Paper Citing NAMD - Abstract
Cho, Kang R.; Salter, E. Alan; De Yoreo, James J.; Wierzbicki, Andrzej; Elhadj, Selim; Huang, Yu; Qiu, S. Roger
Growth inhibition of calcium oxalate monohydrate crystal by linear aspartic acid enantiomers investigated by in situ atomic force microscopy
CRYSTENGCOMM, 15:54-64, 2013
The inhibitory effect of linear enantiomers of L- and D-Asp(6) on the growth of calcium oxalate monohydrate crystal has been investigated using in situ atomic force microscopy. The inhibitory magnitude of D-Asp(6) on the growth of the [(1) over bar 00] step on the (010) face is about 10% larger than that of L-Asp(6). While no chiral effect is observed or expected on the growth of the [(1) over bar0 (1) over bar] step on the ((1) over bar 01) face by both enantiomers, their inhibitory effect on this step is much stronger than that on the [(1) over bar 00] step on the (010) face. In both cases, the step morphology indicates that these enantiomers create the impurity pinning along the steps, while the dependence of step speed on supersaturation shows that they also produce a reduction of the step kinetic coefficients. Analysis of the step speed data within the context of an existing model for step pinning and kink blocking shows that the major impact of Asp(6) is to block active kink sites. The larger inhibition of the [(1) over bar 00] step growth by D-Asp(6) over L-Asp(6) and the substantially larger inhibition of the [(1) over bar0 (1) over bar] step over the [(1) over bar 00] step by both enantiomers both result from larger affinity for adsorption to the (010) face and the ((1) over bar 01) face, respectively. This is because the larger adsorption leads to a higher density of blocking kink sites along the steps. The estimated difference in binding energy of L-and D-Asp(6) to the respective faces from the kinetics model is consistent with the trend predicted by our molecular modeling of the enantiomer binding to the faces.
