Jack Preiss
University Distinguished Professor
- B.S. 1953,City College of New York
- Ph.D. 1957,Duke University.
- Postdoctoral Fellow,1956-58,Duke Univ.
- Postdoctoral Fellow,1958-59, Washington Univ., St. Louis
- Postdoctoral Fellow,1959-60, Stanford School of Medicine
- Scientist,1960-62,National Institutes of Health.
- Faculty Member,1962-84, Univ of Calif. - Davis.
- Guggenheim Memorial Fellowship,1969-70.
- Charles Pfizer Award,1971,American Chemical Society.
- Alexander Von Humboldt Senior U.S. Scientist Award,1984.
- Chair, MSU Biochemistry,1985-89.
- Alsberg-Schoch Memorial,1990,American Assoc. of Cereal Chemists.
- Japanese Society of Starch Science Merit Award,1992.
- Distinguished Faculty Award,1994,MSU.
- Distinguished Faculty Award,1996,CNS Alumni Assoc.
- Distinguished Faculty Award,1997, Mich. Assoc. of Governing Boards.
- Loomis Lecturer,1998,Iowa State University.
- University Distinguished Professor,2001, MSU.
- Highly Cited Researcher,January 2004,ISI (isihighlycited.com)
- Fellow, American Association for the Advancement of Science, 2007
- Elected Fellow of the American Society of Plant Biology, 2008
preiss@msu.edu
309 Biochemistry
Michigan State University
East Lansing, MI 48824-1319
Office:517-353-3137
Lab:353-3247
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Jack Preiss Research Interests
Plants and bacteria use similar reactions to synthesize the major carbohydrate reserve polymers, starch and glycogen. First, ADP-glucose (ADPG) is synthesized from ATP and glucose-1-P via catalysis by ADPG pyrophosphorylase. The glycosyl portion of the sugar nucleotide is then transferred to the non-reducing end of a growing glucose polymer chain to form new 1,4-glucosyl linkages. The synthesis of the 1,6-glucosidic linkage is catalyzed by branching enzyme. Regulation of starch and glycogen synthesis occurs via allosteric regulation of the ADPG pyrophosphorylase-catalyzed reaction. Glycolytic intermediates are activators and either AMP, ADP or Pi are inhibitors. Another regulatory facet observed is the derepression of the glycogen biosynthetic levels in the bacteria when the exponential phase of growth shifts into stationary phase. In maize and other plants, similar observations have been made in the endosperm. The levels of the starch biosynthetic enzymes dramatically increase in the later stages of development.
The glycolytic intermediate activators of the ADPG pyrophosphorylase vary for many of the systems studied, and a rough correlation has been seen with respect to the nature of the activator and the major carbon assimilation pathway in the organism. For example, the activator for the higher plant ADPG pyrophosphorylases is 3-phosphoglycerate and the major activator for the ADPG pyrophosphorylase of the bacteria that utilize glycolysis as their major catabolic pathway is fructose-1,6-P2. Thus, it is of great interest to determine and compare the structure and function of the catalytic and effector sites of the bacterial and plant ADPG pyrophosphorylases. Various techniques and methodologies will be employed. They include the standard techniques of protein purification (including affinity chromatography), chemical modification (including photoaffinity labels), and isolation of peptides via HPLC. Recombinant DNA techniques are employed to clone the bacterial glycogen and starch biosynthetic enzymes in order to obtain levels so protein purification can be facilitated. Via DNA sequencing, we have deduced the amino acid sequences of the various enzymes.
The isolation of several mutants affected in the allosteric function of the E. coli ADPG pyrophosphorylase has been achieved and their genes have been cloned. By DNA sequencing, have determined the nature and location of the amino acid substitution. This has enabled us to do in vitro mutagenesis to further delineate structure and function of the effector sites. Using modern protein analyses and molecular modeling techniques we are attempting to study the various domains involved in allosteric function and catalysis. Another major effort is to crystallize the ADP glucose pyrophosphoylases, branching enzymes and glycogen synthase in order to obtain their three-dimensional structure.
Transfection of higher plants with the allosteric E. coli mutants has resulted in an increase of starch content in the plants and thus the study of these systems are also important on a commercial basis.