Factors affecting the binding of lecithin:cholesterol acyltransferase with interfacial substrates

The esterification of cholesterol on high density lipoproteins (HDL) catalyzed by lecithin:cholesterol acyltransferase (LCAT) maintains a gradient for cholesterol diffusion from cell membranes and atherosclerotic plaques and plays a critical part in the maintenance of cholesterol homeostasis. The principal protein of HDL, apolipoprotein A-I (apoA-I) is a major physiological activator of the LCAT reaction. Despite the importance of this reaction, the factors which influence LCAT affinity for the surface of HDL are poorly understood. To determine what properties of HDL influence LCAT binding affinity and reactivity, three sensitive methods for determining LCAT binding equilibrium with reconstituted HDL (rHDL) were developed: fluorescence energy transfer from DNS-LCAT to rHDL labeled with NBD-stearate; direct binding of $\sp{125}$I-LCAT to microtiter plates coated with rHDL; and an activity inhibition assay. Using these methods, LCAT binding affinity was demonstrated to be independent of apolipoprotein composition, indicating that activation of LCAT by apolipoproteins occurs at a separate reaction step from LCAT binding.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Biochemistry

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2011

Author dc:creator

• Bolin, Delmas John

Contributors dc:contributor

• Jonas, Ana

• Chemistry, Biochemistry

Statement dc:rights

• Copyright 1994 Bolin, Delmas John

Language dc:language

eng

Identifier

AAI9512304
(UMI)AAI9512304

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/20330