TY - JOUR
T1 - Primary structure of apoB-100
AU - Yang, Chao yuh
AU - Gu, Zi Wei
AU - Yang, Manlan
AU - Gotto, Antonio M.
N1 - Funding Information:
We thank S. Kelly for the artwork and L. Brock for the preparation of this manuscript. This work was supported in part by the National Institutes of Health, grant HL-27341 (National Research and Demonstration Center in Atherosclerosis), and grants from the Methodist Hospital Foundation and the DeBakey Heart Center Fund.
PY - 1994/1
Y1 - 1994/1
N2 - Apolipoprotein B-100 (apoB-100) is the major protein in low-density lipoprotein (LDL) and contains the ligand for binding LDL to its cell surface receptor. Lipoprotein [a] (Lp[a]) is a lipoprotein that consists of LDL and apolipoprotein [a] (apo[a]). The primary structure of apoB-100 has been determined by a combination of recombinant DNA and protein sequencing methods. Using high-performance liquid chromatographic techniques, we have identified sulfhydryl and disulfide groups of apoB-100 from LDL. Sixteen of the 25 cysteine residues in apoB-100 exist in disulfide form. All 14 cysteine residues within the N terminal end of apoB-100 are linked in disulfide bridges. Using the fluorescent sulfhydryl probe, 5-iodoacetoamidofluoresceine, two free sulfhydryls of apoB-100 on LDL were identified at positions 3734 and 4190. Based on its differential susceptibility to trypsin, apoB-100 can be divided into five domains: domain 1 (residues 1-1000), largely trypsin-releasable (TR); domain 2 (residues 1001-1700), alternating TR and trypsin non-releasable (TN); domain 3 (residues 1701-3070), largely TN; domain 4 (residues 3071-4100), mainly TR and mixed; and domain 5 (residues 4101-4536), almost exclusively TN. Based on our data, we propose that the structure of apoB-100 in LDL is probably an elongated form that wraps around the LDL particle, and that Cys3734 of apoB-100 may be the cysteine residue linked to a cysteine of apo[a].
AB - Apolipoprotein B-100 (apoB-100) is the major protein in low-density lipoprotein (LDL) and contains the ligand for binding LDL to its cell surface receptor. Lipoprotein [a] (Lp[a]) is a lipoprotein that consists of LDL and apolipoprotein [a] (apo[a]). The primary structure of apoB-100 has been determined by a combination of recombinant DNA and protein sequencing methods. Using high-performance liquid chromatographic techniques, we have identified sulfhydryl and disulfide groups of apoB-100 from LDL. Sixteen of the 25 cysteine residues in apoB-100 exist in disulfide form. All 14 cysteine residues within the N terminal end of apoB-100 are linked in disulfide bridges. Using the fluorescent sulfhydryl probe, 5-iodoacetoamidofluoresceine, two free sulfhydryls of apoB-100 on LDL were identified at positions 3734 and 4190. Based on its differential susceptibility to trypsin, apoB-100 can be divided into five domains: domain 1 (residues 1-1000), largely trypsin-releasable (TR); domain 2 (residues 1001-1700), alternating TR and trypsin non-releasable (TN); domain 3 (residues 1701-3070), largely TN; domain 4 (residues 3071-4100), mainly TR and mixed; and domain 5 (residues 4101-4536), almost exclusively TN. Based on our data, we propose that the structure of apoB-100 in LDL is probably an elongated form that wraps around the LDL particle, and that Cys3734 of apoB-100 may be the cysteine residue linked to a cysteine of apo[a].
KW - ApoB-100 primary structure
KW - Disulfide linkage of Lp[a]
KW - Free sulfhydryl of apoB on LDL
KW - Sulfhydryl and disulfide groups of apoB-100
UR - http://www.scopus.com/inward/record.url?scp=0028097721&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0028097721&partnerID=8YFLogxK
U2 - 10.1016/0009-3084(94)90128-7
DO - 10.1016/0009-3084(94)90128-7
M3 - Article
C2 - 8187250
AN - SCOPUS:0028097721
SN - 0009-3084
VL - 67-68
SP - 99
EP - 104
JO - Chemistry and Physics of Lipids
JF - Chemistry and Physics of Lipids
IS - C
ER -