TY - JOUR

T1 - Shear-induced unfolding of lysozyme monitored in situ

AU - Ashton, Lorna

AU - Dusting, Jonathan

AU - Imomoh, Eboshogwe

AU - Balabani, Stavroula

AU - Blanch, Ewan W.

PY - 2009/5/20

Y1 - 2009/5/20

N2 - Conformational changes due to externally applied physiochemical parameters, including pH, temperature, solvent composition, and mechanical forces, have been extensively reported for numerous proteins. However, investigations on the effect of fluid shear flow on protein conformation remain inconclusive despite its importance not only in the research of protein dynamics but also for biotechnology applications where processes such as pumping, filtration, and mixing may expose protein solutions to changes in protein structure. By combining particle image velocimetry and Raman spectroscopy, we have successfully monitored reversible, shear-induced structural changes of lysozyme in well-characterized flows. Shearing of lysozyme in water altered the protein's backbone structure, whereas similar shear rates in glycerol solution affected the solvent exposure of side-chain residues located toward the exterior of the lysozyme alpha-domain. The results demonstrate the importance of measuring conformational changes in situ and of quantifying fluid stresses by the three-dimensional shear tensor to establish reversible unfolding or misfolding transitions occurring due to flow exposure.

AB - Conformational changes due to externally applied physiochemical parameters, including pH, temperature, solvent composition, and mechanical forces, have been extensively reported for numerous proteins. However, investigations on the effect of fluid shear flow on protein conformation remain inconclusive despite its importance not only in the research of protein dynamics but also for biotechnology applications where processes such as pumping, filtration, and mixing may expose protein solutions to changes in protein structure. By combining particle image velocimetry and Raman spectroscopy, we have successfully monitored reversible, shear-induced structural changes of lysozyme in well-characterized flows. Shearing of lysozyme in water altered the protein's backbone structure, whereas similar shear rates in glycerol solution affected the solvent exposure of side-chain residues located toward the exterior of the lysozyme alpha-domain. The results demonstrate the importance of measuring conformational changes in situ and of quantifying fluid stresses by the three-dimensional shear tensor to establish reversible unfolding or misfolding transitions occurring due to flow exposure.

KW - EXCITED RAMAN-SPECTROSCOPY

KW - EGG-WHITE LYSOZYME

KW - POLY-L-LYSINE

KW - HEN LYSOZYME

KW - COUETTE FLOW

KW - TRANSITION

KW - PROTEINS

KW - BIOMOLECULES

KW - EQUILIBRIUM

KW - BIOREACTOR

U2 - 10.1016/j.bpj.2009.02.024

DO - 10.1016/j.bpj.2009.02.024

M3 - Journal article

VL - 96

SP - 4231

EP - 4236

JO - Biophysical Journal

JF - Biophysical Journal

SN - 0006-3495

IS - 10

ER -