title: Electrochemical detection of oestrogen binding protein interaction with oestrogen in Candida albicans cell lysate.
abstract: Previously we reported an electrochemical method to quantitatively detect vertebrate oestrogens using wild type Saccharomyces cerevisiae cells. That assay required the use of a double mediator system, a five-hour incubation period and had a maximum detection limit of around 11 nM 17β-oestradiol. In the work reported here we have sought to systematically increase the utility and decrease the complexity of the whole cell assay. The steps we took to achieve this goal were in order; lysing the cells to remove transport constraints, removing the lipophilic mediator and conducting the assay with the hydrophilic mediator only and finally performing the assay in a complex medium to demonstrate its specificity. Linear sweep voltammetry was used to investigate the interaction of mediators with NADH. The assay is now cell free and functions in a complex substrate. The linear response range upper limit has been raised to 100 nM with a calculated limit of detection of 0.005 nM with a limit of determination of 0.014 nM and the assay period has been reduced to 20 min.
authors.affiliation: Faculty of Agriculture and Life Sciences, Lincoln University, PO Box 84, Lincoln University, Lincoln 7647, Canterbury, New Zealand.
authors.forename: Venkata
authors.initials: V
authors.lastname: Chelikani
authors.affiliation: Department of Chemistry, University of Canterbury, Private Bag 4800 Christchurch, New Zealand.
authors.forename: Frankie J
authors.initials: FJ
authors.lastname: Rawson
authors.affiliation: Department of Chemistry, University of Canterbury, Private Bag 4800 Christchurch, New Zealand.
authors.forename: Alison J
authors.initials: AJ
authors.lastname: Downard
authors.affiliation: Faculty of Agriculture and Life Sciences, Lincoln University, PO Box 84, Lincoln University, Lincoln 7647, Canterbury, New Zealand.
authors.forename: Ravi
authors.initials: R
authors.lastname: Gooneratne
authors.affiliation: Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), Corrensstr. 3, D-06466 Gatersleben, Germany.
authors.forename: Gotthard
authors.initials: G
authors.lastname: Kunze
authors.affiliation: Lincoln Ventures Ltd, PO Box 133, Lincoln, Christchurch 7640, New Zealand.
authors.forename: Neil
authors.initials: N
authors.lastname: Pasco
authors.affiliation: School of Biological Sciences, University of Canterbury, Private Bag 4800 Christchurch, New Zealand.
authors.forename: Keith H R
authors.initials: KH
authors.lastname: Baronian
mesh_terms: D015374:Biosensing Techniques; D002176:Candida albicans / Q000378:metabolism*; D002352:Carrier Proteins / Q000737:chemistry / Q000302:isolation & purification*; D055664:Electrochemical Techniques; D004967:Estrogens / Q000737:chemistry / Q000378:metabolism*; D011960:Receptors, Estrogen / Q000737:chemistry / Q000302:isolation & purification*
chemical_list: D002352:Carrier Proteins; D004967:Estrogens; D011960:Receptors, Estrogen; C010140:estrophilin