PDBsum entry 1gm2

Hydrolase inhibitor

PDB id: 1gm2

Contents

Protein chain

11 a.a.

PDB id:

1gm2

Name:

Hydrolase inhibitor

Title:

The independent structure of the antitryptic reactive site loop of bowman-birk inhibitor and sunflower trypsin inhibitor-1

Structure:

Bowman-birk inhibitor derived peptide. Chain: a. Fragment: antitryptic reactive site loop. Engineered: yes. Mutation: yes

Source:

Synthetic: yes. Macrotyloma axillare. Organism_taxid: 3876

NMR struc:

30 models

Authors:

A.B.E.Brauer,G.Kelly,S.J.Matthews,R.J.Leatherbarrow

Key ref:

A.B.Brauer et al. (2002). The (1)H-NMR solution structure of the antitryptic core peptide of Bowman-Birk inhibitor proteins: a minimal canonical loop. J Biomol Struct Dyn, 20, 59-70. PubMed id: 12144352 DOI: 10.1080/07391102.2002.10506822

Date:

08-Sep-01 Release date: 29-Aug-02

Protein chain

P01059  (IBB4_MACAX) -  Bowman-Birk type proteinase inhibitor DE-4 from Macrotyloma axillare

Seq: 76 a.a.

Struc: 11 a.a.*

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

DOI no: 10.1080/07391102.2002.10506822

J Biomol Struct Dyn 20:59-70 (2002)

PubMed id: 12144352

The (1)H-NMR solution structure of the antitryptic core peptide of Bowman-Birk inhibitor proteins: a minimal canonical loop.

A.B.Brauer, G.Kelly, S.J.Matthews, R.J.Leatherbarrow.

ABSTRACT

Bowman-Birk inhibitor (BBI) proteins contain an inhibitory motif comprising a disulfide-bonded sequence that interacts with serine proteinases. Recently, a small 14-residue peptide from sunflowers (SFTI-1), which has potent anti-trypsin activity, has been found to have the same motif. However, this peptide also has an unusual head-to-tail cyclisation. To address the role of the core inhibitory sequence itself, we have solved the (1)H-NMR solution structure of an antitryptic 11-residue cyclic peptide that corresponds to the core reactive site loops of both SFTI-1 and Bowman-Birk inhibitor proteins. A comparison is made between the secondary chemical shifts found in this family and the canonical regions of several other inhibitors, giving some insight into relative flexibility and hydrogen bonding patterns in these inhibitors. The solution structure of the core peptide in isolation is found to retain essentially the same three-dimensional arrangement of both backbone and side chains as observed in larger antitryptic BBI and SFTI-1 fragments as well as in the complete proteins. The retention of the canonical conformation in the core peptide explains the peptids inhibitory potency. It therefore represents a minimization of both the BBI and SFTI-1 sequences. We conclude that the core peptide is a conformationally defined, canonical scaffold, which can serve as a minimal platform for the engineering of biological activity.