ABSTRACT
Vanin-1 is an amidohydrolase that catalyses the conversion of pantetheine into the amino-thiol cysteamine and pantothenic acid (coenzyme A precursor), which plays a vital role in multiple physiological and pathological processes. In this study, an enzyme-activated near-infrared (NIR) fluorescent probe (DDAV) has been constructed for sensitively detecting Vanin-1 activity in complicated biosamples on the basis of its catalytic characteristics. DDAV exhibited a high selectivity and sensitivity toward Vanin-1 and was successfully applied to the early diagnosis of kidney injury in cisplatin-induced kidney injury model. In addition, DDAV could serve as a visual tool for in situ imaging endogenous Vanin-1 in vivo. More importantly, Enterococcus faecalis 20247 which possessed high expression of Vanin-1 was screened out from intestinal bacteria using DDAV, provided useful guidance for the rational use of NSAIDs in clinic. Finally, oleuropein as a potent natural inhibitor for Vanin-1 was discovered from herbal medicines library using a high-throughput screening method using DDAV, which held great promise for clinical therapy of inflammatory bowel disease.
ABSTRACT
In order to clarify regions of production and to discriminate processing methods, quantitative and qualitative analyses for saccharides and terpenes in 35 batches of Alismatis Rhizoma were performed. Methodologies included HPLC-PDA, HPLC-VWD and UHPLC-MS , combined with principal component analysis (PCA) and partial least squares regression techniques (PLSR). The inhibitory effects of triterpenes and Alismatis Rhizoma extracts on lipase activity were evaluated . PLSR analysis revealed significant positive correlations ( = 0.5795) between the contents of triterpenes , , , and and the inhibitory effects of Alismatis Rhizoma. The present study establishes an effective method for simultaneous determination of multiple components, and identifies key bioactive triterpenes. These results can be used for systematic and novel analytical strategies for the quality control of Alismatis Rhizoma production.
ABSTRACT
Human cytosolic sulfotransferase 2A1 (SULT2A1) is an important phase II metabolic enzyme. The detection of SULT2A1 is helpful for the functional characterization of SULT2A1 and diagnosis of its related diseases. However, due to the overlapping substrate specificity among members of the sulfotransferase family, it is difficult to develop a probe substrate for selective detection of SULT2A1. In the present study, through characterization of the sulfation of series of bufadienolides, arenobufagin (AB) was proved as a potential probe substrate for SULT2A1 with high sensitivity and specificity. Subsequently, the sulfation of AB was characterized by experimental and molecular docking studies. The sulfate-conjugated metabolite was identified as AB-3-sulfate. The sulfation of AB displayed a high selectivity for SULT2A1 which was confirmed by reaction phenotyping assays. The sulfation of AB by human liver cytosols and recombinant SULT2A1 both obeyed Michaelis-Menten kinetics, with similar kinetic parameters. Molecular docking was performed to understand the interaction between AB and SULT2A1, in which the lack of interaction with Met-137 and Tyr-238 of SULT2A1 made it possible to eliminate substrate inhibition of AB sulfation. Finally, the probe was successfully used to determine the activity of SULT2A1 and its isoenzymes in tissue preparations of human and laboratory animals.