Translational Diffusion Constants of the Amino Acids: Measurement by NMR and Their Use in Modeling the Transport of Peptides
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- 作者：Markus W. Germann ; Tierre Turner ; Stuart A. Allison
- 刊名：Journal of Physical Chemistry A
- 出版年：2007
- 出版时间：March 1, 2007
- 年：2007
- 卷：111
- 期：8
- 页码：1452 - 1455
- 全文大小：42K
- 年卷期：v.111,no.8(March 1, 2007)
- ISSN：1520-5215
文摘
In this work, the translational self-diffusion constants, DT's, of 12 amino acids (Ala, Arg, Asn, Asp, Cys,Glu, His, Ile, Lys, Met, Phe, and Ser) are measured by field gradient NMR and extrapolated to infinite dilution.The experiments were carried out in D2O at 298 K at pD 
3.5 in 50 mM sodium phosphate buffer. Of these12 amino acids, 6 are being reported for the first time (Asp, Cys, Glu, His, Lys, and Met) and the remaining6 (Ala, Arg, Asn, Ile, Phe, and Ser) are compared with DT's from the literature. When corrected for differencesin solvent viscosity and temperature, the discrepancy between DT's measured in the present work and thosereported previously is always <8%, which is reasonable given the range of values reported previously bydifferent groups. With the present work, DT's for all of the amino acids are now available. These diffusionconstants are then used in modeling studies of the diffusion and free solution electrophoretic mobility, 
, ofseveral model peptides. For this set of peptides, it is shown that modeling using revised input parametersresults in improved agreement between model and experimental mobilities.
3.5 in 50 mM sodium phosphate buffer. Of these12 amino acids, 6 are being reported for the first time (Asp, Cys, Glu, His, Lys, and Met) and the remaining6 (Ala, Arg, Asn, Ile, Phe, and Ser) are compared with DT's from the literature. When corrected for differencesin solvent viscosity and temperature, the discrepancy between DT's measured in the present work and thosereported previously is always <8%, which is reasonable given the range of values reported previously bydifferent groups. With the present work, DT's for all of the amino acids are now available. These diffusionconstants are then used in modeling studies of the diffusion and free solution electrophoretic mobility, , ofseveral model peptides. For this set of peptides, it is shown that modeling using revised input parametersresults in improved agreement between model and experimental mobilities.