Comparisons of the Effects of Bacillus subtilis Protease, Type VIII (Subtilopeptidase A), and Insulin on Isolated Adipose Cells

The effects of Bacillus subtilis protease, Type VIII (subtilopeptidase A, EC 3.4.4.16), on the lipolytic action of norepinephrine, corticotropin, caifeine, and theophylline on isolated adipose cells were examined.The results indicate that B. subfilis protease, at concentrations suboptimal and optimal for the enhancement of glucose utilization, inhibited, like insulin, the lipolysis mediated by the above agents.Adipose cells, pretreated with insulin or B. subfilis protease, followed by extensive washing, still exhibited elevated glucose utilization and a reduced response to the lipolytic hormones and compounds.The inhibitory action of B. subfilis protease on the stimulated lipolysis was reduced with increasing concentrations of the lipolytic agents.Other proteolytic enzymes such as trypsin, a-chymotrypsin, and Sfrepfomyces griseus protease (Type VI), also exhibited an antilipolytic action.The antilipolytic action of proteolytic enzymes, which was found to be independent of their ability to stimulate glucose uptake, is considered to result from the proteolytic modification of the plasma membrane of the adipose cells via as yet unknown mechanisms.