Tynorphin is a synthetic

Synthetic

Synthesis, the combination of two or more parts, whether by design or by natural processes. Furthermore, it may imply being prepared or made artificially, in contrast to naturally.-In the sense of combination:* Synthetic position, a concept in finance...

 opioid peptide

Opioid peptide

Opioid peptides are short sequences of amino acids that bind to opioid receptors in the brain; opiates and opioids mimic the effect of these peptides. Opioid peptides may be produced by the body itself, for example endorphins. The effects of these peptides vary, but they all resemble opiates...

 which is a potent

Potency (pharmacology)

In the field of pharmacology, potency is a measure of drug activity expressed in terms of the amount required to produce an effect of given intensity. A highly potent drug evokes a larger response at low concentrations, while a drug of lower potency evokes a small response at low concentrations...

 and competitive

Competitive inhibition

Competitive inhibition is a form of enzyme inhibition where binding of the inhibitor to the active site on the enzyme prevents binding of the substrate and vice versa.-Mechanism:...

 inhibitor

Enzyme inhibitor

An enzyme inhibitor is a molecule that binds to enzymes and decreases their activity. Since blocking an enzyme's activity can kill a pathogen or correct a metabolic imbalance, many drugs are enzyme inhibitors. They are also used as herbicides and pesticides...

 of the enkephalinase

Enkephalinase

Enkephalinases are enzymes which degrade endogenous enkephalin opioid peptides. They include:* Aminopeptidase N * Neutral endopeptidase * Dipeptidyl peptidase 3 * Carboxypeptidase A6 * Angiotensin-converting enzyme...

 class of enzyme

Enzyme

Enzymes are proteins that catalyze chemical reactions. In enzymatic reactions, the molecules at the beginning of the process, called substrates, are converted into different molecules, called products. Almost all chemical reactions in a biological cell need enzymes in order to occur at rates...

s which break down the endogenous

Endogenous

Endogenous substances are those that originate from within an organism, tissue, or cell. Endogenous retroviruses are caused by ancient infections of germ cells in humans, mammals and other vertebrates...

 enkephalin

Enkephalin

An enkephalin is a pentapeptide involved in regulating nociception in the body. The enkephalins are termed endogenous ligands, or specifically endorphins, as they are internally derived and bind to the body's opioid receptors. Discovered in 1975, two forms of enkephalin were revealed, one...

 peptide

Peptide

Peptides are short polymers of amino acid monomers linked by peptide bonds. They are distinguished from proteins on the basis of size, typically containing less than 50 monomer units. The shortest peptides are dipeptides, consisting of two amino acids joined by a single peptide bond...

s. It specifically inactivates dipeptidyl aminopeptidase III (DPP3) with very high efficacy

Efficacy

Efficacy is the capacity to produce an effect. It has different specific meanings in different fields. In medicine, it is the ability of an intervention or drug to reproduce a desired effect in expert hands and under ideal circumstances.- Healthcare :...

, but also inhibits neutral endopeptidase (NEP), aminopeptidase N (APN), and angiotensin-converting enzyme

Angiotensin-converting enzyme

Angiotensin I-converting enzyme , an exopeptidase, is a circulating enzyme that participates in the body's renin-angiotensin system , which mediates extracellular volume , and arterial vasoconstriction...

 (ACE) to a lesser extent. It has a pentapeptide structure

Chemical structure

A chemical structure includes molecular geometry, electronic structure and crystal structure of molecules. Molecular geometry refers to the spatial arrangement of atoms in a molecule and the chemical bonds that hold the atoms together. Molecular geometry can range from the very simple, such as...

 with the amino acid sequence Val-Val-Tyr-Pro-Trp (VVYPW).

Tynorphin was discovered in an attempt to develop an enkephalinase inhibitor of greater potency than spinorphin

Spinorphin

Spinorphin is an endogenous, non-classical opioid peptide of the hemorphin family, which was first isolated from the bovine spinal cord and acts as a regulator of the enkephalinases, a class of enzymes which break down endogenous the enkephalin peptides...

.