Chromomycin A3 Explained

Chromomycin A3 (CMA₃) or Toyomycin is an anthraquinone antibiotic glycoside produced by the fermentation of a certain strain of Streptomyces griseus (No. 7).^[1]

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Fluorescence properties

In the presence of Mg²⁺ ions, Chromomycin A₃ binds reversibly to DNA, preferentially to contiguous G/C base pairs.^{[2] [3]}

When bound to DNA, Chromomycin A₃ has a maximum excitation wavelength of 445 nm (blue), and a maximum emission wavelength of 575 nm (yellow).^[4]

Uses

• in-vitro membrane-impermeant G/C-specific fluorescent DNA-binding dye.
• in-vitro antibiotic of gram-positive bacteria, through inhibition of the incorporation of P_i in the RNA.
• in-vitro anticancer drug that inhibits RNA synthesis.^[5]
• Evaluation of male fertility: Chromomycin A₃ and protamines compete for the same binding sites in the DNA, so CMA₃ positivity in spermatozoa reflects protamine deficiency (affecting sperm morphology and decreasing fertility).^{[6] [7]}

References

1. Kamiyama. M.. Kaziro. Y.. January 1966. Mechanism of action of chromomycin A3. 1. Inhibition of nucleic acid metabolism in Bacillus subtilis cells. Journal of Biochemistry. 59. 1. 49–56. 0021-924X. 4957278. 10.1093/oxfordjournals.jbchem.a128257.
2. Kamiyama. M.. May 1968. Mechanism of action of chromomycin A3. 3. On the binding of chromomycin A3 with DNA and physiochemical properties of the complex. Journal of Biochemistry. 63. 5. 566–572. 0021-924X. 4972707. 10.1093/oxfordjournals.jbchem.a128814.
3. Van Dyke. M. W.. Dervan. P. B.. 1983-05-10. Chromomycin, mithramycin, and olivomycin binding sites on heterogeneous deoxyribonucleic acid. Footprinting with (methidiumpropyl-EDTA)iron(II). Biochemistry. 22. 10. 2373–2377. 0006-2960. 6222762. 10.1021/bi00279a011.
4. https://www.caymanchem.com/pdfs/11315.pdf
5. Kajiro. Y.. Kamiyama. M.. October 1967. Mechanism of action of chromomycin A3. II. Inhibition of RNA polymerase reaction. Journal of Biochemistry. 62. 4. 424–429. 0021-924X. 5587590. 10.1093/oxfordjournals.jbchem.a128685.
6. Iranpour. Farhad Golshan. Nasr-Esfahani. Mohammad Hosein. Valojerdi. Mojtaba Rezazadeh. Al-Taraihi. Taki Mohammad Taki. 2000-01-01. Chromomycin A3 Staining as a Useful Tool for Evaluation of Male Fertility. Journal of Assisted Reproduction and Genetics. en. 17. 1. 60–66. 10.1023/a:1009406231811. 10754785. 1058-0468. 3455193.
7. Nijs. Martine. Creemers. Eva. Cox. Annemie. Franssen. Kim. Janssen. Mia. Vanheusden. Elke. Jonge. Christopher De. Ombelet. Willem. Chromomycin A3 staining, sperm chromatin structure assay and hyaluronic acid binding assay as predictors for assisted reproductive outcome. Reproductive BioMedicine Online. 19. 5. 671–684. 10.1016/j.rbmo.2009.07.002. November 2009. 20021715. free.