The Patterns of Arylsulphatases a and B in Human Normal and Metachromatic Leucodystrophy Tissues and Their Relationship to the Cerebroside Sulphatase Activity

Abstract

Abstract— The arylsulphatase A and B patterns of human tissues and leucocytes have been established by isoelectric focussing. Assay conditions, which enable an evaluation of these patterns as quantitatively as possible, have been studied. The dependences of the enzyme patterns on the origin of the tissues and on the storage conditions have been determined. The arylsulphatase A obtained by isoelectric focussing exhibits cerebroside sulphatase activity in the presence of detergents. A purified preparation of the arylsulphatase B likewise shows a significant, although low, cerebroside sulphatase activity. In cases of the conventional types of metachromatic leucodystrophy the arylsulphatase A activity is missing, while in an atypical form of this disease (‘ML Variant’ according to Austinet al. (1965) the arylsulphatase A, B and C activities are deficient. In both forms, however, residual activities of the deficient enzymes could be detected which showed isoelectric points identical to those of the normal enzymes. The following nomenclature is proposed: ‘Variant B’ for the conventional type, in which the arylsulphatase B activity is present, and ‘Variant O’ for the exceptional cases, in which all arylsulphatase activities are deficient. The significance of the cerebroside sulphatase activity of arylsulphatase B for a possible residual turnover of cerebroside sulphates in the conventional type of the disease is discussed.

Immunologic Studies of Arylsulfatase A in Normal and Metachromatic Leukodystrophy Liver

“…is a lysosomal enzyme (6) present in various human tissues (4,7). Deficiency of this enzyme has been described in a group of familial metabolic disorders, metachromatic leukodystrophies (MLD) (1).…”

Incorporation of Inorganic Sulfate in Rat-Liver Golgi

“…The importance of sulfate metabolism was further emphasized when, in several pathological conditions like mucopolysaccharidoses [36], metachromatic leukodystrophy [37], liver cirrhosis [38], inflammation [39], etc., serious disorders sulfate metabolism were observed.…”

Prenatal Diagnosis of Metachromatic Leukodystrophy by Electrophoretic and Immunologic Techniques

“…In particular, the two lysosomal forms, AS-A and AS-B, differ in molecular weight, subunit composition, isoelectric point, and antigenic properties (13,26,34). The chemical nature of the compounds stored or excreted in MLD and MPS VI (1,37) and in vitro enzymatic studies (14,21) strongly suggests that sulfatides are natural substrates for AS-A, and that N-acetyl galactosamine-4-sulfate residues in chondroitin and dermatan sulfate are natural substrates for AS-B. Both enzymes recognize PNCS as substrate in vitro, but the activity of AS-B towards PNCS is inhibited by sodium pyrophosphate and sodium chloride; this is the basis of an indirect assay system commonly used to mcasure AS-A activity in the presence of AS-B (5).…”