کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1190670 963537 2010 6 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Purification and characterisation of Saccharomyces cerevisiae external invertase isoforms
موضوعات مرتبط
مهندسی و علوم پایه شیمی شیمی آنالیزی یا شیمی تجزیه
پیش نمایش صفحه اول مقاله
Purification and characterisation of Saccharomyces cerevisiae external invertase isoforms
چکیده انگلیسی

Four external invertase isoforms (EINV1, EINV2, EINV3 and EINV4) from Saccharomyces cerevisiae were highly purified by isoelectric precipitation, ethanol precipitation, ion-exchange on QAE-Sephadex and gel filtration using Sephacryl S-200. Unlike previously published procedures for external invertase purification, a specially designed step elution was applied on QAE-Sephadex which enabled the separation of four isoforms. The isoforms have the same molecular mass and catalytic properties: Km for sucrose (25.6 mM), pH optimum (3.5–5.0) and temperature optimum (60 °C), but they exhibit significant difference in pI values, thermal stability and chemical reactivity. Deglycosylation studies showed that the observed differences between isoforms arise from posttranslational modifications. Results showed that external invertase is a mixture of at least four isoforms, but in order to improve the efficiency of food industry processes, only the most stable isoform (EINV1) should be purified and utilised. Substantially different chemical reactivity of the isoforms could be used to improve the yield of covalent immobilization procedures.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Food Chemistry - Volume 120, Issue 3, 1 June 2010, Pages 799–804
نویسندگان
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