Thus, the dipeptide I from hydrolysis by chymotrypsin and peptide I from hydrolysis by trypsin can be conbined to give an amino acid sequence Arg–Trp–Gly–Lys. Gly–Lys–Pro–Val–Gly–Lys–Lys–Arg–Pro–Lys–Val–Tyr C: Val–Tyr–Pro–Asp–Ala–Gly–Glu–Asp–Gln–Ser–Ala–Glu–Ala–Phe–Pro–Leu–Glu–Phe B: Therefore, the following three peptides contain the majority of the amino acids. Both peptide III and peptide II from hydrolysis by chymotrypsin are contained in peptide IV from hydrolysis by trypsin. Both peptide II and peptide III from hydrolysis by trypsin are contained in peptide VI from hydrolysis by chymotrypsin.
What is the amino acid sequence of corticotropin?Īnswer: Both peptide IV and peptide V from hydrolysis by chymotrypsin are contained with peptide V from hydrolysis by trypsin. Val-Tyr-Pro-Asp-Ala-Gly-Glu-Asp-Gln-Ser-Ala-Glu-Ala-Phe-Pro-Leu-Glu-Phe Hydrolysis by trypsin produces lysine, arginine, and five peptides: Gly-Lys-Pro-Val-Gly-Lys-Lys-Arg-Pro-Val-Lys-Val-Tyr Pro-Asp-Ala-Gly-Glu-Asp-Gln-Ser-Ala-Glu-Ala-Phe VI: Hydrolysis by chymotrypsin yields six peptides: I: Glu-Gly-Pro-Trp-Leu-Glu-Glu-Glu-Glu-Ala-Ala-Tyr- Gly- Trp-Met-Asp-Phe 27.54Ĭorticotropin, a pituitary hormone, stimulates the adrenal cortex. Glu-Gly-Pro-Trp- Gly- Trp-Leu-Glu-Glu-Glu-Glu-Ala-Ala-Tyr-Met-Asp-Phe The two possible locations of the dipeptide fragment I are shown in bold face. These two peptides can combine with the octapeptide and dipeptide I in two ways. Based on the end group analysis and fragment II, the sequence of amino acids at the C-terminal position is Met-Asp-Phe, because there is only one phenylalanine in the peptide. Thus, based on the end group analysis and fragment III, the sequence of amino acids from the N-terminal position is Glu-Gly-Pro-Trp. Four of the five glutamic acid residues are in one octapeptide. Write two possible amino acid sequences of feline gastrin.Īnswer: Chymotrypsin cleaves peptides at the C-terminal side of the aromatic amino acids phenylalanine, tyrosine, and tryptophan. Hydrolysis with chymotrypsin yields the following four peptides. Trp-Ala-Arg-Gly-Tyr-Ala-Ser-Gly-Glu 27.53įeline gastrin, a hormone that stimulates secretion of gastric juice in cats, has the amino acid composition (Ala 2,Asp,Gly 2,G1u 5,Leu,Met,Phe,Pro,Trp2,Tyr).Įnd group analysis shows that the C-terminal and N-terminal amino acids are Phe and Glu, respectively. The structure of the sleep peptide is the second of the possible structures given in Exercise 26.51. Only one of the peptides has a C-terminal basic amino acid. What is the amino acid sequence of the sleep peptide?Īnswer: Trypsin cleaves peptides at the C-terminal side of the basic amino acids lysine and arginine. The sleep peptide is hydrolyzed by trypsin to produce Gly-Tyr-Ala-Ser-Gly-Glu and Trp-Ala-Arg. Trp-Ala-Arg-Gly- Tyr-Ala-Ser-Gly-Glu 27.52 The hydrolysis products have two aromatic amino acids, and they can result from either of the following two structures. What two amino acid sequences are possible for the sleep peptide?Īnswer: Chymotrypsin cleaves peptides at the C-terminal side of the aromatic amino acids phenylalanine, tyrosine, and tryptophan. The nonapeptide known as the sleep peptide is hydrolyzed by chymotrypsin to produce Ala-Ser- Gly-Glu and Ala-Arg-Gly-Tyr and Trp. The sites of cleavage are indicated by bold face. The hydrolysis products have two aromatic amino acids and they can result from either of the following two structures. Chymotrypsin cleaves peptides at the C-terminal side of the aromatic amino acids phenylalanine, tyrosine, and tryptophan.
Does this information establish the amino acid sequence of met-enkephalin?Īnswer: No, it does not. The pentapeptide met-enkephalin is hydrolyzed by chymotrypsin to give Met, Tyr, and Gly-Gly-Phe. The site of cleavage is indicated by bold face. The tetrapeptide could be either of the following two structures. Both dipeptides have a C-terminal basic amino acid. Trypsin cleaves peptides at the C-terminal side of the basic amino acids lysine and arginine. Does this information establish the amino acid sequence of tuftsin?Īnswer: No, it does not. The tetrapeptide tuftsin is hydrolyzed by trypsin to produce Pro-Arg and Thr-Lys. Indicate which of the tripeptides in Exercise 26.46 will be cleaved by chymotrypsin and name the products. Indicate which of the tripeptides in Exercise 26.45 will be cleaved by chymotrypsin and name the products.Īnswer: Chymotrypsin cleaves peptides at the C-terminal side of the aromatic amino acids phenylalanine, tyrosine, and tryptophan. (a)Īnswer: Trypsin cleaves peptides at the C-terminal side of the basic amino acids lysine and arginine.
Which of the following tripeptides will be cleaved by trypsin? If cleavage occurs, name the products.
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