Inhibitor of α-Glucosidase (AGH, EC 3.2.1.20). Tyr-Tyr-Pro-Leu which showed a potent inhibition against yeast AGH was selected as a skeleton peptide. As summarized five peptides were synthesized , and the AGH inhibition was determined. In comparison with the inhibitory activity of original tetra-peptide (IC50 = 3.7 mM), lack of Tyr at the N-terminus of the skeleton peptide did not influence on AGH inhibition power (IC50 = 3.9 mM), indicating that the tri-strucutre, Tyr-Pro-Leu, was the essential element for AGH inhibition.
Table 1 AGH inhibitory activity of synthetic analogues of the peptide isolated from muscle hydrolyzate a
Sequence
| IC50 (mM)
| Tyr-Tyr-Pro-Leu | 3.7 ± 0.02 | Tyr-Pro-Leu
| 3.9 ± 0.02
| Pro-Leu
| No inhibition
| Tyr-Pro
| 16.8 ± 0.08
| Tyr-Pro-Gly
| 5.0 ± 0.01
| Tyr-Pro-Tyr
| 25.8 ± 0.12
| a The analogue peptides were synthesized on the basis of the sequence of Tyr-Tyr-Pro-Leu isolated from the hydrolyzate.
|