Pru du 2S albumin or Pru du vicilin?. (June 2015) - Garino, Cristiano
Graphical abstract: Highlights: The current reported sequence of the almond 2S albumin is a partial 28 aa peptide. The translation into protein of an almond EST sequence matches the partial peptide. The in silico generated aa sequence is a member of the vicilin superfamily. The currently known almond 2S albumin is rather a part of a 7S vicilin like protein. Abstract: A short partial sequence of 28 amino acids is all the information we have so far about the putative allergen 2S albumin from almond. The aim of this work was to analyze this information using mainly bioinformatics tools, in order to verify its rightness. Based on the results reported in the paper describing this allergen from almond, we analyzed the original data of amino acids sequencing through available software. The degree of homology of the almond 12 kDa protein with any other known 2S albumin appears to be much lower than the one reported in the paper that firstly described it. In a publicly available cDNA library we discovered an expressed sequence tag which translation generates a protein that perfectly matches both of the sequencing outputs described in the same paper. A further analysis indicated that the latter protein seems to belong to the vicilin superfamily rather than to the prolamin one. The fact that also vicilins are seed storage proteins known to be highly allergenic would explain the IgE reactivity originally observed. Based on our observations we suggest that the IgE reactive 12 kDa protein from almond currently known as Pru du 2S albumin is in reality the cleaved N-terminal region of a 7S vicilin like protein.