Sorting-out of acceptor-donor relationships in the transglutaminase-catalyzed cross-linking of crystallins by the enzyme-directed labeling of potential sites.
The dansyl-conjugated (Dns) peptides Dns-Pro-Gly-Gly-Gln-Gln-Ile-Val and Dns-Ala-Gln-Gln-Ile-Val, patterned on the N-terminal sequence of fibronectin, were synthesized and used for the transglutaminase (protein-glutamine:amine gamma-glutamyltransferase, EC 2.3.2.13)-directed selective blocking of lens proteins that otherwise might participate in donating lysyl side chains in forming N epsilon-(gamma-glutamyl)-lysine cross-linked oligomers and polymers. Labeling profiles with these peptides could be readily visualized by fluorescence as well as by immunoblotting with anti-dansyl antibody. The labeling patterns in rabbit lens homogenates were quite different with the dansylated peptides than those obtained with dansylcadaverine. Use of such glutamine-containing dansylated peptides should clearly aid in identifying, isolating, and sequencing potential donor substrates of transglutaminases in many biological systems.
Lorand
L
L
Department of Biochemistry, Molecular Biology, and Cell Biology, Northwestern University, Evanston, IL 60208.
Parameswaran
K N
KN
Velasco
P T
PT
D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites; D003432:Cross-Linking Reagents; D003459:Crystallins / Q000378:metabolism*; D003619:Dansyl Compounds; D005353:Fibronectins / Q000138:chemical synthesis / Q000494:pharmacology*; D046911:Macromolecular Substances; D008969:Molecular Sequence Data; D009842:Oligopeptides / Q000138:chemical synthesis / Q000494:pharmacology*; D011817:Rabbits; D011503:Transglutaminases / Q000378:metabolism*
D003432:Cross-Linking Reagents; D003459:Crystallins; D003619:Dansyl Compounds; D005353:Fibronectins; D046911:Macromolecular Substances; D009842:Oligopeptides; D011503:Transglutaminases