King K
Biochim Biophys Acta. 1978 Sep 6;542(3):542-6. doi: 10.1016/0304-4165(78)90384-7.
gamma-Carboxyglutamic acid, previously identified in the vertebrate mineralized tissues of bone and dentin, is not detectable in the calcified skeletons of six invertebrate species representing five phyla. Its absence in all analyzed invertebrate tissues (including calcitic, aragonitic, and apatitic mineral phases) indicates that matrix protein-bound gamma-carboxyglutamic acid is not obligatory for the calcification process in the invertebrates. Further, these data raise the possibility that invertebrates as a group may lack the enzymatic capability for biosynthesizing gamma-carboxyglutamic acid. In contrast, the distribution of gamma-carboxyglutamic acid in the vertebrates has been further extended by this study to include an apatitic shark tooth and an aragonitic fish otolith. No gamma-carboxyglutamic acid was detected, however, in the organic matrix of the calcitic hen egg shell.
γ-羧基谷氨酸先前已在脊椎动物的骨和牙本质矿化组织中被鉴定出来，但在代表五个门的六种无脊椎动物的钙化骨骼中却检测不到。在所有分析的无脊椎动物组织（包括方解石、文石和磷灰石矿相）中均未发现它，这表明与基质蛋白结合的γ-羧基谷氨酸对于无脊椎动物的钙化过程并非必不可少。此外，这些数据增加了这样一种可能性，即作为一个群体的无脊椎动物可能缺乏生物合成γ-羧基谷氨酸的酶能力。相比之下，本研究进一步扩展了γ-羧基谷氨酸在脊椎动物中的分布范围，包括一颗磷灰石鲨鱼牙齿和一块文石鱼耳石。然而，在方解石母鸡蛋壳的有机基质中未检测到γ-羧基谷氨酸。
