Post-translational peptide bond formation during concanavalin A processing in vitro.
Post-translational processing of concanavalin A (Con A) is complex, involving deglycosylation, proteolytic cleavage on the carboxy group side of asparagine residues and formation of a peptide bond de novo. This has been studied with the 125I-labelled Con A glycoprotein precursor as a substrate for processing in vitro. Extracts of immature jackbean cotyledons and the commercially available purified preparation of asparaginylendo-peptidase were able to catalyse the above processes. The processing resulted in the conversion of the 33.5 kDa inactive glycoprotein precursor into an active lectin. Processing activity was maximal at approx. pH 5.5. Evidence to support processing at authentic sites was obtained by observation of the release of 125I at positions in the sequence where tyrosine residues were present.
Sheldon
P S
PS
Centre for Plant Biochemistry, University of Leeds, U.K.
Keen
J N
JN
Bowles
D J
DJ
D000595:Amino Acid Sequence; D002846:Chromatography, Affinity; D003208:Concanavalin A / Q000378:metabolism*; D003546:Cysteine Endopeptidases / Q000378:metabolism; D004591:Electrophoresis, Polyacrylamide Gel; D007887:Fabaceae / Q000201:enzymology / Q000378:metabolism; D006023:Glycoproteins / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D037102:Lectins / Q000096:biosynthesis; D008969:Molecular Sequence Data; D009943:Organophosphorus Compounds / Q000378:metabolism; D010455:Peptides / Q000378:metabolism*; D037121:Plant Lectins; D010940:Plant Proteins / Q000378:metabolism; D010946:Plants, Medicinal; D011499:Protein Processing, Post-Translational / Q000502:physiology*; D000099240:Asparaginyl Endopeptidase
D003208:Concanavalin A; D003546:Cysteine Endopeptidases; D006023:Glycoproteins; D037102:Lectins; D009943:Organophosphorus Compounds; D010455:Peptides; D037121:Plant Lectins; D010940:Plant Proteins; D000099240:Asparaginyl Endopeptidase; C043517:2-(4-isothiocyanatophenoxy)-1,3,2-dioxaphosphinene 2-oxide