title: Development of an albumin copper binding (ACuB) assay to detect ischemia modified albumin.
abstract: Myocardial ischemia (MI) induces many changes in the body, including pH decrease and electrolyte imbalance. No obvious symptoms of MI appear until irreversible cellular injuries occur. Since early treatment is critical for recovery from ischemia, the development of reliable diagnostic tool is demanded to detect the early ischemic status. Ischemia modified albumin (IMA), formed by cleavage of the last two amino acids of the human serum albumin (HSA) N-terminus, has been considered so far as the most trustworthy and accurate marker for the investigation of ischemia. IMA levels are elevated in plasma within a few minutes of ischemic onset, and may last for up to 6 h. In the present study, we developed a novel assay for the examination of IMA levels to ameliorate the known albumin cobalt binding (ACB) test established previously. We observed a stronger copper ion bound to the HSA N-terminal peptide than cobalt ion by HPLC and ESI-TOF mass spectrometric analyses. The copper ion was employed with lucifer yellow (LY), a copper-specific reagent to develop a new albumin copper binding (ACuB) assay. The parameters capable of affecting the assay results were optimized, and the finally-optimized ACuB assay was validated. The result of the IMA level measurement in normal versus stroke rat serum suggests that the ACuB assay is likely to be a reliable and sensitive method for the detection of ischemic states.
authors.affiliation: College of Pharmacy, Graduate School of Pharmaceutical Sciences, Ewha Global Top 5 Program, Ewha Womans University.
authors.forename: Ji-Eun
authors.initials: JE
authors.lastname: Eom
authors.forename: Eunyoung
authors.initials: E
authors.lastname: Lee
authors.forename: Kyung-Hwa
authors.initials: KH
authors.lastname: Jeon
authors.forename: Jeongeun
authors.initials: J
authors.lastname: Sim
authors.forename: Minah
authors.initials: M
authors.lastname: Suh
authors.forename: Gil-Ja
authors.initials: GJ
authors.lastname: Jhon
authors.forename: Youngjoo
authors.initials: Y
authors.lastname: Kwon
mesh_terms: D000818:Animals; D015415:Biomarkers / Q000097:blood; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D003035:Cobalt; D003300:Copper; D005456:Fluorescent Dyes; D007546:Isoquinolines; D017202:Myocardial Ischemia / Q000175:diagnosis*; D017207:Rats, Sprague-Dawley; D012709:Serum Albumin; D000075462:Serum Albumin, Human; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*
chemical_list: D015415:Biomarkers; D005456:Fluorescent Dyes; D007546:Isoquinolines; D012709:Serum Albumin; C561522:ischemia-modified albumin; D003035:Cobalt; D003300:Copper; C017475:lucifer yellow; D000075462:Serum Albumin, Human