저해제와 화학 수식에 의한 초파리 myo-inositol-1-phosphate synthase 효소활성 억제양상 분석 = Modification and Inhibition Analysis of Myo-inositol-1-phosphate Synthase of Drosophila melanogaster

다국어 초록 (Multilingual Abstract)

Recombinant myo-inositol-1-phosphate synthase (MIPS) of Drosophila melanogaster
expressed in E. coli was purified to apparent homogeneity by a single step of His-affinity
column chromatography. Addition of the structural analogs of inositol-1-phosphate such
as 2-deoxyglucose-6-phosphate and glucitol-6-phosphate caused to inhibition of the
enzyme activity as a competitive manner. When the enzyme was chemically modified
with phenylmethylsulfonyl fluoride (PMSF), specifically reacted with serine residue on
the enzyme, the activity was eliminated. Phenylglyoxal, which would modify guanidino
group of arginine, did not affect the MIPS activity to a greater extent. This demonstrates
that serine residues of enzyme would participate in a important function of the MIPS
activity. The enzyme activity was inhibited by the modifier which chemically modified
thiol group of cysteine. The ability to titrate the activity of MIPS with substoichiometric
amounts of modification reagent and an essentially complete loss of enzyme activity on
the addition of stoichiometric amount of these materials suggests that modification of
amino acid residue is responsible for the loss of enzyme activity.