Characterization of chloroplast thylakoid polypeptides in the 32-kDa region: Polypeptide extraction and protein phosphorylation affect binding of photosystem II-directed herbicides

Willem Vermaas, Katherine E. Steinback, Charles J. Arntzen

Research output: Contribution to journalArticle

22 Scopus citations


In order to distinguish between two photosystem II proteins with apparent molecular weights of about 32 kDa, mild extraction procedures were used to remove several thylakoid membrane components. A 32-kDa protein that stained intensely with Coomassie brilliant blue could be extracted from the thylakoid membranes without removing the 32-kDa herbicide receptor protein, which stained poorly with Coomassie brilliant blue. The nonextracted protein was readily detectable after in vivo polypeptide labeling with [35S]methionine or after in vitro covalent tagging with [14C]azidoatrazine. The procedures used to extract the intensely stained, 32-kDa polypeptide resulted in changes in herbicide-binding characteristics, presumably due to conformational changes in the herbicide-binding environment. Alterations of membrane surface charge by protein phosphorylation also influenced herbicide binding.

Original languageEnglish (US)
Pages (from-to)226-232
Number of pages7
JournalArchives of Biochemistry and Biophysics
Issue number1
Publication statusPublished - May 15 1984
Externally publishedYes

Cite this