Desmyter A, Transue T R, Ghahroudi M A, Thi M H, Poortmans F, Hamers R, Muyldermans S, Wyns L
Department Ultrastructure, Vlaams Interuniversitair Instituut voor Biotechnologie, Vrije Universiteit, Brussel, Sint Genesius Rode, Belgium.
Nat Struct Biol. 1996 Sep;3(9):803-11. doi: 10.1038/nsb0996-803.
The Camelidae is the only taxonomic family known to possess functional heavy-chain antibodies, lacking light chains. We report here the 2.5 A resolution crystal structure of a camel VH in complex with its antigen, lysozyme. Compared to human and mouse VH domains, there are no major backbone rearrangements in the VH framework. However, the architecture of the region of VH that interacts with a VL in a conventional FV is different from any previously seen. Moreover, the CDR1 region, although in sequence homologous to human CDR1, deviates fundamentally from the canonical structure. Additionally, one half of the CDR3 contacts the VH region which in conventional immunoglobulins interacts with a VL whereas the other half protrudes from the antigen binding site and penetrates deeply into the active site of lysozyme.
骆驼科是已知唯一拥有功能性重链抗体且缺乏轻链的分类科。我们在此报告骆驼重链可变区（VH）与其抗原溶菌酶复合物的2.5埃分辨率晶体结构。与人和小鼠的VH结构域相比，VH框架中没有主要的主链重排。然而，在传统的Fv中与轻链可变区（VL）相互作用的VH区域的结构与以前见过的任何结构都不同。此外，互补决定区1（CDR1）区域虽然在序列上与人的CDR1同源，但在结构上与典型结构有根本偏差。此外，CDR3的一半与VH区域接触，而在传统免疫球蛋白中该区域与VL相互作用，而另一半则从抗原结合位点突出并深入溶菌酶的活性位点。
