Valinomycin

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Valinomycin
Skeletal formula of valinomycin
Ball-and-stick model of the valinomycin molecule
Names
IUPAC name
cyclo[N-oxa-D-alanyl-D-valyl-N-oxa-L-valyl-D-valyl-N-oxa-D-alanyl-D-valyl-N-oxa-L-valyl-L-valyl-N-oxa-L-alanyl-L-valyl-N-oxa-L-valyl-L-valyl]
Identifiers
3D model (
JSmol
)
ChEBI
ChEMBL
ChemSpider
DrugBank
ECHA InfoCard
 100.016.270 Edit this at Wikidata
EC Number
  • 217-896-6
UNII
UN number 2811 2588
  • InChI=1S/C54H90N6O18/c1-22(2)34-49(67)73-31(19)43(61)55-38(26(9)10)53(71)77-41(29(15)16)47(65)59-36(24(5)6)51(69)75-33(21)45(63)57-39(27(11)12)54(72)78-42(30(17)18)48(66)60-35(23(3)4)50(68)74-32(20)44(62)56-37(25(7)8)52(70)76-40(28(13)14)46(64)58-34/h22-42H,1-21H3,(H,55,61)(H,56,62)(H,57,63)(H,58,64)(H,59,65)(H,60,66)/t31-,32-,33-,34+,35+,36+,37-,38-,39-,40+,41+,42+/m0/s1 ☒N
    Key: FCFNRCROJUBPLU-DNDCDFAISA-N ☒N
  • InChI=1S/C54H90N6O18/c1-22(2)34-49(67)73-31(19)43(61)55-38(26(9)10)53(71)77-41(29(15)16)47(65)59-36(24(5)6)51(69)75-33(21)45(63)57-39(27(11)12)54(72)78-42(30(17)18)48(66)60-35(23(3)4)50(68)74-32(20)44(62)56-37(25(7)8)52(70)76-40(28(13)14)46(64)58-34/h22-42H,1-21H3,(H,55,61)(H,56,62)(H,57,63)(H,58,64)(H,59,65)(H,60,66)/t31-,32-,33+,34-,35+,36+,37-,38-,39+,40+,41+,42+/m1/s1
    Key: FCFNRCROJUBPLU-DNDCDFAIBE
  • [1]: C[C@@H]1C(=O)N[C@@H](C(=O)O[C@H](C(=O)N[C@@H](C(=O)O[C@@H](C(=O)N[C@@H](C(=O)O[C@H](C(=O)N[C@H](C(=O)O[C@H](C(=O)N[C@H](C(=O)O[C@H](C(=O)N[C@H](C(=O)O1)C(C)C)C(C)C)C(C)C)C)C(C)C)C(C)C)C(C)C)C)C(C)C)C(C)C)C(C)C
Properties
C54H90N6O18
Molar mass 1111.32 g/mol
Appearance White solid
Melting point 190 °C (374 °F; 463 K)
Solubility Methanol, ethanol, ethyl acetate, petrol-ether, dichloromethane
UV-vis (λmax) 220 nm
Hazards
Occupational safety and health (OHS/OSH):
Main hazards
 Neurotoxicant
GHS labelling:
GHS06: Toxic
Danger
H300, H310
P262, P264, P270, P280, P301+P310, P302+P350, P310, P321, P322, P330, P361, P363, P405, P501
Lethal dose or concentration (LD, LC):
4 mg/kg (oral, rat)[1]
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Valinomycin is a naturally occurring dodeca

S. fulvissimus
being a notable one.

It is a member of the group of natural neutral ionophores because it does not have a residual charge. It consists of enantiomers D- and L-valine (Val), D-alpha-hydroxyisovaleric acid, and L-lactic acid. Structures are alternately bound via amide and ester bridges. Valinomycin is highly selective for potassium ions over sodium ions within the cell membrane.[2] It functions as a potassium-specific transporter and facilitates the movement of potassium ions through lipid membranes "down" the electrochemical potential gradient.[3] The stability constant K for the potassium-valinomycin complex is nearly 100,000 times larger than that of the sodium-valinomycin complex.[4] This difference is important for maintaining the selectivity of valinomycin for the transport of potassium ions (and not sodium ions) in biological systems.

It is classified as an

extremely hazardous substance in the United States as defined in Section 302 of the U.S. Emergency Planning and Community Right-to-Know Act (42 U.S.C. 11002), and is subject to strict reporting requirements by facilities which produce, store, or use it in significant quantities.[5]

Structure

Valinomycin is a dodecadepsipeptide, that is, it is made of twelve alternating

methyl groups are responsible for solvation in nonpolar solvents
. [6] Along with its shape and size this molecular duality is the main reason for its binding properties. K ions must give up their water of hydration to pass through the pore. K+ ions are octahedrally coordinated in a square bipyramidal geometry by 6 carbonyl bonds from Val. In this space of 1.33 Angstrom, Na+ with its 0.95 Angstrom radius, is significantly smaller than the channel, meaning that Na+ cannot form ionic bonds with the amino acids of the pore at equivalent energy as those it gives up with the water molecules. This leads to a 10,000x selectivity for K+ ions over Na+. For polar solvents, valinomycin will mainly expose the carbonyls to the solvent and in nonpolar solvents the isopropyl groups are located predominantly on the exterior of the molecule. This conformation changes when valinomycin is bound to a potassium ion. The molecule is "locked" into a conformation with the isopropyl groups on the exterior [Citation Needed]. It is not actually locked into configuration because the size of the molecule makes it highly flexible, but the potassium ion gives some degree of coordination to the macromolecule.

Applications

Valinomycin was recently reported to be the most potent agent against severe acute respiratory-syndrome coronavirus (SARS-CoV) in infected

Vero E6 cells.[7]

Valinomycin acts as a nonmetallic isoforming agent in potassium selective electrodes.[8][9]

This ionophore is used to study membrane vesicles, where it may be selectively applied by experimental design to reduce or eliminate the electrochemical gradient across a membrane.[citation needed]

References

  1. ^ a b "ChemIDplus - 2001-95-8 - FCFNRCROJUBPLU-DNDCDFAISA-N - Valinomycin - Similar structures search, synonyms, formulas, resource links, and other chemical information". TOXNET. U.S. National Library of Medicine. Archived from the original on 20 December 2015.
  2. PMID 16875886
    .
  3. ISBN 978-3-540-15136-4
    .
  4. doi:10.1016/0304-4165(74)90204-9
    .
  5. ^ "40 C.F.R.: Appendix A to Part 355—The List of Extremely Hazardous Substances and Their Threshold Planning Quantities" (PDF) (July 1, 2008 ed.). Government Printing Office. Archived (PDF) from the original on February 25, 2012. Retrieved October 29, 2011.
  6. doi:10.1016/S0003-2670(01)95308-5
    .
  7. PMID 33012699
    .
  8. S2CID 34918061
    .
  9. ^ "Potassium ionophore Bulletin" (PDF). Archived (PDF) from the original on 2012-03-15. Retrieved 2009-05-19.

External links

Retrieved from "https://en.wikipedia.org/w/index.php?title=Valinomycin&oldid=1214462713"