We use cookies to understand how you use our site and to improve your experience. This includes personalizing content and advertising. To learn more, click here. By continuing to use our site, you accept our use of cookies. Cookie Policy.

Features Partner Sites Information LinkXpress
Sign In
Advertise with Us

Download Mobile App


ATTENTION: Due to the COVID-19 PANDEMIC, many events are being rescheduled for a later date, converted into virtual venues, or altogether cancelled. Please check with the event organizer or website prior to planning for any forthcoming event.

New Avenues for Use of Single-Molecule Detection Assays in Clinical Diagnosis

By LabMedica International staff writers
Posted on 03 Oct 2022
Print article
Image: Phosphate’s electrical signature helps detect peptide phosphorylation (Photo courtesy of Tokyo Institute of Technology)
Image: Phosphate’s electrical signature helps detect peptide phosphorylation (Photo courtesy of Tokyo Institute of Technology)

Each day, millions of biological processes occur in our body at a cellular level. Studying these processes can help us learn more about how cells function, a field that has continued to intrigue researchers. Recently, however, there has been a new player in this field. A new analytical method - single-molecule detection - has gained momentum due to its success in observing specific, biologically relevant molecules and the processes associated with them. Scientists have tried ways to use single-molecule detection assays to study proteins and their post-translational modifications (PTMs). PTMs are enzymatic changes observed after protein synthesis, wherein functional groups are added to the amino acids in the protein, enabling it to perform a specific function. The study of PTMs can help us understand cell signaling and the origin of several diseases. However, assays aiming to do so have to be highly selective and specific to that protein. Given the lack of sensitivity of current techniques, obtaining single-molecule PTM measurements is challenging. Now, a team of researchers has found an “electrifying” way to overcome these limitations, opening up new avenues for the use of single-molecule detection of PTMs in clinical diagnosis and pharmaceutical applications.

In the recent breakthrough, a team of scientists at the Tokyo Institute of Technology (Tokyo, Japan) reported the single-molecule detection of phosphorylation in peptides - short amino acid chains - and the formation of an orthophosphate junction with the help of electronic signatures. To start with, the team studied the electronic properties of phosphorylated peptides using their inorganic analog, orthophosphoric acid (H3PO4). They prepared a phosphate solution (PO43-­) and subjected it to a scanning tunneling microscope (STM)-assisted break-junction (BJ) technique. When the current was passed between two gold STM electrodes, an orthophosphate group was found to bridge the nanogap between the electrodes by forming a stable junction due to the interaction of its negatively charged oxygen atoms with the gold. It was this junction and its signature that drove further experiments.

The single-orthophosphate junction was found to possess a high conductance of 0.4 G0 and distinct electronic properties, the latter of which enabled this procedure to be highly specific and accurately sense the PTM in question (i.e., phosphorylation). To further test their technique, the team carried out in situ single-molecule phosphorylation assays, where they were able to differentiate between phosphorylated and non-phosphorylated peptides with 95% accuracy and 91% specificity. The method demonstrated in this study provides an unforeseen perspective into the world of PTMs in proteins. This novel technique will also open up new avenues for the use of single-molecule detection of PTMs in clinical diagnosis and pharmaceutical applications.

“There is a strong connection between protein phosphorylation and the pathogenesis of a wide range of diseases” said Associate Professor Tomoaki Nishino from the Tokyo Institute of Technology. “Our method will allow scientists to detangle how phosphorylation regulates the cellular events that lead to the origin of a disease and thereby aid in the development of treatments.”

Related Links:
Tokyo Institute of Technology 

Gold Supplier
ESR Analyzer
DNA/RNA Extraction Buffer
Enzymatic DNA/RNA Extraction Buffer
Molecular Diagnostic STI Test
Cellular Allergen Stimulation Test

Print article


Clinical Chem.

view channel
Image: Equivalence of Genetically Elevated LDL and Lipoprotein(a) on Myocardial Infarction (Photo courtesy of Viborg Regional Hospital)

Familial Hypercholesterolemia Patients With ACD Have Elevated Lipoprotein(a)

Familial hypercholesterolemia (FH) is a genetic disorder characterized by high cholesterol levels, specifically very high levels of low-density lipoprotein (LDL cholesterol), in the blood and early cardiovascular... Read more


view channel
Image: Ring-form trophozoites of Plasmodium vivax in a thin blood smear (Photo courtesy of Centers for Disease Control and Prevention)

Immune Regulators Predict Severity of Plasmodium vivax Malaria

Cytokines and chemokines are immune response molecules that display diverse functions, such as inflammation and immune regulation. In Plasmodium vivax infections, the uncontrolled production of these molecules... Read more


view channel
Image: Breast cancer spread uncovered by new molecular microscopy (Photo courtesy of Wellcome Sanger Institute)

New Molecular Microscopy Tool Uncovers Breast Cancer Spread

Breast cancer commonly starts when cells start to grow uncontrollably, often due to mutations in the cells. Overtime the tumor becomes a patchwork of cells, called cancer clones, each with different mutations.... Read more


view channel
Image: With Cell IDx’s acquisition, Leica Biosystems will be moving its multiplexing menu forward (Photo courtesy of Leica Biosystems)

Leica Biosystems Acquires Cell IDx, Expanding Offerings in Multiplexed Tissue Profiling

Leica Biosystems, a technology leader in automated staining and brightfield and fluorescent imaging (Nussloch, Germany), has acquired Cell IDx, Inc. (San Diego, CA, USA), which provides multiplex staining... Read more
Copyright © 2000-2022 Globetech Media. All rights reserved.