Soluble silica with high affinity for aluminium under physiological and natural conditions

Journal of the American Chemical Society

Volumn 119, Issue 38, 1997, Pages 8852-8856

  Taylor, Paul D ^a   Jugdaohsingh, Ravin ^a   Powell, Jonathan J ^a  

^a ST THOMAS HOSPITAL   (United Kingdom)

Author keywords

[No Author keywords available]

Indexed keywords

ALUMINUM; SILICIC ACID; SILICON DIOXIDE;

ARTICLE; BINDING AFFINITY; BINDING KINETICS; CHEMICAL BINDING; COMPLEX FORMATION; IONIC STRENGTH;

EID: 0030819976     PISSN: 00027863     EISSN: None     Source Type: Journal    
DOI: 10.1021/ja964476n     Document Type: Article

References (43)

1. Farmer, V. C. In Silicon Biochemistry; Evered, D., O'Connor, M., Eds.; Ciba Foundation Symposium 121; John Wiley and Sons Ltd.: Chichester, 1986; pp 4-23.
2. Exley, C.; Birchall, J. D. Polyhedron 1992, 11, 1901-1907.
3. Klein, C. In Reviews in Mineralogy vol. 28. Health effects of mineral dust; Guthrie, G. D., Jr., Mossman, B. T., Eds.; Mineralogical Society of America, Washington, D.C.; Bookcrafters Inc.: Chelsea, MI, 1993; p 8.
4. Edwardson, J. A.; Moore, P. B.; Ferrier, I. N.; Lilley, J. S.; Newton, G. W. A.; Barker, J.; Templar, J.; Day, J. P. Lancet 1993, 342, 211-212.
5. Karlsson-Norrgren, L.; Bjorklund, I. B.; Ljungberg, O.; Runn, P. J. Fish. Dis. 1986, 9, 11.
6. Petersen, O. H.; Wakui, M.; Petersen, C. C. H. In Aluminum in Biology and Medicine; Chadwick, D. J., Whelan, J., Eds.; Ciba Foundation Symposium 169; John Wiley and Sons Ltd.: Chichester, 1992; pp 237-253.
7. Birchall, J. D.; Exley, C.; Chappell, J. S.; Phillips, M. J. Nature 1989, 338, 146-148.
8. Laszlo, P. Science 1987, 235, 1473-1477.
9. Martin, R. B. Polyhedron 1990, 9, 193-197.
10. Farmer, V. C.; Lumsdon, D. G. Geochim. Cosmochim. Acta 1994, 58, 3331-3334.
11. Browne, B. A.; Driscoll, C. T. Science 1992, 256, 1667-1670. This high value compared with the calculated (ref 9) and other experimental (ref 10) values is likely to be due to contamination of the solution with low levels of oligomeric silicic acid, rather than differences in the ionic strengths (ref 17).
12. Iler, R. K. The Chemistry of Silica; John Wiley: New York, 1979. Glasser, L. S. D.; Lachowski, E. E. J. Chem. Soc., Dalton Trans. 1980, 393-402. Glasser, L. S. D. Chem. Bri. 1982, 36-39. Sjoberg, S. J. Noncryst. Solids 1996, 196, 51-57. Bogdanova, V. I. Eksp. Issled. Mineral. 1972-1973, 1974, 183; [Chem. Abstr. 82, 160059x].
13. Iler, R. K. The Chemistry of Silica; John Wiley: New York, 1979. Glasser, L. S. D.; Lachowski, E. E. J. Chem. Soc., Dalton Trans. 1980, 393-402. Glasser, L. S. D. Chem. Bri. 1982, 36-39. Sjoberg, S. J. Noncryst. Solids 1996, 196, 51-57. Bogdanova, V. I. Eksp. Issled. Mineral. 1972-1973, 1974, 183; [Chem. Abstr. 82, 160059x].
14. Iler, R. K. The Chemistry of Silica; John Wiley: New York, 1979. Glasser, L. S. D.; Lachowski, E. E. J. Chem. Soc., Dalton Trans. 1980, 393-402. Glasser, L. S. D. Chem. Bri. 1982, 36-39. Sjoberg, S. J. Noncryst. Solids 1996, 196, 51-57. Bogdanova, V. I. Eksp. Issled. Mineral. 1972-1973, 1974, 183; [Chem. Abstr. 82, 160059x].
15. Iler, R. K. The Chemistry of Silica; John Wiley: New York, 1979. Glasser, L. S. D.; Lachowski, E. E. J. Chem. Soc., Dalton Trans. 1980, 393-402. Glasser, L. S. D. Chem. Bri. 1982, 36-39. Sjoberg, S. J. Noncryst. Solids 1996, 196, 51-57. Bogdanova, V. I. Eksp. Issled. Mineral. 1972-1973, 1974, 183; [Chem. Abstr. 82, 160059x].
