Conformational States of Sunflower (Helianthus annuus) Helianthinin: Effect of Heat and pH
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- 作者：Sergio Gonzá ; lez-Pé ; rez ; Johan M. Vereijken ; Karin B. Merck ; Gerrit A. van Koningsveld ; Harry Gruppen ; and Alphons G. J. Voragen
- 刊名：Journal of Agricultural and Food Chemistry
- 出版年：2004
- 出版时间：November 3, 2004
- 年：2004
- 卷：52
- 期：22
- 页码：6770 - 6778
- 全文大小：306K
- 年卷期：v.52,no.22(November 3, 2004)
- ISSN：1520-5118
文摘
The structure and solubility of helianthinin, the most abundant protein of sunflower seeds, wasinvestigated as a function of pH and temperature. Dissociation of the 11S form (hexamer) into the7S form (trimer) gradually increased with increasing pH from 5.8 to 9.0. High ionic strength (I = 250mM) stabilizes the 11S form at pH > 7.0. Heating and low pH resulted in dissociation into themonomeric constituents (2-3S). Next, the 7S and 11S forms of helianthinin were isolated and shownto differ in their secondary and tertiary structure, and to have denaturation temperatures (Td) of 65and 90 
C, respectively. Furthermore, the existence of two populations of the monomeric form ofhelianthinin with denaturation temperatures of 65 and 90 C was described. This leads to thehypothesis that helianthinin can adopt two different conformational states: one with Td = 65 C anda second with Td = 90 C.Keywords: Helianthus annuus; sunflower; helianthinin; stability; conformational states; denaturation
C, respectively. Furthermore, the existence of two populations of the monomeric form ofhelianthinin with denaturation temperatures of 65 and 90 C was described. This leads to thehypothesis that helianthinin can adopt two different conformational states: one with Td = 65 C anda second with Td = 90 C.Keywords: Helianthus annuus; sunflower; helianthinin; stability; conformational states; denaturation