Hexosamine Metabolism, Sialic Acids, and the Phosphotransferase System: Saul Roseman's Contributions to Glycobiology
Year: 2006
Type: article
Abstract: The Sialic Acids. I. The Structure and Enzymatic Synthesis of N-Acetylneuraminic Acid (Comb, D. G., and Roseman, S. (1960) J. Biol. Chem. 235, 2529–2537) Sugar Transport. I. Isolation of a Phosphotransferase System from Escherichia coli (Kundig, W., and Roseman, S. (1971) J. Biol. Chem. 246, 1393–1406) Saul Roseman was born in Brooklyn, New York, in 1921. He received his Bachelor of Science in Chemistry from the City College of New York in 1941 and began his graduate studies in the Biochemistry Department at the University of Wisconsin, earning his masters degree in 1944. He then served for 2 years as an infantryman in Europe in World War II. Upon his return, he completed his Ph.D. in 1947, studying biochemistry with Karl Paul Link and organic chemistry with Homer Atkins. Roseman's graduate work focused on the synthesis and metabolism of coumarin derivatives (e.g. Dicumarol), which Link had discovered and which was the subject of a previous Journal of Biological Chemistry (JBC) Classic (1JBC Classics Campbell H.A. Link K.P. J. Biol. Chem. 1941; 138: 21-33Abstract Full Text PDF Google ScholarStahmann M.A. Huebner C.F. Link K.P. J. Biol. Chem. 1941; 138: 513-527Abstract Full Text PDF Google ScholarOverman R.S. Stahmann M.A. Huebner C.F. Sullivan W.R. Spero L. Doherty D.G. Ikawa M. Graf L. Roseman S. Link K.P. J. Biol. Chem. 1944; 153: 5-24http://www.jbc.org/cgi/content/full/280/8/e5Abstract Full Text PDF Google Scholar). It was during his graduate studies that Roseman's life-long interest in carbohydrates began, when he started working on the metabolism of 4-hydroxycoumarin, which is secreted into the urine of dogs as the glucuronide or glucuronic acid derivative. A growing interest in complex carbohydrates led Roseman to do his postdoctoral studies with Albert Dorfman at the University of Chicago School of Medicine, who was also featured in a previous JBC Classic (2JBC Classics Roseman S. Moses F.E. Ludowieg J. Dorfman A. J. Biol. Chem. 1953; 203: 213-225http://www.jbc.org/cgi/content/full/280/31/e28Abstract Full Text PDF PubMed Google Scholar). With Dorfman, Roseman developed new methods of glycan radioisotopic labeling to study hyaluronic acid and chondroitin sulfate biosynthesis and showed that the carbon chain of glucose was converted in vivo directly, with no cleavage, to that of glucosamine. He remained at Chicago until 1953 and was promoted to Assistant Professor. Roseman then became Assistant Professor of Biological Chemistry at the University of Michigan Medical School and Chemist of the Rackham Arthritis Research Unit. In the next few years, he rose in academic rank to Professor. While at Michigan, Roseman started to work with enzymes and cell-free extracts, which took him to glucosamine metabolism, which, in turn, led to the sialic acids. His work on the identification of the structure and metabolism of sialic acids is the subject of the first JBC Classic reprinted here. In the Classic, Roseman and one of his first postdoctoral fellows, Donald G. Comb (founder and President of New England Biolabs), report on their studies on the structure of one sialic acid in particular, N-acetylneuraminic acid, and the properties of the bacterial enzyme, N-acetylneuraminic acid aldolase, that cleaves the sialic acid into N-acetyl-d-mannosamine (which was not previously known to occur naturally) and pyruvate. Using N-acetylneuraminic acid purified from both human blood and Escherichia coli and N-acetylneuraminic acid aldolase from Clostridium perfringens, Roseman and Comb established the products of the cleavage reaction, showed that it was reversible (yielding NAN), and characterized the enzyme. They also used 1-[14C]- and 6-[14C]glucose to follow the biosynthesis of N-acetylneuraminic acid and concluded that it is the product of a 3-carbon and 6-carbon condensation. At that time, and over a period of 3 decades, over 11 possible structures had been suggested for N-acetylneuraminic acid. Roseman and Comb's work was critical in establishing the correct structure. Subsequently, Roseman and Comb isolated, characterized, and enzymatically synthesized a unique sugar nucleotide, CMP-sialic acid. This led to a series of novel studies on