Thermodynamics of multivalent carbohydrate-lectin cross-linking interactions: importance of entropy in the bind and jump mechanism.
Thermodynamics of multivalent carbohydrate-lectin cross-linking interactions: importance of entropy in the bind and jump mechanism.
复制标题
DOI：
10.1021/bi9002919
复制
发表时间：
2009-05-12
期刊：
影响因子：
2.9
通讯作者：
Brewer, C. Fred
中科院分区：
文献类型：
--
作者：
Dam, Tarun K.;Gerken, Thomas A.;Brewer, C. Fred
大豆凝集素（SBA）是一种四聚体GalNAc特异性凝集素，它与猪上颌下粘蛋白（一种线性糖蛋白，分子质量为~106道尔和~2300 GalNAcα1- o - ser /-Thr残基（n- psm））的高亲和力（Kd = 0.2 nM）归因于一种内部扩散机制，该机制涉及凝集素从GalNAc结合并跳跃到粘蛋白的GalNAc残基上（Dam， T. K., et al., 2007）。化学，282,28256-28263)。原始ITC数据的Hill图分析显示，负协同性增加，这与凝集素-粘蛋白交联相互作用增加和有利结合熵减少有关。然而，在交联过程中，结合SBA对其他Tn-PSM分子的亲和力远高于游离SBA对GalNAcα1-O-Ser（一价类似物）的亲和力。结合的SBA对其他Tn-PSM分子上GalNAc残基的高亲和力似乎是由于与内部扩散机制相关的良好结合熵。此外，SBA与n- psm结合的负协同性增加与发生交联时凝集素在粘蛋白上的内部扩散减少有关。这些发现表明内部扩散机制的重要性，在产生大的，有利的结合熵，驱动凝集素-粘蛋白交联相互作用。这些结果对于理解与细胞表面生物信号相关的凝集素-粘蛋白交联相互作用的能量学以及配体-生物聚合物内部扩散机制的作用具有重要意义。
The high affinity (Kd = 0.2 nM) of the soybean agglutinin (SBA), a tetrameric GalNAc specific lectin, for a modified form of porcine submaxillary mucin, a linear glycoprotein, that possessing a molecular mass of ~106 daltons and ~2300 GalNAcα1-O-Ser/-Thr residues (Tn-PSM) has been ascribed to an internal diffusion mechanism that involves binding and jumping of the lectin from GalNAc to GalNAc residue of the mucin (Dam, T. K., et al. (2007) J. Biol. Chem. 282, 28256-28263). Hill plot analysis of the raw ITC data shows increasing negative cooperativity, which correlates with increasing lectin-mucin cross-linking interactions and decreasing favorable binding entropies. However, the affinity of bound SBA for other Tn-PSM molecules during cross-linking is much higher than that of free SBA for GalNAcα1-O-Ser, a monovalent analog. The high affinity of bound SBA for GalNAc residues on other Tn-PSM molecules appears to be due to the favorable entropy of binding associated with the internal diffusion mechanism. Furthermore, the increasing negative cooperativity of SBA binding to Tn-PSM correlates with decreasing internal diffusion of the lectin on the mucin as cross-linking occurs. These findings indicate the importance of the internal diffusion mechanism in generating large, favorable entropies of binding that drive lectin-mucin cross-linking interactions. The results are important for understanding the energetics of lectin-mucin cross-linking interactions that are associated with biological signaling on the surface of cells, and the role of the internal diffusion mechanism in ligand-biopolymers in general.
登录
查看更多内容
影响因子：
2.9
作者：
Dam, TK;Roy, R;Brewer, CF
通讯作者：
Brewer, CF
影响因子：
4.8
作者：
Gerken, TA;Gilmore, M;Zhang, JX
通讯作者：
Zhang, JX
影响因子：
56.9
作者：
Partridge, EA;Le Roy, C;Dennis, JW
通讯作者：
Dennis, JW
影响因子：
4.8
作者：
Dam, TK;Roy, R;Brewer, CF
通讯作者：
Brewer, CF
DOI：
10.1084/jem.185.10.1851
发表时间：
1997-05-19
期刊：
The Journal of experimental medicine
影响因子：
--
作者：
Perillo NL;Uittenbogaart CH;Nguyen JT;Baum LG
通讯作者：
Baum LG