کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
9890867 | 1540337 | 2005 | 8 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
The contribution of ionic interactions to the conformational stability and function of polygalacturonase from A. niger
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کلمات کلیدی
8-anilino-1-naphthalene sulfonic acidPVDFNaClPolygalacturonaseA. nigerRFIsodium dodecyl sulfate-polyacrylamide gel electrophoresis - الکتروفورز ژل دوده سولفات سدیم پلی آکریل آمیدSDS-PAGE - الکتروفورز ژل پلی آکریل آمیدIonic interactions - تداخلات یونیConformational change - تغییر کنفورماسیونیcircular dichroism - رنگ تابی دورانیANS - سالSodium chloride - سدیم کلریدrelative fluorescence intensity - شدت فلورسانس نسبیhistidine residues - هیستیدین باقی ماندهpolyvinyldifluoride - پلی وینیلدفلوئوریدhigh performance liquid chromatography - کروماتوگرافی مایع با کارایی بالاHPLC - کروماتوگرافی مایعی کارا
موضوعات مرتبط
علوم زیستی و بیوفناوری
بیوشیمی، ژنتیک و زیست شناسی مولکولی
زیست شیمی
پیش نمایش صفحه اول مقاله
![عکس صفحه اول مقاله: The contribution of ionic interactions to the conformational stability and function of polygalacturonase from A. niger The contribution of ionic interactions to the conformational stability and function of polygalacturonase from A. niger](/preview/png/9890867.png)
چکیده انگلیسی
Aspergillus niger produces multiple forms of polygalacturonases with molecular masses ranging from 30 to 60 kDa. The high molecular weight polygalacturonase (61 ± 2 kDa) from A. niger possesses a pH optimum of 4.3 and a pI of 3.9. The enzyme exhibited high sensitivity, both in terms of activity and structure, in the pH range of 4.3-7.0. The enzyme was irreversibly inactivated at pH 7.0. The enzyme is predominantly rich in parallel β structure. There is unfolding of the enzyme molecule between 4.3 and 7.0 resulting in irreversible loss of secondary and tertiary structure with the exposure of hydrophobic surfaces. ANS binding measurements, intrinsic fluorescence and acrylamide quenching measurements have confirmed the unfolding and exposure of hydrophobic surfaces. The midpoint of pH transition for both activity and secondary structure is 6.2 ± 0.1. The pH-induced changes of polygalacturonase confirm the role of histidine residues in structure and activity of the enzyme. The irreversible nature of inactivation is due to the unfolding induced exposure of hydrophobic surfaces leading to association/aggregation of the molecule. Size exclusion chromatography measurements have established the association of enzyme at higher pH. Urea induced unfolding measurements at pH 4.3 and 7.0 have confirmed the loss in stability as we approach neutral pH.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: International Journal of Biological Macromolecules - Volume 36, Issue 5, 28 September 2005, Pages 310-317
Journal: International Journal of Biological Macromolecules - Volume 36, Issue 5, 28 September 2005, Pages 310-317
نویسندگان
T.C. Jyothi, Sridevi Annapurna Singh, A.G. Appu Rao,