Protein Biochemical and Chemical Processing Followed by Mass Spectrometric Analysis

PROTEIN BIOCHEMICAL AND CHEMICAL PROCESSING FOLLOWED BY MASS SPECTROMETRIC ANALYSIS 

To overcome the low throughput characteristic of Edman degradation, amino acid composition analysis was implemented in the protein identification scheme. This method is based on the chromatographic analysis of free amino acids obtained after acid hydrolysis [13, 14, 15]. Amino acid analysis can achieve high throughput protein identification, however, there is a decrease in the confidence of identification [16, 17, 18]. A combination of amino acid analysis and Edman degradation, limited to 3-5 cycles to obtain a short sequence tag, was used to increase the confidence in protein identification [19, 20, 21]. 

Two-dimensional electrophoresis gels (2-DE), a biochemical technique used to separate proteins according to their molecular weight and isoelectric point, emerged 

Peptide mass fingerprinting (PMF) involving analyses of peptides obtained after specific proteolytic digestion of polypeptides has shown its efficacy for protein identification [23, 24, 25, 26, 27). With the recent development of mass spectrometers (MS) such as Matrix Assisted Laser Desorption/Ionisation MS (MALDI-MS) [28] and the Electro-Spray Ionisation MS (ESI-MS) [29, 30], biopolymers can be efficiently measured and rapidly identified by database searches. 

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