Partial purification and identification of hormone-sensitive lipase from chicken adipose tissue

HSL from chicken adipose tissue exhibits remarkable activation upon phosphorylation with cAMP-dependent protein kinase (cAMP-PK) compared La HSL from rat and human adipose tissue. In order to characterize the chicken HSL enzyme, it was purified 3500 fold from a chicken adipose tissue homogenate using pH 5.2 precipitation and anion-exchange chromatography. The purified chicken HSL was identified as all 86 kDa protein using Western blot analysis. The HSL diacylglycerol lipase activity was inhibited by 98% upon incubation with anti-rat ASE antiserum, and the specific activity of chicken HSE was estimated to be approximately the same as for the rat enzyme. Furthermore, the 86 kDa polypeptide was phosphorylated by GAMP-PR to about the same stoichiometry as for the recombinant rat enzyme. Hence, our results demonstrate that HSL from chicken adipose tissue is comparable in size and specific activity to HSL from mammalian species, and not a smaller 42 kDa polypeptide with 1000-fold lower specific activity as previously reported (Berglund, L., Khoo, J. C., Jensen, D., and Steinberg, D., 1980 J. Biol. Chem. 255, 5420-5428). (C) 1997 Academic Press.