Clarification of mechanism of human sputum elastase inhibition by a new inhibitor, ONO-5046, using electrospray ionization mass spectrometry.
Liquid chromatography electrospray ionization mass spectrometry (LC/ESI-MS) to probe the nature of the covalent E-I complex was successfully applied to clarify the mechanism of human sputum elastase (HSE) inhibition by a new inhibitor, ONO-5046. The mass spectrum of the four HSE isozymes displayed their molecular ion peaks at m/z=26,018, 25,929, 25,200, and 25,054, respectively. Immediately after incubation, inactivation of HSE with ONO-5046 increased the four molecular ion peaks by approximately 84 amu, which was assigned to the mass unit of the pivaloyl moiety of ONO-5046. An additional minute of incubation of E-I complex restored the original molecular ion peaks. These observations strongly suggested that ONO-5046 inactivates HSE by a reversible 'acylation-deacylation' mechanism.
Nakayama
Yoshisuke
Y
Medicinal Chemistry Research Laboratories, Minase Research Institute, Ono Pharmaceutical Co., Ltd., Shimamoto, Mishima, Osaka, Japan.
Odagaki
Yoshihiko
Y
Fujita
Setsuko
S
Matsuoka
Shozo
S
Hamanaka
Nobuyuki
N
Nakai
Hisao
H
Toda
Masaaki
M
D000215:Acylation; D002851:Chromatography, High Pressure Liquid; D005998:Glycine / Q000031:analogs & derivatives* / Q000494:pharmacology; D006801:Humans; D007527:Isoenzymes / Q000037:antagonists & inhibitors; D010196:Pancreatic Elastase / Q000037:antagonists & inhibitors*; D015842:Serine Proteinase Inhibitors / Q000494:pharmacology; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*; D013183:Sputum / Q000201:enzymology*; D013449:Sulfonamides / Q000494:pharmacology
D007527:Isoenzymes; D015842:Serine Proteinase Inhibitors; D013449:Sulfonamides; C069195:sivelestat; D010196:Pancreatic Elastase; D005998:Glycine