The alpha-N-acetyl-glucosaminidase gene is transcriptionally activated in male and female gametes prior to fertilization and is essential for seed development in Arabidopsis.
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Lysosomal alpha-N-acetylgalactosaminidase deficiency, the enzymatic defect in angiokeratoma corporis diffusum with glycopeptiduria.
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Recently a novel case of angiokeratoma corporis diffusum with glycoaminoaciduria was described in a 46-yr-old Japanese woman. Known causes of the cutaneous manifestation were eliminated by enzyme analyses, and further characterization of the accumulated urinary O-linked sialopeptides revealed identity to those excreted by patients with an infantile neuroaxonal dystrophy due to lysosomal alpha-N-acetylgalactosaminidase deficiency. Investigation of the alpha-N-acetylgalactosaminidase activity and protein in the proband revealed less than 2% of normal activity and the absence of detectable immunoreactive enzyme protein, findings comparable to those in the patients with infantile neuroaxonal dystrophy and alpha-N-acetylgalactosaminidase deficiency. In addition, the proband's unaffected offspring had half-normal levels of alpha-N-acetylgalactosaminidase activity, consistent with this enzymatic deficiency being the primary metabolic defect in this autosomal recessive trait. Ultrastructural examination of skin and blood cells from the adult proband revealed the presence of prominent lysosomal inclusions containing diffuse amorphous and filamentous material. In contrast, these morphologic findings were not observed in the nonneural tissues from patients with infantile neuroaxonal dystrophy and alpha-N-acetylgalactosaminidase deficiency. These studies document the occurrence of two forms of alpha-N-acetylgalactosaminidase deficiency and sialopeptiduria, a severe infantile-onset form of neuroaxonal dystrophy without angiokeratoma or visceral lysosomal inclusions and an adult-onset form characterized by angiokeratoma, extensive lysosomal accumulation of sialoglycopeptides and the absence of detectable neurologic involvement. (+info)
Cloning, recombinant production, crystallization and preliminary X-ray diffraction analysis of a family 101 glycoside hydrolase from Streptococcus pneumoniae.
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Chemical and immunological characterization of the two alpha-N-acetylgalactosaminidases from squid liver.
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Based on the inherent alpha-galactosidase activity, squid liver contains two different alpha-N-acetylgalactosaminidases (alpha-GalNAcases): alpha-N-acetylgalactosaminidase I (alpha-GalNAcase I), which typically exhibits the alpha-galactosidase activity and alpha-N-acetylgalactosaminidase II (alpha-GalNAcase II), which is devoid of such activity. The molecular properties of the alpha-GalNAcases that may account for their enzymological differences are as yet unknown. In this study, we have characterized and compared the chemical and immunological properties of alpha-GalNAcase I and alpha-GalNAcase II. Analysis of the N-terminal sequence of the first twenty amino acids revealed the striking homology between alpha-GalNAcase I and alpha-GalNAcase II. Digestion of alpha-GalNAcase I and alpha-GalNAcase II generated the peptide maps that display similarities in peptide pattern, indicating their close relationship in structure. Polyclonal antibodies were generated in rabbits against the purified alpha-GalNAcase I and alpha-GalNAcase II for comparison of the immunological properties. Both Western blot and surface plasmon resonance (SPR) studies showed that the anti-alpha-GalNAcase II antibody reacted with both alpha-GalNAcase I and alpha-GalNAcase II, whereas the anti-alpha-GalNAcase I antibody reacted only with alpha-GalNAcase I, indicating the presence of common as well as unique antigenic determinants on alpha-GalNAcase I and alpha-GalNAcase II. Taken together, these results suggest that alpha-GalNAcase I and alpha-GalNAcase II are closely related with regard to structure and that their nonhomologous domains are possibly responsible for the differences in enzymatic properties. (+info)
The 1.9 a structure of human alpha-N-acetylgalactosaminidase: The molecular basis of Schindler and Kanzaki diseases.
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