title: Selection of low-molecular-mass trypsin and chymotrypsin inhibitors based on the binding loop of CMTI-III using combinatorial chemistry methods.
abstract: Using a combinatorial chemistry approach, a decapaptide library containing the N-terminal fragment of trypsin inhibitor CMTI-III was synthesized by the solid-phase method. The peptide library was screened for trypsin and chymotrypsin inhibitory activity applying the iterative method in solution. Two decapeptides were selected and resynthesized for each enzyme. The association equilibrium constants ((1.1+/-0.2)x10(8) and (7.3+/-1.6)x10(7)) determined for peptides with trypsin inhibitory activity indicate that they are 3-4-fold less active than the CMTI inhibitors. On the other hand, they are significantly more effective as compared with the starting sequence. Two peptides selected as chymotrypsin inhibitors displayed about 10 times higher activity (1.7+/-0.4)x10(7) and (1.1+/-0.2)x10(7), respectively) than those monosubstituted in position P(1) of the CMTI-III analogue. Considering low molecular weight of peptides selected and the lack of conformational constraints in their structures, the results are promising. They are good templates as starting sequences for further selection of small, peptidomimetic proteinase inhibitors.
authors.affiliation: Faculty of Chemistry, University of Gdańsk, Poland.
authors.forename: Katarzyna
authors.initials: K
authors.lastname: Kaźmierczak
authors.forename: Ewa
authors.initials: E
authors.lastname: Zabłotna
authors.forename: Anna
authors.initials: A
authors.lastname: Jaśkiewicz
authors.forename: Hanna
authors.initials: H
authors.lastname: Miecznikowska
authors.forename: Krzysztof
authors.initials: K
authors.lastname: Rolka
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites; D002417:Cattle; D002918:Chymotrypsin / Q000037:antagonists & inhibitors*; D020650:Combinatorial Chemistry Techniques; D015723:Gene Library; D006868:Hydrolysis; D007700:Kinetics; D008969:Molecular Sequence Data; D019151:Peptide Library; D010455:Peptides / Q000737:chemistry; D010940:Plant Proteins / Q000737:chemistry* / Q000494:pharmacology*; D011487:Protein Conformation; D017434:Protein Structure, Tertiary; D014361:Trypsin Inhibitors / Q000737:chemistry / Q000494:pharmacology*
chemical_list: C081870:CMTI protein, Cucurbita maxima; D019151:Peptide Library; D010455:Peptides; D010940:Plant Proteins; D014361:Trypsin Inhibitors; D002918:Chymotrypsin