Partial purification of monoglyceride lipase from adipose tissue.
A monoglyceride lipase was partly purified from extracts of rat adipose tissue by ammonium sulfate fractionation, alcohol precipitation, and lyophilization, or by ammonium sulfate fractionation, sodium deoxycholate treatment, and a second ammonium sulfate fractionation. Partial purification and heat denaturation showed the lipase to be different from tributyrinase and from an enzyme(s) which hydrolyzes diglycerides and triglycerides. Although the best preparations hydrolyzed monobutyrin this activity decreased with purification, indicating that the enzyme acts on insoluble substrates and is therefore a lipase and not an esterase. Further-more, classification of the enzyme as a lipase is consistent also with its behavior with inhibitors, since low concentrations of esterase inhibitors, e.g., fluoride, sodium deoxycholate, and physostigmine did not inhibit lipolytic activity. Inhibition studies with EDTA, sodium pyrophosphate, protamine, and fluoride showed that the enzyme differs from clearing factor lipase. The enzyme catalyzed hydrolysis of monostearin in the pH range 6.3-9.0, with a maximum at 7.4-7.6.
D000273:Adipose Tissue / Q000201:enzymology*; D000818:Animals; D055598:Chemical Phenomena; D002621:Chemistry; D002623:Chemistry Techniques, Analytical; D004798:Enzymes / Q000378:metabolism; D005223:Fats / Q000378:metabolism; D005227:Fatty Acids / Q000302:isolation & purification / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D066298:In Vitro Techniques; D008049:Lipase / Q000378:metabolism*; D051381:Rats; D013347:Subcellular Fractions / Q000378:metabolism
D004798:Enzymes; D005223:Fats; D005227:Fatty Acids; D008049:Lipase