Qian T

References (2)

Title : An optimized acetylcholine sensor for monitoring in vivo cholinergic activity - Jing_2020_Nat.Methods_17_1139
Author(s) : Jing M , Li Y , Zeng J , Huang P , Skirzewski M , Kljakic O , Peng W , Qian T , Tan K , Zou J , Trinh S , Wu R , Zhang S , Pan S , Hires SA , Xu M , Li H , Saksida LM , Prado VF , Bussey TJ , Prado MAM , Chen L , Cheng H
Ref : Nat Methods , 17 :1139 , 2020
Abstract : The ability to directly measure acetylcholine (ACh) release is an essential step toward understanding its physiological function. Here we optimized the GRAB(ACh) (GPCR-activation-based ACh) sensor to achieve substantially improved sensitivity in ACh detection, as well as reduced downstream coupling to intracellular pathways. The improved version of the ACh sensor retains the subsecond response kinetics, physiologically relevant affinity and precise molecular specificity for ACh of its predecessor. Using this sensor, we revealed compartmental ACh signals in the olfactory center of transgenic flies in response to external stimuli including odor and body shock. Using fiber photometry recording and two-photon imaging, our ACh sensor also enabled sensitive detection of single-trial ACh dynamics in multiple brain regions in mice performing a variety of behaviors.
ESTHER : Jing_2020_Nat.Methods_17_1139
PubMedSearch : Jing_2020_Nat.Methods_17_1139
PubMedID: 32989318

Title : Crystal Structure of StnA for the Biosynthesis of Antitumor Drug Streptonigrin Reveals a Unique Substrate Binding Mode - Qian_2017_Sci.Rep_7_40254
Author(s) : Qian T , Wo J , Zhang Y , Song Q , Feng G , Luo R , Lin S , Wu G , Chen HF
Ref : Sci Rep , 7 :40254 , 2017
Abstract : Streptonigrin methylesterase A (StnA) is one of the tailoring enzymes that modify the aminoquinone skeleton in the biosynthesis pathway of Streptomyces species. Although StnA has no significant sequence homology with the reported alpha/beta-fold hydrolases, it shows typical hydrolytic activity in vivo and in vitro. In order to reveal its functional characteristics, the crystal structures of the selenomethionine substituted StnA (SeMet-StnA) and the complex (S185A mutant) with its substrate were resolved to the resolution of 2.71 A and 2.90 A, respectively. The overall structure of StnA can be described as an alpha-helix cap domain on top of a common alpha/beta hydrolase domain. The substrate methyl ester of 10'-demethoxystreptonigrin binds in a hydrophobic pocket that mainly consists of cap domain residues and is close to the catalytic triad Ser185-His349-Asp308. The transition state is stabilized by an oxyanion hole formed by the backbone amides of Ala102 and Leu186. The substrate binding appears to be dominated by interactions with several specific hydrophobic contacts and hydrogen bonds in the cap domain. The molecular dynamics simulation and site-directed mutagenesis confirmed the important roles of the key interacting residues in the cap domain. Structural alignment and phylogenetic tree analysis indicate that StnA represents a new subfamily of lipolytic enzymes with the specific binding pocket located at the cap domain instead of the interface between the two domains.
ESTHER : Qian_2017_Sci.Rep_7_40254
PubMedSearch : Qian_2017_Sci.Rep_7_40254
PubMedID: 28074848
Gene_locus related to this paper: 9actn-l7pij2