Identification of the active-site serine in human lecithin: cholesterol acyltransferase

Conference · Fri May 01 04:00:00 EDT 1987 · Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States)

OSTI ID:6359717

Farooqui, J; Wohl, R C; Kezdy, F J; Scanu, A M

Lecithin:cholesterol acyltransferase (LCAT) from human plasma reacts stoichiometrically with diisopropylphosphorofluoridate (DFP) resulting in the complete loss of transacylase activity. Purified LCAT was covalently labeled with (TH) DFP and the labeled protein was reduced and carboxymethylated. Cyanogen bromide cleavage followed by gel permeation chromatography yielded a peptide of 4-5 KDa (LCAT CNBr-III) containing most of the radioactive label. Preliminary studies comparing the amino acid composition of the LCAT-CNBr-III with the sequence of LCAT indicate that this peptide corresponds to fragment 168-220. Automated Edman degradation of the radioactive peptide recovered a radioactive PTC-amino acid at cycle 14. Of all predicted CNBr fragments only peptide 168-220 contained a serine at residue 14 from the amino terminus of the peptide. The authors conclude that serine 181 is the active site serine of LCAT.

• Research Organization: Univ. of Chicago, IL
• OSTI ID: 6359717
• Report Number(s): CONF-870644-
• Conference Information: Journal Name: Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States) Journal Volume: 46:6
• Country of Publication: United States
• Language: English

Related Subjects

550201* -- Biochemistry-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
AMINO ACID SEQUENCE
AMINO ACIDS
ANIMALS
BIOCHEMICAL REACTION KINETICS
CARBOXYLIC ACIDS
CHOLESTEROL
CHROMATOGRAPHY
ENZYME ACTIVITY
ENZYMES
ESTERS
HYDROXY ACIDS
HYDROXY COMPOUNDS
ISOTOPE APPLICATIONS
KINETICS
LABELLED COMPOUNDS
LECITHINS
LIPIDS
MAMMALS
MAN
MOLECULAR STRUCTURE
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC PHOSPHORUS COMPOUNDS
PEPTIDES
PHOSPHOLIPIDS
PRIMATES
PROTEINS
REACTION KINETICS
SEPARATION PROCESSES
SERINE
STEROIDS
STEROLS
TRACER TECHNIQUES
TRANSFERASES
TRITIUM COMPOUNDS
VERTEBRATES