SELDI-TOF-MS as a rapid tool to study food related protein-peptide interactions

The use of SELDI-TOF-MS was investigated as a rapid tool to detect peptides present in a crude protein hydrolysate, which are capable to bind to intact food proteins. A purified and well characterized beta-lactoglobulin preparation was extensively hydrolyzed by the Glu-specific enzyme V8 from Staphylococcus aureus. Characterization of this hydrolysate by SELDI-TOF-MS and MALDI-TOF-MS resulted in sixteen identified peptides, which covered 98% of the primary sequence of b-lactoglobulin. To identify peptides capable to bind non-covalently to intact proteins, the complete hydrolysate was applied to covalently bound ovalbumin, glycinin, beta-lactoglobulin and beta-casein on a SELDI ProteinChip PS-20. Six peptides (AB [f29-45], AB [f90-108], AB [f138-158], B [f63-89], AB [f1-45], AB [f135-162] bound to these four different proteins with decreasing affinity to glycinin > ovalbumin > b-lactoglobulin > b-casein. Peptides, which bound to these proteins were AB [f1-45] and AB [f135-158]. Using different concentrations of Triton X-100 (up to 2%) as a washing step prior to MS detection, enabled a rapid distinction between the peptides bound with respect to protein binding capacity. (C) 2010 Elsevier Ltd. All rights reserved.