Detecting proteins containing 3,4-dihydroxyphenylalanine by silver staining of polyacrylamide gels.
Proteins in which some or all of the tyrosine side chains are post-translationally modified to dihydroxyphenylalanine have been found in several invertebrate phyla. In this paper we describe the unusual silver-staining properties of these 3,4-dihydroxyphenylalanine (Dopa)-proteins in silver-stained polyacrylamide gels. Our evidence suggests that the rapid silver staining of these proteins is due to the 3,4-dihydroxyphenol ring which is a highly effective reducing agent in the alkaline development conditions used in the final step of most silver-staining procedures. Normal proteins comprising the standard 20 amino acids and tyrosine on its own, do not reduce silver under these conditions. Pretreatment of the gels with acid-dichromate solutions abrogates the rapid staining of the Dopa-proteins. This rapid silver-staining technique will facilitate the rapid screening of many additional organisms for Dopa-proteins using sodium dodecyl sulfate gels and small amounts of tissue.
Wells
K
K
Department of Molecular Biology, University of Wyoming, Laramie 82071.
Cordingley
J S
JS
D000818:Animals; D004295:Dihydroxyphenylalanine / Q000032:analysis*; D004591:Electrophoresis, Polyacrylamide Gel / Q000379:methods*; D005260:Female; D015801:Helminth Proteins / Q000737:chemistry*; D007700:Kinetics; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D011499:Protein Processing, Post-Translational; D012550:Schistosoma mansoni / Q000032:analysis*; D012834:Silver; D013194:Staining and Labeling
D015801:Helminth Proteins; D012834:Silver; D004295:Dihydroxyphenylalanine