CHEM 370 Primary amino acid sequence problems < Average amino acid residue MW~110g/mol> Determine the amino acid sequence of the following oligopeptide from the experimental data below. 1. The amino acid composition is found to be [Ala, Lys, Phe, Met, Cys, plus some decomposition products]. 2. The peptide has a molecular weight around 700 Da and absorbs at 280 nm. 3. Treatment with carboxypeptidase results in tryptophan and a peptide. 4. CNBr treatment yields a tetrapeptide and a dipeptide. 5. Trypsin digestion produces an amino acid and a pentapeptide with met on the amino end. 6. Chymotrypsin digestion yields a dipeptide and a tetrapeptide. The tetrapeptide is found to have a free sulfhydryl group #1 TELLS US THER ARE AT LEAST 6 RESIDUES , I . E . THE ONES LISTED & POSSIBLY Trp ( DUE TO PRESENCE OF DEGRD . PRODUCTS #2 700 D A / (110 D A / RESIDUE ) = ~ 6 RESIDUES ( THIS IS CONSISTENT WITH THE FINDINGS FROM #1) #3 TELLS US THAT T RP IS THE CE-TERMINAL RESIDUE <<___ ___ ___ ___ ___ Trp
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