Smith G N, Brandt K D
Rheumatology Division, Indiana University School of Medicine, Indianapolis 46223.
Coll Relat Res. 1987 Oct;7(5):315-21. doi: 10.1016/s0174-173x(87)80024-9.
Type XI collagen (1 alpha 2 alpha 3 alpha) extracted from bovine articular cartilage by pepsin digestion binds strongly to heparin immobilized on agarose. The collagens from cartilage will bind to heparin-agarose in 0.1 M NaCl/2 M urea/0.01 M Tris-HCl and can be eluted with a linear gradient of NaCl. Type XI begins to elute at NaCl concentrations higher than 0.28 M and is totally eluted at 0.40 M NaCl. The peak of elution occurs at 0.37 M NaCl. The other collagens of cartilage bind more weakly and are fully eluted when the NaCl concentration reaches 0.25 M. Collagen types I, III, and V are also bound to the column at low salt concentrations but are fully eluted before type XI begins to elute. All of the type XI preparation binds to heparin-agarose, suggesting that there is at least one binding site per molecule. Denatured 1 alpha and 2 alpha chains bind strongly, suggesting that at least one binding site exists on both of these chains. These data confirm that the interaction between polyanions and type XI collagen is stronger than that with other known collagens and provide a method for purification of type XI without any type II contamination.
通过胃蛋白酶消化从牛关节软骨中提取的XI型胶原蛋白（1α2α3α）与固定在琼脂糖上的肝素强烈结合。软骨中的胶原蛋白在0.1M NaCl/2M尿素/0.01M Tris-HCl中会与肝素-琼脂糖结合，并且可以用NaCl线性梯度洗脱。XI型胶原蛋白在NaCl浓度高于0.28M时开始洗脱，在0.40M NaCl时完全洗脱。洗脱峰出现在0.37M NaCl处。软骨中的其他胶原蛋白结合较弱，当NaCl浓度达到0.25M时完全洗脱。I型、III型和V型胶原蛋白在低盐浓度下也会与柱子结合，但在XI型开始洗脱之前就完全洗脱了。所有XI型制剂都与肝素-琼脂糖结合，这表明每个分子至少有一个结合位点。变性的1α链和2α链结合强烈，这表明这两条链上至少存在一个结合位点。这些数据证实了多阴离子与XI型胶原蛋白之间的相互作用比与其他已知胶原蛋白的相互作用更强，并提供了一种纯化XI型胶原蛋白而无任何II型污染的方法。
