Proteomics of arabinogalactan-proteins (AGP) from Acacia gums

id="offer-description" class="ecl-u-type-heading-2 ecl-u-mt-none ecl-u-mb-l">Offer Description 1. Objectives. Acacia gums are very interesting hydrocolloids used for stabilizing dispersed systems such as emulsions and foams and for coating solid materials due to their excellent adhesive and interfacial properties. These properties would come from the presence of a continuum of molecular species, in particular arabinogalactan-protein and glycoprotein, whose chemical composition and three-dimensional structure promote the adhesion and interaction on solid and liquid interfaces. No work to our knowledge however reports a thorough fundamental understanding of the sequence of proteins linked to polysaccharide blocks of Acacia gum and their three molecular fractions, arabinogalactan-peptide (FI), arabinogalactan-protein or AGP (FII) and glycoprotein (FIII). From literature, deglycosylation by hydrofluoric acid (HF) of Acacia gum revealed two putative core polypeptides (Mahendran et al., 2008) with a molecular mass of approximately 3 × 104 Da and 5 × 103 Da. This suggests the presence of two core polypeptides of ∼250 and ∼45 amino acids, respectively. It seems that a consensus would exist from literature for at least one core polypeptide of 250 amino acids but nobody knows today how many core polypeptides are present in Acacia gums. 2. Previous results. We determined the number of aminoacids in Acacia senegal gum from far-UV circular dichroism data and calculations (Renard et al., B