Immunoaffinity techniques coupled to mass spectrometry for the analysis of human peptide hormones: advances and applications

Abstract

The accurate and comprehensive determination of peptide hormones from biological fluids has represented a considerable challenge to analytical chemists for decades. Besides long-established bioanalytical ligand binding assays (or ELISA, RIA, etc.), more and more mass spectrometry-based methods have been developed recently for purposes commonly referred to as targeted proteomics. Eventually the combination of both, analyte extraction by immunoaffinity and subsequent detection by mass spectrometry, has shown to synergistically enhance the test methods' performance characteristics. Areas covered: The review provides an overview about the actual state of existing methods and applications concerning the analysis of endogenous peptide hormones. Here, special focus is on recent developments considering the extraction procedures with immobilized antibodies, the subsequent separation of target analytes, and their detection by mass spectrometry. Expert commentary: Key aspects of procedures aiming at the detection and/or quantification of peptidic analytes in biological matrices have experienced considerable improvements in the last decade, particularly in terms of the assays' sensitivity, the option of multiplexing target compounds, automatization, and high throughput operation. Despite these advances and progress as expected to be seen in the near future, immunoaffinity purification coupled to mass spectrometry is not yet a standard procedure in routine analysis compared to ELISA/RIA.

Simplified quantification of insulin, its synthetic analogs and C‐peptide in human plasma by means of LC‐HRMS

“…Another aspect is the modest specificity of the sample preparation, which in principle enriches all peptidic analytes more or less well from the blood sample. Here, antibody‐based sample preparations have considerable advantages and should always be performed additionally to confirm the qualitative presence of the respective insulin . The present approach offers advantages in terms of lower costs and simplicity.…”

“…Here, antibody-based sample preparations have considerable advantages and should always be performed additionally to confirm the qualitative presence of the respective insulin. 19,20 The present approach offers advantages in terms of lower costs and simplicity. Furthermore, the aforementioned incompatibility of the method with nano-scale LC systems limits the accomplished sensitivity, which would also be necessary to comprehensively cover fasting states (< 0.2 ng/mL) of insulin in the circulation.…”

Annual banned‐substance review: Analytical approaches in human sports drug testing

“…A variety of insulin‐like growth factor‐I (IGF‐I) preparations and derivatives exist. These represent a complex analytical challenge for doping control laboratories due to several reasons including the high abundance of natural IGF‐I, the largely unknown metabolic degradation of synthetic IGF‐I derivatives and the supposedly low blood and urine concentrations of the drugs and drug candidates . To approach these issues, Thomas et al conducted in vitro metabolism studies with longR 3 ‐IGF‐I, R 3 ‐IGF‐I, and des1‐3‐IGF‐I employing rat skin S9 fraction, human plasma, or human serum.…”

Electrochemical Sensing of Ovalbumin Based on the Interaction between Lysozyme Origin/Tyrosine‐rich Peptides Modified on Magnetic Beads and Oligothreonine/Ovalbumin‐origin Peptide

“…When a peptide with a molecular recognition function combines with an information transfer molecule, the series of the molecule acts as a powerful probe and can be a tool for the sensing of a specific target . This probe‐and‐tool dynamic has been applied to the fluorometric and mass spectrometric detection of biomolecules and cells, and electrochemical procedures are simple and cost‐effective methods to accomplish this. As a recent example, Liu et al.…”

“…When a peptide with a molecular recognition function combines with an information transfer molecule, the series of the molecule acts as a powerful probe and can be a tool for the sensing of a specific target [4][5][6]. This probe-and-tool dynamic has been applied to the fluorometric [7][8][9] and mass spectrometric detection [10][11][12] of biomolecules and cells, and electrochemical procedures are simple and cost-effective methods to accomplish this. As a recent example, Liu et al performed electrochemical measurements of a βamyloid (1-42) peptide, a biomarker for Alzheimer's disease, by using total β-amyloid-based p-aminophenol redox cycling with an antibody-modified gold electrode [13].…”