TY - JOUR
T1 - Effects of detergents on the lecithin
T2 - Cholesterol acyltransferase reaction
AU - Park, Myung C.
AU - McConathy, Walter J.
AU - Lacko, Andras G.
N1 - Funding Information:
This study was supported by grants from the Robert A. Welch Foundation (B-935), The American Heart Association (82-1043), and The National Institutes of Health (AG-03255, HL-23719). The excellent secretarial assistance of Ms. Beverly Baird and Ms. Malinda Pope is gratefully acknowledged.
PY - 1984/8/15
Y1 - 1984/8/15
N2 - This paper describes the effect of an ionic (sodium dodecyl sulfate; SDS) and a nonionic detergent (Triton X-100) on the substrate and enzyme components of the lecithin: cholesterol acyltransferase (LCAT) reaction. When the enzyme sources (purified or partially purified) or the respective substrates [high-density lipoproteins (HDL) or proteoliposomes] were preincubated with detergents, a consistent trend in LCAT activity was only seen when partially purified LCAT was used as the enzyme source. This trend indicated an approximately 25% increase in enzyme activity over the control when 10-4, m SDS and 2 × 10-3 % Triton X-100 were present in the preincubation mixtures, respectively. Those observations suggested that, during the preincubations and subsequent assays, the enzyme (in the presence of detergents) was allowed to dissociate from the endogenous substrate and subsequently interact with the exogenous substrate molecules. Additional experiments utilizing molecular-sieve chromatography with whole plasma and partially purified enzyme also showed that dissociation of LCAT/lipoprotein complexes occurred in the presence of detergent. SDS was also shown to enhance the reaction of LCAT in whole plasma with anti-LCAT antibody in an enzyme-linked immunoassay system, indicating that the detergent treatment facilitated the exposure of additional antigenic sites, perhaps via dissociation of the enzyme from plasma lipoproteins.
AB - This paper describes the effect of an ionic (sodium dodecyl sulfate; SDS) and a nonionic detergent (Triton X-100) on the substrate and enzyme components of the lecithin: cholesterol acyltransferase (LCAT) reaction. When the enzyme sources (purified or partially purified) or the respective substrates [high-density lipoproteins (HDL) or proteoliposomes] were preincubated with detergents, a consistent trend in LCAT activity was only seen when partially purified LCAT was used as the enzyme source. This trend indicated an approximately 25% increase in enzyme activity over the control when 10-4, m SDS and 2 × 10-3 % Triton X-100 were present in the preincubation mixtures, respectively. Those observations suggested that, during the preincubations and subsequent assays, the enzyme (in the presence of detergents) was allowed to dissociate from the endogenous substrate and subsequently interact with the exogenous substrate molecules. Additional experiments utilizing molecular-sieve chromatography with whole plasma and partially purified enzyme also showed that dissociation of LCAT/lipoprotein complexes occurred in the presence of detergent. SDS was also shown to enhance the reaction of LCAT in whole plasma with anti-LCAT antibody in an enzyme-linked immunoassay system, indicating that the detergent treatment facilitated the exposure of additional antigenic sites, perhaps via dissociation of the enzyme from plasma lipoproteins.
UR - http://www.scopus.com/inward/record.url?scp=0021215507&partnerID=8YFLogxK
U2 - 10.1016/0003-9861(84)90628-3
DO - 10.1016/0003-9861(84)90628-3
M3 - Article
C2 - 6431910
AN - SCOPUS:0021215507
VL - 233
SP - 290
EP - 298
JO - Archives of Biochemistry and Biophysics
JF - Archives of Biochemistry and Biophysics
SN - 0003-9861
IS - 1
ER -