Synthesis of Proteins By Chloroplasts from Iron-Deficient Euglena Gracilis
Document Type
Article
Publication Date
10-1-1982
Abstract
Chloroplasts isolated from Euglena gracilis made iron deficient by growth on 0.5 μm iron show distinct qualitative and quantitative changes in their polypeptide composition in comparison with iron-sufficient (40 μm) chloroplasts. These changes were noted in the stromal, thylakoid, and envelope subfractions. Iron-deficient chloroplasts have a sedimentation behavior similar to that of iron-sufficient chloroplasts and also contain substantial amounts of ribulose-1,5-bisphosphate carboxylase. In addition, iron-deficient chloroplasts incorporate [3H]leucine into polypeptides at rates about one-third of those from control chloroplasts (40 μm Fe) on a per-microgram-chlorophyll basis. Incorporation of [3H]leucine into specific polypeptides, resolved by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, shows relatively normal synthesis of the large subunit of ribulose-1,5-bisphosphate carboxylase and two of the three major chloroplast-derived polypeptides of the thylakoids. No incorporation was detected, however, into a polypeptide of ca. 33 kd which is synthesized by normal plastids. Iron-deficient chloroplasts also synthesize a stromal polypeptide of ca. 85 kd not seen in chloroplasts from normal cells. This evidence is consistent with a direct or indirect role for iron in the regulation of synthesis of specific proteins in the chloroplast.
DOI
10.1016/0003-9861(82)90349-6
Montclair State University Digital Commons Citation
Gaynor, John, "Synthesis of Proteins By Chloroplasts from Iron-Deficient Euglena Gracilis" (1982). Department of Biology Faculty Scholarship and Creative Works. 94.
https://digitalcommons.montclair.edu/biology-facpubs/94