Charge repulsion in the conformational stability of melittin.


Electrostatic repulsion between positively charged groups has been suggested to be critical in determining the conformation of melittin. To clarify the role of repulsive forces, we prepared a series of succinylated melittins, an acetylated melittin, and a synthetic melittin mutant, with various degrees of charge repulsion. The conformation of the melittin derivatives was examined by far-UV circular dichroism under various conditions of pH and salt at 20 degrees C. The stability of the tetrameric helical state was found to be dependent on the net charge of the peptides. The charge repulsive forces destabilized the helical state of intact melittin by 600 cal/(charge.mol of tetramer). This value was close to the corresponding one (450 cal/(charge.mol)) obtained for the acidic molten globule of horse cytochrome c [Goto, Y., & Nishikiori, S. (1991) J. Mol. Biol. 222, 679-686], which has a molecular weight and a net charge comparable to those of the tetrameric melittin. Small-angle X-ray scattering of the tetrameric melittin and the molten globule of cytochrome c showed that the two states are also comparable to each other in the radius of gyration. These results suggest that the contribution of electrostatic repulsion to the conformational stability of melittin is similar to that of the molten globule. Study holds ProTherm entries: 4791 Extra Details:

Submission Details

ID: BcPZdV8s3

Submitter: Connie Wang

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

Version: 1

Publication Details
Hagihara Y;Kataoka M;Aimoto S;Goto Y,Biochemistry (1992) Charge repulsion in the conformational stability of melittin. PMID:1445922
Additional Information

Study Summary

Number of data points 1
Proteins Melittin ; Melittin
Unique complexes 1
Assays/Quantities/Protocols Experimental Assay: dG
Libraries Mutations for sequence GIGAVLKVLTTGLPALISWIKRKRQQ

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 UniProtKB Entries

Percent Identity Matching Chains Protein Accession Entry Name
100.0 Melittin P01501 MEL_APIME
100.0 Melittin P59262 MEL_VESMC
98.6 Melittin P0DPR9 MELN_APICE
100.0 Melittin P68407 MEL_APICC
100.0 Melittin P68408 MEL_VESMG
100.0 Melittin P68409 MEL_VESVN
95.8 Melittin P59261 MEL_POLHE
100.0 Melittin Q8LW54 MELS_APICE