Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.1.6.1 (sulfatase)
 3,205 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Fragments of the arylsulfatase A (ARSA) gene from a patient with juvenile-onset metachromatic leukodystrophy (MLD) were amplified by PCR and ligated into MP13 cloning vectors. Clones hybridizing with cDNA for human ARSA were selected, examined for appropriate size inserts, and used to prepare single-stranded phage DNA. Examination of the entire coding and most of the intronic sequence revealed two putative disease-related mutations. One, a point mutation in exon 3, resulted in the substitution of isoleucine by serine. Introduction of this alteration into the normal ARSA cDNA sequence resulted in a substantial decrease in ARSA activity on transient expression in cultured baby hamster kidney cells. About 5% of the control expression was observed, suggesting a small residual activity in the mutated ARSA. The second mutation, a G-to-A transition, occurred in the other allele and resulted in an altered splice-recognition sequence between exon 7 and the following intron. The mutation also resulted in the loss of a restriction site. Apparently normal levels of mRNA were generated from this allele, but no ARSA activity or immuno-cross-reactive material could be detected. A collection of DNA samples from known or suspected MLD patients, members of their families, and normal controls was screened for these mutations. Four additional individuals carrying each of the mutations were found among the nearly 100 MLD patients in the sample. Gene segregation in the original patient's family was consistent with available clinical and biochemical data. No individuals homozygous for either of these two mutations were identified. However, combinations with other MLD mutations suggest that the point mutation in exon 3 does result in some residual enzyme activity and is associated with late-onset forms of the disease. The splice-site mutation following exon 7 produces late-infantile MLD when combined with other enzyme-null mutations, implying that it is completely silent enzymatically.
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PMID:Two new arylsulfatase A (ARSA) mutations in a juvenile metachromatic leukodystrophy (MLD) patient. 168 88

The lysosomal degradation of sulfatide requires the specific enzyme, arylsulfatase A, as well as a heat stable protein called sphingolipid activator protein-1 (SAP-1). While most patients with metachromatic leukodystrophy have defects in arylsulfatase A, some patients have defects in SAP-1. SAP-1 is coded for by a gene on human chromosome 10 that also codes for three other proposed SAP. Examination of the cDNA from two siblings with SAP-1 deficiency revealed a point mutation of nucleotide #650 (counting from the initiation ATG) which is in the SAP-1 coding domain. This C to T transition changed the codon from threonine (ACC) to one coding for isoleucine (ATC). This eliminated the only glycosylation site in mature SAP-1 and could explain the findings made at the protein level.
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PMID:Detection of a point mutation in sphingolipid activator protein-1 mRNA in patients with a variant form of metachromatic leukodystrophy. 230 19

Saposins are small, heat-stable glycoproteins required for the hydrolysis of sphingolipids by specific lysosomal hydrolases. Saposins A, B, C, and D are derived by proteolytic processing from a single precursor protein named prosaposin. Saposin B, previously known as SAP-1 and sulfatide activator, stimulates the hydrolysis of a wide variety of substrates including cerebroside sulfate, GM1 ganglioside, and globotriaosylceramide by arylsulfatase A, acid beta-galactosidase, and alpha-galactosidase, respectively. Human saposin B deficiency, transmitted as an autosomal recessive trait, results in tissue accumulation of cerebroside sulfate and a clinical picture resembling metachromatic leukodystrophy (activator-deficient metachromatic leukodystrophy). We have examined transformed lymphoblasts from the initially reported saposin B-deficient patient and found normal amounts of saposins A, C, and D. After preparing first-strand cDNA from lymphoblast total RNA, we used the polymerase chain reaction to amplify the prosaposin cDNA. The patient's mRNA differed from the normal sequence by only one C----T transition in the 23rd codon of saposin B, resulting in a threonine to isoleucine amino acid substitution. An affected male sibling has the same mutation as the proband and their heterozygous mother carries both the normal and mutant sequences, providing additional evidence that this base change is the disease-causing mutation. This base change results in the replacement of a polar amino acid (threonine) with a nonpolar amino acid (isoleucine) and, more importantly, eliminates the glycosylation signal in this activator protein. One explanation for the deficiency of saposin B in this disease is that the mutation may increase the degradation of saposin B by exposing a potential proteolytic cleavage site (arginine) two amino acids to the amino-terminal side of the glycosylation site when the carbohydrate side chain is absent.
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PMID:Characterization of a mutation in a family with saposin B deficiency: a glycosylation site defect. 232 May 74

