Associate Professor
Associate Dean, Undergraduate Education
Director, Advisory and Learning Assistance Center

Education and Training

B.S. University at Massachusetts (1970)
Microbiology

Ph.D. University of Illinois at Urbana (1975)
Microbiology

Postdoctoral Work, Princeton

Contact

Office: Science Center Rm. 1W14

Rensselaer Polytechnic Institute
110 8th Street
Troy, NY 12180

Research Interests

My laboratory is now studying directed gene/protein evolution, which refers to techniques where a gene is modified such that the protein specified by such modified genes is better than the original protein specified by the starting gene. "Better" is an operational definition meaning a more active enzyme or an enzyme with a new activity, or an enzyme that functions under new environmental conditions. My lab uses in vitro recombination that rejoins randomly generated fragments of related genes using the polymerase chain reaction (PCR) to generate complete, ordered, and unique combinations from the original genes that were fragmented. The advantages of the in vitro recombinational techniques are simplicity, generation of large numbers of unique gene combinations, and knowledge of the protein's structure is not required.

We apply in vitro recombinational methods to engineer proteins classified as small heat-shock proteins (sHSPs). This family of proteins is ubiquitous in eukaryotic and prokaryotic organisms showing regions of remarkable conservation of structure. Cells placed under thermal stress overproduce several different heat-shock proteins (HSPs) that protect the organism during exposure to unfavorable conditions by protecting proteins from complete denaturation and by assisting them in refolding to their normal structure once the stress is removed. The normal activity of many HSPs is to chaperone or assist other proteins in folding to their native structure (referred to as chaperonin activity). Human a-crystallins, the major proteins of the mammalian eye lens, are members of the sHSPs class. The thermophilic archaebacterium Methanococcus jannaschii has a related sHSP called MjHSP16.5. We have the bovine a-A and a-B crystallin genes and the MjHSP16.5 gene, and will use in vitro recombinational techniques to find better heat-shock proteins.

Escherichia coli is the most well-studied microorganism at the physiological, genetic and genomic levels. It is a mesophilic organism that grows at temperatures ranging from 20C to40C. We will create altered sHSPs and examine their ability to extend the growth temperature range of E. coli. We are also developing an assay to detect chaperonin activity using reporter genes. An altered chaperone protein would allow the reporter gene to be expressed better than the unaltered sHSP gene product.

Selected Publications

Salerno, J.C., Hanna, M.H., Koretz, J.C., Crone, D., and Smith, S.M.E. 2000. "Protein Expression System." Disclosure and Provisional Patent application.

Hanna, M.H. 1987. "Applied genetics for biochemical engineers: Recombinant DNA." In Advanced Biochemical Engineering, ed. by H. Bungay and G. Belfort, Wiley Interscience, p. 103-128.

Ellsaesser, C.F., Kuhn, P.E., and Hanna, M.H. 1986. "Analysis of developmentally defective chemical signaling mutants of Polysphondylium violaceum." Journal of Bacteriology 165: 647-649.

Hanna, M.H., Soucek, L.S.. and Carl, P.L.1975. "Triton X-100 dependent in vitro DNA synthesis in an E. coli dnaC mutant." In DNA Synthesis and Its Regulation, ICN-UCLA Symposium on Molecular Biology, p. 640-647.

Hanna, M.H. and Carl, P.L. 1975. "Reinitiation of deoxyribonucleic acid synthesis by deoxyribonucleic acid initiation mutants of Escherichia coli: Role of ribonucleic acid synthesis, protein synthesis and cell division." Journal of Bacteriology 121, 219-226.