Table 1.
Vitamin K–dependent Gla proteins and their available basic characteristics
| Protein | Year of discovery | Size of final protein | Number of Gla sequences | Function |
|---|---|---|---|---|
| Factor VII (proconvertin) | 1951 | 50 kDa | 10 | Zymogen, procoagulant |
| Factor IX (Christmas factor) | 1952 | 56 kDa | 12 | Zymogen, procoagulant |
| Factor X (Stuart–Prower factor) | 1953 | 56 kDa | 11 | Zymogen, procoagulant |
| Gas6 | 1988 (murine fibroblasts) | 75 kDa (678 AAs) | 11 | Likely a growth factor |
| γ-glutamyl carboxylase | 1975 | 758 AA (94 kDa) | Integral membrane enzyme | |
| Prothrombin | 1894 | 72 kDa | 10 | Zymogen, procoagulant |
| Protein C (autoprothrombin II-a) | 1960 | 56 kDa | 9 | Zymogen, anticoagulant |
| Protein S | 1977 | 80 kDa (635 AAs) | 11 | Anticoagulant, cofactor of protein C, immune and vascular system regulation |
| Protein Z | 1977 (bovine plasma), 1984 (human plasma) | 62 kDa (360 AAs) | 13 | Anticoagulant, with PZI blocks factor Xa |
| Matrix Gla protein (MGP) | 1983 | 11 kDa | 5 | Extracellular matrix protein |
| Nephrocalcin | 1981 | 14 kDa (110 AAs) | 2–3 | Inhibitor of the formation of calcium renal stones |
| Osteocalcin (BGP, bone Gla protein) | 1977 | 5.6 kDa (49 AAs) | 3 | Carboxylated – an extracellular matrix protein, uncarboxylated – a hormone |
| Periostin (osteoblastic-specific factor 2, OSF-2) | 1993 | 90 kDa (836) | 0 up to 24b | Extracellular matrix protein influencing the growth and repair of connective tissues |
| Proline-rich Gla proteins (PRGP1, PRGP2) | 1997 | PRGP1: 23 kDa (198 AAs) | ? | Transmembrane receptors likely involved in signaling pathways |
| PRGP2: 17 KDa (153 AAs) | ||||
| Inter-alpha-trypsin inhibitor heavy chain H2 (ITIH2) | 1988 | 72 kDa (648 AAs) | 2 | Heavy chain of inter-α-trypsin inhibitor |
| Transmembrane Gla proteins 3 and 4 (TGM3, TGM4)a | 2000 | TGM3: 23.7 kDa (212 AAs) | TGM3: 15 | Transmembrane receptors |
| TGM4: 19.9 kDa (177 AAs) | TGM4: 9 | |||
| Gla-rich protein (GRP) | 2008 | 15 | Modulator of tissue calcification, anti-inflammatory activity | |
| Transthyretin in Moyamoya disease | 2008 | 27.5 kDa (dimer) | 1 | Unclear; not present in healthy patients |
a
Also known as PRGP3 and PRGP4.
b
There is a report showing that periostin is not a Gla protein, and it is suggested that it can contain up 24 Gla residues (it has 28 glutamyl amino acid residues).
Abbreviations: AAs, amino acids ; PZI, Protein Z–dependent protease inhibitor