Redesigning The Molecules Of Life

The organic chemist is rarely satisfied by a simple "explanation" of the reactivity of organic molecules. Rather, the chemist wants to go one step further, to "control" the behavior of molecules by altering their structure in a controlled way. This is, in fact, a rather stringent definition of "understanding," as it requires the "prediction" of behavior from structure (or structure from behavior). But it also places technical demands on the chemist. He must be able to synthesize the molecules he studies, characterize them at the atomic level of structural resolution, and then measure their behaviors to the precision that his explanation demands. Biological chemistry presents special problems in this regard. Although the tools for synthesis, purification, and structural characterization are now available for manipulating rather large biological macromolecules (proteins and nucleic acids in particular), the theory supporting these manipulations is inadequate. We certainly do not know enough to control generally the behavior of biological macromolecules; still worse, it is not clear that we know enough to design synthetic molecules to expand our understanding about how reactivity in such biological macromolecules might be controlled. Starting from scratch, there are simply too many oligopeptides to make; starting from native proteins, there are simply too many structural mutations that might be introduced.

The organic chemist is rarely satisfied by a simple "explanation" of the reactivity of organic molecules. Rather, the chemist wants to go one step further, to "control" the behavior of molecules by altering their structure in a controlled way. This is, in fact, a rather stringent definition of "understanding," as it requires the "prediction" of behavior from structure (or structure from behavior). But it also places technical demands on the chemist. He must be able to synthesize the molecules he studies, characterize them at the atomic level of structural resolution, and then measure their behaviors to the precision that his explanation demands. Biological chemistry presents special problems in this regard. Although the tools for synthesis, purification, and structural characterization are now available for manipulating rather large biological macromolecules (proteins and nucleic acids in particular), the theory supporting these manipulations is inadequate. We certainly do not know enough to control generally the behavior of biological macromolecules; still worse, it is not clear that we know enough to design synthetic molecules to expand our understanding about how reactivity in such biological macromolecules might be controlled. Starting from scratch, there are simply too many oligopeptides to make; starting from native proteins, there are simply too many structural mutations that might be introduced.

In this issue: From the Editors - GM Cancer Warning Can no Longer Be Ignored Freeing the World from GMOsExcess Cancers & Deaths from GM Feed: Stats Stand UpStudy Confirms GM Crops Increased Pesticide Use Synthetic Biology Good & BadSynthetic Biology Should We Be Afraid?Aptamers for Biosensing, Diagnosis, Drug Delivery and TherapyMass Genome Engineering Contaminated VaccinesDNA Contamination in HPV Vaccines Letters to the Editor Institute of Science in Society Special ReportWhy Glyphosate Should Be Banned News in Brief Technology WatchNanoparticles Bioaccumulate & Harm Soybean CropsPhotosynthetic Bacterium Converts CO2 into Petrochemical & O2 Save Our WaterWorld Water Supply in JeopardyPharmaceutical Cocktails Anyone? No NuclearFukushima Mutant Butterflies Confirm Harm from Low-Dose Radiation

1. K. Kano: Selectivities of Applied Chemistry 2. A. Pl}ckthun: Antibody Engineering to Study Protein-Ligand Interactions and Catalysis: The Phosphorylcholine Binding Antibodies 3. M.W. Hosseini: Supramolecular Catalysis of Phosphoryl Transfer Processes 4. G. von Kiedrowski: Minimal Replicator Theory II: Parabolic versus ExponentialGrowth 5. A. Bacher, W. Eisenreich, K. Kis, R. Ladenstein, G. Richter, J. Scheuring, S. Weinkauf: Biosynthesis of Flavins 6. C.L. Hannon, E.V.Anslyn: The Guanidinium Group: Its Biological Role and Synthetic Analogs.

How small can a free-living organism be? On the surface, this question is straightforward-in principle, the smallest cells can be identified and measured. But understanding what factors determine this lower limit, and addressing the host of other questions that follow on from this knowledge, require a fundamental understanding of the chemistry and ecology of cellular life. The recent report of evidence for life in a martian meteorite and the prospect of searching for biological signatures in intelligently chosen samples from Mars and elsewhere bring a new immediacy to such questions. How do we recognize the morphological or chemical remnants of life in rocks deposited 4 billion years ago on another planet? Are the empirical limits on cell size identified by observation on Earth applicable to life wherever it may occur, or is minimum size a function of the particular chemistry of an individual planetary surface? These questions formed the focus of a workshop on the size limits of very small organisms, organized by the Steering .Group for the Workshop on Size Limits of Very Small Microorganisms and held on October 22 and 23, 1998. Eighteen invited panelists, representing fields ranging from cell biology and molecular genetics to paleontology and mineralogy, joined with an almost equal number of other participants in a wide-ranging exploration of minimum cell size and the challenge of interpreting micro- and nano-scale features of sedimentary rocks found on Earth or elsewhere in the solar system. This document contains the proceedings of that workshop. It includes position papers presented by the individual panelists, arranged by panel, along with a summary, for each of the four sessions, of extensive roundtable discussions that involved the panelists as well as other workshop participants.

A leading microbiologist provides thought-provoking insights into the question of "What is Life?" as he examines the relationship of living things to the inorganic realms of physics and chemistry, explains how lifeless chemicals come together to form living beings, and details the true complexity of seemingly simple microorganisms such as E. coli.

The genomic revolution has opened up systematic investigations and engineering designs for various life forms. Systems biology and synthetic biology are emerging as two complementary approaches, which embody the breakthrough in biology and invite application of engineering principles. Systems Biology and Synthetic Biology emphasizes the similarity between biology and engineering at the system level, which is important for applying systems and engineering theories to biology problems. This book demonstrates to students, researchers, and industry that systems biology relies on synthetic biology technologies to study biological systems, while synthetic biology depends on knowledge obtained from systems biology approaches.

How far should scientists go in exploring the secrets of life? As political responses to the questions this text poses will affect us all, informed public understanding is crucial.