title: Mercury in a commercial preparation of rat amylin.
abstract: The biological activity of amylin is reported to vary widely depending on the source and purity of the material. Three commercial samples of rat amylin were compared for structural differences. The samples were nearly identical using most of the available analytical measures--amino acid analysis, HPLC retention, even Edman sequencing data. When the samples were compared by ion spray ionization mass spectrometry, the molecular mass of one sample was 200 daltons higher than anticipated. Careful analysis of the sample, including atomic emission spectrometry, revealed that a mercury atom was associated with the polypeptide. The mercury presumably resulted from a deprotection step in the synthesis, involving the removal of an acetamidomethyl group from cysteine.
authors.affiliation: Division of Chemistry, Glaxo, Inc., Research Triangle Park, NC 27709.
authors.forename: J E
authors.initials: JE
authors.lastname: Cobb
authors.forename: D B
authors.initials: DB
authors.lastname: Kassel
authors.forename: E E
authors.initials: EE
authors.lastname: Sugg
authors.forename: W
authors.initials: W
authors.lastname: Burkhart
authors.forename: N
authors.initials: N
authors.lastname: Geddie
authors.forename: A
authors.initials: A
authors.lastname: Steele
authors.forename: R J
authors.initials: RJ
authors.lastname: Anderegg
mesh_terms: D000478:Alkylation; D000595:Amino Acid Sequence; D000682:Amyloid / Q000138:chemical synthesis / Q000737:chemistry*; D000818:Animals; D002851:Chromatography, High Pressure Liquid; D003545:Cysteine / Q000737:chemistry; D004340:Drug Contamination; D058228:Islet Amyloid Polypeptide; D008628:Mercury / Q000032:analysis*; D008969:Molecular Sequence Data; D010084:Oxidation-Reduction; D051381:Rats; D016339:Spectrometry, Mass, Fast Atom Bombardment; D013057:Spectrum Analysis; D014357:Trypsin
chemical_list: D000682:Amyloid; D058228:Islet Amyloid Polypeptide; D014357:Trypsin; D008628:Mercury; D003545:Cysteine