Structural studies on peanut lectin complexed with disaccharides involving different linkages: further insights into the structure and interactions of the lectin
Structural studies on peanut lectin complexed with disaccharides involving different linkages: further insights into the structure and interactions of the lectin
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DOI：
10.1107/s0907444906035712
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发表时间：
2006-11-01
影响因子：
2.2
通讯作者：
Vijayan, M.
中科院分区：
文献类型：
--
作者：
Natchiar, S. Kundhavai;Srinivas, O.;Vijayan, M.
花生凝集素与半乳糖β1-3Gal、甲基-T抗原、半乳糖β1-6GalNAc、半乳糖α1-3Gal和半乳糖α1-6Glc的络合物以及在半乳糖α1-3Galβ1-4Gal存在下生长的晶体的晶体结构已被测定。对Gal-β1-3Gal和甲基-T抗原(Galβ1-3GalNAc-α-OMe)的络合物的分析证实了这一点。对复合体中凝集素-糖相互作用的详细分析表明，当β-异构体参与连接时，凝集素-糖相互作用更广泛。正如预期的那样，当连接为1-gt；6时，第二个糖残基是不明确的。在所有以高于2.5埃的分辨率确定的结构的水化壳层中存在20多个水分子。他们中的大多数都参与了稳定结构，特别是环路。参与凝集素-糖相互作用的水分子也基本上是保守的。凝集素分子相当坚硬，似乎不受温度变化的影响。
Crystal structures of peanut lectin complexed with Gal beta 1-3Gal, methyl-T-antigen, Gal beta 1-6GalNAc, Gal alpha 1-3Gal and Gal alpha 1-6Glc and that of a crystal grown in the presence of Gal alpha 1-3 Gal beta 1-4Gal have been determined using data collected at 100 K. The use of water bridges as a strategy for generating carbohydrate specificity was previously deduced from the complexes of the lectin with lactose (Gal beta 1-4Glc) and T-antigen (Gal beta 1-3GalNAc). This has been confirmed by the analysis of the complexes with Gal beta 1-3Gal and methyl-T-antigen (Gal beta 1-3GalNAc-alpha-OMe). A detailed analysis of lectin-sugar interactions in the complexes shows that they are more extensive when the beta-anomer is involved in the linkage. As expected, the second sugar residue is ill-defined when the linkage is 1 -> 6. There are more than two dozen water molecules which occur in the hydration shells of all structures determined at resolutions better than 2.5 angstrom. Most of them are involved in stabilizing the structure, particularly loops. Water molecules involved in lectin-sugar interactions are also substantially conserved. The lectin molecule is fairly rigid and does not appear to be affected by changes in temperature.