ChemBioChem

P450 makes it active: Aurachin RE is a quinoline antibiotic isolated from Rhodococcus erythropolis JCM 6824. The biosynthesis gene cluster (rau) was cloned and characterized. The P450 RauA catalyzes N-hydroxylation of the quinoline ring, thus endowing the compound with antibiotic activity.

Seeing the sugar coating: N-Acetyl-glucosamine and mannosamine derivatives tagged with an isonitrile group are metabolically incorporated into cell-surface glycans and can be detected with a fluorescent tetrazine. This bioorthogonal isonitrile–tetrazine ligation is also orthogonal to the commonly used azide-cyclooctyne ligation, and so will allow simultaneous detection of the incorporation of two different sugars.

O₂^.−scavenger: The rate constant for the rapid reaction of the ROS superoxide with the reduced vitamin B₁₂ radical complex cob(II)alamin was directly determined to be 3.8×10⁸ M⁻¹ s⁻¹. This rate was independent of pH over the range 5.5–8.7. These results have implications for studying the use of B₁₂ supplements to combat diseases associated with oxidative stress.

A fork in the pocket: The bifurcated lobes of the substrate-binding pocket of the ybfF hydrolase from Vibrio cholerae provide distinct contributions to its overall activity and stability. The distinct roles of the two lobes allow the thermal stability and substrate selectivity of ybfF to be decoupled for biocatalyst design.

Growing up: Superoxide dismutase 1 (SOD1), which protects cells from radical oxygen species, requires a chaperone, CCS, for maturation. The solution structure of Cu^I-loaded hCCS domain 1 and analysis of NMR titrations of an hSOD1 disulfide-free mutant with Cu^I-hCCS reveal important aspects of CCS-dependent SOD1 maturation.

Wiley-Blackwell, Weinheim 2012, XXXVIII+612 pp., softcover, € 99.00.—ISBN 978-3-527-32850-5