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Full-Text Articles in Life Sciences
A Molecular Basis For Erythromycin Sensitivity And Resistance In Escherichia Coli, Harold S. Chittum
A Molecular Basis For Erythromycin Sensitivity And Resistance In Escherichia Coli, Harold S. Chittum
Electronic Theses and Dissertations
The effect of erythromycin on the 50S ribosomal subunit during cell growth has been extensively investigated. Sucrose density gradient analysis of ribosomes formed in the presence and absence of the drug revealed a 50S specific assembly defect is partially responsible for erythromycin's inhibitory effects on wild type cells. Examination of two erythromycin-resistant mutants of E. coli (N281 and N282) revealed that mutant N281 (L22 mutant) but not N282 (L4 mutant) was assembly defective in the presence of the drug, although only at much higher drug concentrations (300 ug/ml vs. 75 ug/ml for wild type cells). The altered genes from each …
A Characterization Of Extractable, Hydroxylated Fatty Acid Bearing Components In Legionella Pneumophila, Jonathan R. Lane
A Characterization Of Extractable, Hydroxylated Fatty Acid Bearing Components In Legionella Pneumophila, Jonathan R. Lane
Electronic Theses and Dissertations
Extraction of the lipids of Legionella pneumophila yields phases unlike those produced from other Gram-negative bacteria. A viscous interface forms between the aqueous (wash) and organic phases. More than half of the hydroxylated fatty acids were found distributed between the aqueous phase and the interfacial material, fractions in which such constituents have not been reported in other Gram-negative species. It was further observed that after the material from the aqueous/interfacial phase was dissolved in methanol or chloroform/methanol (2:1 (V/V)), the addition of acetone would create a white, flocculent precipitate. Analyses showed that the supernatant contained fatty acids that were nonhydroxylated …
Human Lung Mast Cell Tryptase Isozymes: Separation And Examination Of Structural And Functional Differences, Susan S. Little
Human Lung Mast Cell Tryptase Isozymes: Separation And Examination Of Structural And Functional Differences, Susan S. Little
Electronic Theses and Dissertations
Tryptases are trypsin-like enzymes found in mast cell granules. Although in vivo substrates have not been positively identified, tryptases cleave a limited number of potential physiological substrates in vitro, including high molecular weight kininogen (HMWK) and vasoactive intestinal peptide (VIP). Purified human lung mast cell tryptase (HLT) apparently exists as a tetramer with an M$\sb{\rm r}$ of 135-144 kDa by gel filtration, whereas SDS-PAGE yielded two bands of M$\sb{\rm r}$ 29 Kda and 33 Kda. Tryptases are resistant to inhibition by most natural trypsin inhibitors and display some affinity for heparin. The existence of tryptase isozymes has been implied from …
Probing Protein-Protein Interactions Among Proteins Of A Nonaggregated Fatty Acid Synthetase From Euglena Gracilis Variety Bacillaris, Sande G. Williams
Probing Protein-Protein Interactions Among Proteins Of A Nonaggregated Fatty Acid Synthetase From Euglena Gracilis Variety Bacillaris, Sande G. Williams
Electronic Theses and Dissertations
Enoyl-acyl carrier protein (ACP) reductase from chloroplast nonaggregated fatty acid synthetase (FAS) of Euglena gracilis variety bacillaris was purified to a single band on a denaturing polyacrylamide gel. The enzyme was partially characterized with respect to substrate specificity, reduced nucleotide requirement, and the effect of ACP and Ca$\sp{++}$ on enzyme activity. Antibodies against the purified protein were raised in hens and isolated from eggs. ACP was purified from Euglena in yields of about 1mg/100g (wet weight) of cells. Antibodies were raised against the purified protein. ACP antibodies inhibited the Euglena chloroplast FAS using Euglena or E. coli ACP as a …