title: Shear-induced unfolding of lysozyme monitored in situ.
abstract: 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.
authors.affiliation: Manchester Interdisciplinary Biocentre & Faculty of Life Sciences, University of Manchester, Manchester M1 7DN, United Kingdom.
authors.forename: Lorna
authors.initials: L
authors.lastname: Ashton
authors.forename: Jonathan
authors.initials: J
authors.lastname: Dusting
authors.forename: Eboshogwe
authors.initials: E
authors.lastname: Imomoh
authors.forename: Stavroula
authors.initials: S
authors.lastname: Balabani
authors.forename: Ewan W
authors.initials: EW
authors.lastname: Blanch
mesh_terms: D000818:Animals; D002645:Chickens; D005260:Female; D008958:Models, Molecular; D009113:Muramidase / Q000737:chemistry* / Q000378:metabolism*; D011487:Protein Conformation; D011489:Protein Denaturation; D012212:Rheology; D013059:Spectrum Analysis, Raman; D013314:Stress, Mechanical
chemical_list: C421864:hen egg lysozyme; D009113:Muramidase