Dihydroxy‐Acid Dehydratases From Pathogenic Bacteria: Emerging Drug Targets to Combat Antibiotic Resistance. Issue 44 (16th June 2022)

• Record Type: Journal Article
• Authors: Bayaraa, Tenuun; Gaete, Jose; Sutiono, Samuel; Kurz, Julia; Lonhienne, Thierry; Harmer, Jeffrey R.; Bernhardt, Paul V.; Sieber, Volker; Guddat, Luke; Schenk, Gerhard
• Is Part Of: Chemistry. Volume 28:Issue 44(2022)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-06-16
• Subjects: antibiotics -- dihydroxy-acid dehydratase -- enzyme activation -- Fe−S cluster -- sustainable chemistry; Chemistry -- Periodicals; 540
• DOI: 10.1002/chem.202200927
• Languages: English
• ISSNs: 0947-6539

Abstract

Abstract: There is an urgent global need for the development of novel therapeutics to combat the rise of various antibiotic‐resistant superbugs. Enzymes of the branched‐chain amino acid (BCAA) biosynthesis pathway are an attractive target for novel anti‐microbial drug development. Dihydroxy‐acid dehydratase (DHAD) is the third enzyme in the BCAA biosynthesis pathway. It relies on an Fe−S cluster for catalytic activity and has recently also gained attention as a catalyst in cell‐free enzyme cascades. Two types of Fe−S clusters have been identified in DHADs, i.e. [2Fe−2S] and [4Fe−4S], with the latter being more prone to degradation in the presence of oxygen. Here, we characterise two DHADs from bacterial human pathogens, Staphylococcus aureus and Campylobacter jejuni ( Sa DHAD and Cj DHAD). Purified Sa DHAD and Cj DHAD are virtually inactive, but activity could be reversibly reconstituted in vitro (up to ∼19, 000‐fold increase with kcat as high as ∼6.7 s −1 ). Inductively‐coupled plasma‐optical emission spectroscopy (ICP‐OES) measurements are consistent with the presence of [4Fe−4S] clusters in both enzymes. N‐isopropyloxalyl hydroxamate (IpOHA) and aspterric acid are both potent inhibitors for both Sa DHAD ( K i =7.8 and 51.6 μM, respectively) and Cj DHAD ( K i =32.9 and 35.1 μM, respectively). These compounds thus present suitable starting points for the development of novel anti‐microbial chemotherapeutics. Abstract : The FeS cluster‐dependent dihydroxy‐acid dehydratases (DHADs) from Staphylococcus aureus and Campylobacter jejuni ( Sa DHAD and Cj DHAD) are emerging targets for biocides. They are virtually inactive after extraction, but a functional [4Fe−4S] cluster can be reconstituted in vitro boosting the activity up to ∼19, 000‐fold.