Enzymatic cross-linking of purple membranes catalyzed by bacterial transglutaminase.
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.
Seitz
A
A
Institute for Physical Chemistry, University of Marburg, D-35032 Marburg, Germany.
Schneider
F
F
Pasternack
R
R
Fuchsbauer
H L
HL
Hampp
N
N
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*
D003432:Cross-Linking Reagents; D005973:Glutamine; D001436:Bacteriorhodopsins; D011503:Transglutaminases; D008239:Lysine