Boskey A L, Dick B L
Hospital for Special Surgery, New York, NY 10021.
Calcif Tissue Int. 1991 Sep;49(3):193-6. doi: 10.1007/BF02556117.
The acidic phospholipid phosphatidylserine (PS) has been reported to have variable effects on in vitro hydroxyapatite proliferation. PS promotes in vitro mineralization in systems in which calcium-PS-phosphate complexes are allowed to form, and inhibits in vitro mineralization when incorporated into liposomes. To investigate these diverse effects, a Langmuir adsorption isotherm was used to determine the affinity of PS for hydroxyapatite crystals, based on binding of 14C-PS to synthetic hydroxyapatite crystals of specific surface 54 m2/g. Using this model, PS was found to bind to hydroxyapatite crystals with an affinity comparable to that of the amino acid phosphoserine (K = 3.33 ml/mumol). Coating the surface of hydroxyapatite seed crystals with PS reduced their rate of proliferation in a metastable calcium phosphate solution in which calcium-PS-phosphate complexes were previously shown to promote hydroxyapatite formation. The extent of inhibition of hydroxyapatite seeded growth was directly related to the proportion of the hydroxyapatite surface covered with PS. These data suggest that PS may have multiple effects on hydroxyapatite formation in situ, and that mineral-PS interactions can retard crystal proliferation.
据报道，酸性磷脂磷脂酰丝氨酸（PS）对体外羟基磷灰石的增殖有不同影响。在允许形成钙 - PS - 磷酸复合物的体系中，PS促进体外矿化，而当掺入脂质体时则抑制体外矿化。为了研究这些不同的影响，基于14C - PS与比表面积为54 m2/g的合成羟基磷灰石晶体的结合，使用朗缪尔吸附等温线来确定PS对羟基磷灰石晶体的亲和力。使用该模型发现，PS与羟基磷灰石晶体的结合亲和力与氨基酸磷酸丝氨酸相当（K = 3.33 ml/μmol）。用PS包覆羟基磷灰石籽晶表面会降低其在亚稳磷酸钙溶液中的增殖速率，在该溶液中先前已表明钙 - PS - 磷酸复合物可促进羟基磷灰石形成。羟基磷灰石籽晶生长的抑制程度与被PS覆盖的羟基磷灰石表面比例直接相关。这些数据表明，PS可能对原位羟基磷灰石形成有多种影响，并且矿物 - PS相互作用可阻碍晶体增殖。
