TY - JOUR
T1 - The binding of acetic anhydride- and citraconic anhydride-modified human low-density lipoprotein to mouse peritoneal macrophages The evidence for separate binding sites
AU - Valente, Anthony J.
AU - Walton, K. W.
N1 - Funding Information:
The authors would like to thank Mr. D. Patton for his excellent technical assistance and Miss. P. Cole for typing the manuscript. This work was supported by a grant (No. G80091705A) from the Medical Research Council.
Copyright:
Copyright 2014 Elsevier B.V., All rights reserved.
PY - 1984/1/17
Y1 - 1984/1/17
N2 - Human plasma low-density lipoprotein (LDL) was modified chemically with either the monocarboxylic acid derivative, acetic anhydride, or the dicarboxylic acid derivative, citraconic anhydride, reagents which react principally with the lysine residues of protein. The modifications increased the net negative charge on the LDL particles, with citraconyl-LDL displaying a greater negative charge than acetylated LDL. Neither the antigenic reactivity nor the overall gross protein/lipid composition of the LDL were affected by the modification procedures, although a small reduction in the total cholesterol content was observed. The altered LDL species lost the ability to bind to the high-affinity cell surface B/E receptor but both bound to mouse peritoneal macrophages with saturable high-affinity kinetics. At 4°C, the macrophages bound 125I-labelled citraconyl-LDL more avidly (K = 21 · 10-3 ml/ng) than they bound labelled acetyl-LDL(K = 2 · 10-3 ml/ng). Competitive inhibition studies indicated that acetyl-LDL and citraconyl-LDL were bound to non-identical sites on the macrophage monolayer surface and that the binding site for citraconyl-LDL was also different from that recognized by hypercholesterolaemic rabbit plasma VLDL (βVLDL).
AB - Human plasma low-density lipoprotein (LDL) was modified chemically with either the monocarboxylic acid derivative, acetic anhydride, or the dicarboxylic acid derivative, citraconic anhydride, reagents which react principally with the lysine residues of protein. The modifications increased the net negative charge on the LDL particles, with citraconyl-LDL displaying a greater negative charge than acetylated LDL. Neither the antigenic reactivity nor the overall gross protein/lipid composition of the LDL were affected by the modification procedures, although a small reduction in the total cholesterol content was observed. The altered LDL species lost the ability to bind to the high-affinity cell surface B/E receptor but both bound to mouse peritoneal macrophages with saturable high-affinity kinetics. At 4°C, the macrophages bound 125I-labelled citraconyl-LDL more avidly (K = 21 · 10-3 ml/ng) than they bound labelled acetyl-LDL(K = 2 · 10-3 ml/ng). Competitive inhibition studies indicated that acetyl-LDL and citraconyl-LDL were bound to non-identical sites on the macrophage monolayer surface and that the binding site for citraconyl-LDL was also different from that recognized by hypercholesterolaemic rabbit plasma VLDL (βVLDL).
KW - (Mouse macrophage)
KW - Chemical modification
KW - LDL
KW - Lipoprotein binding
UR - http://www.scopus.com/inward/record.url?scp=0021365172&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0021365172&partnerID=8YFLogxK
U2 - 10.1016/0005-2760(84)90277-7
DO - 10.1016/0005-2760(84)90277-7
M3 - Article
C2 - 6229285
AN - SCOPUS:0021365172
VL - 792
SP - 16
EP - 24
JO - BBA - Specialised Section On Lipids and Related Subjects
JF - BBA - Specialised Section On Lipids and Related Subjects
SN - 1388-1981
IS - 1
ER -