Protein Buffers for Mass Spectrometric Immunoassay (MSIA)
This buffer is a combination of an anti-oxidant (A) and anti-absorptive (B).
(A) The anti-oxidant is intended to prevent artifactual sulfoxidation of methionine residues (i.e. methionine sulfoxides) when protein-containing solutions are exposed to air. The ability of this anti-oxidant to prevent artifactual cysteine oxidation and subsequent disulfide bond formation (as described by Rehder and Borges [1]) has not been assessed. Maintaining a low solution pH will help preserve cysteine residues in a reduced state without the need to add a disulfide reducing agent.
(B) The anti-adsorptive is intended to prevent adsorptive loss of low concentration protein solutions (i.e., less than 1 micromolar) to test tube walls. This is used in combination with the anti-oxidant to prevent spontaneous loss of eluted, low concentration proteins.
Intended for short-term (~24 hrs) use only and may not be effective at the specified working concentrations for periods longer than this.
Users should be aware of the potential for these substances to interfere with specific applications. They were originally designed for use with liquid chromatography based applications where they are easily separated from most protein and peptide components.
From the laboratory of Chad Borges, PhD, Arizona State University.
Part of The Investigator's Annexe program.
This buffer is a combination of an anti-oxidant (A) and anti-absorptive (B).
(A) The anti-oxidant is intended to prevent artifactual sulfoxidation of methionine residues (i.e. methionine sulfoxides) when protein-containing solutions are exposed to air. The ability of this anti-oxidant to prevent artifactual cysteine oxidation and subsequent disulfide bond formation (as described by Rehder and Borges [1]) has not been assessed. Maintaining a low solution pH will help preserve cysteine residues in a reduced state without the need to add a disulfide reducing agent.
(B) The anti-adsorptive is intended to prevent adsorptive loss of low concentration protein solutions (i.e., less than 1 micromolar) to test tube walls. This is used in combination with the anti-oxidant to prevent spontaneous loss of eluted, low concentration proteins.
Intended for short-term (~24 hrs) use only and may not be effective at the specified working concentrations for periods longer than this.
Users should be aware of the potential for these substances to interfere with specific applications. They were originally designed for use with liquid chromatography based applications where they are easily separated from most protein and peptide components.
From the laboratory of Chad Borges, PhD, Arizona State University.
Part of The Investigator's Annexe program.
| Catalog Number | Product | DataSheet | Size | AVAILABILITY | Price | Qty |
|---|
| Product Type: | Buffer or Chemical |
| Buffer: | Protein Buffers for Mass Spectroscopy (Anti-Oxidant, Anti-Absorptive) |
| Comments: | The anti-oxidant is a methionine-serine dipeptide. The anti-adsorptive is a rabbit anti-human serum albumin polyclonal antibody. |
INSTRUCTIONS
The anti-oxidant and anti-adsorptive may be used separately or together.
Users working with difficult-to-dissolve peptides and proteins may find it useful to employ minimal concentrations of organic solvents such as acetonitrile or dimethylsulfoxide at 5-30% (v/v) in the final working solutions to keep their target proteins / peptides dissolved.
The use of organic solvents is dependent upon the nature of your samples and is not necessary for the function of the anti-oxidant or anti-adsorptive.
The anti-oxidant and anti-absorptive are compatible with low concentrations of trifluoroacetic acid (for example, 0.05 1% v/v).
RECOMMENDED DILUTIONS
Anti-oxidant: Dilute to a final working concentration of 0.24 mg/mL. Stock solutions may be made at higher concentrations provided they are diluted on the day of use.
Anti-adsorptive: Dilute 330-fold to achieve the final recommended working concentration. Users may find that dilutions of up to 660-fold may achieve desired results. Stock solutions may be made at higher concentrations provided they are diluted on the day of use.
Users should be aware of the potential for these substances to interfere with specific applications. They were originally designed for use with liquid chromatography based applications where they are easily separated from most protein and peptide components.
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Rehder DS, Borges CR: Cysteine sulfenic Acid as an Intermediate in Disulfide Bond Formation and Nonenzymatic Protein Folding. Biochemistry 2010, 49(35):7748-7755.
If you publish research with this product, please let us know so we can cite your paper.
