TY - JOUR
T1 - A study of the cystine-containing apolipoprotein of human plasma high density lipoproteins
T2 - Characterization of cyanogen bromide and tryptic fragments
AU - Jackson, Richard L.
AU - Gotto, Antonio M.
PY - 1972/11/28
Y1 - 1972/11/28
N2 - A major protein (or apolipoprotein) constituent has been isolated from human plasma high density lipoproteins and shown to contain two monomeric units covalently linked by a single disulfide bond. The protein is designated apoLP-Gln-II, based on its carboxyl-terminal amino acid. It contains no histidine, arginine or tryptophan and is also devoid of carbohydrate. Amino acid analysis of reduced-aminoethylated apoLP-Gln-II indicates 77 residues and a single methionine per monomeric unit. Two unique cyanogen bromide fragments, CNBr III and IV, have been isolated from the reduced-aminoethylated protein and account for all of the 77 amino acids of the monomer. CNBr IV has 26 residues, a blocked amino-terminus, no isoleucine, one residue of aminoethylcysteine, carboxyl-terminal homoserine and corresponds therefore to the amino-terminal and cystine-containing portion of apoLP-Gln-II. CNBr III has 51 amino acids, including one residue of isoleucine, has carboxyl-terminal glutamine, has no aminoethylcysteine and corresponds to the carboxyl-terminus of apoLP-glutamine-II. CNBr III and IV have each been digested with trypsin and the resulting peptides isolated by a combination of gel filtration and ion-exchange chromatography. Twelve tryptic fragments accounted for the 77 amino acids present in apoLP-Gln-II. This finding and the tryptic fingerprint analysis of reduced aminoethylated apoLP-Gln-II indicate that apoLP-Gln-II must contain two identical or very nearly identical subunits.
AB - A major protein (or apolipoprotein) constituent has been isolated from human plasma high density lipoproteins and shown to contain two monomeric units covalently linked by a single disulfide bond. The protein is designated apoLP-Gln-II, based on its carboxyl-terminal amino acid. It contains no histidine, arginine or tryptophan and is also devoid of carbohydrate. Amino acid analysis of reduced-aminoethylated apoLP-Gln-II indicates 77 residues and a single methionine per monomeric unit. Two unique cyanogen bromide fragments, CNBr III and IV, have been isolated from the reduced-aminoethylated protein and account for all of the 77 amino acids of the monomer. CNBr IV has 26 residues, a blocked amino-terminus, no isoleucine, one residue of aminoethylcysteine, carboxyl-terminal homoserine and corresponds therefore to the amino-terminal and cystine-containing portion of apoLP-Gln-II. CNBr III has 51 amino acids, including one residue of isoleucine, has carboxyl-terminal glutamine, has no aminoethylcysteine and corresponds to the carboxyl-terminus of apoLP-glutamine-II. CNBr III and IV have each been digested with trypsin and the resulting peptides isolated by a combination of gel filtration and ion-exchange chromatography. Twelve tryptic fragments accounted for the 77 amino acids present in apoLP-Gln-II. This finding and the tryptic fingerprint analysis of reduced aminoethylated apoLP-Gln-II indicate that apoLP-Gln-II must contain two identical or very nearly identical subunits.
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U2 - 10.1016/0005-2795(72)90178-X
DO - 10.1016/0005-2795(72)90178-X
M3 - Article
C2 - 4347238
AN - SCOPUS:0015527734
VL - 285
SP - 36
EP - 47
JO - BBA - Protein Structure
JF - BBA - Protein Structure
SN - 0005-2795
IS - 1
ER -