title: Microwave assisted SPPS of amylin and its toxicity of the pure product to RIN-5F cells.
abstract: The 37-amino acid polypeptide islet amyloid polypeptide (IAPP), or amylin, is found as amyloid aggregates in the islets of Langerhans in patients with type II diabetes. Herein, we report an efficient microwave assisted solid phase peptide synthesis of amylin (IAPP). The most efficient synthesis used double and triple couplings and 10 equiv. of amino acids. Double couplings were used for most amino acids, whereas triple couplings were utilized for amino acids in selected regions. The most effective method for formation of the disulfide bond in amylin was found to be iodine oxidation. The highest purity amylin was obtained when the crude peptide was purified with HPLC before formation of the disulfide bond. The cytotoxicity of the synthesized amylin product to RIN-5F cells was determined. The synthesized amylin exhibits an exponential increase of cytotoxicity at concentrations >35 microM. Transmission electron microscope studies of a sample of amylin shows that insoluble amyloid fibrils spontaneously formed when 45 microM solution of synthesized amylin was incubated in a suitable buffer for 6 h.
authors.affiliation: School of Biochemistry, University of KwaZulu Natal, South Africa.
authors.forename: Karen
authors.initials: K
authors.lastname: Muthusamy
authors.forename: Fernando
authors.initials: F
authors.lastname: Albericio
authors.forename: Per I
authors.initials: PI
authors.lastname: Arvidsson
authors.forename: Patrick
authors.initials: P
authors.lastname: Govender
authors.forename: Hendrik G
authors.initials: HG
authors.lastname: Kruger
authors.forename: Glenn E M
authors.initials: GE
authors.lastname: Maguire
authors.forename: Thavendran
authors.initials: T
authors.lastname: Govender
mesh_terms: D000595:Amino Acid Sequence; D000682:Amyloid / Q000138:chemical synthesis* / Q000737:chemistry* / Q000235:genetics / Q000633:toxicity*; D002460:Cell Line / Q000187:drug effects*; D003924:Diabetes Mellitus, Type 2 / Q000378:metabolism / Q000473:pathology; D006801:Humans; D058228:Islet Amyloid Polypeptide; D007515:Islets of Langerhans / Q000378:metabolism; D008872:Microwaves; D008969:Molecular Sequence Data; D016415:Sequence Alignment
chemical_list: D000682:Amyloid; D058228:Islet Amyloid Polypeptide