Fe3+/Fe2+ Mycobactin‐Complex Electrochemistry as an Approach to Determine Mycobactin Levels in Urine. Issue 3 (5th March 2015)

• Record Type: Journal Article
• Authors: McBride, Nicholas S.; Hall, Elizabeth A. H.
• Is Part Of: Electroanalysis. Volume 27:Issue 3(2015:Mar.)
• Page Start: 833
• Page End: 842
• Publication Date: 2015-03-05
• Subjects: Electrochemical analysis -- Periodicals; Chemistry, Analytical -- Periodicals; Electrochemistry -- Periodicals; 543.4
• DOI: 10.1002/elan.201400565
• Languages: English
• ISSNs: 1040-0397

Abstract

<abstract abstract-type="main" xml:lang="en"> <title>Abstract</title> <p>Mycobacterium acquire iron by producing siderophores called mycobactins, with an extremely high affinity complexation of Fe³⁺. The iron complex shows distinctive electrochemistry predicting 18 orders of magnitude greater affinity of the mycobactin for Fe³⁺ than Fe²⁺. A heterogeneous standard rate constant, <italic>k_s</italic> of the order of 10⁻⁵ cm s⁻¹ confirms quasi reversible electrochemistry and based on the equilibrium in the presence of excess solution Fe³⁺/Fe²⁺ the oxidation and reduction peaks for the siderophore complex could be calibrated for ferric mycobactin J (FeMJ). FeMJ spiked urine collected from cows showed a matrix effect on the current peak height. For example, 240±15 µM FeMJ was estimated in 600 µM spiked urine. However, in the presence of excess solution Fe(acac)₃ the same sample yielded an estimated 580±25 µM FeMJ.</p> </abstract>