title: Proton, calcium, and magnesium binding by peptides containing gamma-carboxyglutamic acid.
abstract: gamma-Carboxyglutamic acid (Gla) is believed to bind Ca [II] ions and Mg [II] ions in prothrombin and other coagulation proteins. Binding constants for H+, Ca [II] ions, and Mg [II] ions to Gla-containing peptides are determined using pH and ion selective electrode titrations. The binding constants for peptides containing a single Gla residue are similar to the constants for malonic acid. Peptides containing two Gla residues in sequence (di-Gla peptides) bind Ca [II] ions and Mg [II] ions more strongly. KMgL for the di-Gla peptides is similar to the site-binding constant for Ca [II] ions in denatured BF1. These di-Gla peptides may be useful analogs for metal binding by the disordered Gla domain in BF1.
authors.affiliation: Department of Chemistry, University of North Carolina, Chapel Hill.
authors.forename: S E
authors.initials: SE
authors.lastname: Cabaniss
authors.forename: K C
authors.initials: KC
authors.lastname: Pugh
authors.forename: L G
authors.initials: LG
authors.lastname: Pedersen
authors.forename: R G
authors.initials: RG
authors.lastname: Hiskey
mesh_terms: D015055:1-Carboxyglutamic Acid / Q000378:metabolism*; D001665:Binding Sites; D002118:Calcium / Q000378:metabolism*; D007700:Kinetics; D008274:Magnesium / Q000378:metabolism*; D008314:Malonates / Q000378:metabolism; D008956:Models, Chemical; D015394:Molecular Structure; D009994:Osmolar Concentration; D010455:Peptides / Q000138:chemical synthesis / Q000378:metabolism*; D011485:Protein Binding; D011522:Protons
chemical_list: D008314:Malonates; D010455:Peptides; D011522:Protons; D015055:1-Carboxyglutamic Acid; C030290:malonic acid; D008274:Magnesium; D002118:Calcium