The long-term goal of the proposed research is to determine the size and character of the molecular contractile stroke. This goal is approached in the short term by measurement of distinct steps of shortening in the single sarcomere of the single myofibril, a technique that has come into fruition in this laboratory. Because of high cooperativity among parallel thin filaments, translation in the myofibrillar sarcomere occurs in steps, apparently of the same size range as those found in optical trap experiments on single filaments. Thus, the stepping pattern in single myofibrils may reflect the step produced by the contractile stroke. Shortening steps in the single myofibril will be measured at the level of the single sarcomere or single half-sarcomere, at constant load. The steps are detected using one of two techniques: a photodiode array or a scanning galvanometer mirror plus photomultiplier. Step size will be determined under a variety of physiological conditions to determine how size is affected by these conditions. From the results we will learn much about the nature of contractile dynamics in the single sarcomere, and possibly also about the size and character of the molecular stroke.

Agency
National Institute of Health (NIH)
Institute
National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS)
Type
Research Project (R01)
Project #
5R01AR044813-02
Application #
6171371
Study Section
Physiological Chemistry Study Section (PC)
Program Officer
Lymn, Richard W
Project Start
1999-09-30
Project End
2004-08-31
Budget Start
2000-09-01
Budget End
2001-08-31
Support Year
2
Fiscal Year
2000
Total Cost
$290,221
Indirect Cost
Name
University of Washington
Department
Biomedical Engineering
Type
Schools of Engineering
DUNS #
135646524
City
Seattle
State
WA
Country
United States
Zip Code
98195
Chai, B; Mahtani, A G; Pollack, G H (2012) UNEXPECTED PRESENCE OF SOLUTE-FREE ZONES AT METAL-WATER INTERFACES. Contemp Mater 3:1-12
Zhao, Qing; Coult, Jason; Pollack, Gerald H (2010) Long-range attraction in aqueous colloidal suspensions. Proc SPIE Int Soc Opt Eng 7376:73761C1-73761C13
Chai, Binghua; Pollack, Gerald H (2010) Solute-free interfacial zones in polar liquids. J Phys Chem B 114:5371-5
Klyuzhin, Ivan S; Ienna, Federico; Roeder, Brandon et al. (2010) Persisting water droplets on water surfaces. J Phys Chem B 114:14020-7
Zheng, Jian-ming; Wexler, Adam; Pollack, Gerald H (2009) Effect of buffers on aqueous solute-exclusion zones around ion-exchange resins. J Colloid Interface Sci 332:511-4
Ovchinnikova, Kate; Pollack, Gerald H (2009) Can water store charge? Langmuir 25:542-7
Chai, Binghua; Yoo, Hyok; Pollack, Gerald H (2009) Effect of radiant energy on near-surface water. J Phys Chem B 113:13953-8
Ovchinnikova, Kate; Pollack, Gerald H (2009) Cylindrical phase separation in colloidal suspensions. Phys Rev E Stat Nonlin Soft Matter Phys 79:036117
Zhao, Qing; Ovchinnikova, Kate; Chai, Binghua et al. (2009) Role of proton gradients in the mechanism of osmosis. J Phys Chem B 113:10708-14
Zhao, Qing; Zheng, Jianming; Chai, Binghua et al. (2008) Unexpected effect of light on colloidal crystal spacing. Langmuir 24:1750-5

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