Characterization of a membrane-regulated sugar phosphate phosphohydrolase from Lactobacillus casei.

摘要: One of the key components futile xylitol cycle Lactobacillus casei Cl-16 is a phosphatase which dephosphorylates 5-phosphate to prior expulsion pentitol from cells. This enzyme has been partially purified and characterized. The active against variety four-, five-, six-carbon sugars sugar alcohols phosphorylated at terminal 4, 5, 6 positions, respectively, but exhibits little or no affinity for substrates C-1 position. an apparent molecular weight 62,000 pH optimum between 5.5 6, it requires divalent cation (Mg2+) maximal activity. A single protein band, exhibiting activity, was excised polyacrylamide gels used prepare antiphosphatase sera in rabbits. antiserum detect on determine monomer sodium dodecyl sulfate-polyacrylamide gels. With subunit 32,000, native appears be dimer. Phosphatase activity substrate specificity are regulated by some component associated with cytoplasmic membrane.