Kolesnikov A V, Kozyr A V, Alexandrova E S, Koralewski F, Demin A V, Titov M I, Avalle B, Tramontano A, Paul S, Thomas D, Gabibov A G, Friboulet A
Shemyakin and Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, 16/10 Mikluho-Maklaya Street, Moscow 117871, Russia.
Proc Natl Acad Sci U S A. 2000 Dec 5;97(25):13526-31. doi: 10.1073/pnas.200360497.
The concept of "internal image" of antiidiotypic antibodies has provided the basis for eliciting catalytic antibodies. A monoclonal IgM 9A8 that was obtained as an antiidiotype to AE-2 mAb, a known inhibitor of acetylcholinesterase, displayed esterolytic activity. Study of recombinant Fab fragments and separate light and heavy chains of 9A8 confirmed that the antibody variable domain encodes the catalytic function, whereas neither part of the primary sequence of the Fab exhibited homology with the enzyme. The specific modification of the 9A8 variable domain by an active site-directed covalent inhibitor revealed the presence of an active site Ser residue. A three-dimensional modeling suggests the existence of a functional catalytic dyad Ser-His. Comparison of active sites of 9A8 and 17E8 esterolytic abzyme raised against transition-state analog revealed structural similarity although both antibodies were elicited by two different approaches.
抗独特型抗体的“内影像”概念为诱导催化抗体提供了基础。作为已知乙酰胆碱酯酶抑制剂AE-2单克隆抗体的抗独特型抗体获得的单克隆IgM 9A8表现出酯解活性。对重组Fab片段以及9A8的轻链和重链进行研究证实，抗体可变结构域编码催化功能，而Fab一级序列的任何部分均未显示与该酶具有同源性。活性位点定向共价抑制剂对9A8可变结构域的特异性修饰揭示了活性位点丝氨酸残基的存在。三维建模表明存在功能性催化二元组Ser-His。针对过渡态类似物产生的9A8和17E8酯解抗体酶的活性位点比较显示，尽管两种抗体是通过两种不同方法诱导产生的，但它们在结构上具有相似性。
