The ability of simple oligopeptide complexes of nickel (II) to
react with various dioxygen intermediates was investigated. Under
physiological conditions, nickel (II)-histidine-containing
oligopeptides were found to dismutate superoxide anions and
disproportionate hydrogen peroxide. In the latter process,
chemiluminescence was generated and a strongly oxidizing intermediate
was detected capable of oxidizing uric acid, hydroxylating p-nitrophenol,
and damaging 2-deoxy-D-ribose. The generation of this
reactive intermediate likely occurs without the involvement of free
hydroxyl radicals derived from Haber-Weiss or Fenton-type reactions.
In addition, the Ni(II) complex of glycylglycyl-L-histidine (GGH) was
found to react with mollecular oxygen resulting in the oxidation of the
ligand. An attempt was made to relate these reactions to the
involvement: of the nickel(III)/(II) redox couple which was shown to
exist under physiological conditions. Similar reactivity was observed
for non-histidine-containing oligopeptides but higher pH values were
required.
The oligopeptides used not only represent biologically relevant
ligands but: the histidine containing oligopeptides mimics the specific
copper(II)/nickel(II) binding and transport site of human serum
albumin. The observations made in this study suggest some novel
mechanism for the deleterious effects associated with excessive lifelong
exposure to nickel compounds, especially in relation to cancer of
the respiratory tract. / Thesis / Master of Science (MS)
| Identifer | oai:union.ndltd.org:mcmaster.ca/oai:macsphere.mcmaster.ca:11375/24206 |
| Date | 04 1900 |
| Creators | Tom, Rickey T. |
| Contributors | Nieboer, Evert, Biochemistry |
| Source Sets | McMaster University |
| Language | English |
| Detected Language | English |
| Type | Thesis |
Page generated in 0.0029 seconds