title: Phage matrix for isolation of glioma cell membrane proteins.
abstract: Cell-binding ligands for RG2 rat glioma were identified in our recent study from a library of peptides that are displayed as fusion molecules on phage particles. Here, one of the phage clones was used to affinity purify those cell membrane components to which the displayed peptides bind. This phage clone, displaying the ELRGDSLP peptide, was shown to recognize glioma cells specifically in comparison to control phage-expressing peptides of either similar or irrelevant sequences. Blocking experiments with synthetic RGDS peptide demonstrated that the phage-glioma cell recognition occurs via the RGD motif known to be present in many integrin-binding proteins. To form an affinity matrix that would bind to glioma cell membrane molecules, ELRGDSLP phage particles were cross-linked using dextran polymer. Whole cell lysate from RG2 rat glioma cells was passed through the matrix, resulting in the isolation of cell membrane components having strong affinity to the peptides on phage and molecules associated with those components. One of the isolated proteins was found to be CD44s, a cell surface adhesion molecule involved in glioma cell invasion and migration, which likely formed a complex with an RGD-binding integrin. Cell membrane proteins isolated with this innovative approach could be used for the design of cell-specific anticancer treatments.
authors.affiliation: The Scott-Ritchey Research Center, College of Veterinary Medicine, Auburn University, Auburn, AL 36849, USA. samoiti@vetmed.auburn.edu
authors.forename: Tatiana I
authors.initials: TI
authors.lastname: Samoylova
authors.forename: Nancy R
authors.initials: NR
authors.lastname: Cox
authors.forename: Nancy E
authors.initials: NE
authors.lastname: Morrison
authors.forename: Ludmila P
authors.initials: LP
authors.lastname: Globa
authors.forename: Victor
authors.initials: V
authors.lastname: Romanov
authors.forename: Henry J
authors.initials: HJ
authors.lastname: Baker
authors.forename: Valery A
authors.initials: VA
authors.lastname: Petrenko
mesh_terms: D000818:Animals; D045744:Cell Line, Tumor; D002846:Chromatography, Affinity / Q000379:methods*; D005240:Feasibility Studies; D005910:Glioma / Q000378:metabolism*; D008565:Membrane Proteins / Q000302:isolation & purification*; D009363:Neoplasm Proteins / Q000302:isolation & purification*; D009842:Oligopeptides; D019151:Peptide Library; D051381:Rats
chemical_list: D008565:Membrane Proteins; D009363:Neoplasm Proteins; D009842:Oligopeptides; D019151:Peptide Library; C047981:arginyl-glycyl-aspartic acid