Stability and binding properties of wild-type and c17s mutated human sterol carrier protein 2.


Abstract

The temperature- and solvent-induced denaturation of both the SCP2 wild-type and the mutated protein c71s were studied by CD measurements at 222 nm. The temperature-induced transition curves were deconvoluted according to a two-state mechanism resulting in a transition temperature of 70.5 degrees C and 59.9 degrees C for the wild-type and the c71s, respectively, with corresponding values of the van't Hoff enthalpies of 183 and 164 kJ/mol. Stability parameters characterizing the guanidine hydrochloride denaturation curves were also calculated on the basis of a two-state transition. The transitions of the wild-type occurs at 0.82 M GdnHCl and that of the c71s mutant at 0.55 M GdnHCl. These differences in the half denaturation concentration of GdnHCl reflect already the significant stability differences between the two proteins. A quantitative measure are the Gibbs energies DeltaG(0)(D)(buffer) at 25 degrees C of 15.5 kJ/mol for the wild-type and 8.0 kJ/mol for the mutant. We characterized also the alkyl chain binding properties of the two proteins by measuring the interaction parameters for the complex formation with 1-O-Decanyl-beta-D-glucoside using isothermal titration microcalorimetry. The dissociation constants, K(d), for wild-type SCP2 are 335 microM at 25 degrees C and 1.3 mM at 35 degrees C. The corresponding binding enthalpies, DeltaH(b), are -21. 5 kJ/mol at 25 degrees C and 72.2 kJ/mol at 35 degrees C. The parameters for the c71s mutant at 25 degrees C are K(d)=413 microM and DeltaH(b)=16.6 kJ/mol. These results suggest that both SCP2 wild-type and the c71s mutant bind the hydrophobic compound with moderate affinity. Study holds ProTherm entries: 15099, 15100, 15101, 15102 Extra Details: Additive:EDTA 1mM isothermal titration calorimetry; SCP2; protein stability

Submission Details

ID: FWgkeT564

Submitter: Connie Wang

Submission Date: April 24, 2018, 8:45 p.m.

Version: 1

Publication Details
Jatzke C;Hinz HJ;Seedorf U;Assmann G,Biochim. Biophys. Acta (1999) Stability and binding properties of wild-type and c17s mutated human sterol carrier protein 2. PMID:10407148
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
1QND 2000-07-03 STEROL CARRIER PROTEIN-2, NMR, 20 STRUCTURES
1C44 2000-08-07 1.8 STEROL CARRIER PROTEIN 2 (SCP2) FROM RABBIT
2C0L 2006-11-15 2.3 TPR DOMAIN OF HUMAN PEX5P IN COMPLEX WITH HUMAN MSCP2

Relevant UniProtKB Entries

Percent Identity Matching Chains Protein Accession Entry Name
96.7 Non-specific lipid-transfer protein O62742 NLTP_RABIT
100.0 Non-specific lipid-transfer protein P22307 NLTP_HUMAN
92.7 Non-specific lipid-transfer protein P11915 NLTP_RAT
94.3 Non-specific lipid-transfer protein P07857 NLTP_BOVIN
96.7 Non-specific lipid-transfer protein P32020 NLTP_MOUSE