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

Challenges of protein identification by MALDI-TOF mass spectrometry

The gold standard approach for identifying a protein is Western blot, which uses a primary antibody to recognize the target protein for subsequent visualization of the protein band by chemiluminescence. More recently, various mass spectrometry-based methods have been developed for the detection and identification of proteins.   These techniques could be classified into fragmentation-based methods … More Challenges of protein identification by MALDI-TOF mass spectrometry

Cryo electron microscopy’s increasingly important role in structural biology

Cryo electron microscopy has been increasingly used in determining the structure of biomolecules such as proteins down to the atomic resolution level of 2 to 4 Angstrom. More importantly, capable of determining the native structure of proteins in frozen solutions, the method is finding increasing use in protein structure elucidation. Specifically, cryo electron microscopy find … More Cryo electron microscopy’s increasingly important role in structural biology

Obtaining movies of molecular movement of proteins through serial femtosecond crystallography

Seeing is believing; thus, it would be much better if we could observe real-time molecular level movement of proteins during catalysis, where, for example, binding of a substrate to an active site leads to molecular cleavage and enzymatic action. But, this feat is not realized until recent advent of serial femtosecond crystallography (SFX).   In … More Obtaining movies of molecular movement of proteins through serial femtosecond crystallography

Ultrafast femtosecond imaging of molecular dynamics by tetrahertz scanning tunnelling microscopy

Article in Nature, Vol. 539, 10 November 2016, pp. 263, “Tracking the ultrafast motion of a single molecule by femtosecond orbital imaging”   Summary of article: Low current, low temperature, tetrahertz scanning tunnelling microscopy was used to probe the intrinsic dynamics of molecular motion at the femtosecond timescale.   Link to original article: http://www.nature.com/nature/journal/v539/n7628/full/nature19816.html   … More Ultrafast femtosecond imaging of molecular dynamics by tetrahertz scanning tunnelling microscopy