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 (10) Citing Articles via Google Scholar Google Scholar Articles by Marsh, J. J. Articles by Lebherz, H. G. Search for Related Content PubMed PubMed Citation Articles by Marsh, J. J. Articles by Lebherz, H. G. Agricola Articles by Marsh, J. J. Articles by Lebherz, H. G.

Metabolism and Enzymology

Structural Similarities between Spinach Chloroplast and Cytosolic Class I Fructose 1,6-Bisphosphate Aldolases ¹

Immunochemical and Amino-Terminal Amino Acid Sequence Analysis

Department of Chemistry, San Diego State University, San Diego, California 92182, Applied Biosystems Inc., 850 Lincoln Center Drive, Foster City, California 94404

Immunochemical studies using polyclonal antisera prepared individually against highly purified cytosolic and chloroplast spinach leaf (Spinacia oleracea) fructose bisphosphate aldolases showed significant cross reaction between both forms of spinach aldolase and their heterologous antisera. The individual cross reactions were estimated to be approximately 50% in both cases under conditions of antibody saturation using a highly sensitive enzyme-linked immunosorbent assay. In contrast, the class I procaryotic aldolase from Mycobacterium smegmatis and the class II aldolase from yeast (Saccharomyces cerevisiae) did not cross-react with either type of antiserum. The 29 residue long amino-terminal amino acid sequences of the procaryotic M. smegmatis and the spinach chloroplast aldolases were determined. Comparisons of these sequences with those of other aldolases showed that the amino-terminal primary structure of the chloroplast aldolase is much more similar to the amino-terminal structures of class I cytosolic eucaryotic aldolases than it is to the corresponding region of the M. smegmatis enzyme, especially in that region which forms the first "beta sheet" in the secondary structure of the eucaryotic aldolases. Moreover, results of a systematic comparison of the amino acid compositions of a number of diverse eucaryotic and procaryotic fructose bisphosphate aldolases further suggest that the chloroplast aldolase belongs to the eucaryotic rather than the procaryotic "family" of class I aldolases.