Researchers from NYU Dentistry are investigating a protein found inside the spicules of a sea urchin embryo to understand what makes these proteins such efficient 'brick organizers'
Calcium carbonate, or CaCO3, comprises more than 4% of the earth's crust. Its most common natural forms are chalk, limestone, and marble, produced by the sedimentation of the shells of small fossilized snails, shellfish, and coral over millions of years.
New York University College of Dentistry (NYU Dentistry) researchers are studying how nature creates three-dimensional CaCO3 inorganic/organic based materials to form seashells, invertebrate exoskeletons, and vertebrate bone, dentine, and enamel.
John Evans, DMD, PhD, a professor in NYU Dentistry's Department of Basic Science and Craniofacial Biology, oversees a research group focusing on the study of proteins that modulate the formation of biominerals, which in turn create new composite materials with unique properties, such as increased fracture and puncture resistances.
In a paper recently published in Biochemistry, Gaurav Jain, PhD, a postdoc in Dr. Evans's lab and coauthor of "A model sea urchin spicule matrix protein, rSpSM50, is a hydrogelator that modifies and organizes the mineralization process," looked at how the CaCO3 matrix is organized inside a sea urchin spicule (See figure 1). At first, these spicules are nothing more than chalk, but when combined with sea urchin proteins, they form tiny stacks of "bricks," creating a structure that provides some of the toughest defense against predators and harsh ocean conditions.
"Primary mesenchyme cells (PMCs) inside a sea urchin embryo deposits amorphous CaCO3 within the matrix of spicule proteins where these bricks are shaped into layers of calcium carbonate crystals," notes Dr. Jain. "However, the functional and assembly capabilities of individual spicule matrix proteins aren't clear. We are currently investigating one such protein found inside the spicules of a sea urchin embryo to understand what makes these proteins such efficient 'brick organizers.'"
The researchers looked at SM50, one of the most abundant and well-studied proteins found inside these spicules. They found that a recombinant version of the SM50 protein, rSpSM50, is a highly aggregation-prone protein that forms tiny jelly-like structures called hydrogels in solution. These 'jellies' capture tiny mineral nanoparticles and organize them into crystalline 'bricks.' Moreover, rSpSM50 causes surface texturing and forms randomly interconnected porous channels within these crystals.
"What is unique about rSpSM50 is that it fosters the formation and organization of two different forms of calcium carbonate -- calcite and vaterite within the 'jellies' themselves, inducing fracture resistance to the overall structure," said Dr. Jain.
Researchers used a specific type of titration method that revealed the details about very early events in the spicule formation.
"rSpSM50 turns out to be a really important piece of the puzzle, as it slows the formation kinetics but neither stabilizes nor destabilizes the extremely tiny mineral particles that ultimately form these bricks," says coauthor Martin Pendola, PhD.
CaCo3 has always been a man's favorite construction material to make primitive tools, musical instruments, and craftware since the beginning of civilization. In modern times, CaCO3 is the most widely used mineral in the paper, plastics, paints and coatings industries both as a filler -- and due to its special white color -- as a coating pigment.
"Our current research, funded by U.S. Department of Energy, will enable scientists to better understand the mineralization and assembly process crucial to spicule formation in sea urchin," said Dr. Evans. "Our ultimate goal is to determine the molecular properties of these proteins that allow matrices to assemble, mineralize, and participate in the formation of naturally occurring organic/inorganic skeletal structures. The hope is that the comprehensive understanding of spicule proteins will enable the development of tunable fracture resistant materials that one day will find its use in developing lightweight 'armor' and 'sturdier' dental composites."
**Gaurav Jain1; **Martin Pendola1; Yu-Chieh Huang2; Denis Gebauer2; and John Spencer Evans1
1. Laboratory for Chemical Physics, Center for Skeletal and Craniofacial Biology, New York University College of Dentistry, NY, NY, USA. 2. Department of Chemistry, Physical Chemistry, Universität Konstanz, Universitätstrasse 10, Konstanz D- 78457, Germany.
**Both authors contributed equally to this work
Acknowledgments: AFM imaging was conducted at the Molecular Cytology Core Facility, Memorial Sloan-Kettering Cancer Center, New York. Flow cytometry studies were conducted at the Department of Microbiology, Columbia University, New York. This report represents contribution number 83 from the Laboratory for Chemical Physics, New York University.
Funding sources: Portions of this research (recombinant protein synthesis, LM, flow cytometry, AFM, SEM, FIB, TEM) were supported by the Life Sciences Division, U.S. Army Research Office, under award W911NF-16-1-0262 (JSE). The potentiometric experiments were supported by the Zukunftskoleg of the University of Konstanz (DG).
About NYU College of Dentistry
Founded in 1865, New York University College of Dentistry is the third oldest and the largest dental school in the US, educating more than 8 percent of all dentists. NYU College of Dentistry has a significant global reach with a highly diverse student body. Visit http://dental.
Christopher James | EurekAlert!
Colorectal cancer risk factors decrypted
13.07.2018 | Max-Planck-Institut für Stoffwechselforschung
Algae Have Land Genes
13.07.2018 | Julius-Maximilians-Universität Würzburg
For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.
To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...
For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.
Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...
Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.
A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...
Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.
"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....
Ultra-short, high-intensity X-ray flashes open the door to the foundations of chemical reactions. Free-electron lasers generate these kinds of pulses, but there is a catch: the pulses vary in duration and energy. An international research team has now presented a solution: Using a ring of 16 detectors and a circularly polarized laser beam, they can determine both factors with attosecond accuracy.
Free-electron lasers (FELs) generate extremely short and intense X-ray flashes. Researchers can use these flashes to resolve structures with diameters on the...
13.07.2018 | Event News
12.07.2018 | Event News
03.07.2018 | Event News
13.07.2018 | Event News
13.07.2018 | Materials Sciences
13.07.2018 | Life Sciences