These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: Evidence for two distinct forms of mammalian beta-mannosidase.
    Author: Dawson G.
    Journal: J Biol Chem; 1982 Apr 10; 257(7):3369-71. PubMed ID: 7061483.
    Abstract:
    Liver from goats with an inherited deficiency of beta-D-mannosidase appears only partially deficient in beta-mannosidase (40% of normal values) when assayed with synthetic beta-mannoside substrates at pH 5.0. Other tissues such as brain and cultured skin fibroblasts show an almost complete deficiency of beta-mannosidase activity. Fractionation of supernatant solutions of normal goat liver on columns of concanavalin A bound to Sepharose 4B resolved beta-mannosidase into a bound (acidic) form (pH optimum, 5.0 to 5.5) and an unbound (neutral) form (broad pH optimum from 5.0 to 8.0). Both forms were heat-labile, inhibited by sodium taurocholate (0.1%) and insensitive to divalent cations such as zinc. However, only the acid lysosomal) form was able to hydrolyze a Man beta GlcNAc beta [3H]GlcNAc trisaccharide. Comparable fractionation of liver from affected goats revealed normal levels of the unbound (neutral) form but a complete absence of the bound (acidic, lysosomal) form. Fractionation of liver from an obligate heterozygote goat revealed normal neutral and 50% of the acidic. These studies suggest that goat liver contains both lysosomal beta-mannosidase (acidic form; deficient in beta-mannosidosis) and nonlysosomal beta-mannosidase (neutral) activity.
    [Abstract] [Full Text] [Related] [New Search]