ISOLATION AND CHARACTERIZATION OF A MANNAN-BINDING PROTEIN FROM HUMAN-SERUM
ISOLATION AND CHARACTERIZATION OF A MANNAN-BINDING PROTEIN FROM HUMAN-SERUM
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DOI：
10.1093/oxfordjournals.jbchem.a134437
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发表时间：
1983-01-01
影响因子：
2.7
通讯作者：
YAMASHINA, I
中科院分区：
文献类型：
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作者：
KAWASAKI, N;KAWASAKI, T;YAMASHINA, I
采用Sepahrose 4b -甘露聚糖亲和层析技术，从人血清中分离出甘露糖和n -乙酰氨基葡萄糖胺特异性凝集素。凝集素又称甘露聚糖结合蛋白，是一种富含甘氨酸的蛋白，其分子大小为。apprx。60万道尔顿，其亚基结构由单一组分组成，表观MW为31,000。分离的凝集素与125i标记的甘露聚糖的结合取决于Ca2+的存在，与添加的蛋白质成比例，并且是可逆和饱和的过程。结合数据的Scatchard图分析表明存在Kd为2.3倍的结合位点。10-9 M，最大容量为4.3 pmol /.mu。G蛋白质（2.6 mol甘露聚糖/mol蛋白质）。甘露聚糖结合蛋白不同于c反应蛋白（CRP）和淀粉样蛋白p成分（SAP），两者都是已知在Ca2+存在下结合多糖的血清成分。对甘露聚糖不需要Ca2+的明显结合活性归因于IgG。
A serum lectin specific for mannose and N-acetylglucosamine residues was isolated from human serum to near homogeneity mainly by affinity chromatography on a column of Sepahrose 4B-mannan. The lectin, called mannan-binding protein, was a glycine-rich protein with an apparent molecular size of .apprx. 600,000 daltons, and had a subunit structure consisting of a single component with an apparent MW of 31,000. Binding of the isolated lectin to 125I-labeled mannan was dependent upon the presence of Ca2+, proportional to the protein added, and a reversible and saturable process. Scatchard plot analysis of binding data indicated the presence of a binding site with a Kd of 2.3 .times. 10-9 M and a maximum capacity of 4.3 pmol of 125I-labeled mannan/.mu.g of protein (2.6 mol of mannan/mol of the protein). The mannan-binding protein is different from C-reactive protein (CRP) and amyloid P-component (SAP), both of which are serum components known to bind polysaccharides in the presence of Ca2+. A distinct binding activity toward mannan which did not require Ca2+ was attributed to IgG.