Myriocin, also known as antibiotic ISP-1 and thermozymocidin, is an atypical amino acid

Amino acid

Amino acids are molecules containing an amine group, a carboxylic acid group and a side-chain that varies between different amino acids. The key elements of an amino acid are carbon, hydrogen, oxygen, and nitrogen...

 and an antibiotic

Antibiotic

An antibacterial is a compound or substance that kills or slows down the growth of bacteria.The term is often used synonymously with the term antibiotic; today, however, with increased knowledge of the causative agents of various infectious diseases, antibiotic has come to denote a broader range of...

 derived from certain thermophilic fungi. Among the producing strains are Mycelia sterilia and Isaria sinclairii

Isaria sinclairii

Isaria sinclairii is a species of entomopathogenic fungus. It produces myriocin, from which synthetic drug fingolimod, a treatment for multiple sclerosis, was developed.-Ecology:...

.

Myriocin is a very potent inhibitor of serine palmitoyltransferase, the first step in sphingosine

Sphingosine

Sphingosine is an 18-carbon amino alcohol with an unsaturated hydrocarbon chain, which forms a primary part of sphingolipids, a class of cell membrane lipids that include sphingomyelin, an important phospholipid.-Functions:...

 biosynthesis. Due to this property, it is used in biochemical research as a tool for depleting cells of sphingolipid

Sphingolipid

Sphingolipids are a class of lipids containing a backbone of sphingoid bases, a set of aliphatic amino alcohols that includes sphingosine. They were discovered in brain extracts in the 1870s and were named for the mythological Sphinx because of their enigmatic nature. These compounds play...

s.

Myriocin was shown to inhibit the proliferation of an IL-2-dependent mouse cytotoxic T cell

T cell

T cells or T lymphocytes belong to a group of white blood cells known as lymphocytes, and play a central role in cell-mediated immunity. They can be distinguished from other lymphocytes, such as B cells and natural killer cells , by the presence of a T cell receptor on the cell surface. They are...

 line.

Myriocin possesses immunosuppressant

Immunosuppressant

An immunosuppressant is any substance that performs immunosuppression of the immune system. They may be either exogenous, as immunosuppressive drugs, or endogenous, as ,e. g., testosterone...

 activity. It is reported to be 10 to 100 fold more potent than ciclosporin

Ciclosporin

Ciclosporin , cyclosporine , cyclosporin , or cyclosporin A is an immunosuppressant drug widely used in post-allogeneic organ transplant to reduce the activity of the immune system, and therefore the risk of organ rejection...

.