scholarly journals Germanium nanospheres for ultraresolution picotensiometry of kinesin motors

2020 ◽  
Author(s):  
Swathi Sudhakar ◽  
Mohammad Kazem Abdosamadi ◽  
Tobias Jörg Jachowski ◽  
Michael Bugiel ◽  
Anita Jannasch ◽  
...  
Keyword(s):  
Refractive Index ◽  
Long Range ◽  
Optical Trapping ◽  
Molecular Motion ◽  
Center Of Mass ◽  
High Refractive Index ◽  
Long Range Transport ◽  
Directed Motion ◽  
Range Transport ◽  
Load Conditions

Kinesin motors are essential for transport of cellular cargo along cytoskeletal microtubule filaments. How motors step, detach, and cooperate is still unclear. To dissect the molecular motion of kinesin-1, we have developed germanium nanospheres as ultraresolution optical trapping probes. We found that single motors took 4-nm-center-of-mass steps. Furthermore, motors never detached from microtubules under native hindering load conditions. Instead, motors slid on microtubules with microsecond-long, 8-nm steps and remained in this slip state before detaching or reengaging in directed motion. Surprisingly, reengagement and, thus, rescue of directed motion was prevailing. We argue that teams of motors may be synchronized through this slip state and rescues need to be accounted for to understand long-range transport.One Sentence SummaryOptical trapping of high-refractive-index semiconductor nanoparticles shows how motors detach and walk with 4-nm steps.

scholarly journals Germanium nanospheres for ultraresolution picotensiometry of kinesin motors

Science ◽  
2021 ◽  
Vol 371 (6530) ◽  
pp. eabd9944 ◽  
Author(s):  
Swathi Sudhakar ◽  
Mohammad Kazem Abdosamadi ◽  
Tobias Jörg Jachowski ◽  
Michael Bugiel ◽  
Anita Jannasch ◽  
...  
Keyword(s):  
Long Range ◽  
Optical Trapping ◽  
Molecular Motion ◽  
Center Of Mass ◽  
Long Range Transport ◽  
Directed Motion ◽  
Range Transport ◽  
Mechanochemical Cycle ◽  
Load Conditions

Kinesin motors are essential for the transport of cellular cargo along microtubules. How the motors step, detach, and cooperate with each other is still unclear. To dissect the molecular motion of kinesin-1, we developed germanium nanospheres as ultraresolution optical trapping probes. We found that single motors took 4-nanometer center-of-mass steps. Furthermore, kinesin-1 never detached from microtubules under hindering load conditions. Instead, it slipped on microtubules in microsecond-long, 8-nanometer steps and remained in this slip state before detaching or reengaging in directed motion. Unexpectedly, reengagement and thus rescue of directed motion was more frequent. Our observations broaden our knowledge on the mechanochemical cycle and slip state of kinesin. This state and rescue need to be accounted for to understand long-range transport by teams of motors.

Elemental carbon deposition to Svalbard snow from Norwegian settlements and long-range transport

Tellus B ◽  
2011 ◽  
Vol 63 (3) ◽  
Author(s):  
Borgar Aamaas ◽  
Carl Egede Bøggild ◽  
Frode Stordal ◽  
Terje Berntsen ◽  
Kim Holmén ◽  
...  
Keyword(s):  
Long Range ◽  
Elemental Carbon ◽  
Carbon Deposition ◽  
Long Range Transport ◽  
Range Transport

Long range transport ofCastanea sativapollen

Grana ◽  
1988 ◽  
Vol 27 (3) ◽  
pp. 203-207 ◽  
Author(s):  
Annie Gérard Peeters ◽  
Heinrich Zoller
Keyword(s):  
Long Range ◽  
Long Range Transport ◽  
Range Transport

scholarly journals Analysis of aircraft and satellite measurements from the Intercontinental Chemical Transport Experiment (INTEX-B) to quantify long-range transport of East Asian sulfur to Canada

2008 ◽  
Vol 8 (11) ◽  
pp. 2999-3014 ◽  
Author(s):  
A. van Donkelaar ◽  
R. V. Martin ◽  
W. R. Leaitch ◽  
A. M. Macdonald ◽  
T. W. Walker ◽  
...  
Keyword(s):  
British Columbia ◽  
North America ◽  
Long Range ◽  
East Asian ◽  
Chemical Transport ◽  
Long Range Transport ◽  
Free Troposphere ◽  
Range Transport ◽  
Transport Experiment ◽  
Sulfur Emissions

Abstract. We interpret a suite of satellite, aircraft, and ground-based measurements over the North Pacific Ocean and western North America during April–May 2006 as part of the Intercontinental Chemical Transport Experiment Phase B (INTEX-B) campaign to understand the implications of long-range transport of East Asian emissions to North America. The Canadian component of INTEX-B included 33 vertical profiles from a Cessna 207 aircraft equipped with an aerosol mass spectrometer. Long-range transport of organic aerosols was insignificant, contrary to expectations. Measured sulfate plumes in the free troposphere over British Columbia exceeded 2 μg/m3. We update the global anthropogenic emission inventory in a chemical transport model (GEOS-Chem) and use it to interpret the observations. Aerosol Optical Depth (AOD) retrieved from two satellite instruments (MISR and MODIS) for 2000–2006 are analyzed with GEOS-Chem to estimate an annual growth in Chinese sulfur emissions of 6.2% and 9.6%, respectively. Analysis of aircraft sulfate measurements from the NASA DC-8 over the central Pacific, the NSF C-130 over the east Pacific and the Cessna over British Columbia indicates most Asian sulfate over the ocean is in the lower free troposphere (800–600 hPa), with a decrease in pressure toward land due to orographic effects. We calculate that 56% of the measured sulfate between 500–900 hPa over British Columbia is due to East Asian sources. We find evidence of a 72–85% increase in the relative contribution of East Asian sulfate to the total burden in spring off the northwest coast of the United States since 1985. Campaign-average simulations indicate anthropogenic East Asian sulfur emissions increase mean springtime sulfate in Western Canada at the surface by 0.31 μg/m3 (~30%) and account for 50% of the overall regional sulfate burden between 1 and 5 km. Mean measured daily surface sulfate concentrations taken in the Vancouver area increase by 0.32 μg/m3 per 10% increase in the simulated fraction of Asian sulfate, and suggest current East Asian emissions episodically degrade local air quality by more than 1.5 μg/m3.

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