Advertisement

Molecular and Cellular Biochemistry

, Volume 11, Issue 3, pp 155–159 | Cite as

Chemical modifications of histidine residues in cytoplasmic asparate aminotransferase from beef kidney

  • Polidoro G. 
  • Cola D. Di 
  • Ilio C. Di 
  • Politi L. 
  • Scandurra R. 
General and Review Articles a. general articles

Summary

Holo and apoenzyme of aspartate aminotransferase from beef kidney are 80% inactivated by photoxidation in the presence of 2 × 10−6m tetraiodofluroescein with the modification of two histidine residues per enzyme protomer. At a higher concentration (1 × 10−5m) a tyrosine residue is also modified. The keto substrates, ketoglutarate and oxalacetate, protect the enzyme from photoxidation.

Diethylpyrocarbonate modifies three histidine residues per enzyme protomer and reduces the activity only 10%. These results suggest that the two histidine residues photoxidized through the sensitizer, are located in the active site of the enzyme, at least one of these appears to be involved in ketosubstrate binding. The other three histidines modified by diethylpyrocarbonate are likely located on the enzyme surface and are not involved in the catalytic activity of the enzyme.

Keywords

Aspartate Tyrosine Histidine Chemical Modification Catalytic Activity 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. 1.
    Polidoro, G., Di Cola, D., Cicconetti, M. and Scandurra, R. 1973. Bol. Soc. It. Biol. Sper. 46, 693–696.Google Scholar
  2. 2.
    Westhead, E. 1965. Biochemistry, 4, 2139–2144.Google Scholar
  3. 3.
    Mühlrad, A. Hegyi, G. and Tòth, G. 1967. Acta Biochim. Biophys., 2, 19–29.Google Scholar
  4. 4.
    Thomè-Beau, F., Lê-thi-Lan, Olonuchi, A. and Thoai, N. V. 1971. Eur. J. Biochem., 19, 270–275.Google Scholar
  5. 5.
    Karmen, A. 1955. J. Clin. Invest., 34, 131–133.Google Scholar
  6. 6.
    Polidoro, G., Di Cola, D., Di Ilio, C., Del Boccio, G., Politi, L. and Scandurra, R. 1975. Physiol. Chem. & Physics, 7, 255–261.Google Scholar
  7. 7.
    Ovàdi, J., Libor, S. and Elodi, P. 1967 Acta Biophys. Acad. Sci. Hung. 2, 455–458.Google Scholar
  8. 8.
    Scandurra, R., Polidoro, G., Di Cola, D., Politi, L. and Riordan, J. F. 1975, Biochemistry, 14, 3701–3706.Google Scholar
  9. 9.
    Riordan, J. F., Sokolovsky, M. and Vallee, B. L. 1967 Biochemistry, 6, 358–361.Google Scholar
  10. 10.
    Fasella, P., and Turano, C. 1970 Vitamins and Hormones 28, 157–194.Google Scholar
  11. 11.
    Martinez-Carrion, M., Turano, C., Riva, F., Fasella, P. 1967, J. Biol. Chem. 242, 1426–1430.Google Scholar
  12. 12.
    Scandurra, R. and Cannella, C. 1972, Eur. J. Biochem., 26, 196–206.Google Scholar

Copyright information

© Dr. W. Junk b.v. Publishers 1976

Authors and Affiliations

  • Polidoro G. 
    • 1
    • 2
  • Cola D. Di 
    • 1
    • 2
  • Ilio C. Di 
    • 1
    • 2
  • Politi L. 
    • 1
    • 2
  • Scandurra R. 
    • 1
    • 2
  1. 1.Institute of Biological ChemistryUniversity of ChietiChietiItaly
  2. 2.Institute of Biological Chemistry, Faculty of PharmacyUniversity of RomeRomeItaly

Personalised recommendations