Ko L, Ma G X, Gao H L
National Laboratory of Biomacromolecules, Institute of Biophysics, Beijing, People's Republic of China.
Clin Orthop Relat Res. 1990 Jul(256):229-37.
Implantation of porcine bone morphogenetic protein (pBMP) in the muscle induces differentiation of mesenchymal-type cells and results in endochondral bone formation. pBMP was isolated from porcine demineralized bone matrix and purified by hydroxyapatite chromatography, Sephadex G75 gel filtration, preparative sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), preparative isoelectric focusing (IEF), and chromatofocusing fast protein liquid chromatography (FPLC). Porcine BMP has an MW of 26 K and a range of pI from 4.65 to 4.73 determined by SDS-PAGE and IEF, respectively. Reconstitution with the citrate buffer supernatant fraction enables as little as 50 micrograms of the soluble pBMP fractions to induce osteogenesis in an in vivo assay. Chemical modification studies indicate that the osteoinductive potential of the pBMP molecule depends on tyrosine, carboxyl groups, and disulfide bonds and can be increased by modification of sulfhydryl groups. Modification of arginine and tryptophan has no effect on bioactivity. By pepsin-limited proteolysis, fragments of pBMP with an MW of 6-14 K show definite, although reduced, BMP activity.
将猪骨形态发生蛋白（pBMP）植入肌肉中可诱导间充质型细胞分化并导致软骨内成骨。pBMP是从猪脱矿骨基质中分离出来的，并通过羟基磷灰石色谱法、Sephadex G75凝胶过滤法、制备性十二烷基硫酸钠聚丙烯酰胺凝胶电泳（SDS-PAGE）、制备性等电聚焦（IEF）和色谱聚焦快速蛋白质液相色谱（FPLC）进行纯化。通过SDS-PAGE和IEF分别测定，猪BMP的分子量为26 K，pI范围为4.65至4.73。用柠檬酸盐缓冲液上清液组分重构后，低至50微克的可溶性pBMP组分就能在体内试验中诱导成骨。化学修饰研究表明，pBMP分子的骨诱导潜力取决于酪氨酸、羧基和二硫键，并且可以通过巯基修饰来提高。精氨酸和色氨酸的修饰对生物活性没有影响。通过胃蛋白酶有限水解，分子量为6-14 K的pBMP片段显示出确定的（尽管有所降低）BMP活性。
