Peptide Drugs QSAR Study Based on Topomer CoMFA

Objective: 3D-QSAR study was carried out by using Topomer comparative molecular field analysis method. It was applied for three peptides which are bitter tasting threshold of dipeptide, oxytocin and bradykinin-potentiating peptides. Methods: The structures of all peptide drugs were built by using the Build Protein function and all molecular modeling calculations were performed in the SYBYL2.0. Each peptide was fragmented into different sets of groups. Steric and electrostatic interaction energies were calculated by the carbon sp3 probe. PLS regression was used to obtain QSAR model. Results: In the QSAR model for bitter tasting threshold of di-peptide, cross-validated coefficient (Q2) was 0.614, squared correlation coefficient between predicted and observed activities (R2) was 0.708 and external multiple correlation coefficient (Qext 2) was 0.828. The corresponding data onto the oxytocin were 0.835, 0.899, 0.795 and for bradykinin-potentiating peptides were 0.624, 0.870. 0.670. Conclusion: The present work was employed Topomer CoMFA to perform for three peptide drugs,and the calculated statistical parameters (high Q2, R2, Qext 2, F and SEE values) indicate 3DQSAR models have a high predictability for peptide drugs. It can contribute to the design of novel bioactive peptides.