Peptide binding is an amide bond between polypeptide and protein molecules in amino acids, also known as a peptide chain. A covalent bond is characteristic of peptide binding and is essential for normal peptide synthesis. In other words, peptide bonds link amino acids in a specific order that creates protein polymers and directs the formation of unique, three-dimensional (3D structures. Without peptide binding, important reactions involving amino acids become inhibited.
In terms of molecular chemistry, the linking of two or more amino acids forms a peptide molecule. The peptide bond forms where a carboxylic acid molecule reacts with an amino group in the next amino acid molecule. The resulting molecule is a dipeptide — two amino acids linked together by peptide binding. Peptide bonds are unique to the amino group to which they link.
The process of peptide synthesis, or protein synthesis, involves the formation of a peptide chain and a series of biochemical reactions with various types of ribonucleic acid (RNA) molecules — messenger, ribosomal and transfer RNA — and amino acids. Protein synthesis takes place as the ribosome translates the messenger RNA (mRNA), and a peptide bond forms between two amino acid molecules following translation. Each time peptide binding occurs, a new amino acid is added to what is called a polypeptide chain. Under some circumstances, multiple ribosomes can translate the same strand of mRNA, which results in duplicative peptide binding and, thus, duplicate peptide chains.
When protein synthesis is completed, the polypeptide chain is released by an enzyme-catalyzed reaction and forms a 3D structure that becomes a biologically active protein. The effectiveness of some antibiotics used for treating bacterial infections is based on peptide binding during protein synthesis. By interfering with the formation of proteins needed by the bacteria, antibiotics can stop the bacteria from multiplying.
Antibiotics that inhibit peptide bonding also inhibit protein synthesis. Many antibiotics cannot target unhealthy cells specifically, so they end up affecting healthy cells during the process, although there are some drugs that act only on bacterial cells by targeting bacteria ribosomes. The mechanism of action for antibiotics may prevent transcription of RNA or the growth of peptide chains by inhibiting peptide bond formation. Other mechanisms include incomplete protein coding and prevention of transcription RNA (tRNA), all of which rely on biochemical-mediated peptide binding.
A need for peptide synthesis companies emerged as a result of demand from research and development teams charged with new antibiotic development. In-demand peptide services include custom sequencing with mass spectrometry, or the development of a peptide catalog or peptide library. Some of these service providers also supply modified peptides and synthesis materials.