16. Iler, R. K. The Chemistry of Silica; John Wiley: New York, 1979. Glasser, L. S. D.; Lachowski, E. E. J. Chem. Soc., Dalton Trans. 1980, 393-402. Glasser, L. S. D. Chem. Bri. 1982, 36-39. Sjoberg, S. J. Noncryst. Solids 1996, 196, 51-57. Bogdanova, V. I. Eksp. Issled. Mineral. 1972-1973, 1974, 183; [Chem. Abstr. 82, 160059x].
17. Iler, R. K. The Chemistry of Silica; John Wiley: New York, 1979. Glasser, L. S. D.; Lachowski, E. E. J. Chem. Soc., Dalton Trans. 1980, 393-402. Glasser, L. S. D. Chem. Bri. 1982, 36-39. Sjoberg, S. J. Noncryst. Solids 1996, 196, 51-57. Bogdanova, V. I. Eksp. Issled. Mineral. 1972-1973, 1974, 183; [Chem. Abstr. 82, 160059x].
18. 2(OH)] with stability constants that we have now determined.
19. 2 + ...).
20. Clarke, E. T.; Martell, A. E. Inorg. Chim. Acta. 1992, 191, 57-63.
21. 4) the value is -4.7 (Stability constants of metal-ion complexes; Sillen, L. G., Martell, A. E., compilers; The Chemical Society Special Publications, no. 25 (supplement no. 1); Chemical Society: London, 1971). The Davies correction calculates these to differ by 1.93 log units and is clearly not applicable at these high ionic strengths and with the large changes in charge on complexation. This is a known problem with the equation under such conditions, and thus we feel that a mathematical correction would introduce a larger error than using stability constants with uncorrected ionic strength.
22. Alexander, G. B. J. Am. Chem. Soc. 1975, 75, 5655-5657. The molybdate method measures labile silica that is chiefly monomeric but may include dimers and perhaps linear trimers.
23. Burden, T. J.; Powell, J. J.; Taylor, P. D.; Thompson, R. P. H. JAAS. 1995, 10, 259-266.
24. As shown by competition with the DMHP:Al (1:1) complex, the oligomers that show high affinity for Al are formed within minutes of neutralization of the sodium silicate solution (42 mM), prior to its subsequent dilution (0-2.8 mM). This 42 mM oligomeric silica reaches maximum affinity for aluminum at 3 h and maintains this for 48 h, following which significant polymerization starts and affinity lessens. In parallel to this DMHP affinity assay, the molybdate assay (ref 18), allowed the oligomerization/polymerization of silica to be followed.
25. Taylor, P. D.; Hider, R. C.; Morrison, I. E. G. Talanta 1988, 35, 507.
26. Taylor, P. D. Talanta 1995, 42, 243.
27. Taylor, P. D. Chem. Commun. 1996, 405-406.
28. 3 at neutral pH, has been used to measure the Al binding capacity of physiological ligands (Powell, J. J.; Taylor, P. D.; Thompson, R. P. H. J. Inorg. Biochem. 1993, 51, 188). In a similar manner the maximum aluminum binding capacity of an oligomeric silica solution was measured in 50 mM MOPS buffer at pH 7.2. A total silica concentration of 2.61 mM, prepared from the original 42 mM solution, maintained 72.18 μM Al in solution, giving a Si:Al ratio of 36.16, compared to 34.42 ± 0.77 from the text. Aluminum and silicon concentrations were measured by ICPOES.
