Microwave digestion of proteins

Kröll, J.; Rawel, Harshadrai M.; Kröck, R.

doi:10.1007/s002170050319

Cited by 14 publications

(16 citation statements)

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“…All these additives probably act as free-radical scavengers (Molnár-Perl, 1997). Some common additives include phenol (Muramoto and Kamiya, 1990;Rowan et al, 1992;Weiss et al, 1998;Rutherfurd, 2008), thioglycollic acid (Meltzer et al, 1987;Nakagawa and Fukuda, 1989;Shindo et al, 1998), and tryptamine (Molnár-Perl and Khalifa, 1992) for HCl acid hydrolysis, although not all laboratories use additives (Kroll et al, 1998;Messia et al, 2008).…”

Section: Antioxidants and Scavenging Agentsmentioning

confidence: 99%

Amino Acid Analysis

2009

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Amino acid analysis is used to determine the amino acid content of amino acid-, peptide- and protein-containing samples. With minor exceptions, proteins are long linear polymers of amino acids connected to each other via peptide bonds. The first step of amino acid analysis involves hydrolyzing these peptide bonds. The liberated amino acids are then separated, detected, and quantified. The method was first developed by Moore, Stein and coworkers in the 1950s using HCl acid hydrolysis, and, despite considerable effort by many workers, the basic methodology remains relatively unchanged. This unit provides an overview and strategic planning for amino acid analysis, discussing a range of methodologies and issues. In addition, several common methods used for analysis of L-amino acids are described in detail, including: HCl acid hydrolysis, performic acid oxidation for methionine and cysteine analysis, base hydrolysis for tryptophan analysis, analysis of free amino acids, and analysis of reactive lysine.

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Section: Antioxidants and Scavenging Agentsmentioning

confidence: 99%

Amino Acid Analysis

2009

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“…Several research groups [22][23][24][25][26][27][28][29] have endeavored to speed up enzymatic digestion using microwave heating, and the time required was reduced from several hours to 10 min. We recently showed that using magnetic particles in microwave-assisted enzymatic digestion could further reduce the time to 30 s∼1 min.…”

Section: Introductionmentioning

confidence: 99%

“…To reduce the time required for the entire analysis, we employed microwave-assisted enzymatic digestion to reduce the digestion time. Several research groups − have endeavored to speed up enzymatic digestion using microwave heating, and the time required was reduced from several hours to 10 min. We recently showed that using magnetic particles in microwave-assisted enzymatic digestion could further reduce the time to 30 s∼1 min .…”

Section: Introductionmentioning

confidence: 99%

Rapid Enrichment of Phosphopeptides from Tryptic Digests of Proteins Using Iron Oxide Nanocomposites of Magnetic Particles Coated with Zirconia as the Concentrating Probes

Chen

et al. 2006

J. Proteome Res.

124

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Iron oxide nanocomposites of magnetic particles coated with zirconia were used as affinity probes to selectively concentrate phosphopeptides from tryptic digests of alpha- and beta-caseins, milk, and egg white to exemplify the enrichment of phosphopeptides from complex samples. Phosphopeptides, in quantities sufficient for characterization by matrix-assisted laser desorption/ionization mass spectrometry (MALDI MS), were enriched by the affinity probes within only 30 s. The affinity probe-target species conjugates were separated from the sample solution simply by applying an external magnetic field. The detection limit for tryptic digest of beta-casein using this approach is approximately 45 fmol. Furthermore, we combined this enrichment method with a rapid enzymatic digestion method, that is, microwave-assisted enzymatic digestion using magnetic particles as the microwave absorbers, to speed up the tryptic digest reactions. Thus, we alternatively enriched phosphoproteins on the zirconia-coated particles followed by mixing with trypsin and heated the mixture in a microwave oven for 1 min. The particles remaining in the mixture were used as affinity probes to selectively enrich phosphopeptides from the tryptic digestion product by pipetting, followed by characterization using MALDI MS. Using the bifunctional zirconia-coated magnetic particles as both the affinity probes and the microwave absorbers could greatly reduce the time for the purification and characterization of phosphopeptides from complex samples.

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“…After two and four minutes of heating with 500 W microwaves, the peptide content of fractions 3-7, determined with TNBS, was substantially lower than in blanched samples. Microwaves considerably accelerate the hydrolysis of peptide bonds: two-hour microwave heating of a protein solution in hydrochloric acid produces a comparable quantity of amino acids as traditional 24-hour hydrolysis (KROLL et al 1998).…”

Section: Resultsmentioning

confidence: 99%

Use of selected metal ions for the separation of peptides isolated from thermally processed string beans

Karaś¹,

Baraniak²

2012

J. Elem.

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Recent years have witnessed growing interest in research on the structure and properties of proteins and peptides as physiologically active dietary components. The above has spurred a new interest in the isolation of animal, plant and microbiological peptides and investigation of their biological activity. The isolation and separation of protein and peptide mixture is not an easy procedure. Immobilised Metal Ion Affinity Chromatography (IMAC) is increasingly often used in this process. Affinity chromatography relies on the specific interactions between amino acids, their reactive groups in peptides and metal ions. The objective of this study was to determine whether copper and nickel ions can be used for the separation of peptides isolated from string beans than had been blanched and heated in a microwave oven. In this study, peptides extracted with 1% trichloroacetic acid (TCA) from string beans that had been blanched and heated in a microwave oven, were separated by chromatography on columns with copper and nickel ions immobilised through iminodiacetic acid (IDA). Peptide concentrations of the separated fractions were determined. Peptides found in string beans had similar affinity for metal ions in the Cu > Ni sequence, with selectivity in the Ni > Cu sequence. Microwave heating of string beans decreases the peptide content of extracts isolated with 1% TCA. The resulting changes are dependent on the duration of the process and the type of heating medium. Affinity chromatography with the use of metal ions immobilized to iminodiacetic acid (IDA)-Sephadex G-25 may be successfully used for the separation of peptides isolated from string beans.

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Microwave digestion of proteins

Cited by 14 publications

References 0 publications

Amino Acid Analysis

Amino Acid Analysis

Rapid Enrichment of Phosphopeptides from Tryptic Digests of Proteins Using Iron Oxide Nanocomposites of Magnetic Particles Coated with Zirconia as the Concentrating Probes

Use of selected metal ions for the separation of peptides isolated from thermally processed string beans

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