Abstract:
:The persistence length of titin from rabbit skeletal muscles was measured using a combination of static and dynamic light scattering, and neutron small angle scattering. Values of persistence length in the range 9-16 nm were found for titin-II, which corresponds to mainly physiologically inelastic A-band part of the protein, and for a proteolytic fragment with 100-nm contour length from the physiologically elastic I-band part. The ratio of the hydrodynamic radius to the static radius of gyration indicates that the proteins obey Gaussian statistics typical of a flexible polymer in a -solvent. Furthermore, measurements of the flexibility as a function of temperature demonstrate that titin-II and the I-band titin fragment experience a similar denaturation process; unfolding begins at 318 K and proceeds in two stages: an initial gradual 50% change in persistence length is followed by a sharp unwinding transition at 338 K. Complementary microrheology (video particle tracking) measurements indicate that the viscoelasticity in dilute solution behaves according to the Flory/Fox model, providing a value of the radius of gyration for titin-II (63 +/- 1 nm) in agreement with static light scattering and small angle neutron scattering results.
journal_name
Biophys Jjournal_title
Biophysical journalauthors
Di Cola E,Waigh TA,Trinick J,Tskhovrebova L,Houmeida A,Pyckhout-Hintzen W,Dewhurst Cdoi
10.1529/biophysj.104.054908subject
Has Abstractpub_date
2005-06-01 00:00:00pages
4095-106issue
6eissn
0006-3495issn
1542-0086pii
S0006-3495(05)73460-3journal_volume
88pub_type
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