DNase II in spermatozoa of the loach misgurnus fossilis L
A deoxyribonuclease (DNase) which is active at acid pH in the absence of bivalent cations was found in loach spermatozoa. The enzyme was purified by ion-exchange chromatography and partially characterized. The DNase has optimal activity at pH 5.5 and its molecular weight is about 30 kD; its substrate is covalently closed circular duplex DNA, and its product is the corresponding unit-length linear DNA. The DNase is inhibited by MgCl2 and activated by EDTA. Thus, this endoDNase found in loach spermatozoa can be classified as a DNase II. The biological role of this DNase II is discussed.
Nechaevsky
YV
Institute of Theoretical and Experimental Biophysics, Russian Academy of Sciences, Pushchino, Moscow Region, 142292, Russia; fax: (095) 923-3602. ivanov@ibpm.serpukhov.su.
Ivanov
VA