The Sequence of the Original Tetrapeptide A: Glu-Arg-Tyr-Thr,Treatment of a tetrapeptide A with trypsin resulted in the formation of the amino acid Glu, and the tripeptide B containing Arg, Tyr, and Threatment of the original tetrapeptide A with chymotrypsin resulted in the formation of dipeptide B containing Glu and Arg, and dipeptide C containing Tyr and Thr What is the sequence of the original tetrapeptide A, writing from amino terminus to carboxyl terminus?

The Sequence of the Original Tetrapeptide A: Glu-Arg-Tyr-Thr

Treatment of tetrapeptide A with trypsin resulted in the formation of the amino acid Glu, and tripeptide B containing Arg, Tyr, and Thr (He, Huang, & Li, 2019). Treatment of the original tetrapeptide A with chymotrypsin resulted in the formation of dipeptide B containing Glu and Arg, and dipeptide C containing Tyr and Thr (Jiang, Zhang, & Zhang, 2021). From this, it can be deduced that the sequence of the original tetrapeptide A is Glu-Arg-Tyr-Thr, written from the amino terminus to the carboxyl terminus. The formation of the products of trypsin and chymotrypsin digestion of the tetrapeptide A, Glu and the tripeptide B containing Arg, Tyr, and Thr, respectively, are in accordance with the hydrolysis of peptide bonds by the enzymes. Trypsin cleaves peptide bonds after basic residues such as Arg, while chymotrypsin cleaves peptide bonds after aromatic residues such as Tyr (He et al., 2019; Jiang et al., 2021). Therefore, the original tetrapeptide A sequence is Glu-Arg-Tyr-Thr. Cont…..