Biomedical subjects
Publications and source records attributed to L M Kauvar.
Novel peptide-based (paralog) sorbents are evaluated with respect to performance, reproducibility and reusability in a 96-well test plate screening format, and to utility in protein separations. The results demonstrate that this approach to constructing sorbents provides a new and generally applicable set of tools for separating proteins.
As a mixed mode ligand, a small peptide can mimic an antibody's paratope (antigen recognition site). This report describes the construction of a representative set of paratope analogs, or "paralogs," which can be conjugated to a chromatographic sorbent to combine desirable characteristics of traditional high-performance liquid chromatography columns with the specificity of a moderate affinity antibody. The broad utility of this novel set of protein separatory reagents is illustrated on the complex mixture of proteins in a yeast lysate.
cDNA clones originating from the engrailed gene of Drosophila have been isolated from recombinant phage libraries that were made using poly(A)+ RNA extracted from early embryos. The DNA sequence of one of these clones includes a homeo box, a 180 bp sequence present in several other Drosophila genes important in formation of body pattern during development. The homeo boxes found in the other Drosophila genes, as well as in cognate sequences from a wide range of segmented animals, including higher vertebrates, are highly conserved. By contrast, the homeo box within the engrailed gene diverges substantially and, unlike the other homeo boxes, is interrupted by an intervening sequence. The engrailed homeo box is located near the 3' end of a 1700 bp open reading frame. If translated, this sequence would produce a protein of unusual composition. We also show that a neighboring gene has a large region with strong homology to engrailed, and that it also contains a homeo box.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
The temperature-sensitive paralytic mutant of Drosophila, napts, has been shown to have defects in axonal physiology which suggest that it codes for a component of the voltage-sensitive sodium channel. Ligand binding studies using tritiated tetrodotoxin, a sodium channel antagonist, show a decrease in the apparent number of sodium channels in napts, providing additional support for this hypothesis.
A detailed characterization of the cyclic nucleotide phosphodiesterase (PDEs) from normal Drosophila melanogaster was made, including purification of the two major enzymes to near homogeneity. A third more labile phosphodiesterase also was identified in crude homogenates. The total activity per fly of one of these three enzymes, PDE-II, is strongly influenced by the dunce locus. Two independently derived dunce mutants produce variations of PDE-II with modified intrinsic properties: a marked decrease of thermal stability in dunce and a 10-fold increase in the Michaelis kinetic constant in dunce. These defects, which persisted in purified preparations of PDE-II, were mapped genetically to dunce. The results support the identification of dunce as the structural locus for PDE-II. The tight connection between the dunce gene and the PDE-II enzyme indicates that defective cyclic adenosine 3':5'-monophosphate metabolism is the primary lesion which leads to failure of dunce flies to learn in the olfactory associative conditioning paradigm of Quinn et al. (Quinn, W. G., W. A. Harris, and S. Benzer (1974) Proct. Natl. Acad. Sci. U. S. A. 71: 708-712).