Molecular dynamics simulation with a modified CHARMM (Chemistry at Harvard Macromolecular Mechanics) force field was carried out to investigate the properties of chrome-tanned collagen in comparison with chrome-free collagen under hydrated and dehydrated conditions. An attempt has been made to explain the microcosmic origins of the various properties of the chromium(III)-crosslinked collagen. The present simulation describes the clear crosslinking topology of polychromiums to peptide chains, identifies the linking site and the capacity of the linkage, explains why the efficiency is not 100% in a practical tanning process and provides a new viewpoint on the crosslinking of the polychromium with the side chains of the collagen.
A molecular dynamics (MD) simulation with a modified CHARMM force field was performed to study the effects of various anions (ClO − 4 , Cl − , HPO 2− 4 , SO 2− 4 , CNS − and HCOO − ) on the structure, stability and crosslinking properties of chrome-crosslinked collagen. Calculated results clearly indicate that the crosslinking quality can be improved through selecting the right kind of anion. The utilization of polychromiums could be fine tuned by varying the type of anion. Perchlorate ions can further stabilize chrome-tanned collagen by hydrogen-bonding interactions. The considerable numbers of hydrogen bonds formed from the sulfate ions and the hydroxyl bridges of polychromium effectively stabilize the four chromium-olation structure during the crosslinking process.
Molecular dynamics (MD) simulations were carried out to investigate the conformations of a ferrocenyl cholesteryl N-formanidoformamide (Fc-LS) gelator in methanol and 1-pentanol. Our results showed that Fc-LS molecules form a gel in 1-pentanol, but not in methanol. In the Fc-LS/ methanol system, Fc-LS molecules aggregated into clusters stabilized by intermolecular hydrogen bonds. In the Fc-LS/ 1-pentanol system, the Fc-LS molecules dispersed uniformly in the solvent; in addition, the solvent molecules gathered around the Fc-LS molecules. Calculation of diffusion coefficients showed that the Fc-LS/1-pentanol system behaves like a gel over a wide range of temperatures, while the Fc-LS/ methanol system behaves more like a liquid. Charge-transfer properties of the Fc-LS/methanol and Fc-LS/1-pentanol systems were also investigated by quantum mechanical (QM) calculations. The results indicated that the electron transfer integrals of the Fc-LS/1-pentanol system are larger than those of the Fc-LS/methanol system. This suggests that the former is a favorable system for electron transport. Finally, our study demonstrated that the combination of MD and QM represents an effective approach to investigate conductive-gel systems.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.