title: Characterization of succinimide-type dehydration products of recombinant hirudin variant 1 by electrospray tandem mass spectrometry.
abstract: Two congeners Q4 and Q5 inferred in earlier analyses to be cyclic succinimide-type dehydration products of recombinant hirudin (variant 1) were structurally fully characterized. After isotopic labeling by ring-opening with H2(18)O, the suspected anhydro-positions Asp53 and Asp33 were confirmed by tandem mass spectrometry (MS/MS) sequencing of relevant smaller peptides directly in the enzymatic hydrolysates (V8 protease) using electrospray MS/MS. The chosen strategy proved highly efficient and sensitive.
authors.affiliation: Pharmaceutical Division, Ciba-Geigy AG, Basel, Switzerland.
authors.forename: H
authors.initials: H
authors.lastname: Grossenbacher
authors.forename: W
authors.initials: W
authors.lastname: Märki
authors.forename: M
authors.initials: M
authors.lastname: Coulot
authors.forename: D
authors.initials: D
authors.lastname: Müller
authors.forename: W J
authors.initials: WJ
authors.lastname: Richter
mesh_terms: D006629:Hirudins / Q000096:biosynthesis*; D013058:Mass Spectrometry / Q000379:methods; D011994:Recombinant Proteins / Q000096:biosynthesis*; D012441:Saccharomyces cerevisiae; D013388:Succinimides
chemical_list: D006629:Hirudins; D011994:Recombinant Proteins; D013388:Succinimides; C072298:hirudin HV1