Complete Amino-Acid Sequence of the Naturally Occurring A<sub><b>2</b></sub>Activator Protein for Enzymic Sphingomyelin Degradation: Identity to the Sulfatide Activator Protein (SAP-1)

Kleinschmidt, Traute; Christomanou, H.; Braunitzer, Gerhard

doi:10.1515/bchm3.1988.369.2.1361

Cited by 13 publications

(5 citation statements)

References 17 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Why do a few clones from the patient have 57 nucleotides deleted, leaving the last 9 nucleotides of the insertion? Protein sequencing has not revealed the three amino acids coded for by the 9 base pairs in normal human SAP-1 or in rat sulfated glycoprotein 1 (26,30). A search for the 33 base pairs in GenBank on April 1, 1989, did not yield any clue as to its source.…”

Section: Resultsmentioning

confidence: 98%

Insertion in the mRNA of a metachromatic leukodystrophy patient with sphingolipid activator protein-1 deficiency.

Zhang

Rafi

Degala

et al. 1990

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

The lysosomal catabolism of sulfatide requires arylsulfatase A and a specific sphingolipid activator protein, SAP-1. While most patients with metachromatic leukodystrophy have mutations in the gene for arylsulfatase A, some patients have deficient SAP-1, as determined by immunological techniques. We now describe the molecular findings in a patient who died at 22 years of age with SAP-1 deficiency. The DNA polymerase chain reaction was used to amplify regions of cDNA which were subcloned in M13 phage DNA and sequenced by the dideoxy chain-termination method. The patient was found to have a 33-base-pair insertion between nucleotides 777 and -778 (numbered from the A of the ATG initiation codon). No other changes were found in the coding sequence of the cDNA from this patient. At the site of the insertion some normal people have an additional 9 base pairs, which correspond to the last 9 nucleotides at the 3' end of the insertion. The cDNAs from the second-cousin parents were amplified and sequenced, and in both two alleles were identified, one with the 33-base-pair insertion and one with no insertion. Two brothers were found to have only the normal alleles and a sister was found to have the 33-base-pair insertion and a normal allele. The findings confirm studies performed on leukocyte extracts demonstrating normal antigen levels in the two brothers and a lower level in the sister. The presence of i1 additional amino acids in the coding region of mature SAP-1 in this patient causes significant changes in the hydropathy profile compatible with the previous findings at the protein level.The catabolism of most sphingolipids requires both a specific lysosomal enzyme and a specific, relatively low molecular weight protein we call sphingolipid activator protein (SAP) (1). While at least six SAPs have been identified, the exact number is not known. However, it is now obvious that, while most lysosomal disorders are due to defects in lysosomal enzymes, some very serious and fatal disorders are due to defects in SAP (2-5). These include the AB variant of GM2 gangliosidosis, a variant form of metachromatic leukodystrophy, and a variant form of Gaucher disease. While the patients have clear evidence for decreased catabolism of a specific lipid, the lysosomal enzyme activity measured in vitro is normal and there is evidence for decreased levels of a specific SAP in all cases thus far identified (2,5,6).The cDNA coding for the SAP-1 precursor species, called prosaposin by Morimoto et al. (7), has been cloned and sequenced (8,9). Most recently Nakano et al. (10) published the complete corrected sequence, which is in agreement with our unpublished data, except those authors found a 9-base-pair (bp) insertion between nucleotides 777 and 778 (counting from the A of the ATG initiation codon) in clones from normal people. The SAP-1 precursor protein contains four domains of about 80 amino acids, each with similar structural features, including glycosylation sites and proline and cysteine residues (11-13). The domains are prot...

show abstract

Section: Resultsmentioning

confidence: 98%

Insertion in the mRNA of a metachromatic leukodystrophy patient with sphingolipid activator protein-1 deficiency.

Zhang

Rafi

Degala

et al. 1990

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

show abstract

“…The only major difference in the amino acid sequences predicted by the full-length cDNAs (Gavrieli- Rorman and Grabowski, 1989;Nakano et al, 1989) was the presence of an in-frame 9-bp insertion (three amino acids) in the saposin B coding sequence of cDNAs isolated by Nakano et al (1989) from lung and skin fibroblast libraries. Furthermore, the complete chemically determined sequence of saposin B did not contain the predicted three-amino acid insertion (Kleinschmidt et al, 1988). These results suggest a potential for tissue-specific The 5' end of the gene has not been fully characterized, but is probably composed of several small exons and larger introns.…”

