Development of Single-Molecule Electrical Identification Method for Cyclic Adenosine Monophosphate Signaling Pathway.

Yuki Komoto,Takahito Ohshiro,Masateru Taniguchi

doi:10.3390/nano11030784

Abstract

Cyclic adenosine monophosphate (cAMP) is an important research target because it activates protein kinases, and its signaling pathway regulates the passage of ions and molecules inside a cell. To detect the chemical reactions related to the cAMP intracellular signaling pathway, cAMP, adenosine triphosphate (ATP), adenosine monophosphate (AMP), and adenosine diphosphate (ADP) should be selectively detected. This study utilized single-molecule quantum measurements of these adenosine family molecules to detect their individual electrical conductance using nanogap devices. As a result, cAMP was electrically detected at the single molecular level, and its signal was successfully discriminated from those of ATP, AMP, and ADP using the developed machine learning method. The discrimination accuracies of a single cAMP signal from AMP, ADP, and ATP were found to be 0.82, 0.70, and 0.72, respectively. These values indicated a 99.9% accuracy when detecting more than ten signals. Based on an analysis of the feature values used for the machine learning analysis, it is suggested that this discrimination was due to the structural difference between the ribose of the phosphate site of cAMP and those of ATP, ADP, and AMP. This method will be of assistance in detecting and understanding the intercellular signaling pathways for small molecular second messengers.

Highlights

Accepted: 16 March 2021Second messengers are important for the signal transduction of intracellular signals because they are always released by the cell in response to exposure to extracellular signaling molecules and trigger physiological changes at the cellular level, such as proliferation, differentiation, migration, survival, apoptosis, and depolarization [1,2,3]
Cyclic adenosine monophosphate is an important research target because it activates protein kinases, which are used to regulate the passage of ions and small molecules such as Ca2+
As a result that the chemical properties and structures of nucleic acid molecules (i.e., adenosine triphosphate (ATP), adenosine monophosphate (AMP), and adenosine diphosphate (ADP)) are very similar to those of cyclic adenosine monophosphate (cAMP), the cAMP should be selectively detected in order to detect the chemical reactions related to its intracellular signaling pathway

Summary

Introduction

Accepted: 16 March 2021Second messengers are important for the signal transduction of intracellular signals because they are always released by the cell in response to exposure to extracellular signaling molecules and trigger physiological changes at the cellular level, such as proliferation, differentiation, migration, survival, apoptosis, and depolarization [1,2,3]. Measuring the molecular behavior of second messengers is important to understand the signal transduction events that occur inside cells. Among these second messengers, cyclic adenosine monophosphate (cAMP) is an important research target because it activates protein kinases, which are used to regulate the passage of ions and small molecules such as Ca2+. Fluorescence optical imaging using optically synthesized molecular or protein probes has been as a selective detection method for cAMP. These probes are composed of two functional parts that selectively bind to cAMP and have the ability to detect a fluorescent or Published: 19 March 2021

Methods

Discussion

Conclusion