Lee Y M, Leiby K R, Allar J, Paris K, Lerch B, Okarma T B
Applied Immune Sciences, Inc., Menlo Park, California 94025-1109.
J Biol Chem. 1991 Feb 15;266(5):2715-23.
We report the complete amino acid sequence of bovine conglutinin obtained by structural characterization of peptides derived from the protein by various chemical and enzymatic fragmentation methods. The protein consists of 351 amino acid residues including 55 apparent Gly-X-Y repeats with two interruptions. This 171-residue-long collagenous domain separates a short noncollagenous NH2-terminal region of 25 residues from the 155-residue-long globular COOH terminus revealing the structural relation of conglutinin with mannose-binding proteins, pulmonary surfactant-associated proteins, and a complement component C1q. Eight hydroxylysine residues were found in the collagenous domain. All of these hydroxylysine residues which occupy a Y position in a Gly-X-Y triplet are possible glycosylation sites since no phenylthiohydantoin amino acid was identified in automated Edman degradation cycles corresponding to these sites. The noncollagenous COOH domain of conglutinin, on the other hand, contains a carbohydrate recognition domain which shares substantial sequence homology with C-type animal lectins. Conglutinin has the greatest sequence similarity with mannose-binding proteins and pulmonary surfactant-associated proteins.
我们报道了通过各种化学和酶促片段化方法对牛胶原凝集素衍生肽进行结构表征而获得的完整氨基酸序列。该蛋白质由351个氨基酸残基组成，包括55个明显的Gly-X-Y重复序列，其中有两处中断。这个171个残基长的胶原结构域将一个25个残基的短非胶原NH2末端区域与155个残基长的球状COOH末端分隔开来，揭示了胶原凝集素与甘露糖结合蛋白、肺表面活性物质相关蛋白以及补体成分C1q的结构关系。在胶原结构域中发现了8个羟赖氨酸残基。所有这些在Gly-X-Y三联体中占据Y位置的羟赖氨酸残基都是可能的糖基化位点，因为在与这些位点对应的自动Edman降解循环中未鉴定出苯硫代乙内酰脲氨基酸。另一方面，胶原凝集素的非胶原COOH结构域包含一个碳水化合物识别结构域，它与C型动物凝集素具有大量的序列同源性。胶原凝集素与甘露糖结合蛋白和肺表面活性物质相关蛋白具有最大的序列相似性。
