Dicoumarol-induced 9-γ-carboxyglutamic acid prothrombin: isolation and comparison with the 6-, 7-, 8-, and l0-γ-carboxyglutamic acid isomers
| Autor: | Om P. Malhotra |
|---|---|
| Rok vydání: | 1990 |
| Předmět: |
Quenching (fluorescence)
Chromatography Chemistry Isoelectric focusing Stereochemistry Metal ions in aqueous solution nutritional and metabolic diseases Radioimmunoassay Cell Biology Dicoumarol Biochemistry Residue (chemistry) Protein structure medicine Structural isomer lipids (amino acids peptides and proteins) cardiovascular diseases Molecular Biology hormones hormone substitutes and hormone antagonists medicine.drug |
| Zdroj: | Biochemistry and Cell Biology. 68:705-715 |
| ISSN: | 1208-6002 0829-8211 |
| DOI: | 10.1139/o90-102 |
| Popis: | The role of γ-carboxyglutamic acid (Gla) in prothrombin function can be effectively evaluated by characterizing dicoumarol-induced, Gla-deficient prothrombin structural isomers. In addition to the isolation of 8-, 7-, 6-, 5-, 3-, 2-, 1-, and 0-Gla isomers, we have now purified a variant prothrombin containing 9(8.80) Gla residues by barium citrate adsorption, elution, and finally by DEAE-cellulose and immunoaffinity chromatographies. Agar gel electrophoretic mobilities of the 9-Gla isomer and its fragment 1 were slower than those of the respective 10-Gla (normal) prothrombin and fragment 1, both in the absence and presence of Ca(II). In the presence of Ca(II), both 9- and 10-Gla fragments 1 moved slower than 8- and 7-Gla fragments 1. However, in the absence of metal ions, 9- and 7-Gla fragments 1 migrated at the same rate, but slower than 10- and 8-Gla fragments. Similarly, the 9-Gla fragment 1 electro focused cathodically to 10- and 8-Gla, but comparably with 7-Gla fragment 1. The 9-Gla fragment 1 exhibited a Ca(II)-induced 44% decrease in the intrinsic fluorescence, compared with a 40% decrease in that of 10-Gla; 8-Gla fragment 1 revealed only 23% quenching. Ca(II)-dependent anti-normal prothrombin antibodies are not specific for 10-Gla prothrombin, since only a twofold molar excess of the 9-Gla isomer was required to displace equal amounts of labeled normal prothrombin. The most critical Gla residue for influencing the functional, thrombin-generating properties of prothrombin appears to be the one present in the 9-Gla isomer but absent in the 8-Gla variant, since 9-Gla prothrombin possesses four times the normal coagulant activity (78 versus 20%) of the 8-Gla isomer.Key words: prothrombin, blood clotting, dicoumarol, Warfarin, γ-carboxyglutamic acid, vitamin K deficiency. |
| Databáze: | OpenAIRE |
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