Probing the folding mechanism of a leucine zipper peptide by stopped-flow circular dichroism spectroscopy.


Abstract

Leucine zipper peptides provide simple model systems for studying both the intramolecular and intermolecular interactions that govern protein folding. The synthetic 33-residue peptide GCN4-p1, derived from the yeast transcriptional activator GCN4, forms a stable biomolecular coiled-coil structure [O'Shea, E. K., Klemm, J. D., Kim, P. S., & Alber, T. (1991) Science 254, 539-544]. The guanidine-HCl induced equilibrium unfolding of this peptide at 5 degrees C and pH 7.0 yields a standard state free energy of 10.49 +/- 0.23 kcal (mol dimer)-1 when fit to a two-state model involving the native dimer and the unfolded monomer. The unfolding and refolding kinetics of GCN4-p1 were monitored by stopped-flow circular dichroism spectroscopy as a function of both peptide concentration and final denaturant concentration. The unfolding kinetics displayed single-exponential behavior, consistent with a unimolecular reaction. The refolding kinetics, which are dependent on both peptide and guanidine concentration, are well described by a simple bimolecular association reaction. A simultaneous fit of all of the unfolding and refolding kinetic data to the model, N2[symbol: see text]2U, yields refolding and unfolding rate constants in the absence of denaturant of 4.2 x 10(5) M-1 S-1 and 3.3 x 10(-3) S-1, respectively. The equilibrium unfolding curve is accurately predicted from these rate constants, providing further support for the validity of the two-state kinetic model. Study holds ProTherm entries: 4885 Extra Details:

Submission Details

ID: GiMPgPjC

Submitter: Connie Wang

Submission Date: April 24, 2018, 8:27 p.m.

Version: 1

Publication Details
Zitzewitz JA;Bilsel O;Luo J;Jones BE;Matthews CR,Biochemistry (1995) Probing the folding mechanism of a leucine zipper peptide by stopped-flow circular dichroism spectroscopy. PMID:7548036
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
1CE9 1999-03-18T00:00:00+0000 1.8 HELIX CAPPING IN THE GCN4 LEUCINE ZIPPER
1DGC 1993-07-15T00:00:00+0000 3.0 THE X-RAY STRUCTURE OF THE GCN4-BZIP BOUND TO ATF/CREB SITE DNA SHOWS THE COMPLEX DEPENDS ON DNA FLEXIBILITY
1FAV 2000-07-13T00:00:00+0000 3.0 THE STRUCTURE OF AN HIV-1 SPECIFIC CELL ENTRY INHIBITOR IN COMPLEX WITH THE HIV-1 GP41 TRIMERIC CORE
1FMH 2000-08-17T00:00:00+0000 0 NMR SOLUTION STRUCTURE OF A DESIGNED HETERODIMERIC LEUCINE ZIPPER
1FMH 2000-08-17T00:00:00+0000 0 NMR SOLUTION STRUCTURE OF A DESIGNED HETERODIMERIC LEUCINE ZIPPER
1GCL 1993-10-20T00:00:00+0000 2.1 GCN4 LEUCINE ZIPPER CORE MUTANT P-LI
1GCM 1995-04-25T00:00:00+0000 1.8 GCN4 LEUCINE ZIPPER CORE MUTANT P-LI
1GK6 2001-08-08T00:00:00+0000 1.9 Human vimentin coil 2B fragment linked to GCN4 leucine zipper (Z2B)
1GZL 2002-05-23T00:00:00+0000 1.8 Crystal structure of C14linkmid/IQN17: a cross-linked inhibitor of HIV-1 entry bound to the gp41 hydrophobic pocket
1IHQ 2001-04-19T00:00:00+0000 0 GLYTM1BZIP: A CHIMERIC PEPTIDE MODEL OF THE N-TERMINUS OF A RAT SHORT ALPHA TROPOMYOSIN WITH THE N-TERMINUS ENCODED BY EXON 1B

Relevant UniProtKB Entries

Percent Identity Matching Chains Protein Accession Entry Name
100.0 General control protein GCN4 P03069 GCN4_YEAST