title: Further evidence for the structure of the subtilisin propeptide and for its interactions with mature subtilisin.
abstract: Evidence is presented for some secondary structure, very likely alpha-helical, of the propeptide of subtilisin E in aqueous salt solution, as well as for strong intermolecular interactions between the propeptide and the mature sequence both in the processed and unprocessed states (i.e. in prosubtilisin). Prosubtilisin is shown to exist as a dimer according to size exclusion high performance liquid chromatography under nondenaturing conditions; that dimer may be on the autoprocessing pathway. According to such a model, the prosequence of one prosubtilisin molecule is the template for the refolding of the mature sequence of the second, and, in turn, the hydrolytic process is intermolecular as well. Support for such an intermolecular folding model also includes potent slow binding inhibition of subtilisin by the propeptide, specific proteolysis of the propeptide by subtilisin, and evidence for intermolecular processing under a variety of conditions.
authors.affiliation: Department of Chemistry, Rutgers, the State University of New Jersey, Newark, New Jersey 07102, USA.
authors.forename: Z
authors.initials: Z
authors.lastname: Hu
authors.forename: K
authors.initials: K
authors.lastname: Haghjoo
authors.forename: F
authors.initials: F
authors.lastname: Jordan
mesh_terms: D002851:Chromatography, High Pressure Liquid; D002942:Circular Dichroism; D003001:Cloning, Molecular; D004792:Enzyme Precursors / Q000737:chemistry* / Q000378:metabolism*; D007700:Kinetics; D046911:Macromolecular Substances; D009682:Magnetic Resonance Spectroscopy; D008433:Mathematics; D008961:Models, Structural; D008962:Models, Theoretical; D010446:Peptide Fragments / Q000737:chemistry* / Q000378:metabolism*; D011487:Protein Conformation; D017510:Protein Folding; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000737:chemistry / Q000378:metabolism; D013381:Subtilisins / Q000096:biosynthesis / Q000737:chemistry* / Q000378:metabolism*
chemical_list: D004792:Enzyme Precursors; D046911:Macromolecular Substances; D010446:Peptide Fragments; D011994:Recombinant Proteins; C057107:prosubtilisin; D013381:Subtilisins