Celio M R, Norman A W, Heizmann C W
Calcif Tissue Int. 1984 Jan;36(1):129-30. doi: 10.1007/BF02405306.
Vit-D-Dependent calcium binding protein and parvalbumin have both been detected in ameloblasts and calcified cartilage by immunohistochemical techniques. These two Ca2+ binding proteins may play a crucial role in the local accumulation of Ca2+ ions during the process of mineralization. The mechanisms underlying the deposition of inorganic substances in bone and teeth during physiologic calcification are still the object of intense debate [1, 2]. The hypotheses concerning the factors controlling the initiation of mineralization can be subdivided into three large categories: enzymatic (or non-enzymatic) local elevation of phosphate and calcium [3,4,5,6,7], enzymatic removal of inhibitors of calcification [8] and direct nucleation of CaPO4 crystals on collagen fibrils [9]. In support of the first line of thought we report here the simultaneous occurrence of two different very high affinity Ca2+ binding proteins [vitamin-D-dependent CaBP = VD CaBP and parvalbumin = PV] in bones and teeth. During the studied age period and with immunohistochemical methods, we detected the proteins only in calcified cartilage of bones and in ameloblasts of teeth. We propose that VDCaBP and PV help increase the Ca2+ concentration at the calcification front in some regions involved in mineral deposition.
通过免疫组织化学技术已在成釉细胞和钙化软骨中检测到维生素D依赖性钙结合蛋白和小清蛋白。这两种Ca2+结合蛋白可能在矿化过程中Ca2+离子的局部积累中起关键作用。生理钙化过程中骨和牙齿中无机物质沉积的潜在机制仍是激烈争论的焦点[1,2]。关于控制矿化起始的因素的假说可分为三大类：磷酸盐和钙的酶促（或非酶促）局部升高[3,4,5,6,7]、钙化抑制剂的酶促去除[8]以及CaPO4晶体在胶原纤维上的直接成核[9]。为支持第一种思路，我们在此报告在骨骼和牙齿中同时存在两种不同的高亲和力Ca2+结合蛋白[维生素D依赖性CaBP = VD CaBP和小清蛋白 = PV]。在研究的年龄阶段，通过免疫组织化学方法，我们仅在骨骼的钙化软骨和牙齿的成釉细胞中检测到了这些蛋白。我们提出，VDCaBP和PV有助于在参与矿物质沉积的某些区域增加钙化前沿的Ca2+浓度。
