title: Plasma membrane-associated glycohydrolases activation by extracellular acidification due to proton exchangers.
abstract: In this paper, we show that the pH optimum for the plasma membrane (PM)-associated activity of four glycohydrolases (conduritol B epoxide sensitive β-glucosidase, β-glucosidase GBA2, β-hexosaminidase and β-galactosidase) measured on intact cells is acidic. Moreover, we show that drugs able to modify the efflux of protons across the PM, thus locally affecting the extracellular proton concentration close to the PM, are able to modulate the activities of these enzymes. These data strongly suggest that pH-dependent modulation of PM-associated glycohydrolases activities could be an effective way to locally modulate the cell surface glycoconjugate composition.
authors.affiliation: Dipartimento di Chimica, Biochimica e Biotecnologie per la Medicina, Università degli Studi di Milano, Via Fratelli Cervi 93, 20090 Segrate, Italy.
authors.forename: Massimo
authors.initials: M
authors.lastname: Aureli
authors.forename: Nicoletta
authors.initials: N
authors.lastname: Loberto
authors.forename: Rosaria
authors.initials: R
authors.lastname: Bassi
authors.forename: Anita
authors.initials: A
authors.lastname: Ferraretto
authors.forename: Silvia
authors.initials: S
authors.lastname: Perego
authors.forename: Patrizia
authors.initials: P
authors.lastname: Lanteri
authors.forename: Vanna
authors.initials: V
authors.lastname: Chigorno
authors.forename: Sandro
authors.initials: S
authors.lastname: Sonnino
authors.forename: Alessandro
authors.initials: A
authors.lastname: Prinetti
mesh_terms: D000086:Acetazolamide / Q000494:pharmacology; D000584:Amiloride / Q000031:analogs & derivatives / Q000494:pharmacology; D045744:Cell Line, Tumor; D002462:Cell Membrane / Q000201:enzymology*; D002478:Cells, Cultured; D004533:Egtazic Acid / Q000494:pharmacology; D004789:Enzyme Activation; D005347:Fibroblasts / Q000201:enzymology; D005910:Glioma / Q000201:enzymology; D006801:Humans; D006863:Hydrogen-Ion Concentration; D009447:Neuroblastoma / Q000201:enzymology; D009853:Omeprazole / Q000494:pharmacology; D011522:Protons; D001616:beta-Galactosidase / Q000378:metabolism*; D001617:beta-Glucosidase / Q000378:metabolism*; D001619:beta-N-Acetylhexosaminidases / Q000378:metabolism*
chemical_list: D011522:Protons; D004533:Egtazic Acid; D000584:Amiloride; D001617:beta-Glucosidase; D001616:beta-Galactosidase; D001619:beta-N-Acetylhexosaminidases; D009853:Omeprazole; D000086:Acetazolamide; C039614:ethylisopropylamiloride