Differential solvation of "core" trimannoside complexes of the Dioclea grandiflora lectin and concanavalin A detected by primary solvent isotope effects in isothermal titration microcalorimetry
Differential solvation of "core" trimannoside complexes of the Dioclea grandiflora lectin and concanavalin A detected by primary solvent isotope effects in isothermal titration microcalorimetry
复制标题
DOI：
10.1074/jbc.273.49.32826
复制
发表时间：
1998-12-04
影响因子：
4.8
通讯作者：
Brewer, CF
中科院分区：
文献类型：
--
作者：
Dam, TK;Oscarson, S;Brewer, CF
来自 Dioclea grandiflora (DGL) 的 Man/Glc 特异性种子凝集素与“核心”三甘露糖苷的脱氧类似物 3,6-二-O-(α-D-吡喃甘露糖基)-α-D-吡喃甘露糖苷的结合热力学通过等温滴定微量热法 (ITC) 测定，在本系列的第一篇论文中（Dam，T，K.，Oscarson，S.，和Brewer, C. F. (1998) J. Biol. 273, 32812-32817)。数据显示三甘露糖苷的所有三个残基上的特定羟基的结合，类似于对ConA观察到的结合(Gupta, D.、Dam, T. R.、Oscarson, S.和Brewer, C. F. (1997) J. Biol. Chem. 272, 6388-6392)，然而，在三甘露糖苷的α(1-6) Man残基的单脱氧类似物的结合热力学方面存在差异。三甘露糖苷与两种凝集素。本系列的第二篇论文（Rozwarski, D. A, Swami, B. M., Brewer, C. F., and Sacchettini, J. C. (1998) J, Biol. Chem, 273, 32818-32825）中介绍了与核心三甘露糖苷复合的 DGL 的 X 射线晶体结构，表明该复合物的整体结构与ConA-三甘露糖苷复合物。此外，三甘露糖苷在两种复合物中参与几乎相同的氢键相互作用。然而，两种凝集素结合位点的有序水分子排列存在差异。本研究提出了 ITC 测量的 DGL 和 ConA 与氧化氢 (H2O) 和氧化氘 (D2O) 中三甘露糖苷单脱氧类似物的结合。热力学结合数据中存在的溶剂同位素效应为母体三甘露糖苷复合物在与两种凝集素的 X 射线晶体结构一致的位点处的溶剂化改变提供了证据。结果表明，DGL 和 ConA 与三甘露糖苷的 α(1-6) 单脱氧类似物结合的热力学差异与母体三甘露糖苷复合物的溶剂化差异无关。
The thermodynamics of binding of the Man/Glc-specific seed lectin from Dioclea grandiflora (DGL) to deoxy analogs of the "core" trimannoside, 3,6-di-O-(alpha-D-mannopyranosyl)-alpha-D-mannopyranoside was determined by isothermal titration microcalorimetry (ITC) in the first paper of this series (Dam, T, K., Oscarson, S., and Brewer, C. F. (1998) J. Biol. Chem. 273, 32812-32817). The data showed binding of specific hydroxyl groups on all three residues of the trimannoside, similar to that observed for ConA (Gupta, D., Dam, T. R., Oscarson, S., and Brewer, C. F. (1997) J. Biol. Chem. 272, 6388-6392), However, differences exist in the thermodynamics of binding of monodeoxy analogs of the alpha(1-6) Man residue of the trimannoside to the two lectins. The x-ray crystal structure of DGL complexed to the core trimannoside, presented in the second paper in this series (Rozwarski, D. A, Swami, B. M., Brewer, C. F., and Sacchettini, J. C. (1998) J, Biol. Chem, 273, 32818-32825), showed the overall structure of the complex to be similar to that of the ConA-trimannoside complex. Furthermore, the trimannoside is involved in nearly identical hydrogen bonding interactions in both complexes. However, differences were noted in the arrangement of ordered water molecules in the binding sites of the two lectins, The present study presents ITC measurements of DGL and ConA binding to the monodeoxy analogs of the trimannoside in hydrogen oxide (H2O) and deuterium oxide (D2O). The solvent isotope effects present in the thermodynamic binding data provide evidence for altered solvation of the parent trimannoside complexes at sites consistent with the x-ray crystal structures of both lectins, The results indicate that the differences in the thermodynamics of DGL and ConA binding to alpha(1-6) monodeoxy analogs of the trimannoside do not correlate with solvation differences of the parent trimannoside complexes.