The Structural Features of Concanavalin A Governing Non-proline Peptide Isomerization

Abstract

Lectins are a structurally very diverse class of proteins that bind carbohydrates with considerable specificity but moderate affinities (1). Their ability to bind carbohydrates often depends on the binding of metal ions that mediate with the carbohydrate directly (the Ca 2ϩ -dependent animal lectins (2)) or indirectly (lectins from the Leguminosae family). Leguminosae lectins form a large family of plant lectins that succeed in covering a broad range of fine specificity toward oligosaccharides through subtle variations in length and sequence of five different loops A-E (3-5). All Leguminosae lectins share the need for transition metal ion and calcium binding to stabilize the active conformation of these loops. The five amino acids involved in metal binding are fully conserved. These are a histidine (His-24 in ConA

Efficiency of blocking of non-specific interaction of different proteins by BSA adsorbed on hydrophobic and hydrophilic surfaces

“…Given that a BSA molecule has the dimensions 4 Â 4 Â 14 nm [29], the thickness of a close-packed monolayer of BSA molecules in the flattest orientation is 4 nm. Similarly, for layers of Con A dimers, IgG and SpA, the thickness of the corresponding close-packed monolayers is 3, 5 and 2.5 nm, respectively [30][31][32][33][34][35]. The surface coverage obtained from the best fit of the simulated to the experimental spectra of the adsorbed BSA (1.4 nm) and co-adsorbed Con A (0.7 nm) on the hydrophilic surface (Fig.…”

Purification of a PHA-Like Chitin-binding Protein from Acacia farnesiana Seeds: A Time-dependent Oligomerization Protein

“…Comparisons of these sequences and structures have established that differences in carbohydrate specificity appear to be primarily due to differences in amino acid residues residing in adjacent loops to the carbohydrate-binding site [9][10][11][12]. The conformation of these loops is determined by the presence of calcium and transition metal ions in the protein structure [13][14][15].…”

Onion-like glycodendrimersomes from sequence-defined Janus glycodendrimers and influence of architecture on reactivity to a lectin

“…However, their nature as type-1 membrane proteins hampers studies on GDS aggregation (agglutination). Close similarities between the tissue and legume lectins, resulting in their classification as leguminous-like (L type) (25,26), provide the motivation to run the assays with the tetrameric leguminous lectin Con A (ConA), a popular model often used in glycocluster research (7,9,10,12). The distance between two lectin sites for ConA binding to the surface of the same Janus GDS is about 64 Å or 70 Å, and the cations are bound to ConA to hold amino acid side chains in place for ligand binding (25).…”