Studies of the enzyme activity of Bact. lactis aerogenes (Aerobacter aerogenes) - I. The effects of cellular disruption on the activities of some typical enzymes

Abstract

When cells of Bact. lactis aerogenes (Aerobacter aerogenes) are disrupted by exposure for various times ( a ) to benzene, or ( b ) to ultrasonic vibrations the activity of some representative enzyme systems changes according to one of two patterns. In pattern I it rises to a maximum from which it then declines; in pattern II it falls from the start, the rate of fall varying from enzyme to enzyme. β -galactosidase and asparagine deaminase show pattern I and catalase pattern II, whichever method of disruption is used. Non-induced dehydrogenases in ( b ) show pattern I while fully mobilized dehydrogenases show pattern II. All are very rapidly inactivated in ( a ). Discussion of the results suggests that the susceptibility of the enzyme to damage may be a function of its complexity, and that the pattern of inactivation depends upon how far the normal activity is limited by rate of access, this in turn depending partly upon the actual location of the enzyme, which in some cases is in or near the cell surface.