title: Production and secretion of Leishmania braziliensis proteins.
abstract: The kinetics of secretion of proteins by Leishmania braziliensis was followed by incorporation of [3H]leucine into macromolecules produced by the cells which are released into the growth medium. About 10% of the total protein synthesized by actively growing cells is secreted. Cycloheximide (100 microgram/ml) and puromycin (0.5 mM) inhibited the incorporation of labelled leucine by 85 and 99%, respectively. The secreted proteins do not seem to result from cell lysis since, first, the kinetics of production are linear and, secondly, less than 1% of thymidine or uridine incorporated by the cells is found in the medium. Cells grown with [3H]leucine and then transferred to fresh medium show two phases of secretion. During the first six hours, it is slow and reaches a plateau. The release increases about ten-fold during the next six hours. An analysis of the secreted material showed that following precipitation with methanol and sodium acetate, three isotopically labelled peaks were eluted from Sephadex G-120-150. The first of these, containing 50% of the radioactivity, did not react with anti-leishmanial serum, while the last two did. Since the last two fractions could be labelled with [3H]glucosamine as well as [3H]leucine it is suggested that they are glycoprotein in nature and are similar to the products released by other species of Leishmania.
mesh_terms: D000818:Animals; D003513:Cycloheximide / Q000494:pharmacology; D006023:Glycoproteins / Q000378:metabolism*; D007700:Kinetics; D007891:Leishmania / Q000254:growth & development / Q000378:metabolism*; D011506:Proteins / Q000378:metabolism*; D011691:Puromycin / Q000494:pharmacology
chemical_list: D006023:Glycoproteins; D011506:Proteins; D011691:Puromycin; D003513:Cycloheximide