More Like this

1. Optimizing Oleaginous Yeast Cell Factories for Flavonoids and Hydroxylated Flavonoids Biosynthesis

   https://doi.org/10.1021/acssynbio.9b00193  

   Lv, Yongkun; Marsafari, Monireh; Koffas, Mattheos; Zhou, Jingwen; Xu, Peng (October 2019, ACS Synthetic Biology)
2. Discovery of l-threonine transaldolases for enhanced biosynthesis of beta-hydroxylated amino acids

   https://doi.org/10.1038/s42003-023-05293-0  

   Jones, Michaela A.; Butler, Neil D.; Anderson, Shelby R.; Wirt, Sean A.; Govil, Ishika; Lyu, Xinyi; Fang, Yinzhi; Kunjapur, Aditya M. (September 2023, Communications Biology)

   Abstract Beta-hydroxy non-standard amino acids (β-OH-nsAAs) have utility as small molecule drugs, precursors for beta-lactone antibiotics, and building blocks for polypeptides. While the L-threonine transaldolase (TTA), ObiH, is a promising enzyme for β-OH-nsAA biosynthesis, little is known about other natural TTA sequences. We ascertained the specificity of the TTA enzyme class more comprehensively by characterizing 12 candidate TTA gene products across a wide range (20-80%) of sequence identities. We found that addition of a solubility tag substantially enhanced the soluble protein expression level within this difficult-to-express enzyme family. Using an optimized coupled enzyme assay, we identified six TTAs, including one with less than 30% sequence identity to ObiH that exhibits broader substrate scope, two-fold higher L-Threonine (L-Thr) affinity, and five-fold faster initial reaction rates under conditions tested. We harnessed these TTAs for first-time bioproduction of β-OH-nsAAs with handles for bio-orthogonal conjugation from supplemented precursors during aerobic fermentation of engineeredEscherichia coli, where we observed that higher affinity of the TTA for L-Thr increased titer. Overall, our work reveals an unexpectedly high level of sequence diversity and broad substrate specificity in an enzyme family whose members play key roles in the biosynthesis of therapeutic natural products that could benefit from chemical diversification. 

   more » « less
3. Assessment of Polychlorinated Biphenyls and Their Hydroxylated Metabolites in Postmortem Human Brain Samples: Age and Brain Region Differences

   https://doi.org/10.1021/acs.est.2c00581  

   Li, Xueshu; Hefti, Marco M.; Marek, Rachel F.; Hornbuckle, Keri C.; Wang, Kai; Lehmler, Hans-Joachim (July 2022, Environmental Science & Technology)
4. Photophysics of Ru(II) complexes with hydroxylated diimine ligands: Photoinduced electron/proton transfer to anthraquinone

   https://doi.org/10.1016/j.poly.2021.115376  

   Martinez, Kristina; Benson, Kaitlyn; Paul, Jared; Schmehl, Russell H. (October 2021, Polyhedron)

   null (Ed.)
5. Identifying hydroxylated copper dimers in SSZ-13 via UV-vis-NIR spectroscopy

   https://doi.org/10.1039/D2CY00353H  

   Göltl, Florian; Bhandari, Saurabh; Lebrón-Rodríguez, Edgard A.; Gold, Jake I.; Zones, Stacey I.; Hermans, Ive; Dumesic, James A.; Mavrikakis, Manos (May 2022, Catalysis Science & Technology)

   Cu-Exchanged zeolites are promising materials for the selective conversion of methane to methanol. Their activity is attributed to the presence of small Cu-oxo and Cu-hydroxy clusters, but the nature of active centers in various zeolite structures is still under debate. In this contribution, we combine time dependent density functional theory with spin–orbit coupling to predict the optical spectra of various Cu monomers and dimers in SSZ-13. We furthermore compare theoretical results to experimental measurements and find that the presence of Cu-hydroxy dimers and Cu monomers could potentially explain the experimentally observed UV-vis-NIR spectra. 

   more » « less