کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
10536778 | 962605 | 2015 | 10 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Misfolding caused by the pathogenic mutation G47R on the minor allele of alanine:glyoxylate aminotransferase and chaperoning activity of pyridoxine
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کلمات کلیدی
MTSPBSPLPpH1IFMAlanine:glyoxylate aminotransferase - آلانین: گلیوکسیلات آمینوترانسفرازphosphate buffer - بافر فسفاتCho - برایChinese Hamster Ovary - تخمدان هامستر چینیmitochondrial targeting sequence - توالی هدایت میتوکندریPhosphate buffered saline - فسفات بافر شورImmunofluorescence microscopy - میکروسکوپ ایمونوفلورسانسPrimary hyperoxaluria type 1 - نوع اول hyperoxaluria اولیهPrimary hyperoxaluria type I - نوع اول هیپرکسالورژی اولیهPathogenic variant - نوع پاتوژنیکAGT - هشتpyridoxal 5′-phosphate - پیریدوکسال 5'-فسفاتPyridoxine - پیریدوکسینglycolate oxidase - گلیکول اکسیداز
موضوعات مرتبط
مهندسی و علوم پایه
شیمی
شیمی آنالیزی یا شیمی تجزیه
پیش نمایش صفحه اول مقاله
چکیده انگلیسی
Liver peroxisomal alanine:glyoxylate aminotransferase (AGT), a pyridoxal 5â²-phosphate (PLP) enzyme, exists as two polymorphic forms, the major (AGT-Ma) and the minor (AGT-Mi) haplotype. Deficit of AGT causes Primary Hyperoxaluria Type 1 (PH1), an autosomal recessive rare disease. Although ~Â one-third of the 79 disease-causing missense mutations segregates on AGT-Mi, only few of them are well characterized. Here for the first time the molecular and cellular defects of G47R-Mi are reported. When expressed in Escherichia coli, the recombinant purified G47R-Mi variant exhibits only a 2.5-fold reduction of its kcat, and its apo form displays a remarkably decreased PLP binding affinity, increased dimer-monomer equilibrium dissociation constant value, susceptibility to thermal denaturation and to N-terminal region proteolytic cleavage, and aggregation propensity. When stably expressed in a mammalian cell line, we found ~Â 95% of the intact form of the variant in the insoluble fraction, and proteolyzed (within the N-terminal region) and aggregated forms both in the soluble and insoluble fractions. Moreover, the intact and nicked forms have a peroxisomal and a mitochondrial localization, respectively. Unlike what already seen for G41R-Mi, exposure of G47R-Mi expressing cells to pyridoxine (PN) remarkably increases the expression level and the specific activity in a dose-dependent manner, reroutes all the protein to peroxisomes, and rescues its functionality. Although the mechanism of the different effect of PN on the variants G47R-Mi and G41R-Mi remains elusive, the chaperoning activity of PN may be of value in the therapy of patients bearing the G47R mutation.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Biochimica et Biophysica Acta (BBA) - Proteins and Proteomics - Volume 1854, Issue 10, Part A, October 2015, Pages 1280-1289
Journal: Biochimica et Biophysica Acta (BBA) - Proteins and Proteomics - Volume 1854, Issue 10, Part A, October 2015, Pages 1280-1289
نویسندگان
Riccardo Montioli, Elisa Oppici, Mirco Dindo, Alessandro Roncador, Giovanni Gotte, Barbara Cellini, Carla Borri Voltattorni,