[Effects of induced deletion of repeats in binding domain of the VLDL receptor on its ligand-binding capacity].
The ligand-binding domain of the very low-density lipoprotein receptor (VLDL-R) contains eight cysteine-rich repeat sequences that have been postulated as ligand-binding sites. This is obviously different from that of low-density lipoprotein receptor (LDL-R) that includes seven similar repeats. To make clear the contribution of these repeats to ligand-binding and to explore the reason of both receptors' ligand-binding characteristic, the VLDL-R recombinants lacking different repeat(s) were constructed by oligonucleotide-directed mutagenesis and transfected into ldl-A7 cell. Ligand-binding results showed that repeat 1 and repeat 2 were the most important in binding with apoE-rich lipoprotein(VLDL and beta-VLDL). Repeat 3 and repeat 6 also important for binding VLDL. The results also showed that VLDL-R lacking LBR7 retained partly LDL-R ligand-binding properties. It suggests that LBR7 in VLDL-R may responsible for both receptors' ligand-binding properties differences.
Liu
Zhi-Guo
ZG
Department of Biochemistry & Molecular Biology, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China. shjys@tjmu.edu.cn
Qu
Shen
S
Feng
Ning
N
Zong
Yi-Qiang
YQ
Deng
Yao-Zu
YZ
Feng
Zong-Chen
ZC
D000818:Animals; D001665:Binding Sites / Q000235:genetics; D001667:Binding, Competitive; D016466:CHO Cells; D006224:Cricetinae; D004705:Endocytosis; D008024:Ligands; D008079:Lipoproteins, VLDL / Q000378:metabolism; D008856:Microscopy, Fluorescence; D016297:Mutagenesis, Site-Directed; D011973:Receptors, LDL / Q000235:genetics* / Q000378:metabolism; D012091:Repetitive Sequences, Nucleic Acid / Q000235:genetics*; D017384:Sequence Deletion; D014162:Transfection
D008024:Ligands; D008079:Lipoproteins, VLDL; D011973:Receptors, LDL; C036053:VLDL receptor