Conformational Properties of Circulating and Recombinant Forms of Human Plasma Lecithin Cholesterol ACYL Transferase

Sundarrajan, Geetha, Conformational properties of circulating and recombinant forms of human plasma LCAT Master of Science (Biomedical Sciences), June, 1995, 69pp., 3 tables, 18 figures, 47 references. The relationship between enzymatic activity and conformational properties of the circulating and recombinant forms of human plasma LCAT were examined in the native and denatured states. The two denaturing agents used in this study were guanidine hydrochloride and heat. These studies led to the following conclusions: (1) Although the alpha helical content of desialylated recombinant LCAT (d-LCAT) is comparable to that of the other two forms of the enzyme (p-LCAT and r-LCAT), the desialylation of LCAT is associated with an increase in the beta sheet and a decrease in beta turn content. (2) The presence of sialic acids, in addition, seems to influence the local environments of aromatic amino acid residues. (3) From the denaturation and renaturation studies with guanidine hydrochloride and heat, it appears that the N-glycan structures of p-PCAT and r-LCAT may contribute differentially to the conformational stability of the enzyme. (4) The alpha helical structure of LCAT may not be involved in maintaining the active conformation of the enzyme.