H-NMR signal of Arenicola marina myoglobin in vivo as an index of tissue oxygenation.
Key questions on how intertidal animals adapt to hypoxic stress center on the high energy phosphate response to decreasing oxygenation. With recent 1H/31P-NMR techniques to monitor mammalian tissue metabolism, a novel approach has emerged to observe potentially the intracellular oxygen interaction in invertebrates. The present study indicates that Arenicola marina, a standard model for intertidal animals, exhibits a distinct set of Mb 1H-NMR signals in vivo, corresponding to the two isolated Mb isoforms. Specifically both deoxy-Mb I and deoxy-Mb II exhibit paramagnetically shifted signals at 93.4 ppm and 92.5 ppm at 25 degrees C, respectively, which arise from the proximal histidyl NdeltaH. These signals reflect the cellular oxygenation state and indicate clearly that the phosphotaurocyamine level begins to drop at the onset of anoxia and declines gradually to 50% of control after 3.5 h. 1H Mb spectra indicate protein heterogeneity originating from heme as well as structural disorder.
Kreutzer
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Zoophysiologie, Heinrich-Heine-Universität, Düsseldorf, Germany.
Jue
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D000818:Animals; D004591:Electrophoresis, Polyacrylamide Gel; D007525:Isoelectric Focusing; D009682:Magnetic Resonance Spectroscopy; D009211:Myoglobin / Q000737:chemistry*; D010100:Oxygen / Q000378:metabolism*; D011522:Protons; D012616:Sea Cucumbers / Q000378:metabolism*
D009211:Myoglobin; D011522:Protons; D010100:Oxygen