Peptides are biologically and medically important molecules. In nature they have similar functions as proteins including: acting as structural components of cells and tissues, hormones, toxins, antibiotics, and enzymes. For example, peptide therapeutics are used to treat Alzheimer’s disease.
Echelon carries a comprehensive line of peptides products which are manufactured and analyzed to high quality standards.
KKRAARATSNVFA-NH2 is a substrate for myosin light chain kinase (MLCK). MLCK phosphorylates myosin allowing it to interact with actin producing muscle contraction.
Neuropeptides & Hormones
The neuroendocrine system uses neuropeptides as both neurotransmitters and neurohormones. Neurotransmitters are thought of as substances that are released by one neuron and affects neighboring neurons in a excitatory or inhibitory fashion. These effects are usually constrained spatially and temporally. Hormones however, are released into the bloodstream and can travel to distant sites over long time scales and affect larger tissue or cellular areas. Neuropeptides are unique in that they can have either set or properties.
Enzymes bind with chemical reactants called substrates and a single enzyme may have many substrates. Substrates bind to a specific location on the enzymes called the active site which contains a unique sequence of amino acid residues that confers specificity. This makes it possible to engineer synthetic peptides that are selective for an enzyme active site to monitor enzyme activity. A common approach uses short peptide sequences conjugated to a fluorogenic group. When the synthetic peptide substrate is cleaved by the enzyme the fluorophore is liberated and generates a fluorescent signal that indicates enzyme activity.
Peptide inhibitors generally come in a few broad classes: substrate mimics, allosteric inhibitors, and protein-protein interaction (PPI) inhibitors. Substrate mimics are a type of competitive inhibitor that has a sequence or structure similar to the endogenous substrate but inhibits enzyme activity by occupying the enzyme active site. Allosteric peptide inhibitors work by binding away from the active site and altering enzyme conformations in such a way that the substrate can’t bind or access the active site. Lastly, PPI inhibitors occupy sites on proteins that facilitate interactions and activation of enzyme complexes. Thus, by blocking these interactions the complexes cannot form and activity is lowered or blocked.