Examination of isocyanate adducts of human serum albumin using matrix assisted laser desorption ionisation - mass spectrometry

Author:Tasneem Muharib

Co-authors:Malcolm R. Clench, John White and Duncan A. Rimmer

Abstract/Description:
Isocyanates are a group of highly reactive compounds which contain the NCO group. They are commonly found in many glues and spray paints. Even brief or low level exposure to these compounds has been implicated as a cause of occupational skin disease. This is because once sensitization occurs further low level exposure results in the rapid manifestation of symptoms.

Matrix Assisted Laser Desorption Ionisation - Time of Flight - Mass Spectrometry (MALDI-TOF-MS) is often used in proteomics analysis. Isocyanate-Human Serum Albumin (HSA) conjugates have been formed under physiologic conditions (pH: 7.4 and 370C temperature.

The isocyanate-HSA conjugates were separated on an acrylamide gel (10% resolving: 3.5 stacking). The protein containing bands were then cut using a robotic gel processing system (Shimadzu Biosystems "Xcise") and destained, digested (using trypsin), desalted (using ZipTips) and spotted onto a target plate with (25mg/mL) a-CHCA matrix (in 70% ACN/0.1% TFA) using the same instrument. Parallel lanes of non-reacted HSA were run as controls and processed in the same way. Using MALDI-MS peptide finger prints of both reacted and non-reacted HSA were generated and potential sites of adduction identified by comparison.

Poster presented at:
3rd National Meeting on Environmental Mass Spectrometry - 2006