Interpretation:
The primary structure of somatostatin is to be deduced on the basis of the given information.
Concept Introduction:
Hydrolysis of peptide bonds with the help of enzymes is selective.
Trypsin is a digestive enzyme which catalyzes the hydrolysis of peptide bonds that involve the carboxyl group of arginine or lysine residue.
Chymotrypsin catalyzes the hydrolysis of peptide bonds which involves the carboxyl group of amino acids having an
There are three such amino acids – phenylalanine, tyrosine, and tryptophan.
Cysteine has a
In the Edman degradation, only the N-terminal amide bond is cleaved. It is isolated as a PTH derivative. This helps to determine the sequence of amino acids by each successive degradation.
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- Give the amino acid sequence of hexapeptides that produce the following sets of fragments upon partial acid hydrolysis: (a) Arg, Gly, Ile, Leu, Pro, Val gives Pro-Leu-Gly, Arg-Pro, Gly-Ile-Val (a) N, L, M, W, V2 gives V-L, V-M-W, W-N-Varrow_forwardDetermine the amino acid sequence of a polypeptide from the following data:Acid-catalyzed hydrolysis gives Ala, Arg, His, 2 Lys, Leu, 2 Met, Pro, 2 Ser, Thr, and Val.Carboxypeptidase A releases Val.Edman’s reagent releases PTH-Leu.Treatment with cyanogen bromide gives three peptides with the following amino acid compositions:1. His, Lys, Met, Pro, Ser 2. Thr, Val 3. Ala, Arg, Leu, Lys, Met, Serarrow_forwardDetermine the amino acid sequence of a polypeptide from the following data: Acid-catalyzed hydrolysis gives Ala, Arg, His, 2 Lys, Leu, 2 Met, Pro, 2 Ser, Thr, and Val. Carboxypeptidase A releases Val. Edman’s reagent releases PTH-Leu. Treatment with cyanogen bromide gives three peptides with the following amino acid compositions: 1. His, Lys, Met, Pro, Ser 2. Thr, Val 3. Ala, Arg, Leu, Lys, Met, Ser Trypsin-catalyzed hydrolysis gives three peptides and a single amino acid: 1. Arg, Leu, Ser 2. Met, Pro, Ser, Thr, Val 3. Lys 4. Ala, His, Lys, Metarrow_forward
- Determine the amino acid sequence of a polypeptide from the following data: Complete hydrolysis of the peptide yields Ala, Arg, Gly, 2 Lys, Met, Phe, Pro, 2 Ser, Tyr, and Val. Treatment with Edman’s reagent releases PTH-Val. Carboxypeptidase A releases Ala. Treatment with cyanogen bromide yields the following two peptides: 1. Ala, 2 Lys, Phe, Pro, Ser, Tyr 2. Arg, Gly, Met, Ser, Val Treatment with trypsin yields the following three peptides: 1. Gly, Lys, Met, Tyr 2. Ala, Lys, Phe, Pro, Ser 3. Arg, Ser, Val Treatment with chymotrypsin yields the following three peptides: 1. 2 Lys, Phe, Pro 2. Arg, Gly, Met, Ser, Tyr, Val 3. Ala, Serarrow_forwardDeduce the sequence of a pentapeptide that contains the amino acids Ala, Glu, Gly, Ser, and Tyr, from the following experimental data. Edman degradation cleaves Gly from the pentapeptide, and carboxypeptidase forms Ala and a tetrapeptide. Treatment of the pentapeptide with chymotrypsin forms a dipeptide and a tripeptide. Partial hydrolysis forms Gly, Ser, and the tripeptide Tyr–Glu–Ala.arrow_forwardA nonapeptide released by globulins in the blood in response to a waspsting. Hydrolysis gives the following amino acids: 2 Arg, Gly, 2 Phe, 3 Pro, and Ser.Edman degradation gives phenylthiohydantoin of Arg. Cleavage with carboxypeptidase gives Arg. Partial hydrolysis gives the following di- and tripeptides: Phe-Ser, Pro-GlyPhe, Pro-Pro, Ser-Pro-Phe, Phe-Arg, and Arg-Pro. What is the amino acid sequence of this peptide?arrow_forward
