Quick Start Guide to Peptides

1. Understanding Peptide Basics

Definition

Peptides are short chains of amino acids linked by peptide bonds. They are smaller than proteins and typically contain between 2 and 50 amino acid residues.

Structure

Peptides have a primary structure (amino acid sequence), and some may form secondary structures like alpha-helices or beta-sheets.

Formation

Peptides are formed through the condensation reaction between the carboxyl group of one amino acid and the amino group of another, resulting in a peptide bond.

2. Key Types of Peptides

• Dipeptides: Consist of two amino acids
• Oligopeptides: Contain 3 to 10 amino acids
• Polypeptides: Contain more than 10 amino acids, but are still smaller than proteins

3. Peptide Nomenclature

Peptides are named based on their amino acid sequence, starting from the N-terminus (amino end) to the C-terminus (carboxyl end). For example:

• Gly-Ala: A dipeptide of glycine and alanine
• Met-Glu-His: A tripeptide of methionine, glutamic acid, and histidine

4. Common Applications of Peptides

In medicine

• Hormone replacement therapy (e.g., insulin)
• Cancer treatments
• Antimicrobial peptides

In cosmetics

• Anti-aging products
• Skin-firming creams

In nutrition

• Sports supplements
• Functional foods

5. How to Read Peptide Sequences

Peptide sequences are typically written using one-letter or three-letter amino acid codes. For example:

• One-letter code: KGHY
• Three-letter code: Lys-Gly-His-Tyr

This represents a tetrapeptide composed of lysine, glycine, histidine, and tyrosine.

6. Tools for Peptide Analysis

• Mass Spectrometry
• High-Performance Liquid Chromatography (HPLC)
• Nuclear Magnetic Resonance (NMR) Spectroscopy
• Circular Dichroism (CD) Spectroscopy
• X-ray Crystallography

7. Safety Considerations

• Always wear appropriate personal protective equipment (PPE) when handling peptides
• Follow proper storage and disposal procedures
• Be aware of potential allergenicity of certain peptides
• Consult Safety Data Sheets (SDS) for specific handling instructions