Abstract
Working with sciatic nerves from the South American frog Calyptocephalella gayi we have been able to substantiate the finding of Ungar et al., that nerve proteins undergo a reversible denaturation concomitant with a train of nerve impulses. We also showed that 0.3 mM sodium azide is capable of impairing the reversibility of those changes. Furthermore, 10 meq/liter of calcium ion applied to extracts of resting nerves induce configurational rearrangements in the proteins similar to those produced during stimulation. We also proved that nerves previously kept in low calcium Ringer's solution do not show configurational changes upon stimulation. A tentative interpretation of the results described is that the configurational changes are a consequence of the extra influx of calcium ion due to nerve impulse propagation.
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Selected References
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- Crammer J. L., Neuberger A. The state of tyrosine in egg albumin and in insulin as determined by spectrophotometric titration. Biochem J. 1943 Jul;37(2):302–310. doi: 10.1042/bj0370302. [DOI] [PMC free article] [PubMed] [Google Scholar]
- GEIGER A., DOBKIN J., MAGNES J. Accumulation of acid-soluble nitrogen in the brain cortex of cats during stimulation. Science. 1953 Nov 27;118(3074):655–657. doi: 10.1126/science.118.3074.655. [DOI] [PubMed] [Google Scholar]
- HURLBUT W. P. Effects of azide and choretone on the sodium and potassium contents and the respiration of frog sciatic nerves. J Gen Physiol. 1958 May 20;41(5):959–988. doi: 10.1085/jgp.41.5.959. [DOI] [PMC free article] [PubMed] [Google Scholar]
- LING G. N. The interpretation of selective ionic permeability and cellular potentials in terms of the fixed charge induction hypothesis. J Gen Physiol. 1960 May;43:149–174. doi: 10.1085/jgp.43.5.149. [DOI] [PMC free article] [PubMed] [Google Scholar]
- LUXORO M. Incorporation of amino-acids labelled with carbon-14 in nerve proteins during activity and recovery. Nature. 1960 Dec 24;188:1119–1120. doi: 10.1038/1881119a0. [DOI] [PubMed] [Google Scholar]
- MULLINS L. J. Substrate utilization by stimulated nerve. Am J Physiol. 1953 Dec;175(3):358–362. doi: 10.1152/ajplegacy.1953.175.3.358. [DOI] [PubMed] [Google Scholar]