- Using the information below, determine the amino acid sequence of the peptide, and explain how your structure is consistent with each piece of information. Complete hydrolysis by 6 M HCl at 110°C followed by amino acid analysis indicated the presence of Gly, Leu, Phe, and Tyr in a 2:1:1:1 molar ratio. Treatment of the peptide with1-fluoro-2,4-dinitrobenzene followed by complete hydrolysis and chromatography indicated the presence of the 2,4-dinitrophenyl derivative of tyrosine. No free tyrosine could be found. Complete digestion of he peptide with pepsin (which cleaves on the amino side of aromatic residues) followed by chromatography yielded a dipeptide containing Phe and Leu and a tripeptide containing Tyr and Gly in a 1:2 ratio.arrow_forwardDraw the structure of the tetrapeptide Asp-Arg-Val-Tyr. Please show the appropriate stereochemistry of the natural amino acids in the resulting peptide. Please draw all ionizable groups in their neutral form.arrow_forwardDetermine the primary structure of an octapeptide from the following data: Acid-catalyzed hydrolysis gives 2 Arg, Leu, Lys, Met, Phe, Ser, and Tyr. Carboxypeptidase A releases Ser. Edman’s reagent releases Leu. Treatment with cyanogen bromide forms two peptides with the following amino acid compositions: 1. Arg, Phe, Ser 2. Arg, Leu, Lys, Met, Tyr Trypsin-catalyzed hydrolysis forms the following two amino acids and two peptides: 1. Arg 2. Ser 3. Arg, Met, Phe 4. Leu, Lys, Tyrarrow_forward
- A peptide has the following amino acid composition: 2 Met, 2 Phe, 2 Glu, 1 Arg, 1 Lys, 1 Val, 1 Leu, 1 Gly, 1 Ser Reaction of the intact peptide with dansyl chloride followed by acid hydrolysis creates a derivative of Met. A specific cleavage of the intact peptide produces fragments with the following sequences: Fragment A: Glu-Gly-Lys-Phe Fragment B: Met-Ser-Leu-Arg Fragment C: Met-Val-Glu-Phe What information do this result give about the sequence of the peptide? Explain how you arrived on your answer. a) The sequence is: Met-Val-Glu-Phe-Glu-Gly-Lys-Phe-Met-Ser-Leu-Arg b) The sequence is: Met-Ser-Leu-Arg-Met-Val-Glu-Phe-Glu-Gly-Lys-Phe c) The sequence is: Met-Val-Glu-Phe-Met-Ser-Leu-Arg-Glu-Gly-Lys-Phe d) The sequence is: Met-Ser-Leu-Arg-Glu-Gly-Lys-Phe-Met Val-Glu-Phearrow_forwardDetermine the amino acid sequence of a polypeptide from the following data:Complete hydrolysis of the peptide yields Arg, 2 Gly, Ile, 3 Leu, 2 Lys, 2 Met, 2 Phe, Pro, Ser, 2 Tyr, and Val.Treatment with Edman’s reagent releases PTH-Gly.Carboxypeptidase A releases Phe. Treatment with cyanogen bromide yields the following three peptides:1. Gly-Leu-Tyr-Phe-Lys-Ser-Met 2. Gly-Leu-Tyr-Lys-Val-Ile-Arg-Met 3. Leu-Pro-Phearrow_forwardDetermine the amino acid sequence of a polypeptide from the following data: Complete hydrolysis of the peptide yields Arg, 2 Gly, Ile, 3 Leu, 2 Lys, 2 Met, 2 Phe, Pro, Ser, 2 Tyr, and Val. Treatment with Edman’s reagent releases PTH-Gly. Carboxypeptidase A releases Phe. Treatment with cyanogen bromide yields the following three peptides: 1. Gly-Leu-Tyr-Phe-Lys-Ser-Met 2. Gly-Leu-Tyr-Lys-Val-Ile-Arg-Met 3. Leu-Pro-Phe Treatment with trypsin yields the following four peptides: 1. Gly-Leu-Tyr-Phe-Lys 3. Val-Ile-Arg 2. Ser-Met-Gly-Leu-Tyr-Lys 4. Met-Leu-Pro-Phearrow_forward
- Organic ChemistryChemistryISBN:9781305580350Author:William H. Brown, Brent L. Iverson, Eric Anslyn, Christopher S. FootePublisher:Cengage Learning