1LD5

STRUCTURE OF BPTI MUTANT A16V

1LD5 の概要

• エントリーDOI: 10.2210/pdb1ld5/pdb
• NMR情報: BMRB: 5381
• 分子名称: PANCREATIC TRYPSIN INHIBITOR (1 entity in total)
• 機能のキーワード: bpti, kunitz fold, hydrolase inhibitor
• 由来する生物種: Bos taurus (cattle)
• 細胞内の位置: Secreted: P00974
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 6565.60

構造登録者

Cierpicki, T.,Otlewski, J. (登録日: 2002-04-08, 公開日: 2002-09-11, 最終更新日: 2024-10-30)

主引用文献

Cierpicki, T.,Otlewski, J.
NMR structures of two variants of bovine pancreatic trypsin inhibitor (BPTI) reveal unexpected influence of mutations on protein structure and stability.
J.Mol.Biol., 321:647-658, 2002

PubMed Abstract: Here we determined NMR solution structures of two mutants of bovine pancreatic trypsin inhibitor (BPTI) to reveal structural reasons of their decreased thermodynamic stability. A point mutation, A16V, in the solvent-exposed loop destabilizes the protein by 20 degrees C, in contrast to marginal destabilization observed for G, S, R, L or W mutants. In the second mutant introduction of eight alanine residues at proteinase-contacting sites (residues 11, 13, 17, 18, 19, 34, 37 and 39) provides a protein that denatures at a temperature about 30 degrees C higher than expected from additive behavior of individual mutations. In order to efficiently determine structures of these variants, we applied a procedure that allows us to share data between regions unaffected by mutation(s). NOAH/DYANA and CNS programs were used for a rapid assignment of NOESY cross-peaks, structure calculations and refinement. The solution structure of the A16V mutant reveals no conformational change within the molecule, but shows close contacts between V16, I18 and G36/G37. Thus, the observed 4.3kcal/mol decrease of stability results from a strained local conformation of these residues caused by introduction of a beta-branched Val side-chain. Contrary to the A16V mutation, introduction of eight alanine residues produces significant conformational changes, manifested in over a 9A shift of the Y35 side-chain. This structural rearrangement provides about 6kcal/mol non-additive stabilization energy, compared to the mutant in which G37 and R39 are not mutated to alanine residues.

PubMed: 12206780
DOI: 10.1016/S0022-2836(02)00620-4

実験手法

SOLUTION NMR