definição e significado de Puromycin

Puromycin

IUPAC name 3'-deoxy-N,N-dimethyl-3'-[(O-methyl-L-tyrosyl)amino]adenosine
Identifiers
CAS number	53-79-2^N
PubChem	439530
ChemSpider	388623^Y
DrugBank	DB08437
KEGG	D05653^Y
MeSH	Puromycin
ChEBI	CHEBI:17939^Y
ChEMBL	CHEMBL13840^N
Jmol-3D images	Image 1
SMILES O=C(N[C@@H]3[C@H](O[C@@H](n2cnc1c2ncnc1N(C)C)[C@@H]3O)CO)[C@@H](N)Cc4ccc(OC)cc4
InChI InChI=1S/C22H29N7O5/c1-28(2)19-17-20(25-10-24-19)29(11-26-17)22-18(31)16(15(9-30)34-22)27-21(32)14(23)8-12-4-6-13(33-3)7-5-12/h4-7,10-11,14-16,18,22,30-31H,8-9,23H2,1-3H3,(H,27,32)/t14-,15+,16+,18+,22+/m0/s1^Y Key: RXWNCPJZOCPEPQ-NVWDDTSBSA-N^Y InChI=1/C22H29N7O5/c1-28(2)19-17-20(25-10-24-19)29(11-26-17)22-18(31)16(15(9-30)34-22)27-21(32)14(23)8-12-4-6-13(33-3)7-5-12/h4-7,10-11,14-16,18,22,30-31H,8-9,23H2,1-3H3,(H,27,32)/t14-,15+,16+,18+,22+/m0/s1 Key: RXWNCPJZOCPEPQ-NVWDDTSBBO
Properties
Molecular formula	C₂₂H₂₉N₇O₅
Molar mass	471.51 g mol⁻¹
N (verify) (what is: Y/N?) Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Infobox references

Puromycin is an antibiotic that is a protein synthesis inhibitor by inhibiting translation.

1 Inhibition of translation
2 Peptidase Inhibitor
3 Cell culture
4 Selection of Escherichia coli
5 References
6 External links

Inhibition of translation

Puromycin is an aminonucleoside antibiotic, derived from the Streptomyces alboniger bacterium,^[1] that causes premature chain termination during translation taking place in the ribosome. Part of the molecule resembles the 3' end of the aminoacylated tRNA. It enters the A site and transfers to the growing chain, causing the formation of a puromycylated nascent chain and premature chain release ^[2]. The exact mechanism of action is unknown at this time, but, the 3' position contains an amide linkage instead of the normal ester linkage of tRNA, the amide bond makes the molecule much more resistant to hydrolysis and thus causes the ribosome to become stopped.

It is not selective for either prokaryotes or eukaryotes.

Also of note, puromycin is critical in mRNA display. In this reaction, a puromycin molecule is chemically attached to the end of an mRNA template, which is then translated into protein. The puromycin can then form a covalent link to the growing peptide chain allowing the mRNA to be physically linked to its translational product.

Antibodies that recognize puromycylated nascent chains can also be used to purify newly synthesized polypeptides^[3] and to visualize the distribution of actively translating ribosomes by immunofluorescence^[4].

Peptidase Inhibitor

Puromycin is a reversible inhibitor of dipeptidyl-peptidase II (serine peptidase) and cytosol alanyl aminopeptidase. (metallopeptidase).^[5]^[6] The mechanism of inhibition is not well understood, however puromycin can be used to distinguish between aminopeptidase M (active) and cytosol alanyl aminopeptidase (inhibited by puromycin).

Cell culture

Puromycin is used in cell biology as selective agent in cell culture systems. It is toxic to prokaryotic and eukaryotic cells. Resistance to puromycin is conferred by the Pac gene encoding a puromycin N-acetyl-transferase (PAC) that was found in a Streptomyces producer strain. Puromycin is soluble in water (50 mg/ml) as colorless solution at 10 mg/ml. Puromycin is stable for one year as solution when stored at -20°C. The recommended dose as a selection agent in cell cultures is within a range of 1-10 μg/ml, although it can be toxic to eukaryotic cells at concentrations as low as 1 μg/ml. It acts quickly and can kill up to 99% of nonresistant cells within 2 days.

Selection of Escherichia coli

Puromycin is poorly active on E. coli. Puromycin-resistant transformants are selected in LB agar medium supplemented with 125 µg/ml of puromycin. But use of puromycin for E. coli selection requires precise pH adjustment and also depends on which strain is selected. For hassle–free selection and optimum results the use of special modified puromycin is possible. Plates containing puromycin are stable for 1 month when stored at 4°C.

References

^ Puromycin from Fermentek
^ Pestka, S. (1971) Inhibitors of ribosome functions. Annu. Rev. Microbiol. 25:487–562.
^ Eggers, D.K., Welch, W.J., and Hansen W.J. (1997) Mol Biol Cell. 8: 1559–1573.
^ Starck, S.R., Green, H.M., Alberola-Ila, J. and Roberts R.W. (2004) A general approach to detect protein expression in vivo using fluorescent puromycin conjugates. Chem. Biol. 11:999–1008.
^ Dando, P.M, Young, N.E & Barrett, A.J (1997) Biomed Health Res. 13, 88-95
^ McDonald, J.K, Reilly, T.J, Zeitman, B.B & Ellis, S. (1968) J Bio Chem,. 243, 2028-2037

External links

The MEROPS online database for peptidases and their inhibitors: Puromycin

Antibacterials: protein synthesis inhibitors (J01A, J01B, J01F, J01G, QJ01XQ)

30S

Aminoglycosides
(initiation inhibitors)

-mycin (Streptomyces)	Streptomycin^# Dihydrostreptomycin Neomycin^# Framycetin Paromomycin Ribostamycin Kanamycin^# Amikacin Arbekacin Bekanamycin Dibekacin Tobramycin Spectinomycin^# Hygromycin B Paromomycin

-micin (Micromonospora)	Gentamicin^# Netilmicin Sisomicin Isepamicin Verdamicin Astromicin

Tetracycline antibiotics
(tRNA binding)

Tetracyclines	Doxycycline^# Chlortetracycline Clomocycline Demeclocycline Lymecycline Meclocycline Metacycline Minocycline Oxytetracycline Penimepicycline Rolitetracycline Tetracycline

Glycylcyclines	Tigecycline

50S

Oxazolidinone
(initiation inhibitors)

Peptidyl transferase

Amphenicols	Chloramphenicol^# Azidamfenicol Thiamphenicol Florfenicol

Pleuromutilins	Retapamulin Tiamulin Valnemulin

MLS (transpeptidation/translocation)

Macrolides	Azithromycin^# Clarithromycin Dirithromycin Erythromycin^# Flurithromycin Josamycin Midecamycin Miocamycin Oleandomycin Rokitamycin Roxithromycin Spiramycin Troleandomycin Tylosin Ketolides Telithromycin Cethromycin Solithromycin

Lincosamides	Clindamycin^# Lincomycin Pirlimycin

Streptogramins	Pristinamycin Quinupristin/dalfopristin Virginiamycin