title: Tropomyosin isoform expression and phosphorylation in the human heart in health and disease.
abstract: We determined the isoforms of tropomyosin expressed and the level of tropomyosin phosphorylation in donor, end-stage failing and hypertrophic obstructive cardiomyopathy samples of human heart muscle. Western blots and isoform-specific antibodies showed that α-tropomyosin was the only significant isoform expressed and that tropomyosin was 25-30% phosphorylated at serine 283. Mass spectrometry confirmed directly that α-tropomyosin made up over 95% of tropomyosin but also indicated the presence of up to 4% κ-tropomyosin and much smaller amounts of β-, γ- and smooth β-tropomyosin and about 26% phosphorylation. Neither the isoform distribution nor the level of phosphorylation changed significantly in the pathological heart muscle samples.
authors.affiliation: Myocardial Function, NHLI, Imperial College London, London, W12 0NN, UK, s.marston@imperial.ac.uk.
authors.forename: Steven B
authors.initials: SB
authors.lastname: Marston
authors.forename: O'Neal
authors.initials: O
authors.lastname: Copeland
authors.forename: Andrew E
authors.initials: AE
authors.lastname: Messer
authors.forename: Elyshia
authors.initials: E
authors.lastname: MacNamara
authors.forename: Kristen
authors.initials: K
authors.lastname: Nowak
authors.forename: Cleidiane G
authors.initials: CG
authors.lastname: Zampronio
authors.forename: Douglas G
authors.initials: DG
authors.lastname: Ward
mesh_terms: D000328:Adult; D000368:Aged; D009202:Cardiomyopathies / Q000235:genetics / Q000378:metabolism*; D005260:Female; D006333:Heart Failure / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D008297:Male; D009206:Myocardium / Q000378:metabolism*; D010766:Phosphorylation; D020033:Protein Isoforms; D014335:Tropomyosin / Q000096:biosynthesis / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D055815:Young Adult
chemical_list: D020033:Protein Isoforms; D014335:Tropomyosin