PDBsum entry 1a13

Mast cell degranulation

PDB id: 1a13

Contents

Protein chain

15 a.a.

PDB id:

1a13

Name:

Mast cell degranulation

Title:

G protein-bound conformation of mastoparan-x, nmr, 14 structures

Structure:

Mastoparan-x. Chain: a. Engineered: yes

Source:

Vespa simillima xanthoptera. Japanese yellow hornet. Organism_taxid: 7448. Strain: xanthoptera. Expressed in: escherichia coli. Expression_system_taxid: 562

NMR struc:

14 models

Authors:

H.Kusunoki,K.Wakamatsu,K.Sato,T.Miyazawa,T.Kohno

Key ref:

H.Kusunoki et al. (1998). G protein-bound conformation of mastoparan-X: heteronuclear multidimensional transferred nuclear overhauser effect analysis of peptide uniformly enriched with 13C and 15N. Biochemistry, 37, 4782-4790. PubMed id: 9537994 DOI: 10.1021/bi972756p

Date:

20-Dec-97 Release date: 13-Jan-99

Protein chain

P01515  (MAST_VESXA) -  Mastoparan-X from Vespa xanthoptera

Seq: 14 a.a.

Struc: 15 a.a.

DOI no: 10.1021/bi972756p

Biochemistry 37:4782-4790 (1998)

PubMed id: 9537994

G protein-bound conformation of mastoparan-X: heteronuclear multidimensional transferred nuclear overhauser effect analysis of peptide uniformly enriched with 13C and 15N.

H.Kusunoki, K.Wakamatsu, K.Sato, T.Miyazawa, T.Kohno.

ABSTRACT

Mastoparans, a family of tetradecapeptides from wasp venom, have been used as convenient low molecular weight models of receptors coupled to GTP-binding regulatory proteins (G proteins) for the understanding of the interaction between G proteins and receptors. Sukumar and Higashijima have analyzed the conformation of mastoparan-X (MP-X) bound to the G protein alpha-subunit using proton two-dimensional transferred nuclear Overhauser effect (TRNOE) spectroscopy [Sukumar, M., and Higashijima, T. (1992) J. Biol. Chem., 267, 21421-21424]. The resultant structure, however, was not well-defined due to severe overlap of peptide proton resonances. To determine the G protein-bound conformation of MP-X in detail, we have analyzed this interaction by heteronuclear multidimensional TRNOE experiments of MP-X uniformly enriched with 15N and/or 13C. By solving the overlap problem, we were able to determine the precise conformation of MP-X bound to Gi1alpha: the peptide adopts an amphiphilic alpha-helix from Trp3 to C-terminal Leu14, and the atomic root-mean-square deviation (rmsd) values in this portion about the averaged coordinates were 0.27 +/- 0.07 A for the backbone atoms (N, Calpha, C') and 0.84 +/- 0.16 A for all heavy atoms. These values are much smaller than the corresponding rmsd values of the structures obtained from the proton 2D TRNOE spectrum alone: 1.70 +/- 0.41 A for the backbone atoms (N, Calpha, C') and 2.84 +/- 0.51 A for all heavy atoms. Our results indicate that the heteronuclear multidimensional TRNOE experiments of peptides uniformly enriched with stable isotopes are a very powerful tool for analyzing the conformation of short peptides bound to large proteins. We will also discuss the structure-activity relationships of mastoparans in activating G proteins on the basis of the precise structure of MP-X bound to Gi1alpha.