Grafting of aliphatic and aromatic probes on rapeseed 2S and 12S proteins: influence on their structural and physicochemical properties.
Lysyl residues of rapeseed napin (2S) and cruciferin (12S) were acylated and sulfamidated by means of anhydrides and sulfonyl chlorides, respectively. The secondary and tertiary structures as well as the surface hydrophobicity of the modified proteins were studied using circular dichroism, intrinsic fluorescence, and binding of anilinonaphthalenesulfonic acid. The results showed clearly that grafting of hydrophobic chains induced different structural modifications and surface hydrophobicities on the monomeric (2S) and on the hexameric (12S) proteins. Thus, the original structure of the 2S modified protein seemed to be preserved. Therefore, the surface hydrophobicity increased proportionally with the number of groups grafted. Conversely, after modification, 12S was shown to be expanded. As a result, hydrophobic regions were exposed, leading to a much greater hydrophobization of the protein surface. Acylation and sulfamidation appeared, therefore, to be good methods to hydrophobize efficiently the surface of the two proteins and thus might probably induce new functional properties.
Gerbanowski
A
A
Institut National de Recherche Agronomique, Unité de Biochimie et Technologie des protéines, B.P. 71627, 44316 Nantes Cedex 03, France.
Malabat
C
C
Rabiller
C
C
Guéguen
J
J
D055516:2S Albumins, Plant; D000215:Acylation; D000485:Allergens; D052179:Antigens, Plant; D001937:Brassica; D002942:Circular Dichroism; D005511:Food Handling; D006801:Humans; D015335:Molecular Probes / Q000138:chemical synthesis*; D010940:Plant Proteins / Q000737:chemistry*; D055314:Seed Storage Proteins; D013329:Structure-Activity Relationship; D013499:Surface Properties
D055516:2S Albumins, Plant; D000485:Allergens; D052179:Antigens, Plant; D015335:Molecular Probes; D010940:Plant Proteins; D055314:Seed Storage Proteins; C059777:cruciferin protein, Brassica napus; C050363:napin protein, Brassica napus