کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1926295 1536450 2009 5 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Mitochondrial malic enzyme (ME2) in pancreatic islets of the human, rat and mouse and clonal insulinoma cells: Simple enzyme assay for mitochondrial malic enzyme 2
موضوعات مرتبط
علوم زیستی و بیوفناوری بیوشیمی، ژنتیک و زیست شناسی مولکولی زیست شیمی
پیش نمایش صفحه اول مقاله
Mitochondrial malic enzyme (ME2) in pancreatic islets of the human, rat and mouse and clonal insulinoma cells: Simple enzyme assay for mitochondrial malic enzyme 2
چکیده انگلیسی

Despite interest in malic enzyme(ME)s in insulin cells, mitochondrial malic enzyme (ME2) has only been studied with estimates of mRNA or with mRNA knockdown. Because an mRNA’s level does not necessarily reflect the level of its cognate enzyme, we designed a simple spectrophotometric enzyme assay to measure ME2 activity of insulin cells by utilizing the distinct kinetic properties of ME2. Mitochondrial ME2 uses either NAD or NADP as a cofactor, has a high Km for malate and is allosterically activated by fumarate and inhibited by ATP. Cytosolic ME (ME1) and the other mitochondrial ME (ME3) use only NADP as a cofactor and have lower Kms for malate. The assay easily showed for the first time that substantial ME2 activity is present in pancreatic islets of humans, rats and mice and INS-1 832/13 cells. ME2’s presence was confirmed with immunoblotting. There was no evidence that ME3 is present in these tissues.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Archives of Biochemistry and Biophysics - Volume 488, Issue 2, 15 August 2009, Pages 100–104
نویسندگان
, , ,