The enzyme activities of four strains of Legionella pneumophilia were investigated by using the API ZYM system (API System S.A., F-38390 Montalieu Vercieu, France) and synthetic substrates. Aminopeptidases were detected specifically against L-alanine, L-arginine, L-aspartic acid, L-cystine, L-glutaminic acid, glycine, L-histidine, L-isoleucine, L-leucine, L-lysine, L-methionine, L-phenylalanine, L-tryptophan, L-tyrosine, and L-valine. Furthermore, the bacteria possesses esterase activity splitting propionate, butyrate, caproate, caprylate, and caprate, but not laurate, myristate, palmitate, and stearate, esters. The enzymes studies were inhibited partially by aprotinin. No inhibition of phosphatase (pH range, 5.4 to 8.5) or of phosphoamidase was observed. Activities of arylsulfatase, chymotrypsin, trypsin, and glycosidases could not be detected.
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PMID:Enzymatic profile of Legionella pneumophilia. 616 35

The enzyme spectrum of non proliferating cells of Erysipelothrix rhusiopathiae was investigated by means of different low molecular synthetic substrates. Activities of aminopeptidases were found directed against compounds of L-alanine, L-arginine, L-aspartic acid, glycine, L-isoleucine, L-leucine, L-lysine, L-methionine, L-phenylalanine, L-proline, L-tryptophane, and L-tyrosine, but not against compounds of l-cystine, L-glutaminic acid, L-histidine, L-hydroxyproline, and L-valine (Table 1). The pH optimum of the investigated aminopeptidases ranges from neutral to alkaline reaction (Table 2). Trypsin, chymotrypsin, or chymotrypsin-like proteases were not detected. E. rhusiopathiae possess esterase activity splitting esters of lower carboxylic acids, i. e. acetic acid, propionic acid, butyric acid, caproic acid, and caprylic acid, but no lipase activity. Under the provoked glycosidases only alpha- and beta-D-galactosidase and glucosaminidase were positive. Weak activities of phosphatases and arylsulfatase were found also (Table 3).
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PMID:[Investigations of the enzyme spectrum of Erysipelothrix rhusiopathiae (author's transl)]. 627 98

The arylsulfatase A gene of a Japanese patient who has the juvenile form of metachromatic leukodystrophy, and who has been previously reported as a heterozygote of the 1070A mutation, was investigated. Nucleotide sequence analysis revealed the presence of a previously unreported C-to-T substitution (designated 2330T), 22 nucleotides downstream from the exon 8 splice acceptor site. Although the 2330T mutation itself results in a single amino acid substitution of Thr409 by Ile, the analysis of the patient's cDNA fragments amplified by the reverse transcription-polymerase chain reaction revealed that transcripts of the 2330T allele were spliced both normally and aberrantly. The aberrant splicing produced a 27-nucleotide deletion from the usual exon 8 splice acceptor site. These results indicate that the new mutation is a rare case of an exon mutation affecting splice site selection. The mechanism of this aberrant pre-mRNA splicing is discussed.
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PMID:Single exon mutation in arylsulfatase A gene has two effects: loss of enzyme activity and aberrant splicing. 790 27

We describe the cases of 2 sisters with adult metachromatic leukodystrophy (MLD). Whereas one sister presented with disorganized schizophrenia-like symptoms as the initial manifestation of MLD, the other remained symptom free except for a 4-week period of postpartum depression. In both patients, there was some residual activity of leukocyte arylsulfatase A (1.7% and 5.5% of normal), and a marked increase in urinary sulfatides was present, as measured by tandem mass spectrometry. An arylsulfatase A pseudodeficiency was therefore excluded. The most common mutations of the adult phenotype, Ile-179-Ser and Pro-426-Leu, were not found. In the literature, only 1 case of adult MLD manifesting as disorganized schizophrenia-like symptoms has been described, whereas postpartum depression has been so far unknown as a presenting symptom of MLD.
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PMID:Adult metachromatic leukodystrophy: disorganized schizophrenia-like symptoms and postpartum depression in 2 sisters. 1564 95