title: Denaturing of single electrospun fibrinogen fibers studied by deep ultraviolet fluorescence microscopy.
abstract: Deep ultraviolet (DUV) microscopy is a fluorescence microscopy technique to image unlabeled proteins via the native fluorescence of some of their amino acids. We constructed a DUV fluorescence microscope, capable of 280 nm wavelength excitation by modifying an inverted optical microscope. Moreover, we integrated a nanomanipulator-controlled micropipette into this instrument for precise delivery of picoliter amounts of fluid to selected regions of the sample. In proof-of-principle experiments, we used this instrument to study, in situ, the effect of a denaturing agent on the autofluorescence intensity of single, unlabeled, electrospun fibrinogen nanofibers. Autofluorescence emission from the nanofibers was excited at 280 nm and detected at ∼350 nm. A denaturant solution was discretely applied to small, select sections of the nanofibers and a clear local reduction in autofluorescence intensity was observed. This reduction is attributed to the dissolution of the fibers and the unfolding of proteins in the fibers.
authors.affiliation: Department of Physics, University of Incheon, Incheon 406-772, South Korea. jeongyong@incheon.ac.kr.
authors.forename: Jeongyong
authors.initials: J
authors.lastname: Kim
authors.forename: Hugeun
authors.initials: H
authors.lastname: Song
authors.forename: Inho
authors.initials: I
authors.lastname: Park
authors.forename: Christine R
authors.initials: CR
authors.lastname: Carlisle
authors.forename: Keith
authors.initials: K
authors.lastname: Bonin
authors.forename: Martin
authors.initials: M
authors.lastname: Guthold
mesh_terms: D000596:Amino Acids / Q000378:metabolism; D005340:Fibrinogen / Q000378:metabolism*; D008856:Microscopy, Fluorescence / Q000295:instrumentation / Q000379:methods; D008860:Microscopy, Ultraviolet / Q000295:instrumentation* / Q000379:methods*; D011489:Protein Denaturation; D013050:Spectrometry, Fluorescence / Q000295:instrumentation / Q000379:methods
chemical_list: D000596:Amino Acids; D005340:Fibrinogen