Submitted to: American Peanut Research and Education Society Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: April 28, 2006
Publication Date: July 10, 2006
Citation: Guo, B., Liang, X.Q., Maleki, S.J., Holbrook, Jr., C.C. 2006. Storage protein profiles of spanish-bunch and runner market type peanuts and identification of a new potential allergen protein [abstract]. In: Proceedings of the American Peanut Research and Education Society Meeting, July 11-14, 2006, Savannah, GA. p. 55. Technical Abstract: Total proteins extracted from seeds of 12 different genotypes of cultivated peanut (Arachis hypogaea L.), comprised of Runner market type and Spanish-bunch market type, were separated by electrophoresis on both one-dimensional and two-dimensional SDS-PAGE gels. The protein profiles were similar on one-dimensional gels for all tested peanut genotypes. However, peanut genotype A13 missed one major band with a molecular weight of about 35 kDa. There was one minor band with a molecular weight of 26 kDa protein that presents in all Runner-type peanut genotypes and the derivatives (GT-YY7, GT-YY20, and GT-YY79), which have a Runner-type peanut in their pedigree. The 35 kDa protein in A13 and the 26 kDa protein in Runner-type peanut genotypes were confirmed on the two-dimensional SDA-PAGE gels. Among more than 150 main protein spots on the 2-D gels, four protein spots that were individually marked as spot 1- 4 were showing polymorphic patterns between Runner-type and Spanish-bunch peanuts. Spot 1 (ca. 22.5 kDa, pI 3.9) and spot 2 (ca. 23.5 kDa, pI 5.7) were observed in all Spanish-bunch genotypes, which were not found in those of Runner types. In contrast, spot 3 (ca. 23 kDa, pI 6.6) and spot 4 (ca. 22 kDa, pI 6.8) presented in all Runner type peanut genotypes but not in Spanish-bunch type genotypes. These four protein spots were sequenced. Based on the internal amino acid sequences and N-terminal sequences, these proteins are isoforms of each other. The results revealed that these isoforms of a storage protein exhibit polymorphism of the subunit composition between subspecies of cultivated peanut. Using Western blotting analysis with Ara h3 antibody, we confirmed these protein spots reacting with Ara h3 antibody in a decreased reactivity, resulting in weaker spots in comparison with strong Ara h3 protein spots. These data may conclude that these proteins are subunits or new isoallergens of a new allergen protein of peanut, isoAra h3.