ISSN:
1574-6968
Source:
Blackwell Publishing Journal Backfiles 1879-2005
Topics:
Biology
Notes:
Carboxysomes isolated from Thiobacillus neapolitanus remained intact in buffers of low osmolarity during the first 30 s sonication. The ribulose-1,5-bisphosphate carboxylase activity of these (intact) carboxysomes was 2.1–2.4 μmoles CO2 fixed/min (mg protein). In these intact carboxysomes ribulose-1,5-bisphosphate carboxylase did not interact with antibodies against the large subunit, indicating that this subunit is not exposed to the outer surfaces. Sonication of the carboxysomes for periods exceeding 30 s caused gradual disruption of the carboxysomes, a decrease of the enzyme activity and a release of ribulose-1,5-bisphosphate carboxylase. In preparations containing about 50% disrupted carboxysomes the enzyme activity was decreased by 93%. This large decrease of enzyme activity is most likely caused by a dissociation of the subunits of ribulose-1,5-bisphosphate carboxylase in the carboxysomes.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1111/j.1574-6968.1987.tb02057.x
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