title: The sulphatase of ox liver. XXIII. The nature of substrate-modified sulphatase A.
abstract: An improved method is described for the preparation of milligram quantities of substrate-modified sulphatase A. The latter has the same molecular weight and the same ability to form a tetramer as has native sulphatase A. It has been shown that the modified enzyme prepared with nitrocatechol [35S]sulphate as substrate contains 1 mol 35SO24- per mol enzyme and that any treatment which causes reversion of the modified enzyme to native enzyme is accompanied by the loss of the bound SO24-. Dialysis of the 35S-modified enzyme against a solution containing SO24- causes a loss of 35SO24- with no change in the amount of modified enzyme in the preparation. It has been shown that the activation of the substrate-modified enzyme by SO24- does not lead to the formation of a third stable form of sulphatase A.
mesh_terms: D000818:Animals; D001192:Arylsulfatases / Q000302:isolation & purification / Q000378:metabolism*; D002396:Catechols / Q000378:metabolism; D002417:Cattle; D055598:Chemical Phenomena; D002621:Chemistry; D004355:Drug Stability; D004789:Enzyme Activation / Q000187:drug effects; D007700:Kinetics; D008099:Liver / Q000201:enzymology*; D008970:Molecular Weight; D013056:Spectrophotometry, Ultraviolet; D013429:Sulfatases / Q000378:metabolism*; D013431:Sulfates / Q000494:pharmacology
chemical_list: D002396:Catechols; D013431:Sulfates; D013429:Sulfatases; D001192:Arylsulfatases; C021228:4-nitrocatechol sulfate