JBIC Journal of Biological Inorganic Chemistry

, Volume 11, Issue 8, pp 1049–1062

Zinc-buffering capacity of a eukaryotic cell at physiological pZn

Original Paper

Abstract

In spite of the paramount importance of zinc in biology, dynamic aspects of cellular zinc metabolism remain poorly defined at the molecular level. Investigations with human colon cancer (HT-29) cells establish a total cellular zinc concentration of 264 μM. Remarkably, about 10% of the potential high-affinity zinc-binding sites are not occupied by zinc, resulting in a surplus of 28 μM ligands (average Kdc = 83 pM) that ascertain cellular zinc-buffering capacity and maintain the “free” zinc concentration in proliferating cells at picomolar levels (784 pM, pZn = 9.1). This zinc-buffering capacity allows zinc to fluctuate only with relatively small amplitudes (ΔpZn = 0.3; below 1 nM) without significantly perturbing physiological pZn. Thus, the “free” zinc concentrations in resting and differentiated HT-29 cells are 614 pM and 1.25 nM, respectively. The calculation of these “free” zinc concentrations is based on measurements at different concentrations of the fluorogenic zinc-chelating agent and extrapolation to a zero concentration of the agent. It depends on the state of the cell, its buffering capacity, and the zinc dissociation constant of the chelating agent. Zinc induction of thionein (apometallothionein) ensures a surplus of unbound ligands, increases zinc-buffering capacity and the availability of zinc (ΔpZn = 0.8), but preserves the zinc-buffering capacity of the unoccupied high-affinity zinc-binding sites, perhaps for crucial physiological functions. Jointly, metallothionein and thionein function as the major zinc buffer under conditions of increased cellular zinc.

