Study of human laryngeal muscle protein using two-dimensional electrophoresis and mass spectrometry

Proteomic analysis was performed to construct a protein database for human laryngeal muscle. Thyroarytenoid (TA) muscle specimens were obtained from six post mortem cases within 24 h of death. Isoelectric focusing was performed by using immobilized pH gradient strips followed by 12% sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Silver stained gels were then analyzed using PDQuest software to locate, quantify and match spots. Proteins were identified by matrix-assisted laser desorption/ionization-mass spectrometry on the basis of peptide mass fingerprinting following in-gel digestion with trypsin. Comparison of protein distribution between broad and narrow pH range gels demonstrated that 75% of all protein spots from human TA muscle were located within the pH range 5-8, and between mass 15-120 kDa. Based on peptide mass fingerprinting, 75 proteins were identified and classified into six functional groups. These include membrane proteins (8.5%), cytoskeletal and myofibrillar proteins (14.6%), energy production proteins (28%), proteins associated with stress responses (8.5%), and protein associated with transcription regulation (10.9%). Approximately one-third (29%) were categorized as "other proteins". This data provides an initial reference map for comparative studies of protein expression in human and laryngeal muscle. Further development of this database will provide a valuable resource for molecular analysis of normal and pathologic conditions affecting human striated muscle.