Phenylthiohydantoin

Definition

Phenylthiohydantoin is a chemical compound that is a key intermediate in the Edman degradation, a widely used method for sequencing peptides and proteins. It is formed during the first step of the Edman degradation process, where the N-terminal amino acid of a peptide is selectively cleaved and derivatized.

5 Must Know Facts For Your Next Test

1. Phenylthiohydantoin is formed when the N-terminal amino acid of a peptide is treated with phenyl isothiocyanate during the Edman degradation process.
2. The phenylthiohydantoin derivative can be easily separated and identified using chromatographic techniques, allowing the sequence of the peptide to be determined.
3. The formation of phenylthiohydantoin is a key step in the Edman degradation, as it allows the N-terminal amino acid to be selectively cleaved from the peptide chain.
4. The phenylthiohydantoin derivative is stable and can be analyzed using various analytical techniques, such as high-performance liquid chromatography (HPLC) or mass spectrometry.
5. The identification of the phenylthiohydantoin derivative at each step of the Edman degradation provides the information needed to determine the complete amino acid sequence of the original peptide.

Review Questions

• Explain the role of phenylthiohydantoin in the Edman degradation process for peptide sequencing.
  • Phenylthiohydantoin is a key intermediate formed during the Edman degradation, a method used to sequence peptides and proteins. In the first step of the Edman degradation, the N-terminal amino acid of the peptide is selectively cleaved and derivatized with phenyl isothiocyanate to form the phenylthiohydantoin derivative. This derivative can be easily separated and identified using chromatographic techniques, allowing the sequence of the peptide to be determined one amino acid at a time. The formation of phenylthiohydantoin is a crucial step in the Edman degradation, as it enables the selective removal and identification of the N-terminal amino acid, ultimately leading to the elucidation of the complete peptide sequence.
• Describe the analytical techniques used to identify the phenylthiohydantoin derivative in the Edman degradation process.
  • The phenylthiohydantoin derivative formed during the Edman degradation is stable and can be analyzed using various analytical techniques, such as high-performance liquid chromatography (HPLC) and mass spectrometry. HPLC allows for the separation and identification of the phenylthiohydantoin derivative based on its unique physicochemical properties, while mass spectrometry can provide detailed structural information about the derivative, including the identity of the N-terminal amino acid. The combination of these analytical techniques enables the accurate identification of the phenylthiohydantoin derivative at each step of the Edman degradation, ultimately leading to the determination of the complete amino acid sequence of the original peptide.
• Evaluate the significance of the phenylthiohydantoin derivative in the context of the Edman degradation and its impact on the field of peptide and protein sequencing.
  • The formation of the phenylthiohydantoin derivative is a critical step in the Edman degradation, a widely used method for sequencing peptides and proteins. The phenylthiohydantoin compound allows for the selective cleavage and identification of the N-terminal amino acid of the peptide, which is the key to unraveling the complete amino acid sequence. The stability and unique properties of the phenylthiohydantoin derivative enable the use of advanced analytical techniques, such as HPLC and mass spectrometry, to accurately determine the identity of the N-terminal amino acid at each step of the Edman degradation. This information is essential for piecing together the full sequence of the peptide or protein, which is fundamental to understanding its structure, function, and potential applications in fields like biochemistry, molecular biology, and biotechnology. The pivotal role of the phenylthiohydantoin derivative in the Edman degradation has been a crucial contribution to the advancement of peptide and protein sequencing technologies, with far-reaching implications in various areas of scientific research and development.

Related terms

Edman Degradation:

A method for sequencing peptides and proteins by the stepwise removal and identification of the N-terminal amino acid residue.

N-terminal Amino Acid: The amino acid that is located at the beginning (N-terminus) of a peptide or protein sequence.

Derivatization: The process of chemically modifying a compound to create a new derivative with different properties, often to facilitate analysis or purification.