29. 4) with time, using the molybdic acid assay (ref 18), and this method similarly showed that, in the presence of 8 μM Al, oligomeric silica was stabilized in solution. Depolymerization was not completely inhibited, since silica was in great excess compared to Al, but the rate was dramatically reduced. Furthermore, the ratio of nonmonomeric silica atoms to Al atoms, 48 h after the dilution, was 44.35 ± 5.25 (mean ± SD of six determinations; range 36.85-48.5), compared to 34.42 ± 0.77 from the competition study.
30. A better "maximum estimate" for m was determined by the following method. Total silicon was measured by ICPOES, while monomeric silicic acid was determined chemically with the molybdic acid assay of Alexander (ref 18). Twenty-four after neutralization of the 42 mM silicate solution (i.e., immediately prior to its use in the DMHP competition studies), m = 0.927 ± 0.001 for the oligomeric preparation and 0.009 ± 0.007 for the monomeric preparation. Both values, mean ±SD of four determinations. These m values, however, are the total fraction of nonmonomeric silica in solution, and the proportion of this that is the oligomeric form with high aluminum affinity cannot be calculated.
31. Stabilization of the oligomeric silica with aluminum, was monitored for 50 days. After 17 days affinity of the oligomeric silica solution for aluminum gradually started to decrease, although, even after 50 days, significant oligomeric silica with high affinity for aluminum remained. In contrast oligomeric silica diluted in the absence of aluminum, fully deoligomerized by 24 h and lost its aluminum binding capacity.
32. Similar studies to those in the text with citrate (0-2 mM) competing for DMHP-bound-aluminum (8 μM, 1:1 ratio of DMHP:Al) confirmed that citrate is a considerably weaker competitor than oligomeric silica for aluminum at pH 7.2.
33. Ohman, L.-O. Inorg.Chem. 1988, 27, 2565-2570.
34. Ramsohoye, P.; Fritz, I. B. J. Cellular Physiol. 1995, 165(1), 145-154.
35. Fasman, G. D.; Perczel, A.; Moore, C. D. Proc. Natl. Acad. Sci. U.S.A. 1995, 92, 369-371.
36. Fasman, G. D.; Moore, C. D. Proc. Natl. Acad. Sci. U.S.A. 1994, 91, 11232-11235.
37. Parry, D. W.; Hudson, M. J.; Sangster, A. G. Phil. Trans. Roy. Soc. London. 1984, B304, 537-549.
38. Mann, S.; Perry, C. C. In Silicon Biochemistry; Evered, D., O'Connor, M., Eds.; Ciba Foundation Symposium 121; John Wiley and Sons Ltd.: Chichester, 1986; pp 51-52.
39. Harrison, C. C. Phytochemistry 1996, 41(1), 37-42.
40. Sullivan, C. W. In Silicon Biochemistry; Evered, D., O'Connor, M., Eds.; Ciba Foundation Symposium 121; John Wiley and Sons Ltd.: Chichester, 1986; pp 71-73. Dobbie, J. W.; Smith, M. J. B. In Silicon Biochemistry; Evered, D., O'Connor, M., Eds.; Ciba Foundation Symposium 121; John Wiley and Sons Ltd.: Chichester, 1986; pp 211-212.
41. Sullivan, C. W. In Silicon Biochemistry; Evered, D., O'Connor, M., Eds.; Ciba Foundation Symposium 121; John Wiley and Sons Ltd.: Chichester, 1986; pp 71-73. Dobbie, J. W.; Smith, M. J. B. In Silicon Biochemistry; Evered, D., O'Connor, M., Eds.; Ciba Foundation Symposium 121; John Wiley and Sons Ltd.: Chichester, 1986; pp 211-212.
42. Werner, D. In The Biology of Diatoms; Werner, D., Ed.; Blackwell Scientific Publications: Oxford, 1977; pp 140-141.
43. Stucky, G. D.; Monnier, A.; Schuth, F.; Huo, Q.; Margolese, D.; Kumar, D.; Krishnamurty, M.; Petroff, P.; Firouzi, A.; Janicke, M.; Chmelka, B. F. Mol. Cryst. Liq. Cryst. 1994, 240, 187-200.