Detailed physicochemical characterization of the 2S storage protein from rape (Brassica napus L.).
Chromatographic, chemical, and spectroscopic techniques were used to characterize the physicochemical properties of napin purified by preparative chromatography. The molar extinction coefficient was determined (epsilon = 0.56), and static and dynamic light scattering measurements enabled the average molecular weight (M(w) = 13919), the second virial coefficient (A(2) = 23.95 x 10(-)(5) mol cm(3) g(-)(2)), and the hydrodynamic radius (R(H) = 1.98 nm) to be determined. No conformational changes were observed by fluorescence and circular dichroism measurements in different buffers at pH 3, 4.6, 7, and 12, confirming the high pH stability of this protein. From MALDI-TOF analysis and after enzymatic digestion, it was found that this purified sample, extracted from the rapeseed variety Express, contained mainly isoform 2SS3_BRANA.
Schmidt
Isabelle
I
Unité de Physico-Chimie des Macromolécules and Unité de Recherches sur les Protéines Végétales et leurs Interactions, INRA, Rue de la Géraudière, 44316 Nantes Cedex 03, France.
Renard
Denis
D
Rondeau
David
D
Richomme
Pascal
P
Popineau
Yves
Y
Axelos
Monique Augustin-Viguier
MA
D055516:2S Albumins, Plant; D029688:Brassica napus / Q000737:chemistry*; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D002845:Chromatography; D002942:Circular Dichroism; D004591:Electrophoresis, Polyacrylamide Gel; D008027:Light; D013058:Mass Spectrometry; D008970:Molecular Weight; D010940:Plant Proteins / Q000737:chemistry*; D011487:Protein Conformation; D020033:Protein Isoforms / Q000737:chemistry; D012542:Scattering, Radiation; D013057:Spectrum Analysis
D055516:2S Albumins, Plant; D010940:Plant Proteins; D020033:Protein Isoforms; C050363:napin protein, Brassica napus