Structure - Function Analysis of Peptide Analogs of SQSPA with Respect to α-glucosidase and α-amylase Inhibition
| Autor: | Megan Jean Bester, Mohammed Auwal Ibrahim, Albert W. H. Neitz, Anabella R.M. Gaspar, June C. Serem |
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| Rok vydání: | 2019 |
| Předmět: |
Protein Conformation
Peptide Biochemistry Structure-Activity Relationship Structural Biology Structure–activity relationship Humans Hypoglycemic Agents Computer Simulation Amylase Enzyme Inhibitors chemistry.chemical_classification Binding Sites biology Hydrogen Bonding alpha-Glucosidases General Medicine Alanine scanning In vitro Molecular Docking Simulation Kinetics Enzyme chemistry biology.protein alpha-Amylases Digestion Uncompetitive inhibitor Peptides Protein Binding |
| Zdroj: | Protein and peptide letters. 26(6) |
| ISSN: | 1875-5305 |
| Popis: | Background: Peptide-based therapeutics offer a unique avenue for the development of novel agents for the treatment of diabetes mellitus including α-glucosidase inhibitors. The peptide, SQSPA, was reported to possess to α -glucosidase inhibitory activity in addition to resistance to Gastrointestinal Tract (GIT) digestion. Methods: In this study, the in silico and in vitro structure-activity analyses of the peptide was conducted using alanine scanning to identify key amino acid residues. Results: The alanine scanning led to four analogs viz; AQSPA, SASPA, SQAPA and SQSAA which were GIT stable. Initially, the peptides were subjected to molecular docking on human α- glucosidase and α -amylase where the binding affinities to the enzymes were in the order; AQSPA>SASPA>SQSPA>SQAPA> SQSAA and AQSPA>SQSAA>SASPA>SQSPA> SQAPA, respectively. Hydrogen bond were important for the binding of all peptides but SASPA and AQSPA had the highest hydrogen bonds interactions with the α-glucosidase and α-amylase, respectively. In vitro analysis revealed that the α -glucosidase and α-amylase inhibitory activities of the peptides were in the order AQSPA>SQSPA>SQAPA>SASPA>SQSAA and AQSPA>SASPA> SQAPA>SQSPA>SQSAA, respectively. Using inhibition kinetics, SQSPA was a mixed inhibitor of α-glucosidase while AQSPA, SQAPA and SQSAA showed non-competitive inhibition. For α- amylase inhibition, SQSPA was a non-competitive inhibitor while AQSPA and SQSAA were mixed inhibitors; SASPA and SQAPA showed uncompetitive inhibition. Conclusion: The results indicated that P4 and Q2 are important requirements for the α-glucosidase and α-amylase inhibitory activities of the parent peptide, SQSPA. Furthermore, alanine scanning has led to the design of a novel α-glucosidase inhibitory peptide, AQSPA, with increased activities. |
| Databáze: | OpenAIRE |
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