Acoustic wave biosensors are a real-time, label-free biosensor technology, which have been exploited for the detection of proteins and cells. One of the conventional biosensor approaches involves the immobilization of a monolayer of antibodies onto the surface of the acoustic wave device for the detection of a specific analyte. The method described within includes at least two immobilizations o...

We have studied the pH dependence of the rate of termination of bacterial protein synthesis catalyzed by a class-1 release factor (RF1 or RF2). We used a classical quench-flow technique and a newly developed stopped-flow technique that relies on the use of fluorescently labeled peptides. We found the termination rate to increase with increasing pH and, eventually, to saturate at about 70 s(-1) ...

OxyR, a bacterial peroxide sensor, is a LysR-type transcriptional regulator (LTTR) that regulates the transcription of defense genes in response to a low level of cellular H2O2. Consisting of an N-terminal DNA-binding domain (DBD) and a C-terminal regulatory domain (RD), OxyR senses H2O2 with conserved cysteine residues in the RD. However, the precise mechanism of OxyR is not yet known due to t...

ATP-binding cassette (ABC)-type ATPases are chemomechanical engines involved in diverse biological pathways. Recent genomic information reveals that ABC ATPase domains/subunits act not only in ABC transporters and structural maintenance of chromosome proteins, but also in iron-sulfur (Fe-S) cluster biogenesis. A novel type of ABC protein, the SufBCD complex, functions in the biosynthesis of nas...

Bacterial α-2-macroglobulins have been suggested to function in defence as broad-spectrum inhibitors of host proteases that breach the outer membrane. Here, the X-ray structure of protease-cleaved Escherichia coli α-2-macroglobulin is described, which reveals a putative mechanism of activation and conformational change essential for protease inhibition. In this competitive mechanism, protease c...

COURSE INFORMATION The following text is a summary of a two-hour lecture sequence presented in the course, Advanced Medicinal Chemistry I. This course is required for all MS and PhD students in Duquesne University’s Medicinal Chemistry Graduate Program. It is also available as an elective for undergraduate students in their last semester of didactic work. The course emphasizes the basic chemica...

A key concept in template-based modeling (TBM) is the high correlation between sequence and structural divergence, with the practical consequence that homologous proteins that are similar at the sequence level will also be similar at the structural level. However, conformational diversity of the native state will reduce the correlation between structural and sequence divergence, because structu...

CD studies of the deoxyoligomer series d(pT)(n) and d(pA)(n) show increasing CD maxima for oligo (dT)'s with chain length variation from two to seven, while oligo (dA)'s exhibit a decreasing CD maximum. Concentrated solutions of NaClO(4) cause a decrease in the CD of longer oligo (dT)'s towards the CD of d(pT)(2) which is different from oligo dA's. Probably base-sugar interactions are important...

We investigated mechanistic differences in antigen presentation between murine MHC class I variants H-2K(b) and H-2K(bm)8. H-2K(bm)8 differs from H-2K(b) by four residues at the floor of the peptide-binding site, affecting its B pocket which interacts with the second (P2) residue of the peptide. The rest of the molecule, including the T cell receptor (TCR)-contacting residues, is identical to H...

molecular genetics selection on individual genes is a promising method to genetically improve economically important traits in livestock. the insulin like growth factor-i (igf-i) gene may play important roles in growth of multiple tissues, including muscle cells, cartilage and bone. the objectives of the present study were the estimate the haplotype frequencies of the igf-i gene polymorphisms i...