Detection of peptides covalently modified with multiple fatty acids by MALDI-TOF mass spectrometry.
Analysis and characterization of membrane proteins and hydrophobic peptides by matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) mass spectrometry (MS) is a considerable challenge because of their lower ionization efficiency. Detergents are used to solubilize hydrophobic peptides and proteins. However, in MALDI-MS, the presence of detergents can cause considerable loss of signal intensity. The extent of interference depends on the matrix/sample preparation method and experimental conditions. In the present study, we have analyzed the MALDI response of multiple fatty acylated peptides in the presence of the matrices alpha-cyano-4-hydroxy cinnamic acid (HCCA) and 2,5-dihydroxy benzoic acid (DHB). The effect of adding the nonionic detergent n-octylglucoside (OG) was also examined. The presence of OG facilitated detection of tetrapalmitoylated peptide, particularly when HCCA was used as the matrix. When DHB was used as the matrix, good signal intensity was observed in the absence of OG. Lower laser pulse rate in the linear mode of analysis resulted in good signal intensity for the tetrapalmitoylated peptide. Conditions for obtaining good signal intensities for dipalmitoylated and N-myristoyl peptides with both HCCA and DHB as matrices were also investigated.
Centre for Cellular and Molecular Biology, Uppal Road, Hyderabad 500 007, India.
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MV
Jagannadham
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Nagaraj
D000215:Acylation; D002852:Chromatography, Ion Exchange / Q000379:methods; D003373:Coumaric Acids; D003902:Detergents; D005227:Fatty Acids / Q000737:chemistry; D005841:Gentisates; D005960:Glucosides; D057927:Hydrophobic and Hydrophilic Interactions; D008970:Molecular Weight; D010455:Peptides / Q000032:analysis* / Q000138:chemical synthesis / Q000737:chemistry; D011506:Proteins / Q000737:chemistry*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods*; D014357:Trypsin / Q000737:chemistry
D003373:Coumaric Acids; D003902:Detergents; D005227:Fatty Acids; D005841:Gentisates; D005960:Glucosides; D010455:Peptides; D011506:Proteins; C007175:alpha-cyano-4-hydroxycinnamate; C018619:octyl-beta-D-glucoside; D014357:Trypsin; C010925:2,5-dihydroxybenzoic acid