Analytical Chemistry

National Center For Advancing Translational Sciences

Investigators

Linked publications, trials & patents

Abstract

Over the past year, the COVID-19 global pandemic has significantly impacted the ACC through a necessary lab shutdown, modification of laboratory operating procedures, and a shift to teleworking status. As the majority of ACC tasks and responsibilities require laboratory access, we were presented with the logistical challenge of providing core analytical chemistry services while maintaining the health and safety of DPI staff. Research activities were prioritized with COVID-related projects taking precedence, followed by ongoing projects requiring minimal experiments to complete, especially trainee projects as their time at NCATS was limited. The initiation of new projects was restricted unless they focused on COVID-19. The continued success of DPI research projects, initiatives, and programs depends on the uninterrupted operation of analytical services and resources, which facilitates forward progress and translational discoveries. Furthermore, analytical data and analysis must be made promptly available in a convenient format to allow timely and informed decisions regarding the direction or even continuation of projects. To accomplish this, the ACC needed to develop new and modify existing protocols and workflows to handle the increased workload under the new operational model. This included (i) modifications to the sample purification and processing platform to minimize delays in material transfer to Compound Management, (ii) enabling direct access to instrument data for remote analysis and review, (iii) establishing ways to conduct training in a socially distant manner for new employees and fellows, and (iv) maintaining and updating chemistry software and application in a completely virtual capacity. The ACC has continued to perform the core responsibility of purifying samples with material in the range of milligrams to grams. Major and minor components (< 0.1 percent) have been isolated for additional testing and characterization as required. By utilizing a centralized sample purification and processing platform, compounds can be isolated, purified, concentrated, distributed, registered, and ready for biological testing in a cycle time of one week. Automated protocols and workflows were employed to perform such tasks as consolidation and concentration of purified fractions and the dispensing of material into 1D barcoded vials, Matrix 2D barcoded tubes and/or 96-well plates for efficient tracking, storing, and testing. A variety of high performance and ultra high-performance liquid chromatographs are utilized to determine identity and purity with the capability of automated high-throughput analysis on single quadrupole liquid chromatography/mass spectrometry instrumentation. Due to the wide variety of analytes tested, the teams range of analytical detectors includes ultraviolet (UV), mass spectrometry (MS; positive and negative mode), and evaporative light scattering detector and fluorescence (ELSD). Time-of-flight mass spectrometry (TOF-MS) is employed to achieve formula confirmation and identity determination of unknowns. In addition to purification and analysis of chemical entities related to COVID-19, the ACC established several project collaborations focused on COVID-19 research. One such collaboration is between the ACC, the DPI Informatics Core, and the Early Translational Branch (ETB) 3D Tissue Bioprinting group working on 2D and 3D lung cell omics models to discover chemical and biological markers related to SARS-CoV-2 leveraging our experience in metabolomics, proteomics, tissue printing, MS-based screening assay, and data analysis. Additionally, we are collaborating with ETB focused on the compositional analysis of Mutian, a feline coronavirus treatment, as well as with the ADME team within the Therapeutic Development Branch (TDB) to develop high-throughput MS-based antibody analysis assays related to SARS-CoV-2 and other coronaviruses. The chemical and enantiomeric purity of chiral compounds is routinely determined within the groups full-scale chiral laboratory. Methods development with the chiral chromatography screening protocol involves the utilization of various chiral stationary phases in conjunction with multiple mobile phase conditions. The use of an inline chiral detector allows for the determination of relative optical rotation. Sample purification on a scale of up to hundreds of milligrams is possible. The ACC has performed analysis, separation, and purification of chiral compounds containing a wide range of chemotypes associated with various projects for both internal and external collaborators. There has also been an increase in requests for vibrational circular dichroism (VCD) spectrometry analysis to determine the absolute stereochemistry chiral compounds being synthesized at NCATS. We are in continued collaboration with the NCATS IT team to deploy of conformational analysis software onto the NCATS high-performance computing (HPC) cluster. The reduced computing time needed to generate predicted VCD spectra for comparison with experimental results, as well as the creation of a structural confirmation database will be of great benefit to numerous research projects. NMR and MS analytical capabilities continue to expand within the ACC through the acquisition of advanced instrumentation and the incorporation of new and emerging techniques in order to detect, identify, quantify, and validate a wide array of therapeutic modalities. For NMR spectroscopy, we are building upon our fragment-based screening (FBS) program through the curation, update, and replenishment of our fragment screening libraries. Ligand-protein binding experiments were utilized to investigate protein-protein interactions (PPIs) for various disease states to aid in therapeutic development. Application of Mestrelab Stereofitter software is ongoing for the determination of 3D conformation for chiral small molecules. In collaboration with the ASPIRE program, the ACC is developing an automated quantitative NMR (qNMR) platform for concentration determination, purity determination, and reaction analysis. We have installed a Sirius MicroTasker customized for automated NMR sample preparation, which will help facilitate a more efficient preparation of samples for a wide array of NMR analyses, as well as increase productivity. For mass spectrometry, we acquired a Waters Xevo G2-XS quantitative time-of-flight (QTOF) mass spectrometer, which is a replacement for a obsoleted TOF MS. This more advanced instrument expands our MS capabilities and will be extremely beneficial to metabolomics analysis. In addition to our already established and highly successful proteomics platform, we are expanding into metaboloics and lipidomics as part of an effort to create a multi-omics program for biological analysis. We have continued to improve upon our universal 384-well proteomic sample preparation platform for high-throughput screening and biomarker discovery. This involves upgrades and increased functionality enabling wider applicability to an array of cellular systems, as well as varied assay needs. The successful workflow utilizes an Agilent Bravo liquid handler to automate the majority of process steps leading to greater efficiency, higher throughput, and reduced costs. The sample preparation platform was so successful that an additional Bravo system was installed to meet the workload demands from increased analysis requests. Additionally, the ACC has upgraded an Agilent RapidFire-QQQ high-throughput mass spectrometry system to handle 1536-well assay plates. After developing and validating the new methods, the high-through screening capacity of the system will increase four-fold. The Sample Management and Resource Tracking (SMART) laboratory information management system (LIMS), in conjunction with our centralized purification and sample processing platform is uti