glycosyltransferases. Roseman and colleagues showed that families of glycosyltransferases existed, in which each family transferred a specific sugar, and that each member of the family had specific requirements for the acceptor and/or the linkage of the newly synthesized glycosidic bond. The sum of these studies was to establish the individual steps in the metabolic pathways between fructose-6-P and complex carbohydrates such as the gangliosides (with Basu), the oligosaccharide chains in the mucins (with Schachter), and the carbohydrate termini in the blood glycoproteins (with Jourdian, Carlson, and others). In 1965 Roseman was recruited to the McCollum-Pratt Institute and Department of Biology at the Johns Hopkins University, where he later served as Director and Chairman for two terms (1969–1973 and 1988–1990). Just before leaving Michigan for Baltimore, Roseman, while working on N-acetylmannosamine metabolism, discovered what turned out to be a novel sugar transport system in bacteria, the PTS (phosphotransferase system). The system involves a series of sequential phosphotransfer reactions between proteins and simultaneously phosphorylates and translocates its sugar substrates across the membrane. Surprisingly, the source of the phosphoryl group is not ATP or another nucleoside triphosphate but rather phosphoenolpyruvate. Roseman's isolation of a PTS from E. coli is the subject of the second JBC Classic reprinted here. In the paper, Roseman and Werner Kundig purify the two enzymes (Enzyme I and II) and one protein (HPr) that comprise the system and determine that Enzyme I and HPr are soluble while Enzyme II is part of the cell membrane. Using 32P and 14C to assay the activity of the enzymes, they conclude that Enzyme I catalyzes the transfer of phosphate from phosphoenolpyruvate to HPr and Enzyme II catalyzes the transfer of phosphate from phospho-HPr to the carbohydrate. The phosphate is linked to HPr via an imidazole nitrogen atom on a histidine residue. In two subsequent JBC papers (3Kundig W. Roseman S. Sugar transport. II. Characterization of constitutive membrane-bound Enzymes II of the Escherichia coli phosphotransferase system..J. Biol. Chem. 1971; 246: 1407-1418Abstract Full Text PDF PubMed Google Scholar, 4Anderson B. Weigel N. Kundig W. Roseman S. Sugar transport. III. Purification and properties of a phosphocarrier protein (HPr) of the phosphoenolpyruvate-dependent phosphotransferase system of Escherichia coli..J. Biol. Chem. 1971; 246: 7023-7033Abstract Full Text PDF PubMed Google Scholar), Roseman and Kundig further characterized the enzymes that constitute the PTS, and somewhat later, with Simoni, established that it was, in fact, a sugar transport system, not just a novel kinase. Still at Johns Hopkins, Roseman retains his position of Professor in the Department of Biology. His laboratory continues to make key contributions to the molecular understanding of complex carbohydrate glycosyltransferases, bacterial sugar transport, and intercellular adhesion. Most recently, he has made novel forays into the complex metabolism of chitin, the second most abundant organic compound in nature. More information about the history of glycobiology can be found in Roseman's JBC Reflections (5Roseman S. Reflections on glycobiology..J. Biol. Chem. 2001; 276: 41527-41542Abstract Full Text Full Text PDF PubMed Scopus (229) Google Scholar). In recognition of his contributions to glycobiology, Roseman has been the recipient of many national and international awards and honors, among which was his election, in 1972, to the National Academy of Sciences, and the degree of Doctor of Medicine Honoris causa from the University of Lund. He has also received the Sesquicentennial award from the University of Michigan (1967), the T. Duckett Jones Memorial award from the Helen Hay Whitney Foundation (1973), the Rosenstiehl award from Brandeis University (1974), the International award from the Gairdner Foundation (1981), and the Karl Meyer award from the Society of Glycobiology (1993). Roseman is also a former member of the JBC editorial board and has published 136 papers in the journal over a 60-year period.
Source: Journal of Biological Chemistry
Language: English
Subfield: Molecular Biology
Domain: Life Sciences
Open Access status: hybrid
Estimated APC paid: $3,430
OpenAlex ID: W1536732053