Correlation of cellulose synthesis in vivo and in vitro during the encystment of Acanthamoeba☆☆☆

[摘要] Acanthamoebacastellaniidifferentiateswhenplacedinastarvationmedium.Thematurecystsformedarecharacterizedbyacellulosicwallsynthesizedfromendogenoussourcesduringencystment.Aparticulateenzymesystemwhosespecificactivityincreasessome30-foldduringencystmentcatalyzestheformationofanalkali-solubleandanalkali-insolubleβ-(1→4)-glucan(cellulose).Theactivityinvitroofthisenzymeextractedfrompopulationsofcellsduringencystmentcorrelateswiththeformationinvivoofthematurecystandthealkali-insolubleβ-glucanofthecystwall.Theconclusionisbasedonthefollowingobservations:1.1.Bothalkali-solubleandalkali-insolubleβ-glucanssimilartotheenzymaticproductsoftheisolatedβ-glucansynthetaseoccurincystwalls.2.2.Thedevelopmentalkineticsoftheappearanceoftheβ-glucansynthetase,cystwallcellulose,andthematurecystformsaresosimilarastobeconsideredcoincidentalinthattheonsetoftheperiodofrapidincreaseforallthreeisobservedsome12–14hraftertheinitiationofencystment.3.3.Thepresenceofactinomycinorcycloheximideinencystingcultures,atconcentrationswhichinhibitRNAandproteinsynthesisduringencystment,preventstheformationofmaturecysts,theappearanceofcystwallcellulose,andtheusual30-foldincreaseintheactivityoftheβ-glucansynthetaseduringencystment.Theseprocessesarenotinhibitedwhenthecompoundsareaddedafter14hrofencystment.Theresultssuggestthattheβ-glucansynthetasestudiedinvitroisinvolvedintheinvivosynthesisofcystwallcelluloseandthatthissynthesisisdependentontheoccurrenceofbothRNAandproteinsynthesissometimebetween8and14hrafterthebeginningofencystment.

[学科分类] 生物科学（综合）