Engineering a peptide aptamer to target calmodulin for the inhibition of Magnaporthe oryzae

Publication date: Available online 9 May 2019Source: Fungal BiologyAuthor(s): Qi Xu, Xing Ye, Xiang Ma, Hong Li, Hongqian Tang, Yanqiong Tang, Zhu LiuAbstractTo develop an antimicrobial agent for preventing the devasting damage caused by rice blast, a novel peptide aptamer was identified to interact with calmodulin (CaM) for the inhibition of the spore development in the pathogen Magnaporthe oryzae. A peptide aptamer designated as SNP-D4, consisted of the scaffold protein Staphylococcus aureus nuclease (SN) and an exposed surface loop of 16 random amino acids, was screened from the constructed peptide aptamer libraries by bacterial two-hybrid system using CaM of M. oryzae as the bait. The preliminary inhibition in the sporulation development was observed after treating with the crude extracts expressing SNP-D4. The inhibition efficacies of the purified SNP-D4 were quantified at the stages of conidial germination, germ tube elongation, and appressorium formation in M. oryzae. The binding affinity analysis revealed that SNP-D4 interacted with CaM at a dissociation constant (Kd) of about 20 μM. Moreover, the N-terminus of CaM was identified as the key binding region.
Source: Fungal Biology - Category: Biology Source Type: research