title: Contribution of cationic amino acids toward the inhibition of Arg-specific cysteine proteinase (Arg-gingipain) by the antimicrobial dodecapeptide, CL(14-25), from rice protein.
abstract: CL(14-25), a dodecapeptide, exhibits antimicrobial activity against Porphyromonas gingivalis with the 50% growth-inhibitory concentration (IC50 ) value of 145 µM, and arginine-specific gingipain (Rgp)-inhibitory activity. Kinetic analysis revealed that CL(14-25) is a mixed-type inhibitor, with inhibition constants (Ki and Ki ' values) of 1.4 × 10(-6) M and 4.3 × 10(-6) M, respectively. To elucidate the contributions of four cationic amino acid residues at the N- and C-termini of CL(14-25) toward Rgp-inhibitory activity, we investigated the Rgp-inhibitory activities of truncated and alanine-substituted analogs of CL(14-25). Rgp-inhibitory activities significantly decreased by truncated analogs, CL(15-25) and CL(16-25), whereas those of CL(14-24) and CL(14-23) were almost as high as that of CL(14-25). Rgp-inhibitory activities of alanine-substituted analogs, CL(R14A) and CL(R14A, R15A) also significantly decreased, whereas those of CL(K25A) and CL(R24A, K25A) were higher than that of CL(14-25). These results suggest that the arginine residue at position 15 substantially contributes to the Rgp-inhibitory activity and that the arginine residue at position 14 plays important roles in exerting Rgp-inhibitory activity. In this study, we demonstrated that CL(K25A) was a potent, dual function, peptide inhibitor candidate, exhibiting Rgp-inhibitory activity with Ki and Ki ' of 9.6 × 10(-7) M and 1.9 × 10(-6) M, respectively, and antimicrobial activity against P. gingivalis with an IC50 value of 51 µM.
authors.affiliation: Department of Materials Science and Technology, Graduate School of Science and Technology, Niigata University, Niigata, 950-2181, Japan; Center for Transdisciplinary Research, Niigata University, Niigata, 950-2181, Japan.
authors.forename: Masayuki
authors.initials: M
authors.lastname: Taniguchi
authors.forename: Yoshiyasu
authors.initials: Y
authors.lastname: Matsuhashi
authors.forename: Takako K
authors.initials: TK
authors.lastname: Abe
authors.forename: Yohei
authors.initials: Y
authors.lastname: Ishiyama
authors.forename: Eiichi
authors.initials: E
authors.lastname: Saitoh
authors.forename: Tetsuo
authors.initials: T
authors.lastname: Kato
authors.forename: Akihito
authors.initials: A
authors.lastname: Ochiai
authors.forename: Takaaki
authors.initials: T
authors.lastname: Tanaka
mesh_terms: D018829:Adhesins, Bacterial / Q000378:metabolism*; D000595:Amino Acid Sequence; D000596:Amino Acids / Q000378:metabolism*; D000890:Anti-Infective Agents / Q000494:pharmacology*; D002851:Chromatography, High Pressure Liquid; D056148:Chromatography, Reverse-Phase; D003546:Cysteine Endopeptidases / Q000378:metabolism*; D000080867:Gingipain Cysteine Endopeptidases; D020128:Inhibitory Concentration 50; D007700:Kinetics; D008969:Molecular Sequence Data; D012275:Oryza / Q000737:chemistry*; D010446:Peptide Fragments / Q000737:chemistry / Q000494:pharmacology*; D010455:Peptides / Q000737:chemistry / Q000494:pharmacology*; D010940:Plant Proteins / Q000494:pharmacology*; D011480:Protease Inhibitors / Q000494:pharmacology*
chemical_list: D018829:Adhesins, Bacterial; D000596:Amino Acids; D000890:Anti-Infective Agents; C000608016:CL(14-25); D000080867:Gingipain Cysteine Endopeptidases; D010446:Peptide Fragments; D010455:Peptides; D010940:Plant Proteins; D011480:Protease Inhibitors; D003546:Cysteine Endopeptidases
keywords: Arg-gingipain inhibitor; antimicrobial peptide; bifunctional peptide; cationic peptide; inhibition in a mixed manner