結核菌培養濾液中よりのβ-Glucuronidase inhibitorの分離ならびに性状について

Isolation abd Characterization of β-Glucuronidase Inhibitor from Culture Filtrate of Mycobacterium tuberculosis H37Rv

清谷 克寛

An inhibitory factor against β-glucuronidase activity was detected in and partially puified as a proteinaceous substance from unheated culture filtrate of M. tuberculosis H37Rv. The active principle was mostly recovered in the boundary layer between the butanol and aqueous phases after treating the supernatant culture fluid with 70(null)aturation of ammonium sulfate and 20% (v/v) n-butanol. The β-glucuronidase inhibitor was partially puified by ionexchange chromatography on DEAE-sepharose CL-6B column with approximately a 53-fold increase in the specific activity. The molecular weight was estimated to be about 2.55×10<4> by gel filtration on Sephadex G-75, and the isoelectric point about pH 2.5 by chromatofocusing with Polybufler exchanger (PBE 94). The inhibitor was stable over a relatively wide range of pH (2-10), and resistant to heating at 100℃ for 10min in boiling water, to treatment with micleases, butanol and manganese chrolide, whereas it was sensitive to trypsin. The inhibitor reduced its activity under the effect of salt solution (0.05M) such as sodium chrolide, potassium chrolide, ammonium chrolide, calcinm chrolide, magnecium sulfate, magnecium chrolide, ammonium sulfate and sodium sulfate, especially the latter five. The β-glucuronidase inhibitor acted noncompetitively against β-glucuronidase of PMNs from guinea pigs, with an optimal pH at 4.5. No inhibitory activity was observed on other lysosomal enzymes (acid phosphatase, N-Ac-β-glucosaminidase, β-galactosidase, lysozyme and cathepsin D) from guinea pigs, β- glucuronidase from Escherickia coli, domestic fowls and Helix pomatia, whereas partial inhibition was observed on β-glucronidase from human peripheral blood leukocytes and beef liver. The inhibitor reduced the β-glucurondase activity from guinea pigs immunized with M. bovis BCG in the same degree as that from non-immunized ones.

医学 [ 490 ]

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広島大学