Ca2+-activated protease activity in frog sciatic nerve : Characterization and effect on rapidly transported axonal proteins
(1985) In Brain Research 327(1-2). p.29-36- Abstract
Protease activity was studied in the frog sciatic nerve. The activity was measured as the release of TCA-soluble radioactivity from either 3H-labelled proteins transported by rapid axonal transport (AXT) or 3H-labelled ganglionic proteins. In nerve homogenates containing transported substrates, protease activity exhibited two peaks, one around pH 5 and one around pH 8. Ca2+ at 100 μM or higher concentrations only stimulated the latter, which was inhibited by 1 mM parachloromercuric benzoate, a sulphydryl reagent, but unaffected by ATP (1 mM). The proteolytic activity was recovered in the 105 g supernatant of the homogenate. In desheathed nerves containing 3H-labelled transported... (More)
Protease activity was studied in the frog sciatic nerve. The activity was measured as the release of TCA-soluble radioactivity from either 3H-labelled proteins transported by rapid axonal transport (AXT) or 3H-labelled ganglionic proteins. In nerve homogenates containing transported substrates, protease activity exhibited two peaks, one around pH 5 and one around pH 8. Ca2+ at 100 μM or higher concentrations only stimulated the latter, which was inhibited by 1 mM parachloromercuric benzoate, a sulphydryl reagent, but unaffected by ATP (1 mM). The proteolytic activity was recovered in the 105 g supernatant of the homogenate. In desheathed nerves containing 3H-labelled transported proteins, the protease activity could be activated by exposing the nerve to a Ca2+-ionophore, X-537 A, or to an elevated Ca2+-concentration (50 mM). These conditions were also shown to increase the influx and efflux of 45Ca2+ in the nerves. The results indicate the presence within axons of a Ca2+-activated soluble protease, which degrades rapidly transported proteins. The finding that the protease degraded ganglionic soluble proteins to about the same extent suggests a broad substrate specificity. The present system should be useful for further characterization of protease activity during various physiological conditions.
(Less)
- author
- Kanje, Martin LU ; Lazarewicz, Jerzy ; Ekström, Per LU and Edström, Anders LU
- organization
- publishing date
- 1985-02-18
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- axonal transport, Ca, protease activity
- in
- Brain Research
- volume
- 327
- issue
- 1-2
- pages
- 8 pages
- publisher
- Elsevier
- external identifiers
-
- scopus:0021894523
- pmid:2985175
- ISSN
- 0006-8993
- DOI
- 10.1016/0006-8993(85)91495-7
- language
- English
- LU publication?
- yes
- id
- d2c1f272-f2d5-49b7-923f-ccf50ee24954
- date added to LUP
- 2016-12-07 14:26:54
- date last changed
- 2024-01-04 18:17:51
@article{d2c1f272-f2d5-49b7-923f-ccf50ee24954,
abstract = {{<p>Protease activity was studied in the frog sciatic nerve. The activity was measured as the release of TCA-soluble radioactivity from either <sup>3</sup>H-labelled proteins transported by rapid axonal transport (AXT) or <sup>3</sup>H-labelled ganglionic proteins. In nerve homogenates containing transported substrates, protease activity exhibited two peaks, one around pH 5 and one around pH 8. Ca<sup>2+</sup> at 100 μM or higher concentrations only stimulated the latter, which was inhibited by 1 mM parachloromercuric benzoate, a sulphydryl reagent, but unaffected by ATP (1 mM). The proteolytic activity was recovered in the 10<sup>5</sup> g supernatant of the homogenate. In desheathed nerves containing <sup>3</sup>H-labelled transported proteins, the protease activity could be activated by exposing the nerve to a Ca<sup>2+</sup>-ionophore, X-537 A, or to an elevated Ca<sup>2+</sup>-concentration (50 mM). These conditions were also shown to increase the influx and efflux of <sup>45</sup>Ca<sup>2+</sup> in the nerves. The results indicate the presence within axons of a Ca<sup>2+</sup>-activated soluble protease, which degrades rapidly transported proteins. The finding that the protease degraded ganglionic soluble proteins to about the same extent suggests a broad substrate specificity. The present system should be useful for further characterization of protease activity during various physiological conditions.</p>}},
author = {{Kanje, Martin and Lazarewicz, Jerzy and Ekström, Per and Edström, Anders}},
issn = {{0006-8993}},
keywords = {{axonal transport; Ca; protease activity}},
language = {{eng}},
month = {{02}},
number = {{1-2}},
pages = {{29--36}},
publisher = {{Elsevier}},
series = {{Brain Research}},
title = {{Ca2+-activated protease activity in frog sciatic nerve : Characterization and effect on rapidly transported axonal proteins}},
url = {{http://dx.doi.org/10.1016/0006-8993(85)91495-7}},
doi = {{10.1016/0006-8993(85)91495-7}},
volume = {{327}},
year = {{1985}},
}