Rapid and effective removal of perfluorooctanoic acid from proteomics samples.
We recently demonstrated that perfluorooctanoic acid (PFOA), a volatile surfactant, is as effective as sodium dodecyl sulfate at solubilizing the membrane proteins. PFOA can be removed by repeated evaporation prior to mass spectrometry analysis. However, the removal of PFOA by evaporation is a lengthy process that takes approximately 6 h. Toward the goal of decreasing the length of time required to remove PFOA from protein digests, we tested the efficiency of PFOA removal and subsequent peptide recovery using strong cation exchange (SCX) chromatography, hydrophilic interaction chromatography (HILIC), fluorous solid phase extraction (FSPE), and anion exchange (ANX) chromatography. We found that all these chromatographic techniques except ANX chromatography remove PFOA thoroughly from protein digest. Peptide recovery rates from the SCX chromatography varied widely; nonacidic peptides were recovered at a rate of up to 95%, while acidic peptides were recovered at a rate of less than 10%. On the other hand, acidic peptides were recovered well from HILIC, while peptides whose pIs are greater than 6 were recovered poorly. Peptide recovery using FSPE was considerably lower, less than 10% for most of the peptides. These results indicate that the SCX and HILIC chromatography provide a more rapid alternative to the evaporation method for applications in which recovery of entire set of peptides is not required.
Case Center for Proteomics and Bioinformatics, Case Western Reserve University, Cleveland, OH 44106, USA.
Chandra Sekhar
CS
Rao Kadiyala
Vennela
V
Mullangi
Xiang
X
Zhou
Krishna M
KM
Vukoti
Masaru
M
Miyagi
D000595:Amino Acid Sequence; D000818:Animals; D002210:Caprylates / Q000737:chemistry / Q000302:isolation & purification*; D002417:Cattle; D002852:Chromatography, Ion Exchange; D005466:Fluorocarbons / Q000737:chemistry / Q000302:isolation & purification*; D057927:Hydrophobic and Hydrophilic Interactions; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000032:analysis / Q000737:chemistry; D011506:Proteins / Q000737:chemistry* / Q000302:isolation & purification; D020543:Proteome / Q000737:chemistry; D040901:Proteomics / Q000379:methods*; D012710:Serum Albumin, Bovine / Q000032:analysis / Q000737:chemistry; D052616:Solid Phase Extraction / Q000379:methods*; D013501:Surface-Active Agents / Q000737:chemistry / Q000302:isolation & purification
D002210:Caprylates; D005466:Fluorocarbons; D010446:Peptide Fragments; D011506:Proteins; D020543:Proteome; D013501:Surface-Active Agents; D012710:Serum Albumin, Bovine; C023036:perfluorooctanoic acid