Different proteins could annotate a single mass peak of a mass spectrum

Functional annotation of mass spectrum of bacterial cells obtained by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) generates the biological meaning that underpins the use of mass spectrometry for microbial identification. However, different proteins could have the same mass/charge ratio and thus able to annotate the same mass peak in a mass spectrum. Such … More Different proteins could annotate a single mass peak of a mass spectrum

Conserved mass peaks of bacteria at the genus level

Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) has been validated to be useful in identifying many microbial species to the species level. However, the approach relies on the existence of different mass peaks between different microbial species. Such differences manifest as differences in mass peak distribution in mass spectra of microbes that could be … More Conserved mass peaks of bacteria at the genus level

Informatic challenge in MALDI-TOF imaging mass spectrometry

Imaging mass spectrometry is a relatively new concept in mass spectrometry application that seeks to profile the ensemble of biomolecules in a tissue or sample. Useful for detecting and analysing biomolecules present in a sample in a large area format, imaging mass spectrometry generates huge datasets that must be annotated to obtain rich biological information … More Informatic challenge in MALDI-TOF imaging mass spectrometry

High accuracy timing mechanisms in time-of-flight mass spectrometers enable high mass resolution detection

High accuracy timing in time-of-flight mass spectrometers facilitate the accurate detection of time of arrival of different molecular ions, which when compared to a calibration chart of protein standards with known molecular weight, enables the calculation of mass/charge ratio of high mass resolution. Specifically, accuracy of the timing mechanism at the millisecond timescale provides a … More High accuracy timing mechanisms in time-of-flight mass spectrometers enable high mass resolution detection

Conserved mass peaks in mass spectra of bacterial species

Conserved mass peaks were found in mass spectra of individual bacterial species that highlighted a deep biological basis in the use of mass spectrometry for identifying bacteria. Specifically, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) could profile biomolecules (mostly proteins) from bacterial cells that result in a mass spectrum useful for identification purposes. While … More Conserved mass peaks in mass spectra of bacterial species

Long flight tube in time-of-flight mass spectrometer enables better separation of different analyte ions

Molecular ions literally fly through the flight tube of the time-of-flight mass spectrometer where at the end of the travel, they are detected as an electrical charge on the detector. The duration of flight was measured and is a key parameter for calculation of the mass/charge ratio of the molecular ion based on a calibration … More Long flight tube in time-of-flight mass spectrometer enables better separation of different analyte ions

Transfer of laser energy from matrix coating helps prevent fragmentation of molecules

Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) ionizes molecules without inducing fragmentation, thereby allowing molecular ion to be detected, which helps data interpretation of mass spectrum. The mechanisms underlying the ability of the mass spectrometry technique to ionize molecules without inducing fragmentation lies in the use of special matrix compounds that help transfer laser … More Transfer of laser energy from matrix coating helps prevent fragmentation of molecules

Is there a theoretical mass limit to MALDI-TOF mass spectrometry?

Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) uses a laser to ionize molecules from a matrix coated sample surface, accelerate them along a vacuum tube through the application of an electric field, and obtained a mass/charge ratio of the molecular ion by timing the flight of the ion. Given that time-of-flight of the molecular … More Is there a theoretical mass limit to MALDI-TOF mass spectrometry?

How do we obtain structural information of protein?

Readers would often find scientific papers describing the structure of a single protein or molecule. However, given that we do not have the capability of manipulating single protein or molecule with ease, how do we image a single protein or molecule to obtain its structural information?   The answer lies in the use of X-ray … More How do we obtain structural information of protein?

Genomics enabled mass spectrometry-based proteomics

Mass spectrometry has developed into a critical tool for proteomics where a large number of studies had used mass spectrometry instruments for profiling the proteome of cells and tissues. However, identification of the mass peaks profiled in the mass spectrum would require the support of a library of molecular mass of all proteins profiled in … More Genomics enabled mass spectrometry-based proteomics