生物膜脂参与的非晶碳酸钙形成和稳定

非晶碳酸钙(amorphous calcium carbonate,ACC)是碳酸钙矿物体系中极不稳定的矿物相。但由海鞘类动物的研究表明,ACC可作为碳酸钙晶体矿物的前驱体在生物体内稳定存在,并且这些生物成因的ACC常常是由膜包裹着的。文中选用生物膜的主要成分卵磷脂(PC)为主要矿化调节剂,通过调控与碳酸钙矿化过程密切相关的无机离子Mg2+的浓度,模拟生物膜表面碳酸钙矿化作用过程。在空气/水界面处的膜脂调控下合成出可在溶液中稳定存在数天的非晶碳酸钙。该结果有力地证明了在生物矿化过程中,除了受生物体中可溶性有机大分子调控外,生物膜可能对ACC的形成和稳定也有显著的调控作用。

Formation and stabilization of amorphous calcium carbonate modified by phosphatidylcholine

Amorphous calcium carbonate(ACC)is highly unstable under the ambient conditions.However,studies on marine ascidian skeletons have revealed that ACC as a transient precursor to crystalline CaCO3 can stably exist for long time in organisms,and the stable ACC is usually membrane-embedded.In this paper,phosphatidylcholine(PC)as the main component of biomembrane was used as mineralization additives to biomimic calcium carbonate mineralization.The mineralized products were characterized by X-ray diffraction(XRD),Fourier transform infrared spectrometry(FTIR),and filed-emission scanning electron microscope(FESEM)techniques.As a result,we found that PC indeed facilitates the formation and stabilization of ACC at the air/solution interface.Therefore,our experimental results may provide a further insight into formation and stabilization of biogenic ACC.