HOME >> BIOLOGY >> NEWS
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
    john.toon@edi.gatech.edu
    404-894-6986
    Georgia Institute of Technology Research News
    3-Jun-2001


    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:4/17/2014)... in bone marrow need to produce hydrogen sulfide in ... to a new study from the Center for Craniofacial ... of USC. , Professor Songtao Shi, principal investigator on ... by the cells governs the flow of calcium ions. ... that results in osteogenesis, or the creation of new ...
    (Date:4/17/2014)... deforestation and fragmentation of forests in the Amazon ... forests, contributing to rapid and widespread forest loss ... researchers., The findings show that forests in the ... droughts coupled with forest fires lead to large-scale ... Jennifer Balch, assistant professor of geography, Penn State. ...
    (Date:4/17/2014)... -- Indiana University researchers have detected new early-warning signs ... This discovery could have far-reaching implications for the diagnosis ... of over 25 million Americans. , "We had not ... at such early stages," said Ann Elsner, professor and ... lead author of the study. "We set out to ...
    Breaking Biology News(10 mins):Drought and fire in the Amazon lead to sharp increases in forest tree mortality 2Drought and fire in the Amazon lead to sharp increases in forest tree mortality 3New technique detects microscopic diabetes-related eye damage 2New technique detects microscopic diabetes-related eye damage 3
    (Date:1/15/2014)... Automotive, a group of car dealerships headquartered in ... Center and offering free oil change coupons for participation in ... 18 at the Bill Jacobs Cadillac and Chevrolet location from ... )  The Bill Jacobs Auto annual blood ...
    (Date:1/15/2014)... SAN JOSE, California , January 15, 2014 ... for cancer, today announced the appointment of Thomas C Reynolds ... over 20 years, development experience gained in the biotechnology industry, ... "I am delighted to welcome Tom at this transformative ...
    (Date:1/15/2014)... (PRWEB) January 15, 2014 Two champions ... continued their sponsorship of an annual competition for middle ... and access to, innovative STEM study. The competition presents ... TEAMS: Tests of Engineering Aptitude, Mathematics, and Sciences ...
    (Date:1/15/2014)... AudioNotch is the internet's leading provider ... treatment of tinnitus. Patients listen to sound therapy that ... period of weeks to months, their tinnitus volume decreases. , ... Notched Music and Notched White Noise. Now, AudioNotch is pleased ...
    Breaking Biology Technology:Join the Bill Jacobs Auto blood drive and receive a free oil change 2Oxford BioTherapeutics Appoints Thomas C Reynolds MD, PhD to its Board of Directors 2Oxford BioTherapeutics Appoints Thomas C Reynolds MD, PhD to its Board of Directors 3Technology Student Association Partners with Leaders in STEM Education Advocacy for Annual Competition 2Technology Student Association Partners with Leaders in STEM Education Advocacy for Annual Competition 3Technology Student Association Partners with Leaders in STEM Education Advocacy for Annual Competition 4Technology Student Association Partners with Leaders in STEM Education Advocacy for Annual Competition 5
    Cached News: