1B6I

T4 LYSOZYME MUTANT WITH CYS 54 REPLACED BY THR, CYS 97 REPLACED BY ALA, THR 21 REPLACED BY CYS AND LYS 124 REPLACED BY CYS (C54T,C97A,T21C,K124C)

1B6I の概要

• エントリーDOI: 10.2210/pdb1b6i/pdb
• 分子名称: PROTEIN (LYSOZYME), 2-HYDROXYETHYL DISULFIDE (3 entities in total)
• 機能のキーワード: hydrolase(o-glycosyl), hydrolase
• 由来する生物種: Enterobacteria phage T4
• 細胞内の位置: Host cytoplasm : P00720
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 18758.62

構造登録者

Vetter, I.R.,Baase, W.A.,Snow, S.,Matthews, B.W. (登録日: 1999-01-14, 公開日: 2000-01-12, 最終更新日: 2023-12-27)

主引用文献

Yang, G.,Cecconi, C.,Baase, W.A.,Vetter, I.R.,Breyer, W.A.,Haack, J.A.,Matthews, B.W.,Dahlquist, F.W.,Bustamante, C.
Solid-state synthesis and mechanical unfolding of polymers of T4 lysozyme.
Proc.Natl.Acad.Sci.USA, 97:139-144, 2000

PubMed Abstract: Recent advances in single molecule manipulation methods offer a novel approach to investigating the protein folding problem. These studies usually are done on molecules that are naturally organized as linear arrays of globular domains. To extend these techniques to study proteins that normally exist as monomers, we have developed a method of synthesizing polymers of protein molecules in the solid state. By introducing cysteines at locations where bacteriophage T4 lysozyme molecules contact each other in a crystal and taking advantage of the alignment provided by the lattice, we have obtained polymers of defined polarity up to 25 molecules long that retain enzymatic activity. These polymers then were manipulated mechanically by using a modified scanning force microscope to characterize the force-induced reversible unfolding of the individual lysozyme molecules. This approach should be general and adaptable to many other proteins with known crystal structures. For T4 lysozyme, the force required to unfold the monomers was 64 +/- 16 pN at the pulling speed used. Refolding occurred within 1 sec of relaxation with an efficiency close to 100%. Analysis of the force versus extension curves suggests that the mechanical unfolding transition follows a two-state model. The unfolding forces determined in 1 M guanidine hydrochloride indicate that in these conditions the activation barrier for unfolding is reduced by 2 kcal/mol.

PubMed: 10618384
DOI: 10.1073/pnas.97.1.139

実験手法

X-RAY DIFFRACTION (1.9 Å)