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Design of serine protease inhibitors with conformation restricted by amino acid side-chain–side-chain CH/π interaction

✍ Scribed by Yasuyuki Shimohigashi; Takeru Nose; Yasuko Yamauchi; Iori Maeda


Publisher
Wiley (John Wiley & Sons)
Year
1999
Tongue
English
Weight
232 KB
Volume
51
Category
Article
ISSN
0006-3525

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✦ Synopsis


A novel type of conformationally restricted peptides with the structure of H-D-Xaa-Phe-NH-CH 2 -C 6 H 5 has been developed as inhibitors of serine proteinase chymotrypsin. The D-Xaa-alkyl and Phe-phenyl groups resulted in a formation of the hydrophobic core due to the side-chain-side-chain CH/ interaction. Their spatial proximity was evidenced by 400 MHz 1 H-nmr measurements, observing large upfield shifts of proton signals of D-Xaa-alkyl and nuclear Overhauser effect (NOE) enhancements between the D-Xaa-alkyl and Phe-phenyl groups. This conformational restriction brought by CH/ interaction produced an inhibitory structure, in which the C-terminal amide-benzyl group fits the chymotrypsin S 1 site and the hydrophobic core binds to the S 2 site. The inhibitory conformation was demonstrated crystallographically for the complex between the dipeptide H-D-Leu-Phe-NH-CH 2 -C 6 H 4 (p-F) and ␥-chymotrypsin. Detailed structure-activity studies have substantiated the structure of dipeptides in the active center of the enzyme.