Thermal stability and mode of oligomerization of the tetrameric peanut agglutinin: a differential scanning calorimetry study.


Abstract

Peanut agglutinin is a homotetrameric legume lectin. The crystal structure of peanut agglutinin shows that the four subunits associate in an unusual manner, giving rise to open quaternary structure [Banarjee, R., et al. (1994) Proc. Natl. Acad. Sci. U.S.A. 91, 227-231]. The thermal unfolding of peanut agglutinin has been characterized by differential scanning calorimetry and gel filtration to elucidate its thermal stability and its mode of oligomerization. The unfolding process is reversible and could be described by a three-state model with two transitions occurring at around 331 and 336 K. For the tetramer, the ratio of DeltaHc/DeltaHv for the first transition is close to 4 and for the second transition is close to 0.25, suggesting that 4 and 0.25 cooperative unit(s) of the tetramer are involved in the first and second transitions, respectively. The agreement between the model-independent DeltaHv(S) determined from the values of the temperatures of the peak maximum (Tp1) with the protein concentration with the values of DeltaHv obtained from the fit of the data to the transition confirms that the first peak is associated with the dissociation of peanut agglutinin tetramers (A4) to "folded" monomers (4A), whereas the second peak describes the unfolding (4U) of these monomers. The overall process for the thermal unfolding of peanut agglutinin could therefore be summarized as A4 <==> 4A <==> 4U. Gel filtration studies confirm this process, as peanut agglutinin elutes as a tetramer up to 50 degrees C, and at and above 56 degrees C (Tm of first transition), it elutes at a position commensurate with that of the folded monomer of peanut agglutinin. The unfolding behavior of peanut agglutinin in the presence of saturating amounts of carbohydrate ligands is similar to that observed for the unligated form. The temperature of maximal stability of the peanut agglutinin tetramer at pH 7.4 is calculated to be around 33 degrees C with a maximal free energy of stabilization of 8.70 kcal/mol. The results demonstrate that unfolding of peanut agglutinin goes through two distinct phases with folded monomer being the intermediate. Study holds ProTherm entries: 5598, 5599, 5600, 5601, 5602, 5603, 5604, 5605, 5606, 5607, 5608, 5609, 5610, 5611, 5612, 5613 Extra Details: the transition is from native to intermediate

Submission Details

ID: eovooDPY3

Submitter: Connie Wang

Submission Date: April 24, 2018, 8:30 p.m.

Version: 1

Publication Details
Reddy GB;Bharadwaj S;Surolia A,Biochemistry (1999) Thermal stability and mode of oligomerization of the tetrameric peanut agglutinin: a differential scanning calorimetry study. PMID:10194368
Additional Information

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
1V6I 2004-02-10 2.15 Peanut lectin-lactose complex in acidic pH
2DVA 2006-11-07 2.2 Crystal structure of peanut lectin GAL-BETA-1,3-GALNAC-ALPHA-O-ME (Methyl-T-antigen) complex
2DVD 2006-11-07 2.25 Crystal structure of peanut lectin GAL-ALPHA-1,3-GAL complex
2PEL 1996-12-07 2.25 PEANUT LECTIN
2DVB 2006-11-07 2.25 Crystal structure of peanut lectin GAl-beta-1,6-GalNAc complex
1V6K 2004-02-10 2.4 Peanut lectin-lactose complex in the presence of peptide(IWSSAGNVA)
2DV9 2006-11-07 2.48 Crystal structure of peanut lectin GAL-BETA-1,3-GAL complex
1V6L 2004-02-10 2.5 Peanut lectin-lactose complex in the presence of 9mer peptide (PVIWSSATG)
2TEP 1999-04-08 2.5 PEANUT LECTIN COMPLEXED WITH T-ANTIGENIC DISACCHARIDE
1CR7 2001-04-21 2.6 PEANUT LECTIN-LACTOSE COMPLEX MONOCLINIC FORM
1V6M 2004-02-10 2.7 Peanut Lectin with 9mer peptide (IWSSAGNVA)
1CIW 1999-07-27 2.7 PEANUT LECTIN COMPLEXED WITH N-ACETYLLACTOSAMINE
1BZW 1998-11-11 2.7 PEANUT LECTIN COMPLEXED WITH C-LACTOSE
2DVF 2006-11-07 2.74 Crystals of peanut lectin grown in the presence of GAL-ALPHA-1,3-GAL-BETA-1,4-GAL
2DVG 2006-11-07 2.78 Crystal structure of peanut lectin GAL-ALPHA-1,6-GLC complex
1QF3 1999-07-27 2.8 PEANUT LECTIN COMPLEXED WITH METHYL-BETA-GALACTOSE
1RIT 2004-12-28 2.85 Crystal structure of Peanut lectin in complex with meso-tetrasulphonatophenylporphyrin and lactose
1RIR 2004-12-28 2.9 Crystal structure of meso-tetrasulphonatophenylporphyrin in complex with Peanut lectin.
1V6J 2004-02-10 2.9 peanut lectin-lactose complex crystallized in orthorhombic form at acidic pH
1V6O 2004-02-10 3.0 Peanut lectin complexed with 10mer peptide (PVRIWSSATG)
1CQ9 2002-05-01 3.5 PEANUT LECTIN-TRICLINIC FORM
1V6N 2004-02-10 3.5 Peanut lectin with 9mer peptide (PVIWSSATG)
2DH1 2006-08-15 7.65 Crystal structure of peanut lectin lactose-azobenzene-4,4'-dicarboxylic acid-lactose complex

Relevant UniProtKB Entries

Percent Identity Matching Chains Protein Accession Entry Name
100.0 Galactose-binding lectin P02872 LECG_ARAHY