Separation and characterization of 61- and 57-kDa lipases from Geotrichum candidum ATCC 66592.
Two lipolytic proteins (61 and 57 kDa) present in a Sephadex G-100 fraction of extracellular lipase from Geotrichum candidum ATCC 66592 were separated using high-performance liquid chromatography. Crossed electrofocusing immunoelectrophoresis was used to demonstrate that the 61-kDa lipase fraction contained two forms of lipase with pI 4.5 and 4.7. However, when deglycosylated with endoglycosidase H, the two forms gained an identical pI, 4.6. The 57-kDa lipase fraction contained one form of lipase with pI close to 4.5. Although the 61- and 57-kDa lipases were immunologically identical, the substrate specificity differed. Thus, the 61-kDa lipase hydrolysed palmitic acid methyl ester at an initial velocity of hydrolysis that was 60% of the initial velocity of hydrolysis of oleic acid methyl ester, whereas the 57-kDa lipase hydrolysed palmitic acid methyl ester at an initial velocity of hydrolysis that was only 7% of the initial velocity of hydrolysis of oleic acid methyl ester.
Jacobsen
T
T
Department of General Microbiology, University of Copenhagen, Denmark.
Poulsen
O M
OM
D002851:Chromatography, High Pressure Liquid; D005848:Geotrichum / Q000201:enzymology*; D007123:Immunoelectrophoresis, Two-Dimensional; D007526:Isoelectric Point; D007527:Isoenzymes / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism; D008049:Lipase / Q000737:chemistry / Q000302:isolation & purification* / Q000378:metabolism; D008970:Molecular Weight; D013379:Substrate Specificity
D007527:Isoenzymes; D008049:Lipase