کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
2015204 1541968 2012 7 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Identification of a novel phosphatase with high affinity for nucleotides monophosphate from common bean (Phaseolus vulgaris)
موضوعات مرتبط
علوم زیستی و بیوفناوری علوم کشاورزی و بیولوژیک دانش گیاه شناسی
پیش نمایش صفحه اول مقاله
Identification of a novel phosphatase with high affinity for nucleotides monophosphate from common bean (Phaseolus vulgaris)
چکیده انگلیسی

Common bean (Phaseolus vulgaris) seedlings accumulate ureides derived from purines after germination. The first step in the conversion of purines to ureides is the removal of the 5′-phosphate group by a phosphatase that has not been established yet. Two main phosphatase activities were detected in the embryonic axes of common bean using inosine monophosphate as substrate in an in-gel assay. Both activities differed in their sensitive to the common phosphatase inhibitor molybdate, with the molybdate-resistant as the first enzyme induced after radicle protrusion. The molybdate-resistant phosphatase has been purified to electrophoretic homogeneity and this is the first enzyme which shows this resistance purified and characterized from plant tissues. The native enzyme was a monomer of 55 kDa and it showed highest activity with nucleotides as substrates, with the Km values in the micromolar range. Among nucleotides, the highest specific constant (Vmax/Km) was observed for adenosine monophosphate. Furthermore, the enzyme was inhibited by nucleosides, the products of the enzymatic reaction, with maximum effect for adenosine. Common bean seedlings imbibed in the presence of adenosine monophosphate in vivo showed the highest molybdate-resistant phosphatase activity in the axes in addition to increased ureide content. The data presented suggests that purified phosphatase is involved in nucleotide metabolism in embryonic axes from common bean.

Figure optionsDownload as PowerPoint slideHighlights
► Two main phosphatases are induced in common bean axes after radicle protrusion.
► One of the induced phosphatase was insensitive to molybdate.
► The molybdate-resistant phosphatase has been purified to homogeneity.
► The purified enzyme had higher affinity for nucleotides monophosphate.
► Kinetic properties suggest that purified enzyme is a nucleotidase.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Plant Physiology and Biochemistry - Volume 53, April 2012, Pages 54–60
نویسندگان
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