We report for the very first time self-assembly
of Cysteine and Methionine to discrenible strucutres under neutral condition.
To get insights into the structure formation, thioflavin T and Congo red
binding assays were done which revealed that aggregates may not have amyloid
like characteristics. The nature of interactions which lead to such
self-assemblies was purported by coincubating assemblies in urea and
mercaptoethanol. Further interaction of aggregates with short amyloidogenic
dipeptide diphenylalanine (FF) was assessed. While cysteine aggregates
completely disrupted FF fibres, methionine albeit triggered fibrillation. The cytotoxicity
assays of cysteine and methionine structures were performed on Human Neuroblastoma
IMR-32 cells which suggested that aggregates are not cytotoxic in nature and thus,
may not have amyloid like etiology. The results presented in the manuscript are
striking, since to the best of our knowledge,this is the first report which
demonstrates that even non-aromatic amino acids (cysteine and methionine) can
undergo spontaneous self-assembly to form ordered aggregates.
UV-catalyzed cross-linking of Escherichia coli uracil-DNA glycosylase to DNA. Identification of amino acid residues in the single-stranded DNA binding site.
