Antimicrobial activity studies on a trypsin-chymotrypsin protease inhibitor obtained from potato.
A 5.6 kDa trypsin-chymotrypsin protease inhibitor was isolated from the tubers of the potato (Solanum tuberosum L cv. Gogu) by extraction of the water-soluble fraction, dialysis, ultrafiltration, and C18 reversed-phase high performance liquid chromatography. This inhibitor, which we named potamin-1 (PT-1), was thermostable and possessed antimicrobial activity but lacked hemolytic activity. PT-1 strongly inhibited pathogenic microbial strains, including Candida albicans, Rhizoctonia solani, and Clavibacter michiganense subsp. michiganinse. Automated Edman degradation showed that the N-terminal sequence of PT-1 was NH2-DICTCCAGTKGCNTTSANGAFICEGQSDPKKPKACPLNCDPHIAYA-. The sequence had 62% homology with a serine protease inhibitor belonging to the Kunitz family, and the peptide inhibited chymotrypsin, trypsin, and papain. This protease inhibitor, PT-1, was composed of polypeptide chains joined by disulfide bridge(s). Reduced PT-1 almost completely lost its activity against fungi and proteases indicating that disulfide bridge is essential for its protease inhibitory and antifungal activity. These results suggest that PT-1 is an excellent candidate as a lead compound for the development of novel oral or other anti-infective agents.
Kim
Jin-Young
JY
Research Center for Proteineous Materials (RCPM), Chosun University, 375 Seosuk-Dong, Dong-Ku, Kwangju 501-759, Republic of Korea.
Park
Seong-Cheol
SC
Kim
Mi-Hyun
MH
Lim
Hak-Tae
HT
Park
Yoonkyung
Y
Hahm
Kyung-Soo
KS
D000595:Amino Acid Sequence; D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*; D002918:Chymotrypsin / Q000037:antagonists & inhibitors* / Q000378:metabolism; D006461:Hemolysis / Q000187:drug effects; D006801:Humans; D008837:Micrococcus / Q000187:drug effects; D003904:Mitosporic Fungi / Q000187:drug effects; D008969:Molecular Sequence Data; D008970:Molecular Weight; D010940:Plant Proteins / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology; D016415:Sequence Alignment; D015842:Serine Proteinase Inhibitors / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*; D011198:Solanum tuberosum / Q000737:chemistry*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D014357:Trypsin / Q000378:metabolism*
D000900:Anti-Bacterial Agents; D010940:Plant Proteins; D015842:Serine Proteinase Inhibitors; D002918:Chymotrypsin; D014357:Trypsin