Molecular interactions of 4-acetoxy-plakinamine B with peripheral anionic and other catalytic subsites of the aromatic gorge of acetylcholinesterase: computational and structural insights.
| Title: | Molecular interactions of 4-acetoxy-plakinamine B with peripheral anionic and other catalytic subsites of the aromatic gorge of acetylcholinesterase: computational and structural insights. |
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| Authors: | Khan I; Department of Pharmacy, University of Peshawar, Peshawar, Pakistan. inam_marwat333@yahoo.com; Samad A; Khan AZ; Habtemariam S; Badshah A; Abdullah SM; Ullah N; Khan A; Zia-Ul-Haq M |
| Source: | Pharmaceutical biology [Pharm Biol] 2013 Jun; Vol. 51 (6), pp. 722-7. Date of Electronic Publication: 2013 Apr 09. |
| Publication Type: | Journal Article |
| Language: | English |
| Journal Info: | Publisher: Taylor & Francis Country of Publication: England NLM ID: 9812552 Publication Model: Print-Electronic Cited Medium: Internet ISSN: 1744-5116 (Electronic) Linking ISSN: 13880209 NLM ISO Abbreviation: Pharm Biol Subsets: MEDLINE |
| Imprint Name(s): | Publication: [London] : Taylor & Francis; Original Publication: Lisse, the Netherlands : Swets & Zeitlinger, c1998- |
| MeSH Terms: | Drug Design*; Acetylcholinesterase/*drug effects ; Alkaloids/*pharmacology ; Cholinesterase Inhibitors/*pharmacology ; Steroids/*pharmacology; Acetylcholinesterase/chemistry ; Acetylcholinesterase/metabolism ; Binding Sites ; Computer Simulation ; Hydrogen Bonding ; Hydrophobic and Hydrophilic Interactions ; Molecular Docking Simulation |
| Abstract: | Context: A steroidal alkaloid, 4-acetoxy-plakinamine B (4APB), is a recently discovered marine natural product with inhibitory effect against acetylcholinesterase (AChE), but its mechanism of interaction with the enzyme remains to be elucidated.; Objective: The main objective was to study molecular binding mode of the compound, its interactions with catalytic subsites and molecular mechanism behind its significant inhibitory effect.; Materials and Methods: All possible interactions of ligands in the binding sites were analyzed using FRED 2.1 and the OMEGA pre-generated multi-conformer library.; Results: Dipole-dipole interactions were observed between the secondary amino group of 4APB and Ser200 at a distance of 3.91 Å and also with Gly117 and Gly118. A further dipole-dipole interaction was between Arg289 and the heterocyclic nitrogen. Hydrogen bonding interactions were observed between Tyr130 and secondary amino and C-4 acetyl groups as well as between heterocyclic nitrogen and Phe288 at a distance of 3.04 Å. Hydrophobic interactions were evident between rings C/D of 4APB and with Phe288, Phe330 and Phe331. The computational studies revealed 4APB's critical molecular interaction with amino acids of peripheral active (PAS) and anionic (AS) subsites.; Discussion: Our data provided molecular evidence for the mixed competitive inhibitory effect of 4APB. For lead optimization, structural insights revealed the N-methyl group of 4APB could be replaced by NH2 moiety to generate a more favorable hydrogen bonding with Glu199. A polar group insertion such as NH2 or OH at certain sites of the 4APB skeleton is also recommended.; Conclusion: These computational insights explained the mixed-competitive enzyme kinetic behavior of 4APB. This study outlines a strategy for designing novel derivatives of 4APB with potentially better AChE inhibitory activities through interaction at the PAS and AS sites. |
| Substance Nomenclature: | 0 (4-acetoxyplakinamine B); 0 (Alkaloids); 0 (Cholinesterase Inhibitors); 0 (Steroids); EC 3.1.1.7 (Acetylcholinesterase) |
| Entry Date(s): | Date Created: 20130411 Date Completed: 20131223 Latest Revision: 20130516 |
| Update Code: | 20260130 |
| DOI: | 10.3109/13880209.2013.764329 |
| PMID: | 23570516 |
| Database: | MEDLINE |
Journal Article