Polypeptide ligation occurs during post-translational modification of concanavalin A

  title={Polypeptide ligation occurs during post-translational modification of concanavalin A},
  author={D. M. Carrington and Anthony D. Auffret and David E. Hanke},
Lectins are proteins with multivalent carbohydrate-binding sites, which confer the ability to agglutinate. The seeds of legumes are particularly rich in lectins, for example, concanavalin A (Con A) comprises up to 15% of the protein in the cotyledons of jack bean (Canavalia ensiformis) seeds. The amino acid sequences of Con A and several other legume lectins have been partially or fully determined, and comparison of these sequences from different species reveals a circular homology1,2 (Fig. 1A… 
Concanavalin A is synthesized as a glycoprotein precursor
Results indicate that Con A is cotranslationally processed by the removal of a signal sequence and the addition of an oligosaccharide side chain of corresponding size, and the implications of the conversion of a glycoprotein pro-Con A to mature Con A are discussed.
Transport and processing of the glycosylated precursor of Concanavalin A in jack-bean
This is the first demonstration that the transport of a glycoprotein in plant cells is dependent on the presence of the glycan, and that the processing of pro-ConA occurs in the protein bodies.
Structural and biochemical analyses of concanavalin A circular permutation by jack bean asparaginyl endopeptidase.
By reconstituting conA biosynthesis in vitro, it is proved CeAEP1 alone can perform both cleavage and cleavage-coupled transpeptidation to form conA and structural analysis reveals how it is capable of carrying out both reactions.
A Novel Protease from Jack-Bean Seeds: Asparaginyl Endopeptidase
The results suggest that the bean at least in its premature state contains an asparaginyl endopeptidase which may have a dual function, proteolysis and transpeptidation, which was confirmed by isolating it from commercially available jack-bean meal and showed its high utility in protein sequence analysis.
Posttranslational processing of concanavalin A precursors in jackbean cotyledons
Pulse-chase experiments and analyses of immunoprecipitated lectin forms indicated a complex series of events involving seven distinct species and consideration of the tertiary structure of the glycosylated precursor and mature lectin showed that the entire series of processing events could occur without significant refolding of the initial translational product.
Structural basis for a natural circular permutation in proteins
By reconstituting the biosynthesis of conA in vitro, it is proved CeAEP1 alone can perform both the cleavage and cleavage-coupled transpeptidation to form conA, and structural analysis reveals how it is capable of carrying out both these reactions.
Molecular cloning and characterization of ConBr, the lectin of Canavalia brasiliensis seeds.
The hypothesis that substitution of amino acids located at the subunit interface of structurally related lectins of the same protein family can lead to different quaternary conformations that may account for their different biological activities is supported.
Establishment of a heterologous system for the expression of Canavalia brasiliensis lectin: a model for the study of protein splicing.
During its biosynthesis in developing Canavalia brasiliensis seeds, the lectin ConBr undergoes a form of protein splicing in which the order of the N- and C-domains of the protein is reversed. To
Post-translational proteolytic processing and the isolectins of lentil and other Viciae seed lectins
Electrospray mass spectrometry was used to identify precisely the proteolytic cleavage points within, and at the C-termini of, the proprotein forms of four Viciae lectins that give rise to their


Cloning of Pea Storage Protein Genes
Comparisons have confirmed that the legumin α and β subunits as initially synthesized are covalently joined together and that a small peptide is subsequently removed by endoproteolysis to give the disulphide linked subunits of the mature seed legumins.
An efficient mRNA-dependent translation system from reticulocyte lysates.
A simple method is described for converting a standard rabbit reticulocyte cell-free extract (lysate) into an mRNA-dependent protein synthesis system, and no residual nuclease activity could be detected, and the tRNA is functionally unimpaired.
Multiple forms in the subunit structure of concanavalin A.
Protein Fusion: A Novel Reaction in Bacteriophage λ Head Assembly
Parts of two phage-coded head proteins, pE and pC, become fused during bacteriophage λ head assembly, and only a specific subset of the sequences of each protein is found in the fusion products, and these sequences are found inThe products in equimolar amounts.
Involvement of Lipid-linked Oligosaccharides in Synthesis of Storage Glycoproteins in Soybean Seeds.
Membrane preparations from developing soybean cotyledon tissue catalyze the sequential assembly of lipid-linked oligosaccharides which show similar characteristics to polyisoprenyl diphosphate derivatives on diethylaminoethyl-cellulose chromatography and are potential intermediates in glycoprotein biosynthesis in this tissue.
Cleavage of Structural Proteins during the Assembly of the Head of Bacteriophage T4
Using an improved method of gel electrophoresis, many hitherto unknown proteins have been found in bacteriophage T4 and some of these have been identified with specific gene products. Four major
Transfer of proteins from gels to diazobenzyloxymethyl-paper and detection with antisera: a method for studying antibody specificity and antigen structure.
We describe a rapid and very sensitive method for detecting proteins as antigens after their separation in polyacrylamide/agarose composite gels, with or without sodium dodecyl sulfate. The