Affinity maturation of Cry1Aa toxin to the Bombyx mori cadherin‐like receptor by directed evolution based on phage display and biopanning selections of domain II loop 2 mutant toxins

MicrobiologyOpen

Haruka Endo¹  Yuki Kobayashi¹  Yasushi Hoshino¹  Shiho Tanaka¹  Shingo Kikuta¹  Hiroko Tabunoki² 

[1] Graduate School of Bio-Applications and Systems Engineering, Tokyo University of Agriculture and Technology, Koganei, Tokyo, Japan;Department of Biological Production, Faculty of Agriculture, Tokyo University of Agriculture and Technology, Fuchu, Tokyo, Japan

关键词: Biopanning;    cadherin‐like receptor;    Cry toxin;    directed evolution;    phage display;   

DOI  :  10.1002/mbo3.188

来源: Wiley

【 摘 要 】

Abstract

Directed evolution of a Cry1Aa toxin using phage display and biopanning was performed to generate an increased binding affinity to the Bombyx mori cadherin-like receptor (BtR175). Three mutant toxins (₃₇₁WGLA₃₇₄, ₃₇₁WPHH₃₇₄, ₃₇₁WRPQ₃₇₄25) with 16-, 16-, and 50-fold higher binding affinities, respectively, for BtR175 were selected from a phage library containing toxins with mutations in domain II loop 2. However, the observed toxicities of the three mutants against B. mori larvae and cultured cells expressing the BtR175 toxin-binding region did not increase, suggesting that increased binding affinity to cadherins does not contribute to the insecticidal activity. Affinity maturation of a Cry toxin to a receptor via directed evolution was relatively simple to achieve, and seems to have potential for generating a toxin with increased insecticidal activity.

【 授权许可】

CC BY   
© 2014 The Authors. MicrobiologyOpen published by John Wiley & Sons Ltd.

Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.