The activity and intracellular partition of carbonic anhydrase (CA) were studied in alkalophilic cyanobacteria, an inhabitant of soda lakes at pH 9–10. In the homogenates of Rhabdoderma lineare, Rhabdoderma sp., and Microcoleus chthonoplastes, high activity of CA was found, similar to that in eukaryotic microalgae. The activity of CA calculated on the basis of chlorophyll and protein was higher for the soluble (sCA) than for membrane (mCA) protein fraction. Intact cells of all cyanobacteria under investigation also showed CA activity that implies the presence of extracellular form(s). The extracellular CA in benthic M. chthonoplastes was localized, at least partly, in a vast glycocalix (gCA) as shown by Western blotting and the measurement of enzyme activity in the isolated glycocalix preparations. Probing gCA from M. chthonoplastes with the antibodies against thylakoid CA from Chlamydomonas reinhardtii (Cah3) demonstrated that gCA belongs to the α-type of enzyme and has the structure identical to that of Cah3. The extracellular CA of M. chthonoplastes manifested the maximum activity at pH 7 and 10, but not at pH 6 and 9. An increase in medium pH from 7.2 to 9.6 resulted only in slight alkalization of the cytoplasm in R. lineare, from 7.1 to 7.5. It follows that true alkalophils can maintain the pH inside the cell at the near-neutral level in spite of high pH (10.2) level in the cultural medium.
Russian Journal of Plant Physiology – Springer Journals
Published: Oct 11, 2004
It’s your single place to instantly
discover and read the research
that matters to you.
Enjoy affordable access to
over 18 million articles from more than
15,000 peer-reviewed journals.
All for just $49/month
Query the DeepDyve database, plus search all of PubMed and Google Scholar seamlessly
Save any article or search result from DeepDyve, PubMed, and Google Scholar... all in one place.
Get unlimited, online access to over 18 million full-text articles from more than 15,000 scientific journals.
Read from thousands of the leading scholarly journals from SpringerNature, Elsevier, Wiley-Blackwell, Oxford University Press and more.
All the latest content is available, no embargo periods.
“Hi guys, I cannot tell you how much I love this resource. Incredible. I really believe you've hit the nail on the head with this site in regards to solving the research-purchase issue.”Daniel C.
“Whoa! It’s like Spotify but for academic articles.”@Phil_Robichaud
“I must say, @deepdyve is a fabulous solution to the independent researcher's problem of #access to #information.”@deepthiw
“My last article couldn't be possible without the platform @deepdyve that makes journal papers cheaper.”@JoseServera