title: Using electrospray laser desorption ionization mass spectrometry to rapidly examine the integrity of proteins stored in various solutions.
abstract: Electrospray laser desorption ionization mass spectrometry (ELDI/MS) allows the rapid desorption and ionization of proteins from solutions under ambient conditions. In this study, we have demonstrated the use of ELDI/MS to efficiently examine the integrity of the proteins stored in various solutions before they were further used for other biochemical tests. The protein standards were prepared in the solutions containing buffers, organic salts, inorganic salts, strong acid, strong base, and organic solvents, respectively, to simulate those collected from solvent extraction, filtration, dialysis, or chromatographic separation. Other than the deposit of a drop of the sample solution on the metallic sample plate in an ELDI source, no additional sample pretreatment is needed. The sample drop was then irradiated with a pulsed laser; this led to desorption of the analyte molecules, which subsequently entered the ESI plume to undergo post-ionization. Because adjustment of the composition of the sample solution is unnecessary, this technique appears to be useful for rapidly evaluating the integrity of proteins after storage or prior to further biochemical treatment. In addition, when using acid-free and low-organic-solvent ESI solutions for ELDI/MS analysis, the native conformations of the proteins in solution could be detected.
authors.affiliation: Department of Cosmetic Applications and Management, Yuh-Ing Junior College of Health Care & Management, No.15 Lane 420 Dachang 2nd Rd, Kaohsiung 807, Taiwan, ytcho@ms.yuhing.edu.tw.
authors.forename: Yi-Tzu
authors.initials: YT
authors.lastname: Cho
authors.forename: Min-Zong
authors.initials: MZ
authors.lastname: Huang
authors.forename: Sih-You
authors.initials: SY
authors.lastname: Wu
authors.forename: Ming-Feng
authors.initials: MF
authors.lastname: Hou
authors.forename: Jianjun
authors.initials: J
authors.lastname: Li
authors.forename: Jentaie
authors.initials: J
authors.lastname: Shiea
mesh_terms: D000818:Animals; D002021:Buffers; D002417:Cattle; D045304:Cytochromes c / Q000032:analysis*; D006863:Hydrogen-Ion Concentration; D009211:Myoglobin / Q000032:analysis*; D055550:Protein Stability; D012996:Solutions; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
chemical_list: D002021:Buffers; D009211:Myoglobin; D012996:Solutions; D045304:Cytochromes c