Skip Navigation



PEDS Advance Access published online on August 24, 2007
Protein Engineering Design and Selection, doi:10.1093/protein/gzm039
This Article
Right arrow Full Text Freely available
Right arrow FREE Full Text (PDF) Freely available
Right arrow All Versions of this Article:
20/9/433    most recent
gzm039v2
gzm039v1
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Add to My Personal Archive
Right arrow Download to citation manager
Right arrowRequest Permissions
Google Scholar
Right arrow Articles by Prak, K.
Right arrow Articles by Utsumi, S.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Prak, K.
Right arrow Articles by Utsumi, S.
Social Bookmarking
Add to CiteULike   Add to Connotea   Add to Del.icio.us  
What's this?

© The Author 2007. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oxfordjournals.org

C-terminus engineering of soybean proglycinin: improvement of emulsifying properties

Krisna Prak, Kazuyo Nakatani, Nobuyuki Maruyama and Shigeru Utsumi*

Laboratory of Food Quality Design and Development, Graduate School of Agriculture, Kyoto University, Uji, Kyoto 611-0011, Japan

* To whom correspondence should be addressed. E-mail: sutsumi{at}kais.kyoto-u.ac.jp

Introduction of the extension region of ß-conglycinin {alpha}' subunit at the C-terminus of proglycinin A1aB1b results in the improvement of its emulsifying properties. To understand the basic for such improvement, we introduced the {alpha}' and {alpha} extension regions to the A2B1a C-terminus, and the {alpha} extension and A5A4B3 hypervariable regions, and an oligopeptide composed of 20 negatively or positively charged residues to the A1aB1b C-terminus, creating A2B1a{alpha}', A2B1a{alpha}, and A1aB1b{alpha}, A1aB1bA4IV, A1aB1bNeg and A1aB1bPos, respectively. All the modified versions were produced in Escherichia coli. Their molecular size, thermal stability, surface hydrophobicity, solubility and emulsifying ability were studied. Analyses of molecular size and thermal stability suggested that all the modified versions formed the proper conformation similar to that of the wild type (WT). Solubility was intrinsic to each mutant. At ionic strength 0.5, the emulsifying abilities of all mutants were better than that of the WT except A1aB1bPos and A1aB1bNeg, and at ionic strength 0.08, all mutants especially A1aB1bPos exhibited better emulsifying ability than did the WT. The order of stability of the emulsion at both ionic strengths (0.08 and 0.5) was A1aB1b{alpha} ≥ A2B1a{alpha} > A1aB1b{alpha}' ≥ A2B1a{alpha}' >> A1aB1bPos > A1aB1bA4IV ≥ A1aB1bNeg > A1aB1b, A2B1a. These results indicate that the emulsion stability of proglycinin mutants depends on length and hydropathy profile of the polypeptides added to the C-terminus of proglycinin.

Keywords: emulsion/proglycinin/protein engineering/solubility/soybean

Received September 21, 2006; revised June 17, 2007; accepted June 21, 2007.


Add to CiteULike CiteULike   Add to Connotea Connotea   Add to Del.icio.us Del.icio.us    What's this?




Disclaimer: Please note that abstracts for content published before 1996 were created through digital scanning and may therefore not exactly replicate the text of the original print issues. All efforts have been made to ensure accuracy, but the Publisher will not be held responsible for any remaining inaccuracies. If you require any further clarification, please contact our Customer Services Department.