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Oxygen Bonding to Haemoglobin. 17O NMR Spectrum A Second Look

G. Pifat ; »Ruder Boskovic« Institute, Zagreb, Yugoslavia
S. Maričić ; Institute of Biology, University of Zagreb
M. Petrinović ; »Ruder Boskovic« Institute, Zagreb, Yugoslavia
V. Kramer ; »Jozef Stefan« Institute, Ljubljana, Yugoslavia
J. Marsel ; »Jozef Stefan« Institute, Ljubljana, Yugoslavia
K. Bonhard ; Wissenschaftliche Abteilung, Biotest-Serum-Institut GmbH, Frankfurt, B. R. Deutschland

Sažetak

It was found that the upper concentration limit in detecting
the oxygen-17 NMR signal from ordinary solvent water in solutions
of oxyhaemoglobin is about 12 · 10-3 M (in haem). From samples
of oxyhaemoglobin prepared with oxygen gas enriched to 62° /o in
170 a signal could be detected within a few days in spite of
higher protein concentrations. Such signals increased in couple of
weeks up to three times. However, within this period of time the
sealed, dissolved oxyhaemoglobin became deoxygenated showing
the characteristic colour change, while the NMR 170 signal persisted.
The pressure above such sealed solutions diminished and
the mass-spectroscopic analyses showed two- to threefold enrichment
in 170 of solvent water after the deoxy-conversion, while
in the gas phase oxygen ¥,Tas replaced by carbon dioxide. There
is no deoxy-conversion in samples prepared under sterile conditions
or in presence of sodium azide (equimolar with haem).
It is concluded that owing to bacterial contamination in haemoglobin
solutions prepared under ordinary conditions oxygen from
the gas-phase is being reduced into water through bacterial metabolism.
Thus, the observed 170 NMR signals were due to the
solvent water enriched in 170. A former paper* claiming detection
of 170 NMR signal from oxygen bound to haemoglobin is thus
invalidated.

Ključne riječi

Hrčak ID:

207937

URI

https://hrcak.srce.hr/207937

Datum izdavanja:

1.2.1970.

Posjeta: 409 *