Effect of detergents and hexafluoroisopropanol on the conformation of a non-helical and a helical plant protease inhibitor

摘要: We have earlier reported the purification of a non-helical proteinase inhibitor from Cajanus cajan and helical proteinase/amylase Phaseolus aureus. The effect detergents, viz. sodium dodecyl sulfate (SDS), deoxycholate (DOC) 3-[(3-cholamidopropy) dimethylammonio]-1-propane sulfonate (CHAPS) hexafluoroisopropanol on conformation these proteinaceous inhibitors was investigated using circular dichroism spectroscopy. present report focuses changes in polypeptide backbone with respect to induction structure. SDS causes minimal tertiary as well secondary structure C. inhibitor. In presence anionic bile salt, deoxycholate, minor far-UV CD spectrum were accompanied by loss inhibitory activity while CHAPS did not affect function. As judged dichroic curves ([Theta](MRW) at 208 222 nm), primarily disorganized chain converted 3,3,3,3',3',3'-hexafluoro-2-propanol (HFIP) into conformation. P. aureus showed increased helicity nm) nm). Fluorescence measurements show slight alterations emission intensities. HFIP caused cooperative increase alpha-helical