Articles by Gregory Smutzer

The ability of cells to degrade and rearrange extracellular matrix proteins is crucial for an organism's growth and development. Nearly 40 years ago, Jerome Gross and Charles Lapiere discovered that when tadpole tail fins resorb, their skin releases an enzyme that degrades native collagen triple helixes in the underlying support matrix.1 This enzyme, called collagenase, is present in a wide variety of vertebrates, invertebrates, and plants. Critical as it is, collagenase is just one member of a

In 1940, nearly 30 years after Danish physicist Neils Bohr explained how light energy affects the electrons orbiting atomic nuclei, Coleman Instruments produced an instrument to take advantage of this principle. The device was an attachment to the company's pH meter that could measure absorbance of light in the ultraviolet (UV) region.1 In the 61 years since, absorption spectroscopy has become one of the most widely used analytical techniques in scientific research. Investigators routinely emplo

Yeast possesses many characteristics that make it especially useful as a model system in the laboratory, including an entirely sequenced genome. Recently, a number of researchers published studies detailing the transition from genome sequencing to functional genomics. Notably, these scientists have developed new high-throughput approaches to the characterization of large numbers of yeast genes. In aggregate, these studies make yeast one of the most well-characterized eukaryotic organisms known.

Updated! Suppliers of Tools for X-ray Crystallography Courtesy of Amersham Pharmacia BiotechDetail of the electron density map of deacetoxycephalosporin C synthase from Streptomyces clavuligerus. Two important approaches can be used to determine the three-dimensional structure of macromolecules. Nuclear magnetic resonance (NMR) spectroscopy yields information on the structure of proteins in solution, but it has a size limitation of approximately 150 amino acid residues (about 16,500 daltons),

In Vitro Translation Systems Researchers synthesize recombinant proteins in cell-free extracts to verify the identity of cloned genes, to study protein-protein, protein-nucleic acid, and protein-drug interactions, and to carry out mutagenesis studies. In vitro protein translation studies rely on the efficient and selective transcription of cloned genes in vitro, which is now not only possible, but also routine, thanks to the identification of bacteriophage (phage) DNA-dependent RNA polymerases a

Gene Delivery Systems Stratagene's AdEasy adenoviral vector system One of the most promising approaches to treating genetic diseases, infectious diseases, and cancer is gene therapy, in which genes are transferred directly to an organism. These transferred genes may replace defective genes or target cancerous tissue for selective inhibition of gene activity. Gene therapy has the potential to treat the cause of disease at the genetic level. In ex vivo gene therapy, cells with defective genes ar

The standard approach for extraction of poly(A)+ RNA from cell lysates is by oligo(dT) cellulose affinity chromatography. However, recent advances in peptide nucleic acid chemistry have produced another method for poly(A)+ RNA extraction. This novel technology uses phosphono-peptide nucleic acids (pPNA). These molecules are similar to DNA except A, T, G, or C bases are covalently attached to an N-(2-aminoethyl) glycine backbone.1 Water-soluble pPNAs hybridize to both DNA and RNA but are not degr