کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1178616 962706 2006 7 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Biochemical characterization of the class B acid phosphatase (AphA) of Escherichia coli MG1655
موضوعات مرتبط
مهندسی و علوم پایه شیمی شیمی آنالیزی یا شیمی تجزیه
پیش نمایش صفحه اول مقاله
Biochemical characterization of the class B acid phosphatase (AphA) of Escherichia coli MG1655
چکیده انگلیسی

The AphA enzyme of Escherichia coli, a molecular class B periplasmic phosphatase that belongs to the DDDD superfamily of phosphohydrolases, was purified and subjected to biochemical characterization. Kinetic analysis with several substrates revealed that the enzyme essentially behaves as a broad-spectrum nucleotidase highly active on 3′- and 5′-mononucleotides and monodeoxynucleotides, but not active on cyclic nucleotides, or nucleotides di- and triphosphate. Mononucleotides are degraded to nucleosides, and AphA apparently does not exhibit any nucleotide phosphomutase activity. However, it can transphosphorylate nucleosides in the presence of phosphate donors. Kinetic properties of AphA are consistent with structural data, and suggest a role for the hydrophobic pocket present in the active site crevice, made by residues Phe 56, Leu71, Trp77 and Tyr193, in conferring preferential substrate specificity by accommodating compounds with aromatic rings. AphA was inhibited by several chelating agents, including EDTA, EGTA, 1,10-phenanthroline and dipicolinic acid, with EDTA being apparently the most powerful inhibitor.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Biochimica et Biophysica Acta (BBA) - Proteins and Proteomics - Volume 1764, Issue 1, January 2006, Pages 13–19
نویسندگان
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