Quantitation of nonspecific protein adsorption at solid–liquid interfaces for single-cell proteomics

Abstract

Protein nonspecific adsorption that occurred at the solid–liquid interface has been subjected to intense physical and chemical characterizations due to its crucial role in a wide range of applications, including food and pharmaceutical industries, medical implants, biosensing, and so on. Protein-adsorption caused sample loss has largely hindered the studies of single-cell proteomics; the prevention of such loss requires the understanding of protein–surface adsorption at the proteome level, in which the competitive adsorption of thousands and millions of proteins with vast dynamic range occurs. To this end, we feel the necessity to review current methodologies on their potentials to characterize — more specifically to quantify — the proteome-wide adsorption. We hope this effort can help advancing single-cell proteomics and trace proteomics.

Protein Adsorption Loss─The Bottleneck of Single-Cell Proteomics

“…AL refers to the immobilization of analytes due to adsorption and renders them unavailable for analyses in solution. Adsorption, particularly surface adsorption, is a common event in molecular interactions, and the adsorption of analytes (also called adsorbates) to foreign surfaces (also called adsorbents) can lower their surface energy; , therefore, adsorption is energetically favored and spontaneous. All molecules, including nucleic acids, proteins, and small molecules, are subject to AL.…”

Characterization of Sample Loss Caused by Competitive Adsorption of Proteins in Vials Using Sodium Dodecyl Sulfate–Polyacrylamide Gel Electrophoresis

“…The challenge lies in the limited approaches that are available to quantify trace yet complex proteins adsorbed on irregular surfaces. 25 However, commonly used tubes and vials to handle biological samples are always having an irregularly curved surface with limited area of a few centimeters. For classic characterization techniques such as quartz crystal microbalance, surface plasma resonance, and atomic force microscopy, special instruments are often required, the surface that can be characterized are restricted, and only total proteins can be studied but not the individual proteins in mixture.…”

“…Alternatively, an affinity compound is required such as antibodies for enzymatically linked immunosorbent assay. 25 These extra steps consume time, have varied yields, or can alter the conformation thereof the adsorption property of proteins. Current understanding and prevention of adsorption are mostly built from the characterization of individual model protein(s), yet it is known that adsorption event highly depends on proteins and their interacting substrates.…”

“…The challenge lies in the limited approaches that are available to quantify trace yet complex proteins adsorbed on irregular surfaces . However, commonly used tubes and vials to handle biological samples are always having an irregularly curved surface with limited area of a few centimeters.…”

“…However, commonly used tubes and vials to handle biological samples are always having an irregularly curved surface with limited area of a few centimeters. For classic characterization techniques such as quartz crystal microbalance, surface plasma resonance, and atomic force microscopy, special instruments are often required, the surface that can be characterized are restricted, and only total proteins can be studied but not the individual proteins in mixture. , Surface-flexible techniques such as fluorescence or radioisotope characterization, which are also suitable for multiplexed analysis, often need labeling of target proteins. Alternatively, an affinity compound is required such as antibodies for enzymatically linked immunosorbent assay .…”