Azizkhan J C, Khagsbrun M
Proc Natl Acad Sci U S A. 1980 May;77(5):2762-6. doi: 10.1073/pnas.77.5.2762.
Bovine scapular and articular chondrocytes were isolated from fresh cartilage and disrupted by sonication. The disrupted cells had the ability to stimulate DNA synthesis and cell division in vitro in chondrocytes and in 3T3 cells. Subcellular fractions were prepared by two methods, enucleation with cytochalasin B and lysis of cells with Nonidet P-40. After enucleation of chondrocytes, karyoplasts and cytoplasts were collected, disrupted by sonication, and tested for their ability to stimulate DNA synthesis. Over 95% of the cellular growth factor activity was localized in the karyoplast. In addition, after lysis of chondrocytes in Nonidet P-40, over 95% of the growth factor activity was recovered in the nuclear fraction. Chondrocyte chromatin was prepared by low ionic strength detergent treatment of karyoplasts. All of the growth factor activity of the karyoplast was found to be associated with chromatin. The growth factor activity of chondrocytes, cytoplasts, karyoplasts, and chromatin was analyzed by gel filtration on Bio-Gel A-0.5 m equilibrated with 4 M guanidine . HCl and 5 mM dithiothreitol. Chondrocytes, chondrocyte karyoplasts, and chondrocyte chromatin had similar column elution profiles, with molecular weights in the range of 12,000-22,000.
牛肩胛关节软骨细胞从新鲜软骨中分离出来，通过超声破碎。破碎的细胞能够在体外刺激软骨细胞和3T3细胞的DNA合成和细胞分裂。通过两种方法制备亚细胞组分，即使用细胞松弛素B去核和用Nonidet P-40裂解细胞。软骨细胞去核后，收集核体和胞质体，超声破碎，并检测它们刺激DNA合成的能力。超过95%的细胞生长因子活性定位于核体中。此外，用Nonidet P-40裂解软骨细胞后，超过95%的生长因子活性在核组分中回收。通过用低离子强度去污剂处理核体制备软骨细胞染色质。发现核体的所有生长因子活性都与染色质相关。通过在以4 M盐酸胍和5 mM二硫苏糖醇平衡的Bio-Gel A-0.5 m上进行凝胶过滤，分析软骨细胞、胞质体、核体和染色质的生长因子活性。软骨细胞、软骨细胞核体和软骨细胞染色质具有相似的柱洗脱图谱，分子量在12,000 - 22,000范围内。
