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Inhibition of digestive proteinase of stored grain coleoptera by oryzacystatin, a cysteine proteinase inhibitor from rice seed
Author(s) -
Liang C.,
Brookhart G.,
Feng G.H.,
Reeck G.R.,
Kramer K.J.
Publication year - 1991
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/0014-5793(91)80102-9
Subject(s) - rice weevil , red flour beetle , casein , sitophilus , midgut , food science , biology , sodium dodecyl sulfate , chemistry , biochemistry , botany , insect , larva
Electrophoresis of midgut extracts from the rice weevil, Sithopilus oryzae , and the red flour beetle, Tribolium castaneum , in polyacrylamide gels containing sodium dodecyl sulfate and gelatin revealed there was one major proteinase (apparent molecular mass = 40 000) in the rice weevil and two major proteinase (apparent molecular masses = 20 000 and 17 000) in the red flour beetle. The pH optima using [ 3 PH]casein as substrate were about pH 6.8. for the rice weevil and pH 5.2 for the red flour beetle. Use of specific inhibitors, including L‐ trans ‐epoxysuccinyl‐leucylamino‐(4‐guanidino)‐butane (E‐64). p ‐chloromercuriphenylsulfonic acid (PCMS), and oryzacystatin, indicated that nearly all of the proteinase activity against casein was contributed by cysteine proteinases. The estimated IC 10 values for oryzacystatin were 2 × 10 −6 M and 4 × 10 −7 M when tested against midgut extracts from T. castaneum and S. oryzae , respectively.