Structure-guided product determination of the bacterial type II diterpene synthase Tpn2

張晉源助理教授研究團隊發表研究成果於Communications Chemistry

連結網址:https://www.nature.com/articles/s42004-022-00765-6

Abstract

A grand challenge in terpene synthase (TS) enzymology is the ability to predict function from protein sequence. Given the limited number of characterized bacterial TSs and significant sequence diversities between them and their eukaryotic counterparts, this is currently impossible. To contribute towards understanding the sequence-structure-function relationships of type II bacterial TSs, we determined the structure of the terpentedienyl diphosphate synthase Tpn2 from Kitasatospora sp. CB02891 by X-ray crystallography and made structureguided mutants to probe its mechanism. Substitution of a glycine into a basic residue changed the product preference from the clerodane skeleton to a syn-labdane skeleton, resulting in the first syn-labdane identified from a bacterial TS. Understanding how a single residue can dictate the cyclization pattern in Tpn2, along with detailed bioinformatics analysis of bacterial type II TSs, sets the stage for the investigation of the functional scope of bacterial type II TSs and the discovery of novel bacterial terpenoids.

Circular Polarization Luminescence of Groove Anchor Driving Optically Active Poly(methyl methacrylate) Stereocomplexes

李明家副教授研究團隊發表研究成果於ACS Macro Lett

連結網址:https://pubmed.ncbi.nlm.nih.gov/36326692/

Abstract

This paper presents a facile method for fabricating a thin-film sample with a high asymmetry value of induced circularly polarized luminescence (iCPL) (|glum| = 2.0 × 10-3). The method involves mixing stereoregular poly(methyl methacrylate) (PMMA) and chiral chromophore (2,2,2-trifluoro-1-(9-anthryl)ethanol (TFAE)) to form a complex with a dynamic helical conformation of poly(methyl methacrylate) (PMMA) associated with TFAE via hydrogen bonding. This dynamic helical conformation can be stabilized by the stereocomplexation of a pair of stereoregular PMMA, where the TFAE is sandwiched between a double-helix isotactic PMMA and single-helix syndiotactic PMMA, resulting in a preferential one-handed helical conformation with a high value of iCPL from self-assembly.

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