Unfolding studies on soybean agglutinin and concanavalin a tetramers: a comparative account.


The unfolding pathway of two very similar tetrameric legume lectins soybean agglutinin (SBA) and Concanavalin A (ConA) were determined using GdnCl-induced denaturation. Both proteins displayed a reversible two-state unfolding mechanism. The analysis of isothermal denaturation data provided values for conformational stability of the two proteins. It was found that the DeltaG of unfolding of SBA was much higher than ConA at all the temperatures at which the experiments were done. ConA had a T(g) 18 degrees C less than SBA. The higher conformational stability of SBA in comparison to ConA is largely due to substantial differences in their degrees of subunit interactions. Ionic interactions at the interface of the two proteins especially at the noncanonical interface seem to play a significant role in the observed stability differences between these two proteins. Furthermore, SBA is a glycoprotein with a GlcNac2Man9 chain attached to Asn-75 of each subunit. The sugar chain in SBA lies at the noncanonical interface of the protein, and it is found to interact with the amino acid residues in the adjacent noncanonical interface. These interactions further stabilize SBA with respect to ConA, which is not glycosylated. Study holds ProTherm entries: 19171, 19172, 19173, 19174, 19175, 19176, 19177, 19178, 19179, 19180, 19181, 19182, 19183, 19184, 19185, 19186, 19187, 19188, 19189, 19190, 19191, 19192, 19193 Extra Details: lectins; two-state unfolding; noncanonical interface

Submission Details

ID: hpi5vyYB3

Submitter: Connie Wang

Submission Date: April 24, 2018, 8:51 p.m.

Version: 1

Publication Details
Sinha S;Mitra N;Kumar G;Bajaj K;Surolia A,Biophys. J. (2005) Unfolding studies on soybean agglutinin and concanavalin a tetramers: a comparative account. PMID:15542553
Additional Information

Study Summary

Number of data points 48
Proteins Lectin ; Lectin ; Concanavalin-A ; Concanavalin-A
Unique complexes 2
Assays/Quantities/Protocols Experimental Assay: dCp ; Experimental Assay: Tm ; Experimental Assay: dHvH ; Experimental Assay: m temp:312 K ; Experimental Assay: dG_H2O temp:312 K ; Experimental Assay: m temp:294 K ; Experimental Assay: dG_H2O temp:294 K ; Experimental Assay: m temp:291 K ; Experimental Assay: dG_H2O temp:291 K ; Experimental Assay: m temp:285 K ; Experimental Assay: dG_H2O temp:285 K ; Experimental Assay: m temp:280 K ; Experimental Assay: dG_H2O temp:280 K ; Experimental Assay: m temp:323 K ; Experimental Assay: dG_H2O temp:323 K ; Experimental Assay: m temp:318 K ; Experimental Assay: dG_H2O temp:318 K ; Experimental Assay: m temp:313 K ; Experimental Assay: dG_H2O temp:313 K ; Experimental Assay: m temp:306 K ; Experimental Assay: dG_H2O temp:306 K ; Experimental Assay: m temp:303 K ; Experimental Assay: dG_H2O temp:303 K ; Experimental Assay: m temp:300 K ; Experimental Assay: dG_H2O temp:300 K ; Experimental Assay: m temp:298 K ; Experimental Assay: dG_H2O temp:298 K ; Experimental Assay: m temp:295 K ; Experimental Assay: dG_H2O temp:295 K ; Experimental Assay: m temp:293 K ; Experimental Assay: dG_H2O temp:293 K ; Experimental Assay: m temp:288 K ; Experimental Assay: dG_H2O temp:288 K ; Experimental Assay: m temp:283 K ; Experimental Assay: dG_H2O temp:283 K ; Experimental Assay: m temp:281 K ; Experimental Assay: dG_H2O temp:281 K

Structure view and single mutant data analysis

Study data

No weblogo for data of varying length.
Colors: D E R H K S T N Q A V I L M F Y W C G P

Data Distribution

Studies with similar sequences (approximate matches)

Correlation with other assays (exact sequence matches)

Relevant PDB Entries

Structure ID Release Date Resolution Structure Title
4L8Q 2013-06-17T00:00:00+0000 2.3 Crystal structure of Canavalia grandiflora seed lectin complexed with X-Man.
5U3E 2016-12-02T00:00:00+0000 2.3 Crystal Structure of Native Lectin from Canavalia bonariensis Seeds (CaBo) complexed with alpha-methyl-D-mannoside
5F5Q 2015-12-04T00:00:00+0000 2.52 Crystal structure of Canavalia virosa lectin in complex with alpha-methyl-mannoside
6GW9 2018-06-22T00:00:00+0000 2.1 Concanavalin A structure determined with data from the EuXFEL, the first MHz free electron laser
2A7A 2005-07-05T00:00:00+0000 1.75 On the Routine Use of Soft X-Rays in Macromolecular Crystallography, Part III- The Optimal Data Collection Wavelength
2G4I 2006-02-22T00:00:00+0000 2.4 Anomalous substructure of Concanavalin A
3QLQ 2011-02-03T00:00:00+0000 1.7 Crystal structure of Concanavalin A bound to an octa-alpha-mannosyl-octasilsesquioxane cluster
4CZS 2014-04-22T00:00:00+0000 1.73 Discovery of Glycomimetic Ligands via Genetically-encoded Library of Phage displaying Mannose-peptides
4K1Y 2013-04-07T00:00:00+0000 2.5 Crystal structure of Canavalia boliviana lectin in complex with Man1-3Man-OMe
4K1Z 2013-04-07T00:00:00+0000 2.3 Crystal structure of Canavalia boliviana lectin in complex with Man1-4Man-OMe

Relevant UniProtKB Entries

Percent Identity Matching Chains Protein Accession Entry Name
100.0 Lectin P05046 LEC_SOYBN
91.5 Concanavalin-A P58906 LECA_CANBN
98.6 Concanavalin-A P14894 CONA_CANGL
100.0 Concanavalin-A P02866 CONA_CANEN
94.1 Concanavalin-A A0A067XG71 LECA_CANGR
97.5 Concanavalin-A A0A023GPI8 LECA_CANBL
98.3 Concanavalin-A P81460 CONA_CANLI
98.3 Concanavalin-A P55915 CONA_CANBR
98.3 Concanavalin-A C0HJY1 CONV_CANCT
98.3 Concanavalin-A P81461 CONA_CANCT