Investigations on the heat lability of enzyme activities in bovine lenses following incubation under various culture conditions.

The quality of different culture media and incubation procedures has occasionally been tested by measurements of the specific enzyme activities in incubated lenses. New methodology developments in the field of enzymology, such as partial heat denaturation of enzyme activities have so far rarely been used in the investigations on the physiologic conditions of incubated lenses. Investigations with bovine lenses separated into cortex and nucleus, involving different media and incubation periods, indicate that tests on the heat lability of the enzyme phosphofructokinase (PFK) allow early recognition of intra-molecular alterations which lead to changes in the stability. The method is based on the fact that the PFK in the lens nucleus forms a metastable component (metazyme) during aging, which is more susceptible to heat (50 degrees C) than the native PFK component.