title: Modification of a specific tyrosine enables tracing of the end-to-end distance during apomyoglobin folding.
abstract: In order to follow the overall geometry of the apomyoglobin molecule during folding, we have converted a specific tyrosine residue into 3-nitro-tyrosine. The specificity of the modification was verified by proteolytic cleavage of the modified protein and mass spectroscopy of the resulting fragments. By measuring the energy transfer from the tryptophanyl side-chains to the modified residue the average end-to-end distance can be followed. The experiment shows that after initiation of folding the N- and C-termini are rapidly brought into proximity, possibly to a near-native distance.
authors.affiliation: Carlsberg Laboratorium, Kemisk Afdeling, Copenhagen Valby, Denmark.
authors.forename: C
authors.initials: C
authors.lastname: Rischel
authors.forename: F M
authors.initials: FM
authors.lastname: Poulsen
mesh_terms: D000818:Animals; D001059:Apoproteins / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D013058:Mass Spectrometry; D009211:Myoglobin / Q000378:metabolism*; D011487:Protein Conformation; D017510:Protein Folding; D014443:Tyrosine / Q000031:analogs & derivatives* / Q000378:metabolism
chemical_list: D001059:Apoproteins; D009211:Myoglobin; C010857:apomyoglobin; C002744:3-nitrotyrosine; D014443:Tyrosine