The four-stranded i-motif (iM) conformation of cytosine-rich DNA has importance to a wide variety of biochemical systems that range from their use in nanomaterials to potential roles in oncogene regulation. The iM structure is formed at slightly acidic pH, where hemiprotonation of cytosine results in a stable C-C(+) basepair. Here, we performed fundamental studies to examine iM formation from a C-rich strand from the promoter of the human c-MYC gene.
View Article and Find Full Text PDFElastin-like polypeptides (ELPs) are large, nonpolar polypeptides under investigation as components of a novel drug delivery system. ELPs are soluble at low temperatures, but they desolvate and aggregate above a transition temperature (TT). This aggregation is being utilized for targeting systemically delivered ELP-drug conjugates to heated tumors.
View Article and Find Full Text PDFEB1 is a highly conserved microtubule (MT) plus end tracking protein (+TIP) involved in regulating MT dynamics, but the mechanisms of its effects on MT polymerization remain undefined. Resolving this question requires understanding how EB1 interacts with MTs. Previous electron microscopy of the S.
View Article and Find Full Text PDFThe therapeutic potential of elastin-like polypeptide (ELP) conjugated to therapeutic compounds is currently being investigated as an approach to target drugs to solid tumors. ELPs are hydrophobic polymers that are soluble at low temperatures and cooperatively aggregate above a transition temperature (TT), allowing for thermal targeting of covalently attached drugs. They have been shown to cooperatively transition from a disordered structure to a repeating type II β-turn structure, forming a β-spiral above the TT.
View Article and Find Full Text PDFSedimentation velocity analytical ultracentrifugation is a classical biophysical technique that is commonly used to analyze the size, shape, and interactions of biological macromolecules in solution. Fluorescence detection provides enhanced sensitivity and selectivity relative to the standard absorption and refractrometric detectors, but data acquisition is more complex and can be subject to interference from several photophysical effects. Here, we describe methods to configure sedimentation velocity measurements using fluorescence detection and evaluate the performance of the fluorescence optical system.
View Article and Find Full Text PDFWe have identified 2 relatively young patients with significant hypertension, an elongated single aberrant renal artery supplying blood to a renal segment, and evidence for localization of the elevated plasma renin activity to the side and vein draining the affected kidney. Furosemide-induced diuresis and acute oral captopril stimulated the renal vein/contralateral renin ratios to 4.3:1 and 6.
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