Open AccessActivity of ribulose‐1,5‐bisphosphate carboxylase in intact and disrupted carboxysomes of Thiobacillus neapolitanus
Author(s) -
Holthuijzen Yolande A.,
Kuenen J.Gijs,
Konings Wil N.
Publication year - 1987
Publication title -
fems microbiology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.899
H-Index - 151
eISSN - 1574-6968
pISSN - 0378-1097
DOI - 10.1111/j.1574-6968.1987.tb02057.x
Subject(s) - pyruvate carboxylase , ribulose 1,5 bisphosphate , rubisco , biochemistry , thiobacillus , enzyme , protein subunit , biology , ribulose , chemistry , bacteria , genetics , gene
Abstract 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 CO 2 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.