Comparative Study of Immunoactivity and Bioactivity of Sodium Insulin

Kowarski, Chana R.; Bado, B.; Shah, Swetang; Kowarski, A. Avinoam; Kowarski, David

doi:10.1002/jps.2600720623

Cited by 9 publications

(6 citation statements)

References 6 publications

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“…44,45 Insulin regulates blood glucose by signaling when high levels of glucose are present in the body; it aids the intake of glucose by muscle tissue and works with another hormone, glucagon, to maintain a controlled level of blood glucose. 46 Several analytical methods are available for the detection of insulin, including bioassays, [47][48][49] radioimmunoassays, 50 chemiluminescence immunoassays 51 and immunoenzymometric assays. 52 The most commonly used methods for the detection of insulin are mass spectrometry, 53 photolytic electrochemical detection 54 and high-performance liquid chromatography coupled with UV absorption 55 and fluorescence.…”

Section: Resultsmentioning

confidence: 99%

Stable organic thin film transducers for biochemical and label-free sensing under physiological conditions

2012

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Section: Resultsmentioning

confidence: 99%

Stable organic thin film transducers for biochemical and label-free sensing under physiological conditions

2012

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“…Present analytical methods for the detection of insulin include bioassays, immunoassays and chromatography. The development of bioassays – and immunoassays – for the detection of insulin has been well reported in the literature. Of these, radioimmunoassays (RIA) – and enzyme-linked immunosorbent assays (ELISA) – are the most commonly used methods.…”

Section: Introductionmentioning

confidence: 99%

Electrochemical Study of Insulin at the Polarized Liquid−Liquid Interface

2008

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This paper reports on the electrochemical behavior of bovine insulin at the interface between two immiscible electrolyte solutions (ITIES). The voltammetric ion-transfer response obtained in the presence of insulin was dependent on the aqueous phase pH conditions and on the nature of the organic phase electrolyte employed in experiments. Optimal detection was obtained at acidic pH below the isoelectric point of insulin where it was positively charged. A shift in transfer potentials to lower potential values was observed with decreasing hydrophobicity of the anion of the organic phase electrolyte. No ion-transfer response was observed at pH values of the aqueous phase above the isoelectric point, where insulin was negatively charged. These results suggest that the voltammetric response is due to ion-pairing interactions at the ITIES between positively charged insulin and the hydrophobic anion of the organic phase electrolyte, together with adsorption of the ion-pair at the interface. The voltammetric response was obtained for insulin at concentrations down to 1 muM. These results show that electrochemistry is useful in studying the behavior of this important protein molecule at the polarized water-1,2-DCE interface and provides an alternative detection mode for bioanalytical applications.

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“…Insulin monitoring is an important topic in studies of pathophysiology of various disorders especially diabetes. The standard analytical methods for insulin include bioassays, immunoassays, , and chromatography. − The assays are typically slow analytical methodologies that frequently require derivatizations of insulin with isotopes or fluorogenic labels to increase the sensitivity of detection.…”

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confidence: 99%

Insulin Oxidation and Determination at Carbon Electrodes

2005

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The redox chemistry of insulin was investigated at glassy carbon (GC) electrodes that were coated with films of chitosan (CHIT) and multiwalled carbon nanotubes (CNT). While bare electrodes deactivated quickly during insulin oxidation, the GC electrodes coated with CHIT and CHIT-CNT films generated stable insulin currents. The GC/CHIT-CNT electrodes were used for investigating the electrooxidation process of insulin and amperometric determination of insulin. The mass spectrometric, electron paramagnetic resonance, and separation studies of electrolyzed insulin solutions suggested that the loss of 4 mass units upon insulin oxidation at CNT could be accounted for by the formation of two dityrosine cross-links intramolecularly. At a potential of 0.700 V and physiological pH 7.40, the GC/CHIT-CNT electrodes displayed a detection limit of approximately 30 nM insulin (S/N = 3), sensitivity of 135 mA M(-1) cm(-2), linear dynamic range from 0.10 to 3.0 microM (R2 = 0.995), and superior operational and long-term stability. The CNT-based electrodes are promising new insulin detectors for diabetes-related studies such as fast chromatographic analysis of therapeutic insulin formulations or evaluation of quality of pancreatic islets prior to their transplantation.

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Comparative Study of Immunoactivity and Bioactivity of Sodium Insulin

Cited by 9 publications

References 6 publications

Stable organic thin film transducers for biochemical and label-free sensing under physiological conditions

Stable organic thin film transducers for biochemical and label-free sensing under physiological conditions

Electrochemical Study of Insulin at the Polarized Liquid−Liquid Interface

Insulin Oxidation and Determination at Carbon Electrodes

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