PDBsum entry 1fb9

Signaling protein

PDB id: 1fb9

Contents

Protein chain

33 a.a. *

* Residue conservation analysis

PDB id:

1fb9

Name:

Signaling protein

Title:

Effects of s-sulfonation on the solution structure of salmon calcitonin

Structure:

Calcitonin analogue. Chain: a. Engineered: yes

Source:

Oncorhynchus gorbuscha. Pink salmon. Organism_taxid: 8017. Organ: parotid. Expressed in: escherichia coli. Expression_system_taxid: 562. Fusion vector

NMR struc:

10 models

Authors:

H.Wu,J.Mao,Y.Wang,H.Dou

Key ref:

Y.Wang et al. (2003). Solution structure and biological activity of recombinant salmon calcitonin S-sulfonated analog. Biochem Biophys Res Commun, 306, 582-589. PubMed id: 12804605

Date:

14-Jul-00 Release date: 01-Jul-03

Protein chain

Q8QG84  (Q8QG84_ONCGO) -  Calcitonin (Fragment) from Oncorhynchus gorbuscha

Seq: 32 a.a.

Struc: 33 a.a.*

* PDB and UniProt seqs differ at 2 residue positions (black crosses)

Biochem Biophys Res Commun 306:582-589 (2003)

PubMed id: 12804605

Solution structure and biological activity of recombinant salmon calcitonin S-sulfonated analog.

Y.Wang, H.Dou, C.Cao, N.Zhang, J.Ma, J.Mao, H.Wu.

ABSTRACT

Salmon calcitonin S-sulfonated analog (abbreviated as [S-SO(3)(-)]rsCT) was prepared by introducing two sulfonic groups into the side chains of Cys1 and Cys7 of recombinant salmon calcitonin. The hypocalcemic potency of this open-chain analog is 5500IU/mg, which is about 30% higher than that (4500IU/mg) of the wild type. The solution conformation of [S-SO(3)(-)]rsCT was studied in aqueous trifluoroethanol solution by CD, 2D-NMR spectroscopy, and distance geometry calculations. In the mixture of 60% TFE and 40% water, the peptide assumes an amphipathic alpha-helix in the region of residues 4-22, which is one turn longer than that of the native sCT. The structural feature analysis of the peptide revealed the presence of hydrophobic surface composed of five hydrophobic side chains of residues Leu4, Leu9, Leu12, Leu16, and Leu19, and a network of salt-bridges that consisted of a tetrad of oppositely charged side chains (Cys7-SO(3)(-)-Lys11(+)-Glu15(-)-Lys18(+)). The multiple salt bridges resulted in the stabilization of the longer amphipathic alpha-helix. Meanwhile, the higher hypocalcemic potency of the peptide could be attributed to the array of hydrophobic side chains of five leucine residues of the amphipathic alpha-helix.