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 Web of Science 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 Web of Science (5) Citing Articles via Google Scholar Google Scholar Articles by Stephenson, M. Articles by Thompson, G. A. Search for Related Content PubMed PubMed Citation Articles by Stephenson, M. Articles by Thompson, G. A., Jr. Agricola Articles by Stephenson, M. Articles by Thompson, G. A.

Metabolism and Enzymology

Fatty Acid Acylated Proteins of the Halotolerant Alga Dunaliella salina¹

Department of Botany, The University of Texas, Austin, Texas 78713

The unicellular, wall-less alga Dunaliella salina has been shown to contain an array of proteins modified by the covalent attachment of fatty acids. Myristic acid (14:0) comprised approximately 80% by weight of the protein-linked acyl groups in samples derived from cells cultured in medium containing 1.7 molar NaCl and 93% in samples from cells grown in medium containing 3.0 molar NaCl. Palmitic and stearic acids accounted for most of the remaining protein-bound acyl chains. Approximately 0.2% of the incorporated radioactivity was estimated to be in linkage with protein. The bulk of acyl chains (about 99%) were resistant to cleavage by alkali, indicating a preponderance of amide bonding. The sodium dodecyl sulfate-polyacrylamide electrophoresis labeling pattern of proteins from [³H]myristic-labeled cells was significantly different from that of proteins from cells exposed to [³H]palmitate. The appearance of radioactivity in certain proteins was also influenced by the salinity of the culture medium. Thus growth in moderate (1.7 molar) salt favored the acylation of a 48-kilodalton polypeptide whereas in high (3.0 molar) salt, a 17-kilodalton polypeptide was more heavily labeled.