α-Mannosidase-2: A developmentally regulated enzyme in Dictyostelium discoideum☆
[摘要] Apreviouslyundectedisozymeofα-mannosidasewasobservedinseveralindependentmutantstrainsofDictyosteliumdiscoideumselectedfortheabsenceofthemajorisozyme,α-mannosidase-1.Theactivityinthemutantstrains,α-mannosidase-2,differsfromthemajorisozymewithrespecttopHoptimum,substrateaffinity,sensitivitytoinhibitionbyl-cysteine,andisparticulatebound.Theenzymecanbesolubilizedbytreatmentoftheextractwithnonionicdetergents.α-Mannosidase-2beginstoaccumulateonlyafter12hrofdevelopmentandreachesapeakspecificactivityofaboutatenthofthatofα-mannosidase-1duringculmination.Theincreaseinspecificactivityofα-mannosidase-2isblockedbyeithercycloheximideoractinomycinD,drugsknowntoinhibitproteinandRNAsynthesis,respectively,andprobablyresultsfromaccumulationofdenovosynthesizedenzyme.α-Mannosidase-2,therefore,providesaconvenientmarkerenzymeforbiochemicaldifferentiationduringthepseudo-plasmodialstage.
[发布日期] [发布机构]
[效力级别] [学科分类] 生物科学（综合）
[关键词] [时效性]
