Ibrahim Abdulganiyyu A

Title : Conformational analysis of a cyclic AKH neuropeptide analog that elicits selective activity on locust versus honeybee receptor

Abstract:

Neuropeptides belonging to the adipokinetic hormone (AKH) family elicit metabolic effects as their main function in insects, by mobilizing trehalose, diacylgycerol, or proline, which are released from the fat body into the hemolymph as energy sources for muscle contraction required for energy-intensive processes, such as locomotion. One of the AKHs produced in locusts is a decapeptide, Locmi-AKH-I (pELNFTPNWGT-NH2). A head-to-tail cyclic, octapeptide analog of Locmi-AKH-I, cycloAKH (cyclo[LNFTPNWG]) was synthesized to severely restrict the conformational freedom of the AKH structure. In vitro, cycloAKH selectively retains full efficacy on a pest insect (desert locust) AKH receptor, while showing little or no activation of the AKH receptor of a beneficial insect (honeybee). Molecular dynamic analysis incorporating NMR data indicate that cycloAKH preferentially adopts a type II β-turn under micelle conditions, whereas its linear counterpart and natural AKH adopts a type VI β-turn under similar conditions. CycloAKH, linear LNFTPNWG-NH2, and Locmi-AKH-I feature the same binding site during docking simulations with the desert locust AKH receptor (Schgr-AKHR), but differ in the details of the ligand/receptor interactions. However, cycloAKH failed to enter the binding pocket of the honeybee receptor 3D model during docking simulations. Since the locust AKH receptor has a greater tolerance than the honeybee receptor for the cyclic conformational constraint in vitro receptor assays, it could suggest a greater tolerance for a shift in the direction of the type II β turn exhibited by cycloAKH from the type VI β turn of the linear octapeptide and the native locust decapeptide AKH. Selectivity in biostable mimetic analogs could potentially be enhanced by incorporating conformational constraints that emphasize this shift. Biostable mimetic analogs of AKH offer the potential of selectively disrupting AKH-regulated processes, leading to novel, environmentally benign control strategies for pest insect populations.

Biography:

Ibrahim Abduganiyyu A has completed his PhD at the University of Cape Town, and he will be 36 years old by the 10th of July. Ibrahim is from Maigatari a small town in jigawa. He was a two time head of Department in the department of nutrition and community health jigawa state polytechnic Dutse.  He has currently has 5 publications and has been appointed an assistant professor with Mariam Abacha University. My research interest are 1. Solution Structure of Neuropeptides: NMR used, together with Computational methods, to determine the solution structure of neuropeptides. The neuropeptides of interest are insect adipokinetic hormones, and it is hoped that from a knowledge of the structure of the peptide a structure-activity relationship can be developed. Alternately this could lead to new, biological active pesticide that is selective in their activity, negatively affecting the aimed pest species without causing damage to valuable insect species, to curb the massive, indiscriminate killing of insects the world over. 2. Molecular modelling, Molecular Docking, NMR of Peptides, GPCRs and all computational related Bioinformatics and cheminformatics.