PITC

Definition

PITC, or Phenylisothiocyanate, is a chemical reagent used in the Edman degradation process, a widely employed technique for determining the amino acid sequence of peptides and proteins.

5 Must Know Facts For Your Next Test

1. PITC reacts with the N-terminal amino acid of a peptide or protein to form a phenylthiohydantoin (PTH) derivative, which can then be identified and sequenced.
2. The Edman degradation process using PITC allows for the sequential identification of amino acids in a peptide or protein, one residue at a time.
3. PITC is a key reagent in the Edman degradation because it selectively cleaves the N-terminal amino acid without affecting the rest of the peptide chain.
4. The PTH derivative formed during the Edman degradation is stable and can be analyzed using techniques such as high-performance liquid chromatography (HPLC) or mass spectrometry.
5. The Edman degradation using PITC is a powerful tool for protein sequencing and is widely used in proteomics research and analysis.

Review Questions

• Explain the role of PITC in the Edman degradation process for peptide sequencing.
  • PITC, or Phenylisothiocyanate, is a key reagent used in the Edman degradation technique for sequencing the amino acids of peptides and proteins. During the Edman degradation, PITC selectively reacts with the N-terminal amino acid of the peptide chain, forming a stable phenylthiohydantoin (PTH) derivative. This PTH derivative can then be identified and removed, allowing the next amino acid in the sequence to be targeted and analyzed. The Edman degradation using PITC is a powerful method for determining the complete amino acid sequence of a peptide or protein, one residue at a time.
• Describe how the PTH derivative formed during the Edman degradation process is used to identify the N-terminal amino acid.
  • The phenylthiohydantoin (PTH) derivative formed when PITC reacts with the N-terminal amino acid during the Edman degradation is a crucial intermediate for identifying the amino acid sequence. The PTH derivative is a stable, cyclic compound that can be separated and analyzed using techniques such as high-performance liquid chromatography (HPLC) or mass spectrometry. By comparing the characteristics of the PTH derivative, such as its retention time or mass-to-charge ratio, to reference data, the identity of the N-terminal amino acid can be determined. This process is then repeated sequentially, cleaving off and identifying each amino acid in the peptide or protein, allowing the complete sequence to be elucidated.
• Evaluate the significance of the Edman degradation using PITC in the field of proteomics and protein analysis.
  • The Edman degradation process utilizing PITC is a cornerstone technique in the field of proteomics and protein analysis. It provides a reliable and efficient method for determining the amino acid sequence of peptides and proteins, which is essential for understanding their structure, function, and interactions. The ability to sequentially identify each amino acid in a protein, facilitated by the PITC reagent and the formation of the PTH derivative, has made the Edman degradation a widely adopted tool in proteomics research, protein characterization, and the identification of post-translational modifications. The technique's versatility, accuracy, and the wealth of information it provides about protein structure and composition have made it an indispensable analytical method in modern biochemistry and molecular biology.

Related terms

Edman Degradation:

A method for sequencing amino acids in a peptide or protein by cleaving off the N-terminal amino acid as a phenylthiohydantoin derivative.

Phenylthiohydantoin (PTH): The stable cyclic compound formed when the N-terminal amino acid is cleaved from a peptide chain during the Edman degradation process.

N-terminal Amino Acid: The first amino acid at the beginning of a peptide or protein sequence, which is targeted for identification during the Edman degradation.