This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via CrossRef Citing Articles via Google Scholar Google Scholar Articles by Thompson, M. P. Articles by Farrell, H. M. Search for Related Content PubMed PubMed Citation Articles by Thompson, M. P. Articles by Farrell, H. M., Jr. Agricola Articles by Thompson, M. P. Articles by Farrell, H. M.

Metabolism and Enzymology

Purification and Characterization of Calmodulins from Papaver somniferum and Euphorbia lathyris

Eastern Regional Research Center, 600 East Mermaid Lane, Philadelphia, Pennsylvania 19118

Calmodulins (CaM) were isolated and characterized from two well-known latex producing plants, Papaver somniferum and Euphorbia lathyris. The molecular weights of both were determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis to be 17,000 comparable to that of bovine brain CaM. Amino acid compositions also compared similarly with those of known CaMs, with regard to the presence of trimethyllysine and the ratio of phenylalanine to tyrosine. The Cornish-Bowden equation (Sn) revealed strong statistical correlations of P. somniferum and E. lathyris CaM with those of other plants and animals, although their amino acid compositions were not identical. Both plant CaM stimulated CaM dependent cAMP phosphodiesterase: for Papaver somniferum the K_a was found to be 1.09 nanomolar and for Euphorbia lathyris, 2.01 nanomolar.