Dataset Information

First demonstration of in vivo mapping for regional brain monoacylglycerol lipase using PET with [11C]SAR127303.

ABSTRACT: Monoacylglycerol lipase (MAGL) is a main regulator of the endocannabinoid system within the central nervous system (CNS). Recently, [11C]SAR127303 was developed as a promising radioligand for MAGL imaging. In this study, we aimed to quantify regional MAGL concentrations in the rat brain using positron emission tomography (PET) with [11C]SAR127303. An irreversible two-tissue compartment model (2-TCMi, k4?=?0) analysis was conducted to estimate quantitative parameters (k3, Ki2-TCMi, and ?k3). These parameters were successfully obtained with high identifiability (<10 %COV) for the following regions ranked in order from highest to lowest: cingulate cortex?>?striatum?>?hippocampus?>?thalamus?>?cerebellum?>?hypothalamus???pons. In vitro autoradiographs using [11C]SAR127303 showed a heterogeneous distribution of radioactivity, as seen in the PET images. The Ki2-TCMi and ?k3 values correlated relatively highly with in vitro binding (r?>?0.4, P?

SUBMITTER: Yamasaki T

PROVIDER: S-EPMC5976552 | biostudies-literature | 2018 Aug

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

First demonstration of in vivo mapping for regional brain monoacylglycerol lipase using PET with [11C]SAR127303.

Yamasaki Tomoteru T Mori Wakana W Zhang Yiding Y Hatori Akiko A Fujinaga Masayuki M Wakizaka Hidekatsu H Kurihara Yusuke Y Wang Lu L Nengaki Nobuki N Ohya Tomoyuki T Liang Steven H SH Zhang Ming-Rong MR

NeuroImage 20180505

Monoacylglycerol lipase (MAGL) is a main regulator of the endocannabinoid system within the central nervous system (CNS). Recently, [11C]SAR127303 was developed as a promising radioligand for MAGL imaging. In this study, we aimed to quantify regional MAGL concentrations in the rat brain using positron emission tomography (PET) with [11C]SAR127303. An irreversible two-tissue compartment model (2-TCMi, k4 = 0) analysis was conducted to estimate quantitative paramet ...[more]

PMID: 29738910

Similar Datasets

Project description:BackgroundLipolytic enzymes of hyperthermophilic archaea generally prefer small carbon chain fatty acid esters (C2-C12) and are categorized as esterases. However, a few have shown activity with long-chain fatty acid esters, but none of them have been classified as a true lipase except a lipolytic enzyme AFL from Archaeglobus fulgidus. Thus, our main objective is to engineer an archaeal esterase into a true thermostable lipase for industrial applications. Lipases which hydrolyze long-chain fatty acid esters display an interfacial activation mediated by the lid domain which lies over active site and switches to open conformation at the oil-water interface. Lid domains modulate enzyme activities, substrate specificities, and stabilities which have been shown by protein engineering and mutational analyses. Here, we report engineering of an uncharacterized monoacylglycerol lipase (TON-LPL) from an archaeon Thermococcus onnurineus (strain NA1) into a triacylglycerol lipase (rc-TGL) by replacing its 61 N-terminus amino acid residues with 118 residues carrying lid domain of a thermophilic fungal lipase-Thermomyces lanuginosus (TLIP).ResultsTON-LPL and rc-TGL were cloned and overexpressed in E. coli, and the proteins were purified by Ni-NTA affinity chromatography for biochemical studies. Both enzymes were capable of hydrolyzing various monoglycerides and shared the same optimum pH of 7.0. However, rc-TGL showed a significant decrease of 10 °C in its optimum temperature (Topt). The far UV-CD spectrums were consistent with a well-folded α/β-hydrolase fold for both proteins, but gel filtration chromatography revealed a change in quaternary structure from trimer (TON-LPL) to monomer (rc-TGL). Seemingly, the difference in the oligomeric state of rc-TGL may be linked to a decrease in temperature optimum. Nonetheless, rc-TGL hydrolyzed triglycerides and castor oil, while TON-LPL was not active with these substrates.ConclusionsHere, we have confirmed the predicted esterase activity of TON-LPL and also performed the lid engineering on TON-LPL which effectively expanded its substrate specificity from monoglycerides to triglycerides. This approach provides a way to engineer other hyperthermophilic esterases into industrially suitable lipases by employing N-terminal domain replacement. The immobilized preparation of rc-TGL has shown significant activity with castor oil and has a potential application in castor oil biorefinery to obtain value-added chemicals.

Dataset Information

First demonstration of in vivo mapping for regional brain monoacylglycerol lipase using PET with [11C]SAR127303.

Publications

First demonstration of in vivo mapping for regional brain monoacylglycerol lipase using PET with [<sup>11</sup>C]SAR127303.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure