Comparative biochemistry and physiology. B. Comparative biochemistry, 116(3), 1997, pp. 303-309
The isolation and properties of F-1-mitochondrial ATPase from rat test
is are described. The isolation medium involves a chloroform extractio
n, and it is suitable even with small amounts of starting material tha
t have a relatively low specific activity as in the case of rat testis
submitochondrial particles. The isolated enzyme from rat testis had a
specific activity of 30-45 mu mol Pi/min/mg protein, which could be i
ncreased up to 90 mu mol Pi/min/mg protein only in the presence of bic
arbonate and maleate. The isolated enzyme represented less than 0.6% o
f the initial membrane proteins. It exhibited a typical five-band patt
ern in sodium dodecyl sulfate gel electrophoresis. However, it showed
a ratio of subunits alpha:beta higher than the heart enzyme; its signi
ficance is unknown. The purified enzyme was cold labile and inhibited
by natural ATPase inhibitor protein from bovine heart mitochondria and
by dicyclohexylcarbodiimide. The results presented suggest that the l
ow ATPase activity of testis submitochondrial particles is due to a re
duced content of the F-1-ATPase. (C) 1997 Elsevier Science Inc.