Navigation Links
Bionanomachines -- proteins as resistance fighters
Date:8/14/2009

A Dresden research team used laser tweezers to measure the friction between a single motor protein molecule and its track. The team found that also within our cells, motors work against the resistance of friction and are restrained in its operationusually by far not as much though as their macroscopic counterparts. These first experimental measurements of protein friction could help researchers to better understand key cellular processes such as cell division which is driven by such molecular machines.

Friction is the force that resists the relative motion of two bodies in contact. The same is true on the nanoscale: Molecular motors have to fight the friction created between them and their tracks. However, since the frictional forces acting on such motors had not been measured before, it was not known how they depend on the speed and the direction of motion.

Friction Slows Down Proteins

Scientists in Dresden at the Biotechnology Center (BIO-TEC) of the Technical University of Dresden and at the Max Planck Institute of Molecular Cell Biology and Genetics (MPI-CBG) immobilized the molecular motor kinesin on a microsphere which was held by laser tweezers and dragged over its track, a so-called microtubule. In this manner, the friction force between the motor and its microtubule track was measured very precisely. "Just like for macroscopic machines, protein friction limits the speed and efficiency of the small bio-motors", says Erik Schffer, group leader at the BIOTEC and Jonathon Howard, director and group leader at the MPI-CBG.

The researchers explain that the protein, in the absence of an energy source, takes eight nanometer (a millionth of a millimeter) wide "diffusive hops", corresponding to the length of the tubulin subunits that make up a microtubule. The motors step from one tubulin subunit to the adjacent one by forming a new bond with the microtubule filament as another bond is broken. When pulled by the tweezers, the energy released from these breaking bonds is lost as friction.

Efficient nanomachines

Protein friction also gives insight into the efficiency of kinesin. "About half of the energy from the motors fuel ATP is dissipated as friction between the motor and its substrate" Howard comments. Schffer adds: "What remains after further dissipation inside the motor is used for mechanical workthe efficiency is usually much better than for man-made machines". The dissipated energy is eventually converted to heat, that contributes to the heating of our body. Thus, for example our muscles are partly heated by protein friction as the muscle motor proteins do their work.


'/>"/>

Contact: Florian Frisch
frisch@mpi-cbg.de
49-035-121-02840
Max-Planck-Gesellschaft
Source:Eurekalert

Related biology news :

1. Proteins in gel
2. Targeting helpers of heat shock proteins could help treat cancer, cardiovascular disease
3. TRAPping proteins that work together inside living cells
4. Pliable proteins keep photosynthesis on the light path
5. Autopilot guides proteins in brain
6. New method for detection of phosphoproteins reveals regulator of melanoma invasion
7. New high-throughput screening technique makes probing puzzling proteins possible
8. Scripps research scientists watch as individual alpha-synuclein proteins change shape
9. Inactivity of proteins behind longer shelf life when freezing
10. Caltech and UCSD researchers shed light on how proteins find their shapes
11. Inhibiting proteins may prevent cartilage breakdown in arthritis patients
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:4/28/2016)... -- First quarter 2016:   , Revenues ... first quarter of 2015 The gross margin was 49% ... and the operating margin was 40% (-13) Earnings per ... from operations was SEK 249.9 M (21.2) , Outlook ... 7,000-8,500 M. The operating margin for 2016 is estimated ...
(Date:4/15/2016)... -- Research and Markets has announced the ...  report to their offering.  ,      ... gait biometrics market is expected to grow at ... Gait analysis generates multiple variables such ... compute factors that are not or cannot be ...
(Date:3/29/2016)... RATON, Florida , March 29, 2016 ... or the "Company") LegacyXChange "LEGX" and SelectaDNA/CSI Protect are ... DNA in ink used in a variety of writing ... theft. Buyers of originally created collectibles from athletes on ... through forensic analysis of the DNA. ...
Breaking Biology News(10 mins):
(Date:6/23/2016)... --  EpiBiome , a precision microbiome engineering company, today ... from Silicon Valley Bank (SVB). The financing will allow ... drug development efforts, as well as purchase additional lab ... been an incredible strategic partner to us – one ... provide," said Dr. Aeron Tynes Hammack , EpiBiome,s ...
(Date:6/23/2016)... , June 23, 2016 Apellis Pharmaceuticals, ... 1 clinical trials of its complement C3 inhibitor, ... and multiple ascending dose studies designed to assess ... of subcutaneous injection in healthy adult volunteers. ... either as a single dose (ranging from 45 ...
(Date:6/23/2016)... ... June 23, 2016 , ... ClinCapture, the only ... Center and will showcase its product’s latest features from June 26 to June ... scientific poster on Disrupting Clinical Trials in The Cloud during the conference. ...
(Date:6/23/2016)... June 23, 2016 ReportsnReports.com ... report to its pharmaceuticals section with historic and ... and much more. Complete report on ... pages, profiling 15 companies and supported with 261 ... http://www.reportsnreports.com/reports/601420-global-cell-culture-media-industry-2016-market-research-report.html . The Global Cell ...
Breaking Biology Technology: