Elasticity of the Transition State Leading to an Unexpected Mechanical Stabilization of Titin Immunoglobulin Domains.
Angew Chem Int Ed Engl
; 56(20): 5490-5493, 2017 05 08.
Article
in En
| MEDLINE
| ID: mdl-28394039
ABSTRACT
The giant protein titin plays a critical role in regulating the passive elasticity of muscles, mainly through the stochastic unfolding and refolding of its numerous immunoglobulin domains in the I-band of sarcomeres. The unfolding dynamics of titin immunoglobulin domains at a force range greater than 100â
pN has been studied by atomic force microscopy, while that at smaller physiological forces has not been measured before. By using magnetic tweezers, it is found that the titin I27 domain unfolds in a surprising non-monotonic force-dependent manner at forces smaller than 100â
pN, with the slowest unfolding rate occurring around 22â
pN. We further demonstrate that a model with single unfolding pathway taking into account the elasticity of the transition state can reproduce the experimental results. These results provide important novel insights into the regulation mechanism of the passive elasticity of muscle tissues.
Key words
Full text:
1
Database:
MEDLINE
Main subject:
Elasticity
/
Connectin
/
Immunoglobulin Domains
Limits:
Humans
Language:
En
Year:
2017
Type:
Article