Thionin
| Plant thionin | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Identifiers | |||||||||||
| Symbol | Thionin | ||||||||||
| Pfam | PF00321 | ||||||||||
| InterPro | IPR001010 | ||||||||||
| PROSITE | PDOC00244 | ||||||||||
| SCOP2 | 1cnb / SCOPe / SUPFAM | ||||||||||
| TCDB | 1.C.44 | ||||||||||
| OPM protein | 2plh | ||||||||||
| |||||||||||
Thionins (without an e) can also refer to a family of peptides found solely in higher plants. Typically, a thionin consists of 45–48 amino acid residues. 6–8 of these are cysteine forming 3–4 disulfide bonds. Some thionins have cytotoxic activity and they are therefore interesting in the development of new drugs against cancer with novel action mechanisms.[1] As of yet, no thionin has ever been developed into an anti-cancer drug.
The proteins are toxic to animal cells, presumably attacking the cell membrane and rendering it permeable: this results in the inhibition of sugar uptake and allows potassium and phosphate ions, proteins, and nucleotides to leak from cells[2]. Thionins are mainly found in seeds where they may act as a defence against consumption by animals. A barley (Hordeum vulgare) leaf thionin that is highly toxic to plant pathogens and is involved in the mechanism of plant defence against microbial infections has also been identified[3]. The hydrophobic protein crambin from the Abyssinian kale (Crambe abyssinica) is also a member of the thionin family[2].
Databases
A database for antimicrobial peptides, including thionins is available: PhytAMP (http://phytamp.pfba-lab-tun.org)[4].
Notes and references
- ^ Florack DE, Stiekema WJ (1994). "Thionins: properties, possible biological roles and mechanisms of action". Plant Mol. Biol. 26 (1): 25–37. doi:10.1007/BF00039517. PMID 7948874.
{{cite journal}}: Unknown parameter|month=ignored (help) - ^ a b Vernon LP, Evett GE, Zeikus RD, Gray WR (1985). "A toxic thionin from Pyrularia pubera: purification, properties, and amino acid sequence". Arch. Biochem. Biophys. 238 (1): 18–29. doi:10.1016/0003-9861(85)90136-5. PMID 3985614.
{{cite journal}}: CS1 maint: multiple names: authors list (link) - ^ Apel K, Andresen I, Becker W, Schluter K, Burges J, Parthier B (1992). "The identification of leaf thionin as one of the main jasmonate-induced proteins of barley (Hordeum vulgare)". Plant Mol. Biol. 19 (2): 193–204. doi:10.1007/BF00027341. PMID 1377959.
{{cite journal}}: CS1 maint: multiple names: authors list (link) - ^ Hammami R, Ben Hamida J, Vergoten G, Fliss I, (2008). "PhytAMP: a database dadicated to plant antimicrobial peptides". Nucleic Acid Research. 37 (Database issue): D963–8. doi:10.1093/nar/gkn655. PMC 2686510. PMID 18836196.
{{cite journal}}: CS1 maint: extra punctuation (link) CS1 maint: multiple names: authors list (link)
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