A laser mass spectrometry platform for in situ analysis of proteins and their complexes in tissue
Lead Research Organisation:
University of Birmingham
Department Name: Sch of Biosciences
Abstract
Proteins are a class of hugely important biomolecules. They perform all the functions necessary for life, as well as finding applications as therapeutics. To fully understand the roles of proteins in health and disease, it is necessary to understand their structure and interactions on the molecular level and, most importantly, to gain that understanding in the actual biological context, i.e., in tissue.
To address that challenge, we have developed native ambient mass spectrometry (NAMS). NAMS allows the identification and spatial mapping of proteins in tissue, in addition to providing information on structure and interactions with other molecules, including proteins, drugs, small molecule ligands and metal ions. NAMS offers advantages over other spatial biology methods, such as immunohistochemistry, as there is no requirement for labelling and, consequently, no requirement for prior knowledge of a protein's identity. All proteins have a mass, therefore, in principle, all proteins can be detected by mass spectrometry.
The potential of NAMS for applications in molecular pathology and drug discovery is truly exciting; however, to date, NAMS has been limited to the characterisation of proteins with higher abundance. Our recent work has focused on the development of the sampling technique nanospray desorption electrospray ionisation (nano-DESI), which offers higher spatial resolution than previous NAMS techniques for direct analysis of proteins from tissue. There is a pressing need to improve both the sensitivity and robustness of NAMS, beyond that achieved with nano-DESI, and to complement these with improved confidence in protein identifications.
The aim of this proposal is to realise these required improvements through scientific instrument development, specifically by the integration of lasers with the existing mass spectrometry platform. The first development focuses on the protein sampling device. A new NAMS probe that couples laser desorption, via a pulsed infrared laser, with liquid microdroplet capture of biological material and subsequent ionisation, will be designed, constructed, and validated. The new probe will address the challenge of robustness and advance NAMS towards cellular resolution protein imaging. The second development will integrate a CO2 infrared laser with the mass spectrometer which will improve sensitivity and augment the system with new techniques for protein identification. Together, these modifications will comprise the step-change required to deliver next-generation NAMS and realise its potential to transform life science research.
To address that challenge, we have developed native ambient mass spectrometry (NAMS). NAMS allows the identification and spatial mapping of proteins in tissue, in addition to providing information on structure and interactions with other molecules, including proteins, drugs, small molecule ligands and metal ions. NAMS offers advantages over other spatial biology methods, such as immunohistochemistry, as there is no requirement for labelling and, consequently, no requirement for prior knowledge of a protein's identity. All proteins have a mass, therefore, in principle, all proteins can be detected by mass spectrometry.
The potential of NAMS for applications in molecular pathology and drug discovery is truly exciting; however, to date, NAMS has been limited to the characterisation of proteins with higher abundance. Our recent work has focused on the development of the sampling technique nanospray desorption electrospray ionisation (nano-DESI), which offers higher spatial resolution than previous NAMS techniques for direct analysis of proteins from tissue. There is a pressing need to improve both the sensitivity and robustness of NAMS, beyond that achieved with nano-DESI, and to complement these with improved confidence in protein identifications.
The aim of this proposal is to realise these required improvements through scientific instrument development, specifically by the integration of lasers with the existing mass spectrometry platform. The first development focuses on the protein sampling device. A new NAMS probe that couples laser desorption, via a pulsed infrared laser, with liquid microdroplet capture of biological material and subsequent ionisation, will be designed, constructed, and validated. The new probe will address the challenge of robustness and advance NAMS towards cellular resolution protein imaging. The second development will integrate a CO2 infrared laser with the mass spectrometer which will improve sensitivity and augment the system with new techniques for protein identification. Together, these modifications will comprise the step-change required to deliver next-generation NAMS and realise its potential to transform life science research.
