Lascombe M B, Alzari P M, Boulot G, Saludjian P, Tougard P, Berek C, Haba S, Rosen E M, Nisonoff A, Poljak R J
Département d'Immunologie, Institut Pasteur, Paris, France.
Proc Natl Acad Sci U S A. 1989 Jan;86(2):607-11. doi: 10.1073/pnas.86.2.607.
The crystal structure of Fab R19.9, derived from an anti-p-azobenzenearsonate monoclonal antibody, has been determined and refined to 2.8-A resolution by x-ray crystallographic techniques. Monoclonal antibody R19.9 (IgG2b kappa) shares some idiotopes with a major idiotype (CRIA) associated with A/J anti-p-azobenzenearsonate antibodies. The amino acid sequences of the variable (V) parts of the heavy (VH) and light (VL) polypeptide chains of monoclonal antibody R19.9 were determined through nucleotide sequencing of their mRNAs. The VL region is very similar to that of CRIA-positive anti-p-azobenzenearsonate antibodies as is VH, except for its third complementarity-determining region, which is three amino acids longer; it makes a loop, unique to R19.9, that protrudes into the solvent. A large number of tyrosine residues in the complementarity-determining region of VH and VL, with their side chains pointing towards the solvent, may have an important function in antigen binding.
源自抗对氨基苯砷酸单克隆抗体的Fab R19.9的晶体结构已通过X射线晶体学技术确定并精修至2.8埃分辨率。单克隆抗体R19.9(IgG2b κ)与与A/J抗对氨基苯砷酸抗体相关的主要独特型(CRIA)共享一些独特位。通过对其mRNA进行核苷酸测序,确定了单克隆抗体R19.9重链(VH)和轻链(VL)多肽链可变(V)部分的氨基酸序列。VL区域与CRIA阳性抗对氨基苯砷酸抗体的VL区域非常相似,VH区域也是如此,只是其第三个互补决定区除外,该区域长三个氨基酸;它形成了一个R19.9特有的环,伸向溶剂。VH和VL互补决定区中有大量酪氨酸残基,其侧链指向溶剂,可能在抗原结合中起重要作用。