Characterization of proteins and protein complexes is a major keystone of structural biology. As our understanding of cellular processes continues to evolve from simple pathways to complicated networks, our need for advanced analytical methods is quite apparent. Mass spectrometry (MS)-based structural approaches can be used to study protein conformational changes and dynamics, protein motion/flexibility, ligand-protein binding, and protein-protein interfaces.
Written by: Vanessa Yoon Calvelo, PhD Updated: January 19, 2023 (Published: June 2, 2022) Contents What are post-translational modifications (PTMs)? Impact of PTMs Types of PTMs PTMs increase microheterogeneity of antibodies PTM Analysis by LC-MS The Importance of Post-Translational Modifications (PTMs) Post-translational modifications (PTMs) are processing [...]
Written by: Yuning Wang, PhD Updated: January 26, 2023 (Published: June 3, 2022) Contents Introduction The Four Levels of Protein Structure How are Protein Structures Studied? Introduction Structural information provides a great deal of understanding of how a protein works, which can allow us to [...]
The origin of hydrogen-deuterium exchange (HDX) dates back to the 1950s, when protein scientist Linderstrøm-Lang created a method involving protein deuteration to distinguish amide hydrogens participating in secondary structures. Today, scientists frequently rely on HDX data to investigate protein structure, conformational dynamics, and protein-ligand interaction.
To develop robust mAb biologics, it is vital to fully characterize the protein, including its primary sequence, mutations, and important post-translational modifications
In this study, we conducted a large-scale statistical analysis of protein sequencing data from samples digested with multiple proteases to understand the impact of using different combinations of proteases to improve the depth of sequence coverage in the application of de novo protein sequencing.
Amino acids are small organic molecules that make up peptides and proteins. All living organisms share the same set of amino acids. Amino acids come together in different orders (sequences) to form proteins. As such, each type of protein has a different three-dimensional structure and biological activity.
Protein sequencing is a method that typically utilizes mass spectrometry (MS) to determine the amino acid code of a protein1. Prior to the development of mass spectrometry, Edman degradation, a method involving the stepwise degradation of peptides to derive the order of amino acids, was the mainstream approach. Nowadays, mass spectrometry is favored due to its ease of use and high throughput capabilities, though Edman degradation is still employed for specific applications in which the technique is well suited.
Monoclonal antibodies (mAbs) are homogenous antibodies that bind to a single epitope on an antigen. Kohler and Milstein generated the first mAbs when they developed hybridoma technology in the 1970s. Because of the specificity, homogeneity and unlimited availability, mAbs are valuable reagents used in a variety of important applications including treatment and diagnosis of diseases
Amino acids (aa)—the building blocks of proteins—are simple molecules characterized by a variable R group flanked either side by an amino group and a carboxyl group. With around 20 different commonly found amino acids, each one can bond with another to produce chains that can be classified as peptides (typically below 50 aa) and proteins (sequences above 50 aa)—molecules ubiquitous to every known organism.
Amino acid sequencing is commonly performed using Edman degradation or mass spectrometry (MS). While mass spectrometry is favoured for its high throughput capabilities and ease of use, both techniques possess their own features and limitations. This article summarizes some of the key pain points inherent in the two methodologies when determining the amino acid sequence.
Antibodies are used in a variety of ways in academia and industry, from tools to therapeutics. Because antibodies are produced using live processes, which are naturally error-prone, validation is required from time to time. Furthermore, to develop biological therapeutics, the protein sequence must be confirmed as part of the regulatory process.
DNA sequencing is the process of determining the precise order of four nucleotides bases—adenine (A), guanine (G), cytosine (C), and thymine (T)—that make up the DNA molecule. From Sanger sequencing to next-generation sequencing (NGS), DNA sequencing’s accessibility and ease of use make it one of the most widely used technologies in life sciences.
As proteins are assembled, they fold into different structural orders: from primary to quaternary. The exact sequence of the primary structure (the amino acid sequence) will dictate how a protein will fold and function. The importance of the primary structure has been noted in several studies, where changes in the original amino acid sequence have resulted in affinity problems, binding disruption, reduced half-life, and higher aggregation odds.
Proteins are composed of peptide chains, which in turn are made up of a string or linear sequence of amino acids. Every amino acid has a basic structure containing an amino (-NH2) group and a carboxylic (-COOH) group (Figure 1B). To form a peptide, amino acids link to each other via a peptide bond, which involves the reaction between the carboxylic group of one amino acid and the amine group of another amino acid.
Protein mass spectrometry refers to the use of mass spectrometry in studying and characterizing proteins, including their quantification, profiling, interaction mapping, and identification of their post-translational modifications. Protein mass spectrometry may also be referred to as mass spectrometry-based proteomics. Mass spectrometry-based proteomics comprises three approaches: top-down, middle-down, and bottom-up proteomics.
Antibody sequences are critical for antibody engineering and protein characterization in therapeutic development. For antibody reagent users, knowing the sequences allows them to perform sequence analysis/alignment to identify binding and cross-reactivity so they can conduct rational experiment design.
Because they share the same mass, isoleucine and leucine are known as isobaric amino acids. Conventional mass spectrometry-based proteomics cannot be easily used to distinguish between isoleucine and leucine.
Amino acid sequencing is the process of identifying the arrangement of amino acids in proteins and peptides. Numerous distinct amino acids have been discovered in nature but all proteins in the human body are comprised of just twenty different types.
Monoclonal antibodies (mAbs) are widely used in research, diagnosis, and pharmaceutical purposes. Lately, the relatively lower quality of research-purpose mAbs is a point of concern within the research community.
The DNA sequences of antibodies are highly diverse due to the V-(D)-J recombination and hypersomatic mutations. As such, relying on homology-based searches to sequence novel antibodies can introduce bias to sequences obtained from proteomics approaches.
In this on-demand webinar, our scientific sales executive Jennifer, will briefly cover the fundamentals of protein sequencing, how researchers have benefited from implementing protein sequencing into their pipelines, and discuss how Rapid Novor is able to routinely and robustly achieve 100% accuracy and 100% coverage for both monoclonal and oligoclonal antibodies.
Nowadays, DNA sequencing is so popular that it is easy to forget that the first sequenced biological material was protein – insulin, by Sanger. Sanger, and another researcher, Edman, separately pioneered protein sequencing.
In this on-demand webinar, we discuss why it is important to characterize antibodies based on their physical properties not just by what they bind, and how you can easily do the former via mass spectrometry-based protein sequencing.
One of the most important pieces of information researchers need to know during early stage antibody drug research and development is the sequence information of the antibody protein. With the advancement of mass spectrometry instrumentation and technologies, it is helpful, and sometimes critical, to conduct sequence analysis using mass spectrometry experiments.