Putting randomness to work: unique form of nanoscale random motion may drive key cellular functions

of a phosphate -- releases from the microtubule.
  • ATP hydrolysis makes the switch mechanism irreversible. Though ATP normally provides energy for macromolecular synthesis, Fox argues that in motor proteins ATP performs a switching role, changing the protein conformation and its binding affinity.
  • The unbound head -- just 5-7 nanometers in diameter -- is moved about randomly by Brownian motion in the cellular fluid until it encounters a new site where it can bind. Reported in the early 1800s by biologist Robert Brown, Brownian motion is the irregular activity of tiny particles suspended in a fluid. It results from the thermally driven movement of molecules in a fluid, the velocity of the particles depending on the temperature temperature.
  • Because of structural limits in the kinesin and spacing of binding sites on the microtubules, the moving head can reach only one possible binding site -- 8 nanometers past the bound head, which temporarily remains attached to the microtubule.
  • The head binds to the new site, moving the kinesin and its cargo about 8 nanometers along the microtubule.
  • The process quickly starts anew with the original two heads in interchanged positions.
  • "Normally, Brownian motion cannot do anything concerted or with directionality, because it is random," Fox explained. "But what happens here is a random process in a system that has asymmetric boundary conditions created by the ATP switching. That makes it possible to get a net directed motion along the microtubule."

    The model described by Fox and post-doctoral colleague Mee Hyang Choi depends on two unique properties of structures at the nanometer-scale: thermal energy can be a robust source of power, and random motion occurs very rapidly.

    "Normally, we would t

    Contact: John Toon
    Georgia Institute of Technology Research News

    Page: 1 2 3 4

    Related biology news :

    1. Putting energy into heart protection
    2. Putting GPS to work, researchers shed light on road-following by pigeons
    3. Putting genes in a pill
    4. Putting microRNAs in their place
    5. Putting muscle in the nucleus
    6. Putting muscle in the nucleus
    7. Putting a price tag on paradise
    8. Putting medical research on-line to give patients the information they need
    9. Putting Doesnt Pollute, Research Finds
    10. Putting A Price Tag On Pollution
    11. Putting Down Your Roots: How Plants Know To Do It

    Post Your Comments:

    (Date:5/20/2016)... 20, 2016  VoiceIt is excited to announce ... By working together, VoiceIt and VoicePass ... and VoicePass take slightly different approaches to voice ... security and usability. ... new partnership. "This marketing and technology ...
    (Date:4/28/2016)... India , April 28, 2016 ... Infosys (NYSE: INFY ), and Samsung SDS, a ... that will provide end customers with a more secure, ... services.      (Logo: http://photos.prnewswire.com/prnh/20130122/589162 ) , ... services, but it also plays a fundamental part in enabling ...
    (Date:4/15/2016)... April 15, 2016  A new partnership announced ... accurate underwriting decisions in a fraction of the ... priced and high-value life insurance policies to consumers ... With Force Diagnostics, rapid testing (A1C, Cotinine ... readings (blood pressure, weight, pulse, BMI, and activity ...
    Breaking Biology News(10 mins):
    (Date:6/23/2016)... 2016 Houston Methodist Willowbrook Hospital has ... Association to serve as their official health care ... Willowbrook will provide sponsorship support, athletic training services, ... coaches, volunteers, athletes and families. "We ... Association and to bring Houston Methodist quality services ...
    (Date:6/23/2016)... ... 23, 2016 , ... Supplyframe, the Industry Network for electronics ... Lab . Located in Pasadena, Calif., the Design Lab’s mission is to bring ... designed, built and brought to market. , The Design Lab is Supplyframe’s physical ...
    (Date:6/23/2016)... LONDON , June 23, 2016 ... & Hematology Review, 2016;12(1):22-8 http://doi.org/10.17925/OHR.2016.12.01.22 ... Review , the peer-reviewed journal from touchONCOLOGY, ... the escalating cost of cancer care is placing ... a result of expensive biologic therapies. With the ...
    (Date:6/23/2016)...  Amgen (NASDAQ: AMGN ) today announced ... life sciences incubator to accelerate the development of new ... at QB3@953 was created to help high-potential life science ... early stage organizations - access to laboratory infrastructure. ... two "Amgen Golden Ticket" awards, providing each winner with ...
    Breaking Biology Technology:
    Cached News: