Open AccessAmino acid sequence of human platelet factor 4.
Author(s) -
Thomas F. Deuel,
Pamela S. Keim,
Martha Farmer,
Robert L. Heinrikson
Publication year - 1977
Publication title -
proceedings of the national academy of sciences of the united states of america
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.011
H-Index - 771
eISSN - 1091-6490
pISSN - 0027-8424
DOI - 10.1073/pnas.74.6.2256
Subject(s) - amino acid , tryptophan , peptide sequence , methionine , biochemistry , phenylalanine , amino acid residue , residue (chemistry) , polypeptide chain , chemistry , sequence (biology) , binding site , biology , stereochemistry , gene
Human platelet factor 4, a protein that binds heparin, has been purified to apparent homogeneity and the complete amino acid sequence of the protein has been determined. The 70-residue polypeptide chain contains no methionine, tryptophan, or phenylalanine, and contains only a single tyrosyl residue. The sequence analysis demonstrates a highly negatively charged amino-terminal region. The carboxyl-terminal region of the polypeptide is unusual in that it contains a repetitive clustering of positively charged and hydrophobic pairs of amino acids; preliminary evidence suggests that this domain may play a role in the binding of heparin.