title: Lysosomal arylsulfatases A and B from horse blood leukocytes: purification and physico-chemical properties.
abstract: Lysosomal arylsulfatases A and B (aryl-sulfate sulfohydrolases, EC 3.1.6.1) from horse leukocytes were purified about 680-fold and 70-fold, respectively, starting from a crude extract of the azurophil and specific granules of leukocytes, by affinity, ion exchange, and gel filtration chromatography. Purified arylsulfatase A displayed anomalous kinetics, a pH optimum at 5.2, an isoelectric point at 4.3, and a Km value for p-nitrocatechol sulfate (pNCS) of 0.37 mM. This enzyme was found to exist in two association states depending on pH: a high molecular weight form at pH 5.0 and a low molecular weight form at pH 7.5. Arylsulfatase B displayed normal kinetics, a pH optimum at 5.8, two isoelectric points at pH 8.6 and 8.9, and a Km value for pNCS of 3.38 mM. The thermostability of the two enzymes was different: arylsulfatase B was found to be more stable than arylsulfatase A. Arylsulfatase A was inhibited by sulfate, sulfite, silver, magnesium, manganese and calcium ions and arylsulfatase B by chloride, sulfate, sulfite and silver ions.
mesh_terms: D000818:Animals; D002553:Cerebroside-Sulfatase / Q000097:blood* / Q000302:isolation & purification; D002803:Chondro-4-Sulfatase / Q000097:blood* / Q000302:isolation & purification; D004795:Enzyme Stability; D006736:Horses; D006358:Hot Temperature; D007700:Kinetics; D007962:Leukocytes / Q000201:enzymology*; D008247:Lysosomes / Q000201:enzymology*; D008970:Molecular Weight; D013429:Sulfatases / Q000097:blood*; D013816:Thermodynamics
chemical_list: D013429:Sulfatases; D002553:Cerebroside-Sulfatase; D002803:Chondro-4-Sulfatase