Section: Molecular Biology Of the Activator Proteinsmentioning

confidence: 91%

“…7, the full-length human "proactivator" cDNA (Gavrieli- Rorman and Grabowski, 1989; contains regions of high amino acid similarity (>80%). The existence of these activators has been demonstrated by their partial or complete amino acid sequence determined from proteins isolated from human (Morimoto et al, 1988(Morimoto et al, , 1989Kleinschmidt et al, 1988;Dewji et al, 1987) or guinea pig (Sano et al, 1988) sources. The only major difference in the amino acid sequences predicted by the full-length cDNAs (Gavrieli- Rorman and Grabowski, 1989;Nakano et al, 1989) was the presence of an in-frame 9-bp insertion (three amino acids) in the saposin B coding sequence of cDNAs isolated by Nakano et al (1989) from lung and skin fibroblast libraries.…”

Section: Molecular Biology Of the Activator Proteinsmentioning

confidence: 99%

Gaucher Disease

Grabowski

1993

Advances in Human Genetics 21

View full text Add to dashboard Cite

“…In addition to the facilitation of CS turnover, CSAct is believed to have other functions. It is identical with the activator protein for the hydrolysis of ganglioside GM1, ceramide trihexoside and possibly other glycolipids 1, 11, 12. CSAct binds a limited repertoire of lipids with highest affinity for gangliosides and CS 13.…”

Section: Introductionmentioning

confidence: 99%

Hydrogen-deuterium exchange signature of porcine cerebroside sulfate activator protein

et al. 2000

View full text Add to dashboard Cite

Hydrogen–deuterium exchange can be a sensitive indicator of protein structural integrity. Comparisons were made between cerebroside sulfate activator protein (CSAct) in the native state and after treatment with guanidine hydrochloride plus dithiothreitol. Native protein has three internal disulfide bonds and treated protein has no internal disulfide bonds. The comparisons were made using hydrogen–deuterium exchange measured by electrospray ionization mass spectrometry, percentage α‐helical content measured by circular dichroism and biological activity measured by the ability to support arylsulfatase A‐catalyzed sulfate hydrolysis from cerebroside sulfate. In acidic solvent native protein has 59 exchange refractory protons and treated protein has 20 exchange refractory protons (44 and 14% of the exchangeable proton populations, respectively). In native protein the size of the exchange refractory proton population is sensitive to changes in pH, temperature and the presence of a ligand. It is uninfluenced by the presence or absence of glycosyl groups attached to Asn21. Helical content is virtually identical in native and treated protein. Biological activity is significantly reduced but not obliterated in treated protein. The hydrogen–deuterium exchange profile appears to be a sensitive signature of the correctly folded protein, and reflects a dimension of the protein structure that is not apparent in circular dichroic spectra or in the ability of the protein to support arylsulfatase A‐catalyzed sulfate hydrolysis from sulfatide. The hydrogen–deuterium exchange profile will be a valuable criterion for characterizing mutant forms of CSAct produced by recombinant and synthetic paradigms and also the native and mutant forms of related proteins. Copyright © 2000 John Wiley & Sons, Ltd.

show abstract

Complete Amino-Acid Sequence of the Naturally Occurring A₂Activator Protein for Enzymic Sphingomyelin Degradation: Identity to the Sulfatide Activator Protein (SAP-1)

Cited by 13 publications

References 17 publications

Insertion in the mRNA of a metachromatic leukodystrophy patient with sphingolipid activator protein-1 deficiency.

Insertion in the mRNA of a metachromatic leukodystrophy patient with sphingolipid activator protein-1 deficiency.

Gaucher Disease

Hydrogen-deuterium exchange signature of porcine cerebroside sulfate activator protein

Contact Info

Product

Resources

About

Complete Amino-Acid Sequence of the Naturally Occurring A2Activator Protein for Enzymic Sphingomyelin Degradation: Identity to the Sulfatide Activator Protein (SAP-1)

Cited by 13 publications

References 17 publications

Insertion in the mRNA of a metachromatic leukodystrophy patient with sphingolipid activator protein-1 deficiency.

Insertion in the mRNA of a metachromatic leukodystrophy patient with sphingolipid activator protein-1 deficiency.

Gaucher Disease

Hydrogen-deuterium exchange signature of porcine cerebroside sulfate activator protein

Contact Info

Product

Resources

About

Complete Amino-Acid Sequence of the Naturally Occurring A₂Activator Protein for Enzymic Sphingomyelin Degradation: Identity to the Sulfatide Activator Protein (SAP-1)