Ultrastructural localization of the C-propeptide released from type II procollagen in fetal bovine growth plate cartilage
Ultrastructural localization of the C-propeptide released from type II procollagen in fetal bovine growth plate cartilage
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DOI：
10.1177/44.5.8627001
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发表时间：
1996-05-01
影响因子：
3.2
通讯作者：
Poole, AR
中科院分区：
文献类型：
--
作者：
Lee, ER;Smith, CE;Poole, AR
我们使用免疫化学和免疫电子金技术来确定之前在软骨内软骨（CPII）基质中鉴定的c -前肽是否仍然是II型前胶原分子的一部分或已经从其中释放出来，盐酸胍提取，SDS-PAGE和Western blotting技术和免疫电子定位显示，主要只检测到释放形式（以下简称释放CPII）。在包埋树脂存在或不存在的情况下，用亲和纯化抗体和免疫金或免疫过氧化物酶定位技术检测了该CPII的超微结构分布，这些方法得到了相似的结果。虽然在盐酸胍提取后，这种CPII在基质中没有大量保留，但在正常情况下，它存在于两个可识别的部位，即在非矿化基质中，它局部集中在与胶原原纤维的随机关联中，在矿化基质中，它主要集中在纤维间矿化部位。这些结果表明，从II型前胶原中释放的c -前肽与胶原原纤维结合，然后在软骨内软骨中形成矿化位点时优先与矿化位点结合，这种对矿物质的偏好的意义尚不清楚，但可能与它对羟基磷灰石的高亲和力有关。
We used immunochemical and immunoelectron gold techniques to determine whether the C-propeptide previously identified in the matrix of endochondral cartilage (CPII) was still a part of the Type II procollagen molecule or had been released from it, Guanidinium hydrochloride extraction, followed by SDS-PAGE and Western blotting techniques and immunoelectron localization, revealed that predominantly only the released form (hereafter referred to as released CPII) was detected. The ultrastructural distribution of this CPII was examined with affinity-purified antibodies and with immunogold or immunoperoxidase localization techniques in the presence or absence of embedding resins, These methods yielded similar results. Although no significant amount of this CPII was retained in the matrix after guanidinium hydrochloride extraction, it was present in two recognizable sites under normal conditions, i.e., locally concentrated in a random association with collagen fibrils in the nonmineralized matrix and mainly concentrated in interfibrillar mineralizing sites in the mineralized matrix, These results suggest that the C-propeptide that has been released from Type II procollagen associates with collagen fibrils and then preferentially associates with mineralizing sites when these form in the endochondral cartilage, The significance of this preference for mineral is not known but may have something to do with its high affinity for hydroxyapatite.