CONTRIBUTION TO THE STUDY OF THE ALTERATION OF LIPASE ACTIVITY OF CANDIDA-RUGOSA BY IONS AND BUFFERS

A semipurified C. rugosa lipase (LS) has been prepared from commercial lipase (LC) using an economical procedure. The presence of sugars and glycopeptides has been detected in LS and LC. Pure lipase only has co valently bonded sugars. The hydrolysis of olive oil catalyzed by LS an d commercial lipase (LC) is sensitive to the presence of cations Na(I) , Mg(II), Ca(II), and Ba(II) and to the nature of buffer. Highest enzy me activity is obtained with 0.1M Tris/HCl buffers and the combination of NaCl 0.11M and CaCl2 0.11M. Fluorescence spectroscopy analysis of LC, LS, and both pure isoenzymes lipases A and B, was used to analyze the interaction of the lipase with these effecttors. Inorganic cations Na or Ca do not interact with pure enzyme LA but do interact with LC and LS and do so slightly with LB. The organic cations (morfolinium or tris) interact with pure lipases. We postulate that the increase in t he lipase activity produced by Na(I) or Ca(II) is related with interfa cial phenomena, but the increase might be more specific in the hydroly sis of olive oil in the presence of Tris-HCl or morfoline-HCl buffer, owing to enzyme-buffer interaction.