Identification and synthesis of a novel 15 kDa beta-galactoside-binding lectin in human leukocytes.
Identification and synthesis of a novel 15 kDa beta-galactoside-binding lectin in human leukocytes.
复制标题
人类白细胞中新型 15 kDa β-半乳糖苷结合凝集素的鉴定和合成。
DOI：
10.1093/glycob/2.4.285
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发表时间：
1992
期刊：
影响因子：
4.3
通讯作者：
Allen,HJ
中科院分区：
文献类型：
--
作者：
Sharma,A;DiCioccio,RA;Allen,HJ
白细胞对β-半乳糖苷结合凝集素的识别、合成和分泌的了解非常重要，因为存在于白细胞表面的乳糖胺聚糖可能是生理上重要的凝集素受体，可介导自分泌或旁分泌功能和/或细胞粘附。本文提供的数据表明，以前确定的15.5-16.5 kDa乳糖结合蛋白体外合成的人外周血白细胞实际上是由三种不同的多肽。其中之一与一种新的15 kDa凝集素有关，该凝集素从人脾中分离并由B淋巴母细胞合成。脾脏含有至少六种乳糖结合多肽，其碳水化合物结合活性不依赖于二价阳离子和巯基乙醇的存在。脾15 kDa多肽似乎与先前表征的β-半乳糖苷结合凝集素没有免疫学相关性。它与半乳糖苷结合凝集素（半乳糖苷结合凝集素）（亚基mol. wt 14.5kDa）。用代谢标记的细胞进行的Western印迹分析和免疫沉淀/荧光实验表明，在外周血白细胞和EB病毒永生化的B类淋巴母细胞中存在15 kDa凝集素。15 kDa凝集素经溴化氰（CNBr）降解后产生约6.2和约8.6 kDa的多肽片段。对这些片段进行部分测序，鉴定出12个残基/片段。对SWISS PROT蛋白数据库的相似性搜索没有揭示15 kDa多肽与已知凝集素（包括半乳糖凝集素）的关系。除了15 kDa凝集素外，外周白细胞还合成29 kDa凝集素和另外两种16和18 kDa的低分子量β-半乳糖苷结合凝集素，它们在免疫学上不同于15 kDa凝集素和半乳糖苷。发现这些凝集素的合成在外周白细胞和B淋巴母细胞中受到调节。
Knowledge of the identity, synthesis and secretion of β-galactoside-binding lectins by leukocytes is of importance because lactosaminoglycans present at the leukocyte cell surface may be physiologically significant lectin receptors that could mediate autocrine or paracrine functions and/or cell adhesion. This paper presents data that show that a previously identified 15.5–16.5 kDa lactose-binding protein synthesizedin vitroby human peripheral leukocytes is actually comprised of three different polypeptides. One of these is related to a novel 15 kDa lectin isolated from human spleen and which is synthesized by B lymphoblastold cells. Spleen contains at least six lactose-binding polypeptides for which the carbohydrate-binding activity is independent of the presence of divalent cations and mercaptoethanol. The splenic 15 kDa polypeptide does not appear to be immunologically related to previously characterized β-galactoside-binding lectins. It is separable from galaptin, another galactoside-binding lectin (subunit mol. wt 14.5 kDa) by chromatography on DEAE-Sephacel. Western blot analyses and immunoprecipitation/fluorography experiments with metabolically labelled cells showed the presence of the 15 kDa lectin in peripheral leukocytes and in Epstein-Barr virus-immortalized B lymphoblastoid cells. The 15 kDa lectin yielded polypeptide fragments of ˜6.2 and ˜8.6 kDa after cyanogen bromide (CNBr) degradation. These fragments were partially sequenced and 12 residues/fragment were identified. A similarity search of the SWISS PROT protein data base did not reveal a relationship of the 15 kDa polypeptide to known lectins, including galaptin. In addition to the 15 kDa lectin, peripheral leukocytes synthesize a 29 kDa lectin and two other low molecular weight β-galactoside-binding lectins of 16 and 18 kDa that are immunologically distinct from the 15 kDa lectin and galaptin. The synthesis of these lectins was found to be modulated in peripheral leukocytes and B lymphoblastoid cells.