The incorporation of microinjected <sup>14</sup>C‐amino acids into TCA insoluble fractions of the giant axon of the squid

Journal of Cellular PhysiologyPublished 1 August 1967

Siegmund Fischer, S. Litvak

DOI10.1002/jcp.1040700110

Source URL

Citations50

SJR quartileQ1

SJR score1.38

SNIP1.09

TL;DR

Giant squid axons were microinjected with serine, valine and leucine‐C14 under controlled electrophysiological conditions and these amino acids were incorporated into TCA insoluble fraction in the isolated axon.

Abstract

Abstract Giant squid axons were microinjected with serine, valine and leucine‐C 14 under controlled electrophysiological conditions. These amino acids are incorporated into TCA insoluble fraction in the isolated axon. This incorporation is higher in the stimulated axons as compared to non‐stimulated ones. By processing separately the axoplasm and axon sheath, it was found that the last one is responsible almost entirely for the observed incorporation. Through differential centrifugation of homogenates of microinjected axons was shown that the highest incorporation occurred in the 1500 × g sediment, which probably corresponds to membranes. The incorporation of amino acids in stimulated axons, is strongly inhibited by chloramphenicol and actinomycin D.

Keywords

NeuroscienceBiochemistry, Genetics and Molecular Biology

Biochemical and Biophysical Research CommunicationsA convenient, rapid and sensitive method for measuring the incorporation of radioactive amino acids into protein

330 Citations1960Rusty J. Mans, G. David Novelli

The assay technique combines features of the filter-paper assay, efficient washing and extraction procedure, and a filter- paper counting procedure to permit the handling of 50 to 100 samples simultaneously with the same counting efficiency as the conventional method.

ScienceDelayed Appearance of Labeled Protein in Isolated Nerve Endings and Axoplasmic Flow

65 Citations1964Samuel H. Barondes

Subcellular fractions of mouse brain were prepared by differential and sucrose density-gradient centrifugation at intervals up to 130 hours after intracerebral injection of C14- labeled leucine and data are interpreted as being consistent with the appearance of protein in nerve endings by axoplasmic flow.

NatureMicro-injection of Trypsin into Axons of Squid

62 Citations1963Emilio Rojas, Mario Luxoro

Attempts to demonstrate that protease had entered squid axons without producing changes in electrophysiological properties may have been in error even though the controls at the time seemed appropriate.

ScienceIntracellular Perfusion of Chilean Giant Squid Axons

22 Citations1964Ichiji Tasaki, Mario Luxoro

Axons of the Chilean giant squid were subjected to continuous intracellular perfusion with either potassium- or sodium-rich salt solutions, and action potentials were observed which exceeded the value calculated from the Nernst equation applied to sodium-ion activity.

NatureIncorporation of Amino-Acids labelled with Carbon-14 in Nerve Proteins during Activity and Recovery

10 Citations1960Mario Luxoro

Evidence is presented in support of suggestions that a small fraction of the nerve proteins may split, probably to the level of amino-acids, during nerve activity, and that this process should be fully reversible, appearing as an increased turnover of proteins during impulse conduction or shortly afterwards.