English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

In the present paper we demonstrate that the conformational state of the Afunctional enzyme ribulose-1,5-bisphosphate carboxylase oxygenase is different in the tobacco mulanl Susu when compared to the wild type tobacco or spinach. The conformational state of the tobacco mu- tant enzyme is characterized by the presence of a higher number of antigenic determinants ac- cessible to antibody binding. This seems to be correlated to a higher oxygenase activity in the mutant. The Afunctional enzyme ribulose-1,5-bisphosphate carboxylase oxygenase of the wild type tobacco Nicotiana tabacum var. John William’s Broadleaf, of the tobacco mutant Su.su and of spinach (Spinacia oleracea) was characterized by comparative immunological methods. Although the enzyme of the tobacco mutant appears identical to the enzyme of the wild type, when analyzed in immunodiffusion tests and immuno electrophoretical analyses, it exhibits a higher oxygenase activity. On the other hand the spinach enzyme exhibits only par- tial serological identity to the two tobacco enzymes. For the comparative studies pure IgG-fractions were prepared from the respective antisera. RuBP-carboxylasc oxygenase was used as a 70% purified enzyme preparation. Determination of the antibody binding capacity showed that the enzymes bind from the homologous antisera the highest amount of antibodies, which means that the antisera reflect the complementary picture of the enzyme structure. The enzyme molecules of N. tabacum var. JWB and of spinach bind 9 antibody molecules each. I lowevcr, the binding capacity of the tobacco mutant enzyme exhibiting the higher oxygenase activity is 30% higher. Measurement of the oxygenase function under the influence of the homologous as well as of the non-homologous antisera has led to the result that the oxygenase activity of all enzymes is inhibited. However, it is the degree of inhibition which differs. The antiserum to the mutant enzyme causes with the spinach as well as with the JWB-enzyme a higher degree of inhibition than that produced by the homologous antiserum. Therefore, a correlation between inhibitory effect brought about by this antiserum and the amount of antibodies bound does not exist. Whereas the enzyme of the tobacco wild type binds 20% less antibodies out of this antiserum its oxygenase activity is 60% more inhibited and the function of the spinach enzyme is 20% stronger inhibited although binding of antibodies from the antiserum to the tobacco enzyme is 50% lower. These observations permit the conclusion that the antiserum towards the mutant enzyme contains more antibodies with a higher binding affinity towards reactive regions of the oxy- genase function. This in turn means that the structure of this enzyme or its conformation must be different in comparison to the wild type enzyme.

Effect of Antisera to RuBP-Carboxylase/Oxygenase of TV. tabacum and Spinacia oleracea on the Oxygenase-Function of the Enzyme