Navigation Links
Scientists watch as peptides control crystal growth with 'switches, throttles and brakes'

LIVERMORE, Calif. - By producing some of the highest resolution images of peptides attaching to mineral surfaces, scientists have a deeper understanding how biomolecules manipulate the growth crystals. This research may lead to a new treatment for kidney stones using biomolecules.

The research, which appears in the Nov. 23 online edition of the journal Proceedings of the National Academy of Sciences, explores how peptides interact with mineral surfaces by accelerating, switching and inhibiting their growth.

The team, made up of researchers from Lawrence Livermore National Laboratory, the Molecular Foundry at Lawrence Berkeley, the University of California, Davis and the University of Alabama, for the first time produced single-molecule resolution images of this peptide-mineral interaction.

Inorganic minerals play an important role in most biological organisms. Bone, teeth, protective shells or the intricate cell walls of marine diatoms are some displays of biomineralization, where living organisms form structures using inorganic material. Some minerals also can have negative effects on an organism such as in kidney and gallstones, which lead to severe suffering and internal damage in humans and other mammals.

Understanding how organisms limit the growth of pathological inorganic minerals is important in developing new treatment strategies. But deciphering the complex pathways that organisms use to create strong and versatile structures from relatively simple materials is no easy feat. To better understand the process, scientists attempt to mimic them in the laboratory.

By improving the resolution power of an Atomic Force Microscope (AFM), the PNAS authors were able to image individual atomic layers of the crystal interacting with small protein fragments, or peptides, as they fell on the surface of the crystal.

"Imaging biomolecules that are weakly attached to a surface, while simultaneously achieving single-molecule resolution, is normally difficult to do without knocking the molecules off," said Raymond Friddle, an LLNL postdoctoral fellow. But the team improved upon previous methods and achieved unprecedented resolution of the molecular structure of the crystal surface during the dynamic interaction of each growing layer with peptides. "We were able to watch peptides adhere to the surface, temporarily slow down a layer of the growing crystal, and surprisingly 'hop' to the next level of the crystal surface."

The images also revealed a mechanism that molecules can use to bind to surfaces that would normally repel them. The high resolution images showed that peptides will cluster together on crystal faces that present the same electronic charge. Under certain conditions the peptides would slow down growth, while under other conditions the peptides could speed up growth.

On another face of the crystal, where the peptides were expected to bind strongly, the researchers found instead that the peptides did not attach to the surface unless the crystal growth slowed. The peptides needed to bind in a specific way to the face, which takes more time than a non-specific attachment. As a result, the growing layers of the crystal were able to shed off the peptides as they attempted to bind.

But when the researchers slowed down the crystal growth rate, the peptides collapsed onto the surface so strongly that they completely stopped growth. The researchers proposed that the phenomenon is due to the unique properties of bio-polymers, such as peptides or polyelectrolytes, which fluctuate in solution before resting in a stable configuration on a surface.

"The results of the catastrophic drop in growth by peptides suggest ways that organisms achieve protection against pathological mineralization," said Jim De Yoreo, the project lead and deputy director of research at LBNL's Molecular Foundry. "Once growth is halted, a very high concentration of the mineral will be needed before growth can again reach significant levels."

He said designing polyelectrolyte modifiers in which the charge, size and ability to repel water can be systematically varied would allow researchers to create the equivalent of "switches, throttles and brakes" for directing crystallization.


Contact: Anne Stark
DOE/Lawrence Livermore National Laboratory

Related biology news :

1. Reference genome of maize, most important US crop, is published by team co-led by CSHL scientists
2. ORNL, Los Alamos pioneer new approach to assist scientists, farmers
3. Scripps research scientists find new link between insulin and core body temperature
4. Smithsonian scientists find the frog legs trade may facilitate spread of pathogens
5. Scientists unravel evolution of highly toxic box jellyfish
6. Members of Congress, university leaders, scientists launch ScienceWorksForUS
7. Scientists guide immune cells with light and microparticles
8. Scientists put interactive flu tracking at publics fingertips
9. Singapore scientists join international study of 10,000 vertebrates genomes
10. Scientists are first to unlock the mystery of creating cultured pearls from the queen conch
11. UM scientists create fruit fly model to help unravel genetics of human diabetes
Post Your Comments:
(Date:4/5/2017)... , April 5, 2017 Today ... announcing that the server component of the HYPR platform ... for providing the end-to-end security architecture that empowers biometric ... HYPR has already secured over 15 million users ... including manufacturers of connected home product suites and physical ...
(Date:3/30/2017)... The research team of The Hong Kong ... identification by adopting ground breaking 3D fingerprint minutiae recovery and matching ... and accuracy for use in identification, crime investigation, immigration control, security ... ... A research team led by ...
(Date:3/24/2017)... , March 24, 2017 The Controller General of ... Mr. Abdulla Algeen have received the prestigious international IAIR Award ... Continue Reading ... ... and Deputy Controller Abdulla Algeen (small picture on the right) have received ...
Breaking Biology News(10 mins):
(Date:10/10/2017)... CALIFORNIA (PRWEB) , ... October 10, 2017 , ... ... technological innovation and business process optimization firm for the life sciences and healthcare ... BoxWorks conference in San Francisco. , The presentation, “Automating GxP Validation for ...
(Date:10/9/2017)... ... October 09, 2017 , ... At its national board meeting in ... professor in Harvard University’s Departments of Physics and Astronomy, has been selected for membership ... the winning team for the 2015 Breakthrough Prize in Fundamental physics for the discovery ...
(Date:10/7/2017)... ... October 06, 2017 , ... ... technologies, launched its ProxiMeta™ Hi-C metagenome deconvolution product, featuring the first commercially ... cloud-based bioinformatics software to perform Hi-C metagenome deconvolution using their own facilities, ...
(Date:10/5/2017)... ... October 05, 2017 , ... LabRoots , the leading ... around the world, is giving back to cancer research with a month-long promotion supporting ... Now through October 31, shoppers can use promo code PinkRibbon to get 10 percent ...
Breaking Biology Technology: