Navigation Links
UCLA physicists report nanotechnology feat with proteins

The new measurements, by UCLA physics professor Giovanni Zocchi and former UCLA physics graduate student Yong Wang, are approximately 100 times higher in resolution than previous mechanical measurements, a nanotechnology feat which reveals an isolated protein molecule, surprisingly, is neither a solid nor a liquid. "Proteins are the molecular machines of life, the molecules we are made of," Zocchi said. "We have found that sometimes they behave as a solid and sometimes as a liquid.

"Solids have a shape while liquids flow for simple materials at low stresses. However, for complex materials, or large stresses, the behavior can be in-between. Subjected to mechanical forces, a material might be elastic and store mechanical energy (simple solid), viscous and dissipate mechanical energy (simple fluid), or visco-elastic and both store and dissipate mechanical energy (complex solid, complex fluid). The viscoelastic behavior characteristic of more complex matter had not been clearly seen before on isolated proteins because mechanical measurements tend to destroy the proteins."

Zocchi and Wang's new nanotechnology method allowed them to apply stresses and probe the mechanics of the protein without destroying it. Wang, now a physics postdoctoral fellow at the University of Illinois in UrbanaChampaign, and Zocchi discovered a "transition to a viscoelastic regime in the mechanical response" of the protein.

"Below the transition, the protein responds elastically, like a spring," Zocchi said. "Above the transition, the protein flows like a viscous liquid. However, the transition is reversible if the stress is removed. Functional conformational changes of enzymes (changes in the shape of the molecule) must typically operate across this transition."

The measurements were performed on the enzyme guanylate kinase, or GK, a member of an essential class of enzymes called kinases. Specifically, GK transfers a phosphate group from ATP (the universal "fuel" of the cell) to GMP, producing GDP, an essential metabolic component, Zocchi said.

The study on the characterization of the "visco-elastic transition" is reported this month in the online journal PLoS ONE, a publication of the Public Library of Science. The research was federally funded by the National Science Foundation's division of materials research and by a grant from the University of California Lab Research Program.

Zocchi and Wang published related findings earlier this year in the journal Europhysics Letters, a publication of the European Physical Society, and the journal Physical Review Letters.

In previous research, Zocchi and colleagues reported a significant step in controlling chemical reactions mechanically last year, made a significant step toward a new approach to protein engineering in 2006, created a mechanism at the nanoscale to externally control the function and action of a protein in 2005, and created a first-of-its-kind nanoscale sensor using a single molecule less than 20 nanometers long in 2003. A nanometer is roughly 2,000 times smaller than the width of a human hair.

Contact: Stuart Wolpert
University of California - Los Angeles

Related biology technology :

1. UCSB physicists identify room temperature quantum bits in widely used semiconductor
2. Physicists to develop new way of electronic computing
3. UCSB physicists demonstrate the quantum von Neumann architecture
4. Penn physicists undo the coffee ring effect
5. Penn physicists observe campfire effect in blinking nanorod semiconductors
6. Physicists measure current-induced torque in nonvolatile magnetic memory devices
7. Penn physicists develop scalable method for making graphene
8. Physicists isolate bound states in graphene-superconductor junctions
9. UCSB physicists challenge classical world with quantum-mechanical implementation of shell game
10. Physicists take new look at the atom
11. Rice physicists discover ultrasensitive microwave detector
Post Your Comments:
(Date:11/27/2015)... , Nov. 27, 2015 /PRNewswire/--  Mallinckrodt plc ... announced today that it has closed the sale of ... to Guerbet (GBT- NYSE Euronext) in a transaction valued ... four manufacturing facilities and a total of approximately 1,000 ... the St. Louis area. This ...
(Date:11/26/2015)... 26, 2015 ... Accutest Research Laboratories, a leading independent ... (CRO), has formed a strategic partnership ... Temple Health for joint work on ... ) , --> ...
(Date:11/25/2015)... 25, 2015  PharmAthene, Inc. (NYSE MKT: PIP) announced ... stockholder rights plan (Rights Plan) in an effort to ... (NOLs) under Section 382 of the Internal Revenue Code ... PharmAthene,s use of its NOLs could be substantially limited ... in Section 382 of the Code. In general, an ...
(Date:11/25/2015)... HOLLISTON, Mass. , Nov. 25, 2015 /PRNewswire/ ... ), a biotechnology company developing bioengineered organ implants for ... will present at the LD Micro "Main Event" ... p.m. PT. The presentation will be webcast live and ... will also be available at the conference for one-on-one ...
Breaking Biology Technology:
(Date:11/11/2015)...   MedNet Solutions , an innovative SaaS-based eClinical technology ... pleased to announce that it will be a Sponsor of ... to be held November 17-19 in Hamburg ... of iMedNet , MedNet,s easy-to-use, proven and ... has been able to deliver time and cost savings of ...
(Date:11/4/2015)... ALBANY, New York , November 4, 2015 /PRNewswire/ ... According to a new market report published by Transparency ... Size, Share, Growth, Trends and Forecast 2015 - 2022", ... value of US$ 30.3 bn by 2022. The market ... during the forecast period from 2015 to 2022. Rising ...
(Date:10/29/2015)... 2015  Rubicon Genomics, Inc., today announced an ... its DNA library preparation products, including the ThruPLEX ... Plasma-seq kit. ThruPLEX Plasma-seq has been optimized for ... libraries for liquid biopsies--the analysis of cell-free circulating ... in cancer and other conditions. Eurofins Scientific is ...
Breaking Biology News(10 mins):