title: Modifications of ribonuclease A induced by p-benzoquinone.
abstract: The nature of ribonuclease A (RNase) modifications induced by p-benzoquinone (pBQ) was investigated using several analysis methods. SDS-PAGE experiments revealed that pBQ was efficient in producing oligomers and polymeric aggregates when RNase was incubated with pBQ. The fluorescence behavior and anisotropy changes of the modified RNase were monitored for a series of incubation reactions where RNase (0.050 mM) was incubated with pBQ (0.050, 0.25, 0.50, 1.50 mM) at 37 °C in phosphate buffer (pH 7.0, 50 mM). The modified RNase exhibited less intense fluorescence and slightly higher anisotropy than the unmodified RNase. UV-Vis spectroscopy indicated that pBQ formed covalent bonds to the modified RNase. Confocal imaging analysis confirmed the formation of the polymeric RNase aggregates with different sizes upon exposure of RNase to high concentrations of pBQ. The interaction between the modified RNase and salts affecting biomineralization of salts was also investigated by scanning electron microscopy. Overall, our results show that pBQ can induce formation of both RNase adducts and aggregates thus providing a better understanding of its biological activity.
authors.affiliation: Department of Chemistry, Box 2252, University of Tennessee at Chattanooga, Chattanooga, TN 37403, United States. Electronic address: jisook-kim@utc.edu.
authors.forename: Jisook
authors.initials: J
authors.lastname: Kim
authors.affiliation: Department of Chemistry, Box 2252, University of Tennessee at Chattanooga, Chattanooga, TN 37403, United States.
authors.forename: Albert R
authors.initials: AR
authors.lastname: Vaughn
authors.affiliation: Department of Chemistry, Box 2252, University of Tennessee at Chattanooga, Chattanooga, TN 37403, United States.
authors.forename: Chris
authors.initials: C
authors.lastname: Cho
authors.affiliation: Department of Chemistry, Box 5055, Tennessee Technological University, Cookeville, TN 38505, United States.
authors.forename: Titus V
authors.initials: TV
authors.lastname: Albu
authors.affiliation: Department of Biological and Environmental Sciences, Box 2653, University of Tennessee at Chattanooga, Chattanooga, TN 37403, United States.
authors.forename: Ethan A
authors.initials: EA
authors.lastname: Carver
mesh_terms: D016227:Benzoquinones / Q000737:chemistry*; D004591:Electrophoresis, Polyacrylamide Gel; D005454:Fluorescence Polarization; D018613:Microscopy, Confocal; D008855:Microscopy, Electron, Scanning; D012259:Ribonuclease, Pancreatic / Q000737:chemistry* / Q000378:metabolism; D013056:Spectrophotometry, Ultraviolet
chemical_list: D016227:Benzoquinones; C004532:quinone; D012259:Ribonuclease, Pancreatic