a peptide contains amino acids Phe,Gly Met,Ala, and Ser. N-terminal analysis yielded the PTH derivative of alanine. Partial hydrolysis of the petapeptide yielded the dipeptides Gly-Ser, Ala-Gly, and Ser-Met. The peptide sequence is what?
Ala-Gly-Ser-Phe-Met
Ala-Gly-Ser-Met-Phe
Phe-Ser-Gly-Met-Ala
Phe-Met-Ser-Gly-Ala
Phe-Ala-Gly-Ser-Met
To determine the peptide sequence, we need to analyze the information provided. Let's break it down step by step.
1. N-terminal analysis: The analysis yielded the PTH derivative of alanine. This means that the first amino acid in the peptide is alanine (Ala).
2. Partial hydrolysis: The partial hydrolysis resulted in three dipeptides: Gly-Ser, Ala-Gly, and Ser-Met.
Based on this information, we can deduce the following:
- Gly-Ser: This indicates that the second amino acid in the peptide is glycine (Gly), followed by serine (Ser).
- Ala-Gly: This tells us that after the first amino acid (alanine), we have a glycine (Gly).
- Ser-Met: This suggests that after the glycine (Gly), we have serine (Ser), followed by methionine (Met).
Putting all the information together, we can determine the peptide sequence:
Ala-Gly-Ser-Met-Phe.
Therefore, the correct answer is "Ala-Gly-Ser-Met-Phe."