Separation and further characterization of human adipose tissue neutral and alkaline lipolytic activities.

Neutral lipolytic activity (hydrolysis of olive oil at 37”, pH 7.0) and alkaline lipolytic activity (hydrolysis of tributyrin at 47’, pH 8.0) have previously been demonstrated in human adipose tissue. Neutral lipolytic activity has currently been shown to be present in a large molecular weight substance, associated with lipid, and separable from most alkaline lipolytic activity by ammonium sulfate precipitation and Sephadex G-ZOO gel filtration. Alkaline lipolytic activity (ALA) has been shown to exist as three separable fractions: ALA-I, ALA-II, and ALA-III. ALA-I represents a small percentage of the total alkaline lipolytic activity, is eluted from Sephadex with neutral lipolytic activity, exists as a lipid-protein complex of ALA-II, and has no mobility during starch gel electrophoresis. ALA-II is a smaller molecule than ALA-I and exists primarily as four electrophoretically separable bands of activity. ALA-III is considerably smaller than ALA-II, is a subunit of ALA-II, and exists primarily as a fifth band of electrophoretically separable activity.