title: Beta-hydroxyaspartic acid in vitamin K-dependent proteins.
abstract: A method for the quantitation of beta-hydroxyaspartic acid in proteins is described. After hydrolysis in 6 M HCl, the beta-hydroxyaspartic acid released is quantitated on an automatic amino acid analyzer employing a pH 2.0 eluting buffer and postcolumn reaction with o-phthalaldehyde for detection. The sensitivity is about 0.01 nmol. Among vitamin K-dependent proteins, factor IX, factor X, protein C, and protein Z each contain about one residue of beta-hydroxyaspartic acid whereas protein S contains two or three residues. Prothrombin lacks beta-hydroxyaspartic acid as do a number of non-vitamin K-dependent proteins also analyzed.
mesh_terms: D000596:Amino Acids / Q000032:analysis; D000818:Animals; D001224:Aspartic Acid / Q000031:analogs & derivatives* / Q000032:analysis; D002417:Cattle; D003165:Complement System Proteins; D005164:Factor IX; D005170:Factor X; D006801:Humans; D006868:Hydrolysis; D008297:Male; D011506:Proteins; D011516:Prothrombin; D014812:Vitamin K / Q000494:pharmacology*
chemical_list: D000596:Amino Acids; D011506:Proteins; D014812:Vitamin K; C011274:3-hydroxyaspartic acid; D001224:Aspartic Acid; D011516:Prothrombin; D005164:Factor IX; D005170:Factor X; D003165:Complement System Proteins