Functional characterization of Kunitz-type protease inhibitor Pr-mulgins identified from New Guinean Pseudechis australis.
Kunitz-type protease inhibitors, which consist of around 60 amino acid residues and three distinctive disulfide bridges, exhibit a broad range of physiological functions such as protease inhibitor and ion channel blocker. In this study, we identified cDNAs encoding Kunitz-type protease inhibitors, Pr-mulgins 1, 2 and 3, from the venom gland cDNA library of Papuan pigmy mulga snake (New Guinean Pseudechis australis). The deduced amino acid sequences of the Pr-mulgins are 92.4-99.3% identical with their orthologs in Australian P. australis. Pr-mulgin proteins were recombinantly prepared and subjected to inhibitory assays against proteases. Pr-mulgin 1 significantly affected matrix metalloprotease (MMP) 2; Pr-mulgins 2 and 3 showed potent inhibition to trypsin and plasma plasmin; and Pr-mulgin 2 inhibited α-chymotrypsin. Pr-mulgins 1, 2, and 3, however, had essentially no effect on Drosophila K(+) channels (Shaker) and rat K(+) channels (K(v) 1.1).
Biomedical Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), 1-1-1 Higashi, Tsukuba, Ibaraki 305-8566, Japan. h-inagaki@aist.go.jp
Hidetoshi
H
Inagaki
Hikari
H
Kimoto
Yoko
Y
Yamauchi
Michihisa
M
Toriba
Tai
T
Kubo
D000818:Animals; D002417:Cattle; D004546:Elapid Venoms / Q000737:chemistry*; D004594:Electrophysiology; D015723:Gene Library; D061965:Matrix Metalloproteinase Inhibitors; D008969:Molecular Sequence Data; D009865:Oocytes; D015221:Potassium Channels / Q000737:chemistry; D011480:Protease Inhibitors / Q000737:chemistry* / Q000302:isolation & purification; D051381:Rats; D030162:Reptilian Proteins / Q000737:chemistry* / Q000302:isolation & purification / Q000502:physiology; D020539:Sequence Analysis, Protein; D014982:Xenopus laevis
D004546:Elapid Venoms; D061965:Matrix Metalloproteinase Inhibitors; D015221:Potassium Channels; D011480:Protease Inhibitors; C026235:Pseudechis venom; D030162:Reptilian Proteins