Keywords

Zinc buffering FluoZin-3 “Free” zinc Metallothionein Thionein 

References

  1. 1.
    O’Halloran TV, Culotta VC (2000) J Biol Chem 275:25057–25060PubMedCrossRefGoogle Scholar
  2. 2.
    Thompson RB (2005) Curr Opin Chem Biol 9:526–532PubMedCrossRefGoogle Scholar
  3. 3.
    Gaither LA, Eide DJ (2001) Biometals 14:251–270PubMedCrossRefGoogle Scholar
  4. 4.
    Outten CE, O’Halloran TV (2001) Science 292:2488–2492PubMedCrossRefGoogle Scholar
  5. 5.
    Peck EJ Jr, Ray WJ Jr (1971) J Biol Chem 246:1160–1167PubMedGoogle Scholar
  6. 6.
    Simons TJB (1991) J Membr Biol 123:63–71PubMedCrossRefGoogle Scholar
  7. 7.
    Benters J, Flögel U, Schäfer T, Leibfritz D, Hechtenberg S, Beyersmann D (1997) Biochem J 322:793–799PubMedGoogle Scholar
  8. 8.
    Adebodun F, Post JF (1995) J Cell Physiol 163:80–86PubMedCrossRefGoogle Scholar
  9. 9.
    Atar D, Backx PH, Appel MM, Gao WD, Marban E (1995) J Biol Chem 270:2473–2477PubMedCrossRefGoogle Scholar
  10. 10.
    Ayaz M, Turan B (2006) Am J Physiol Heart Circ Physiol 290:H1071–H1080PubMedCrossRefGoogle Scholar
  11. 11.
    Bozym RA, Thompson RB, Stoddard AK, Fierke CA (2006) ACS Chem Biol 1:103–111CrossRefGoogle Scholar
  12. 12.
    Frederickson CJ, Bush AI (2001) Biometals 14:353–366PubMedCrossRefGoogle Scholar
  13. 13.
    Frederickson CJ, Koh J-Y, Bush AI (2005) Nat Rev Neurosci 6:449–462PubMedCrossRefGoogle Scholar
  14. 14.
    Grynkiewicz G, Poenie M, Tsien RY (1985) J Biol Chem 260:3440–3450PubMedGoogle Scholar
  15. 15.
    Hitomi Y, Outten CE, O’Halloran TV (2001) J Am Chem Soc 123:8614–8615PubMedCrossRefGoogle Scholar
  16. 16.
    Hirano T, Kikuchi K, Urano Y, Nagano T (2002) J Am Chem Soc 124:6555–6562PubMedCrossRefGoogle Scholar
  17. 17.
    Shaw CF, Laib JE, Savas M, Petering DH (1990) Inorg Chem 29:403–408CrossRefGoogle Scholar
  18. 18.
    Smith PK, Krohn RJ, Hermanson GT, Mallia AK, Gartner FH, Provenzano M, Fujimoto EK, Goeke NM, Olson GJ, Klenk DC (1985) Anal Biochem 150:76–85PubMedCrossRefGoogle Scholar
  19. 19.
    Eyer P, Worek F, Kiderlen D, Sinko G, Stuglin A, Simeon-Rudolf V, Reiner E (2003) Anal Biochem 312:224–227PubMedCrossRefGoogle Scholar
  20. 20.
    Yang Y, Maret W, Vallee BL (2001) Proc Natl Acad Sci USA 98:5556–5559PubMedCrossRefGoogle Scholar
  21. 21.
    Raaflaub J (1956) Methods Biochem Anal 3:301–325PubMedGoogle Scholar
  22. 22.
    Kirlin WG, Cai J, Thompson SA, Diaz D, Kavanagh TG, Jones DP (1999) Free Radical Biol Med 27:1208–1218CrossRefGoogle Scholar
  23. 23.
    Nagel WW, Vallee BL (1995) Proc Natl Acad Sci USA 92:579–583PubMedCrossRefGoogle Scholar
  24. 24.
    Neutra M, Louvard D (1989) In: Matlin KS, Valentich JD (eds) Functional epithelial cells in culture. Liss, New York, pp 363–398Google Scholar
  25. 25.
    Gee KR, Zhou Z-L, Qian W-E, Kennedy R (2002) J Am Chem Soc 124:776–778PubMedCrossRefGoogle Scholar
  26. 26.
    Sensi SL, Ton-That D, Sullivan PG, Jonas EA, Gee KR, Kaczmarek LK, Weiss JH (2003) Proc Natl Acad Sci USA 100:6157–6162PubMedCrossRefGoogle Scholar
  27. 27.
    Kimura E, Shiota T, Koike T, Shiro M, Kodoma M (1990) J Am Chem Soc 112:5805–5811CrossRefGoogle Scholar
  28. 28.
    Schwarzenbach G, Freitag E (1951) Helv Chim Acta 34:1492–1502CrossRefGoogle Scholar
  29. 29.
    Chaberek S, Martell AE (1952) J Am Chem Soc 74:6228–6231CrossRefGoogle Scholar
  30. 30.
    Frausto da Silva JJR, Calado JG (1963) Rev Port Quim 5:121–128Google Scholar
  31. 31.
    Martell AE, Smith RM (2001) NIST critical stability constants of metal complexes. NIST standard reference database 46, version 6.0Google Scholar
  32. 32.
    Anderegg G (1964) Helv Chim Acta 47:1801–1814CrossRefGoogle Scholar
  33. 33.
    Holloway JH, Reilley CN (1960) Anal Chem 32:249–256CrossRefGoogle Scholar
  34. 34.
    Gee KR, Zhou ZL, Ton-That D, Sensi SL, Weiss JH (2002) Cell Calcium 31:245–251PubMedCrossRefGoogle Scholar
  35. 35.
    Kägi JHR (1993) In: Suzuki KT, Imura N, Kimura M (eds) Metallothionein III. Biological roles and medical implications. Birkhäuser, Basel, pp 29–55Google Scholar
  36. 36.
    Krężel A, Wójcik J, Maciejczyk M, Bal W (2003) Chem Commun 704–705Google Scholar
  37. 37.
    Rabenstein DL, Isab AA (1980) FEBS Lett 121:61–64PubMedCrossRefGoogle Scholar
  38. 38.
    Günes C, Heuchel R, Georgiev O, Müller KH, Lichtlen P, Blüthmann H, Marino S, Aguzzi A, Schaffner W (1998) EMBO J 17:2846–2854PubMedCrossRefGoogle Scholar
  39. 39.
    Krężel A, Bal W (1999) Acta Biochim Pol 46:567–580PubMedGoogle Scholar
  40. 40.
    Krężel A, Bal W (2004) Bioinorg Chem Appl 2:293–305Google Scholar
  41. 41.
    Chang CJ, Nolan EM, Jaworski J, Burdette SC, Sheng M, Lippard SJ (2004) Chem Biol 11:203–210PubMedCrossRefGoogle Scholar
  42. 42.
    Kikuchi K, Komatsu K, Nagano T (2004) Curr Opin Chem Biol 8:182–191PubMedCrossRefGoogle Scholar
  43. 43.
    Dineley KE, Malaiyandi LM, Reynolds IJ (2002) Mol Pharmacol 62:618–627PubMedCrossRefGoogle Scholar
  44. 44.
    Haase H, Hebel S, Engelhardt G, Rink L (2006) Anal Biochem 352:222–230PubMedCrossRefGoogle Scholar
  45. 45.
    Maret W, Jacob C, Vallee BL, Fischer EH (1999) Proc Natl Acad Sci USA 96:1936–1940PubMedCrossRefGoogle Scholar
  46. 46.
    Knipp M, Charnock JM, Garner CD, Vasak M (2001) J Biol Chem 276:40449–40456PubMedCrossRefGoogle Scholar
  47. 47.
    Haase H, Maret W (2003) Exp Cell Res 291:289–298PubMedCrossRefGoogle Scholar
  48. 48.
    Heinz U, Kiefer M, Tholey A, Adolph H-W (2005) J Biol Chem 280:3197–3207PubMedCrossRefGoogle Scholar
  49. 49.
    Thomas RC, Coles JA, Deitmer JW (1991) Nature 350:564PubMedCrossRefGoogle Scholar

Copyright information

© SBIC 2006

Authors and Affiliations

  1. 1.Division of Human Nutrition, Department of Preventive Medicine and Community HealthUniversity of Texas Medical BranchGalvestonUSA
  2. 2.Department of AnesthesiologyUniversity of Texas Medical BranchGalvestonUSA

Personalised recommendations