title: Enzymatic cross-linking of purple membranes catalyzed by bacterial transglutaminase.
abstract: It was found that bacterial transglutaminase (TGase) facilitates selective cross-linking of bacteriorhodopsin (BR) in purple membrane (PM) form under mild conditions. Fluorescent probes were used to detect that the membrane protein BR may act as a glutamine donor as well as a lysine donor for TGase. The binding sites were determined to be Gln-3 as the reactive glutamine, and Lys-129 is the corresponding lysine residue. Upon incubation of PM with TGase, cross-linking of PM patches can be achieved without an additional spacer molecule. To our knowledge, this is the first time that an intermembrane cross-linking of membrane-bound proteins is reported. Furthermore, this finding may provide the ability to achieve covalent linkage of complete purple membrane patches to synthetic polymers.
authors.affiliation: Institute for Physical Chemistry, University of Marburg, D-35032 Marburg, Germany.
authors.forename: A
authors.initials: A
authors.lastname: Seitz
authors.forename: F
authors.initials: F
authors.lastname: Schneider
authors.forename: R
authors.initials: R
authors.lastname: Pasternack
authors.forename: H L
authors.initials: HL
authors.lastname: Fuchsbauer
authors.forename: N
authors.initials: N
authors.lastname: Hampp
mesh_terms: D001436:Bacteriorhodopsins / Q000737:chemistry / Q000378:metabolism*; D002384:Catalysis; D002853:Chromatography, Liquid; D003116:Color; D003432:Cross-Linking Reagents / Q000378:metabolism; D004591:Electrophoresis, Polyacrylamide Gel; D005973:Glutamine / Q000378:metabolism; D006217:Halobacterium / Q000737:chemistry / Q000166:cytology*; D007700:Kinetics; D008239:Lysine / Q000378:metabolism; D008954:Models, Biological; D011485:Protein Binding; D018717:Purple Membrane / Q000737:chemistry / Q000378:metabolism*; D013302:Streptomyces / Q000201:enzymology*; D013997:Time Factors; D011503:Transglutaminases / Q000378:metabolism*
chemical_list: D003432:Cross-Linking Reagents; D005973:Glutamine; D001436:Bacteriorhodopsins; D011503:Transglutaminases; D008239:Lysine