Extracellular mannose-6-phosphatase of Phanerochaete chrysosporium: a lignin peroxidase-modifying enzyme.

摘要: Abstract The lignin peroxidase (LIP) isozyme profile of the white-rot fungus Phanerochaete chrysosporium changes markedly with culture age. This change occurs extracellularly and results from enzymatic dephosphorylation LIP isozymes. In this study, a novel mannose 6-phosphatase (M6Pase) extracellular fluid filtrate P. chrysosporium, shown to be responsible for postranslational modification LIP, was purified characterized. vitro incubation M6Pase H2 resulted in its conversion H1, an equimolar release orthophosphate. Using different sugar phosphates as substrate, enzyme exhibited narrow specificity, showing activity mostly 6-phosphate ( K m = 0.483 mM). displayed molecular mass 82 kDa, determined by gel filtration, 40.4 39.1 on SDS–PAGE, suggesting that native form is dimer. N-terminal sequence has no homology other reported phosphatases. metaloprotein manganese cobalt preferred metal ions. It N-glycosylated proteins isoelectric point 4.7-4.8 pH optimum 5. Based characteristics, seems unique phosphatase posttranslation