Light chain somatic mutations change thermodynamics of binding and water coordination in the HyHEL-10 family of antibodies.
Light chain somatic mutations change thermodynamics of binding and water coordination in the HyHEL-10 family of antibodies.
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DOI：
10.1016/j.molimm.2009.08.018
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发表时间：
2009-12
影响因子：
3.6
通讯作者：
Smith-Gill SJ
中科院分区：
文献类型：
--
作者：
Acchione M;Lipschultz CA;DeSantis ME;Shanmuganathan A;Li M;Wlodawer A;Tarasov S;Smith-Gill SJ
热力学和结构研究使用 ITC、带有 van’t Hoff 分析的 SPR 和 X 射线晶体学，解决了亲和力成熟 IgG 抗体 HyHEL-10 家族中 L 链体细胞突变导致的亲和力增加问题。与亲本抗体 H26L26 相比，与溶菌酶结合的 H26L10 和 H26L8 嵌合体显示出有利的 ΔGo 增加为 -1。 2 ± 0. 1 Kcal mol−1 和−1。分别为 3 ± 0. 1 Kcal mol−1。 H26L10嵌合体的亲和力增加是由于有利的焓变的净增加，与H26L26相比，熵变几乎没有差异。 H26L8嵌合体表现出有利的焓的最大增加，但也显示出不利的熵变的增加，结果是两种嵌合体的亲和力基本相等。定点 L 链突变体鉴定出共享体细胞突变 S30G 是增加溶菌酶亲和力的主要贡献者。该突变不受H链体细胞突变的影响。残基 30L 位于结合界面的外围，S30G 会增加疏水性并降低氢键结合能力和大小，但不会产生任何新的重要的抗原接触。 H10L10-HEL 复合物的新 1. 2-Å 结构显示分子间和分子内水桥模式的变化，与 H26L26-HEL 复合物相比，结合界面附近没有其他显着的结构变化。这些结果强调了研究与引入突变相关的结构和热力学的必要性，以便更好地评估和理解它们对结合的影响。此外，它提供了一个重要的例子，说明主链柔性和水桥如何有利地影响抗体-抗原相互作用的热力学。
Thermodynamic and structural studies addressed the increased affinity due to L-chain somatic mutations in the HyHEL-10 family of affinity matured IgG antibodies, using ITC, SPR with van’t Hoff analysis, and x-ray crystallography. When compared to the parental antibody H26L26, the H26L10 and H26L8 chimeras binding to lysozyme showed an increase in favorable ΔGo of −1. 2 ± 0. 1 Kcal mol−1 and −1. 3 ± 0. 1 Kcal mol−1, respectively. Increase in affinity of the H26L10 chimera was due to a net increase in favorable enthalpy change with little difference in change in entropy compared to H26L26. The H26L8 chimera exhibited the greatest increase in favorable enthalpy but also showed an increase in unfavorable entropy change, with the result being that the affinities of both chimeras were essentially equivalent. Site-directed L-chain mutants identified the shared somatic mutation S30G as the dominant contributor to increasing affinity to lysozyme. This mutation was not influenced by H-chain somatic mutations. Residue 30L is at the periphery of the binding interface and S30G effects an increase in hydrophobicity and decrease in H-bonding ability and size, but does not make any new energetically important antigen contacts. A new 1. 2-Å structure of the H10L10-HEL complex showed changes in the pattern of both inter- and intra-molecular water bridging with no other significant structural alterations near the binding interface compared to the H26L26-HEL complex. These results highlight the necessity for investigating both the structure and the thermodynamics associated with introduced mutations, in order to better assess and understand their impact on binding. Furthermore, it provides an important example of how backbone flexibility and water-bridging may favorably influence the thermodynamics of an antibody-antigen interaction.
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DOI：
10.1038/nsb930
发表时间：
2003-06-01
期刊：
NATURE STRUCTURAL BIOLOGY
影响因子：
--
作者：
Li, YL;Li, HM;Mariuzza, RA
通讯作者：
Mariuzza, RA
影响因子：
7.3
作者：
Fornabaio, M;Spyrakis, F;Kellogg, GE
通讯作者：
Kellogg, GE
影响因子：
2.7
作者：
Braden, BC;Fields, BA;Poljak, RJ
通讯作者：
Poljak, RJ
影响因子：
3
作者：
Arcangeli, Caterina;Cantale, Cristina;Rosato, Vittorio
通讯作者：
Rosato, Vittorio
影响因子：
3.6
作者：
Lavoie, TB;Mohan, S;Smith-Gill, SJ
通讯作者：
Smith-Gill, SJ