Perez H D, Kelly E, Chenoweth D, Elfman F
Rosalind Russell Arthritis Research Laboratory, University of California, San Francisco 94143.
J Clin Invest. 1988 Jul;82(1):360-3. doi: 10.1172/JCI113595.
The chemotactic activity of human C5a des Arg is enhanced significantly by an anionic polypeptide (cochemotaxin) in normal human serum and plasma. The cochemotaxin attaches to sialic acid residues within the oligosaccharide chain of native C5a des Arg to form a complex with potent chemotactic activity for human PMN. We investigated the nature of the cochemotaxin and found that vitamin D-binding protein is the putative cochemotaxin. Vitamin D-binding protein enhanced the chemotactic activity of native C5a des Arg, but had no effect on the chemotactic activity of either native C5a or FMLP. Sialic acid prevented both enhancement by vitamin D-binding protein of the chemotactic activity of native C5a des Arg and formation of C5a des Arg-vitamin D-binding protein complexes, detected by molecular sieve chromatography. Furthermore, vitamin D-binding protein and cochemotaxin exhibited identical molecular weights, isoelectric points, antigenic reactivity, and amino acid composition.
人C5a去精氨酸在正常人血清和血浆中可被一种阴离子多肽（共趋化因子）显著增强趋化活性。该共趋化因子附着于天然C5a去精氨酸寡糖链内的唾液酸残基上，形成一种对人中性粒细胞具有强大趋化活性的复合物。我们研究了共趋化因子的性质，发现维生素D结合蛋白是假定的共趋化因子。维生素D结合蛋白增强了天然C5a去精氨酸的趋化活性，但对天然C5a或FMLP的趋化活性均无影响。唾液酸可阻止维生素D结合蛋白对天然C5a去精氨酸趋化活性的增强以及C5a去精氨酸-维生素D结合蛋白复合物的形成，这可通过分子筛色谱法检测到。此外，维生素D结合蛋白和共趋化因子表现出相同的分子量、等电点、抗原反应性和氨基酸组成。
