The Use of Electrochemical Voltammetric Techniques and High-Pressure Liquid Chromatography to Evaluate Conjugation Efficiency of Multiple Sclerosis Peptide-Carrier Conjugates

Abstract

Recent studies have shown the ability of electrochemical methods to sense and determine, even at very low concentrations, the presence and quantity of molecules or analytes including pharmaceutical samples. Furthermore, analytical methods, such as high-pressure liquid chromatography (HPLC), can also detect the presence and quantity of peptides at very low concentrations, in a simple, fast, and efficient way, which allows the monitoring of conjugation reactions and its completion. Graphite/SiO2 film electrodes and HPLC methods were previously shown by our group to be efficient to detect drug molecules, such as losartan. We now use these methods to detect the conjugation efficiency of a peptide from the immunogenic region of myelin oligodendrocyte to a carrier, mannan. The HPLC method furthermore confirms the stability of the peptide with time in a simple one pot procedure. Our study provides a general method to monitor, sense and detect the presence of peptides by effectively confirming the conjugation efficiency. Such methods can be used when designing conjugates as potential immunotherapeutics in the treatment of diseases, including multiple sclerosis.

Myelin Peptide–Mannan Conjugate Multiple Sclerosis Vaccines: Conjugation Efficacy and Stability of Vaccine Ingredient

“…The superfluity of the free (KG) 5 -MOG 35-55 peptide that was not conjugated with oxidized mannan and which resulted in the final complex of the oxidized mannan-(KG) 5 -MOG 35-55 conjugate, probably caused the broad oxidation peak to occur on the CV. These results correlate well with the differential pulse voltammetry (DPV) signals we presented in a recent study of ours for the same purpose [24]. However, it should be noted that this is a proof-of-concept study, and we plan in the near future to further study the quantification of this and other conjugates using both voltametric techniques.…”

“…The graphite/SiO 2 film electrodes were prepared using our previously published method [24]. Electrochemical experiments were performed on an Autolab PGSTAT-101 potentiostat (Metrohm, Herisau, Switzerland).…”

“…The reaction between (KG) 5 -MOG 33 -55 and oxidized mannan was quick, and the reaction was completed within 6 h. Figure 3 shows the completion of the conjugation reaction versus time. There was no free peptide and no fragmentation of the peptide (adapted from our previous paper [24]).…”

“…Figure 2. HPLC graph of the conjugation reaction shows the starting material peptide (KG)5-MOG35-55 at (A) zero time of the reaction and (B) after 6 h showing complete conjugation.There was no free peptide and no fragmentation of the peptide (adapted from our previous paper[24]). …”

Research developments in carbon materials based sensors for determination of hormones

“…Variety of analytical methods for hormone analysis were already reported, such as bioassay [4], immunoassay [5], high-performance liquid chromatography [6], capillary electrophoresis [7], spectrophotometry [8], etc. All these techniques give accurate results, but they require expensive instruments with complex methodologies, what considerably restricts their application [9][10][11][12]. Electroanalytical methods, which are suitable for recognizing hormones observed in the human blood serum, urine, and plasma samples could overcome this problem.…”