Swann D A, Slayter H S, Silver F H
J Biol Chem. 1981 Jun 10;256(11):5921-5.
Lubricating glycoprotein-I (LGP-I) was prepared from bovine synovial fluid by density gradient sedimentation and gel-permeation chromatography. The LGP-I sample obtained was able to lubricate articular cartilage in a manner equivalent to that of whole synovial fluid. Chemical, physical, and electron microscope measurements were carried out to determine the structure of the LGP-I molecules. The molecular weight calculated from sedimentation equilibrium measurements was 2 X 10(5), and the solute distribution obtained indicated that LGP-I was relatively monodisperse. The s(0)20,w value was 4.84, and the intrinsic viscosity was 92 ml/g. The molecular weight and diffusion coefficient calculated from later light-scattering measurements was 2.06 x 10(5) and 1.10 x 10(-7) cm2/s, respectively. The electron microscope measurements showed that the LGP-I molecules had a number average length of 204 nm, a weight average length of 222 nm (with a standard deviation of 54 nm), and a width of 1-2 nm. These data and the kinked appearance of the molecules indicate that LGP-I is a partially extended flexible rod. The hydrodynamic measurements also indicate that LGP-I has the same structure in solution, although the apparently high s(0)20,w value, compared to other rod-like molecules, suggests that due to its flexibility LGP-I can occupy a more compact domain than would be expected based on its extended dimensions. The name of "lubricin" is suggested for this lubricating glycoprotein.
润滑糖蛋白-I（LGP-I）是通过密度梯度沉降和凝胶渗透色谱法从牛滑液中制备的。所获得的LGP-I样品能够以与全滑液相当的方式润滑关节软骨。进行了化学、物理和电子显微镜测量以确定LGP-I分子的结构。根据沉降平衡测量计算出的分子量为2×10⁵，所获得的溶质分布表明LGP-I相对单分散。s(0)20,w值为4.84，特性粘度为92 ml/g。根据动态光散射测量计算出的分子量和扩散系数分别为2.06×10⁵和1.10×10⁻⁷ cm²/s。电子显微镜测量表明，LGP-I分子的数均长度为204 nm，重均长度为222 nm（标准偏差为54 nm），宽度为1-2 nm。这些数据以及分子的扭结外观表明LGP-I是部分伸展的柔性杆。流体动力学测量还表明，LGP-I在溶液中具有相同的结构，尽管与其他棒状分子相比，其明显较高的s(0)20,w值表明，由于其柔韧性，LGP-I可以占据比基于其伸展尺寸预期的更紧凑的区域。建议将这种润滑糖蛋白命名为“润滑素”。
