An MIT researcher's mathematical model explains for the first time the distinctive structure of collagen, a material key to healthy human bone, muscles and other tissues. The new model shows collagen's structure from the atomic to the tissue scale.
An improved understanding of nature's most abundant protein could aid the search for cures to such ailments as osteoporosis, joint hyperextensibility and scurvy, all recognized as arising from diseased collagen. It could also guide engineers' development of synthetic versions of the protein, which in its healthy state is several times stronger than steel per molecule.
Biological experiments in the past have shown that collagen's universal design consists of molecules staggered lengthwise, arranged like fibers in a steel cable. Each tiny tropocollagen molecule--the smallest collagen building block--is around 300 nanometers long and only 1.5 nanometers thick. (A nanometer is one-billionth of a meter.) But why these ropy strands of amino acids--the molecular building blocks of proteins--associate to form tropocollagen molecules consistently at the same length has been unexplained until now.
The molecular model of collagen developed by Markus Buehler, an assistant professor in the Department of Civil and Environmental Engineering, started on the atomic scale. Buehler then combined elements of quantum mechanics and molecular dynamics to scale his model up and show precisely which length and arrangement of molecules were best for sustaining large weights pulling in opposite directions, a process known as tensile loading.
Buehler discovered that the ideal length of tropocollagen molecules was indeed close to 300 nanometers. His work has shown that the characteristic nanopatterned structure of collagen is responsible for its high extensibility and strength. "This is the first time a predictive, molecular model was used to explain the design features that experiments have shown for decades without understanding the rationale behind them," he explained.
"The response of materials to tensile loading has been studied in materials science for computer chips, cars and buildings, but is still poorly understood for biological materials. What we are doing is looking at biological systems on a molecular level, the same way we would examine glass or metal," said Buehler. "This represents a new way of thinking about biological matter, and it may hold the key to engineering biological systems as we design man-made devices today."
The next step in the research will be to delve deeper into the structure of collagen. "We've developed a reference point for healthy collagen. This enables us now to study how diseases or genetic mutations impact the structure," said Buehler. Learning more about the structural differences between diseased and healthy collagen could help in the development of biomimetic materials.
Buehler is optimistic about the future. "Understanding the mechanical properties of protein materials--in particular their deformation and fracture--is a frontier in materials science. We're trying to figure out how nature creates better materials than we can," he said.
The current work, which appeared in a recent issue of the Proceedings of the National Academy of Sciences, was funded by startup grants Buehler received from MIT's Department of Civil and Environmental Engineering and MIT's School of Engineering.
Elizabeth Thomson | EurekAlert!
Ion treatments for cardiac arrhythmia — Non-invasive alternative to catheter-based surgery
20.01.2017 | GSI Helmholtzzentrum für Schwerionenforschung GmbH
Seeking structure with metagenome sequences
20.01.2017 | DOE/Joint Genome Institute
An important step towards a completely new experimental access to quantum physics has been made at University of Konstanz. The team of scientists headed by...
Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...
Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.
While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...
Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales
Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...
Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.
As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...
19.01.2017 | Event News
10.01.2017 | Event News
09.01.2017 | Event News
20.01.2017 | Awards Funding
20.01.2017 | Materials Sciences
20.01.2017 | Life Sciences