Urinary biomarker values for mine site employees.^α

α<p>Values are means<u>±</u>SE.</p>*<p>Indicates values are significantly greater than PRE value (P<0.01).</p>#<p>Indicates value significantly greater than PRE value (P<0.05).</p

LC- MS/MS identifies the LG3 peptide of endorepellin, a C-terminal bioactive fragment of Perlecan.

<p>a) Perlecan (<b><u>underlined bold lower case</u></b>), the C terminal of Perlecan containing Endorepellin (lowercase text) and the LG3 Peptide of endorepellin (<b>BOLD CAPITALS</b>). Individual peptides identified by LC-MS/MS of tryptic in-gel digest in </p><p><b>LIGHT GREY</b></p> and <p><b><u>DARK GREY</u></b></p> highlights. Sequence coverage includes the LG3 peptide, however, the first 25 residues of the LG3 peptide were not detected. <b>b</b>) Western blot analysis confirmed that the ∼20 kDa protein observed by SDS-PAGE and the spectral feature at m/z 16881 are derived from endorepellin. Western Blot of worker urine samples using goat anti-human endorepellin polyclonal antibody (1∶10,000).<p></p

Urinary urea and cortisol levels trend toward recovery in operators but not in maintenance crew.

<p><b>a</b>) Urinary, urea levels were determined by an automated kinetic assay (analytic coefficient of variation being <4%). <b>b</b>) Urinary cortisol levels were determined by competitive immunoassay (analytic coefficient of variation being<4%). Both urea and cortisol measurements were standardised for dieresis against urinary creatinine levels which were determined by the Jaffe method (analytic coefficient of variation being<3%).</p

The ∼20 kDa band excised from the SDS-PAGE gel is a fragment of perlecan.

<p>Mascot search results.</p>α<p>Ions score is −10*log(P), where P is the probability that the observed match is a random event. Individual ion scores >52 indicate identity of extensive homology (p<0.05).</p

The spectral feature at m/z 16881 is a broad tri-phasic peak, visible by SDS-PAGE.

<p><b>a</b>) The hypothesised pattern of intensity of m/z 16881 in stacked replicate spectra, expected to be observed in an SDS-PAGE gel. <b>b</b>) A band which matched the expected pattern of intensity for the feature at m/z 16881 was detected at ∼20 kDa by SDS-PAGE (<b>arrow)</b> suggesting that the bands at ∼20 kDa in the gel were the proteins which constituted m/z 16881 in the spectra. <b>c</b>) The protein at ∼20 kDa was extracted from excised bands from a non-stained replicate SDS-PAGE gel. Examination of the extracted protein by SELDI-TOF MS confirmed that the ∼20 kDa band was the feature originally detected at m/z 16881.</p

Summary of physical exposure relative to different postures and activity.

*<p> <b> = p<0.05.</b></p

Photophysics of Threaded sp-Carbon Chains: The Polyyne is a Sink for Singlet and Triplet Excitation

We have used single-crystal X-ray diffraction and time-resolved UV–NIR–IR absorption spectroscopy to gain insights into the structures and excited-state dynamics of a rotaxane consisting of a hexayne chain threaded through a phenanthroline macrocycle and a family of related compounds, including the rhenium­(I) chlorocarbonyl complex of this rotaxane. The hexayne unit in the rhenium-rotaxane is severely nonlinear; it is bent into an arc with an angle of 155.6(1)° between the terminal C1 and C12 atoms and the centroid of the central C–C bond, with the most acute distortion at the point where the polyyne chain pushes against the Re­(CO)₃Cl unit. There are strong through-space excited-state interactions between the components of the rotaxanes. In the metal-free rotaxane, there is rapid singlet excitation energy transfer (EET) from the macrocycle to the hexayne (τ = 3.0 ps), whereas in the rhenium-rotaxane there is triplet EET, from the macrocycle complex ³MLCT state to the hexayne (τ = 1.5 ns). This study revealed detailed information on the short-lived higher excited state of the hexayne (lifetime ∼1 ps) and on structural reorganization and cooling of hot polyyne chains, following internal conversion (over ∼5 ps). Comparison of the observed IR bands of the excited states of the hexayne with results from time-dependent density functional calculations (TD DFT) shows that these excited states have high cumulenic character (low bond length alternation) around the central region of the chain. These findings shed light on the complex interactions between the components of this supramolecular rotaxane and are important for the development of materials for the emerging molecular and nanoscale electronics

Temperature-Induced Effects on the Structure of Gramicidin S

We report on the structure of Gramicidin S (GS) in a model membrane mimetic environment represented by the amphipathic solvent 1-octanol using one-dimensional (1D) and two-dimensional (2D) IR spectroscopy. To explore potential structural changes of GS, we also performed a series of spectroscopic measurements at differing temperatures. By analyzing the amide I band and using 2D-IR spectral changes, results could be associated to the disruption of aggregates/oligomers, as well as structural and conformational changes happening in the concentrated solution of GS. The ability of 2D-IR to enable differentiation in melting transitions of oligomerized GS structures is attributed to the sensitivity of the technique to vibrational coupling. Two melting transition temperatures were identified; at Tm1 in the range 41–47 °C where the GS aggregates/oligomers disassemble and at Tm2 = 57 ± 2 °C where there is significant change involving GS β-sheet-type hydrogen bonds, whereby it is proposed that there is loss of interpeptide hydrogen bonds and we are left with mainly intrapeptide β-sheet and β-turn hydrogen bonds of the smaller oligomers. Further analysis with quantum mechanical/molecular mechanics (QM/MM) simulations and second derivative results highlighted the participation of active GS side chains. Ultimately, this work contributes toward understanding the GS structure and the formulation of GS analogues with improved bioactivity

Infrared Spectroscopy of Nicotinamide Adenine Dinucleotides in One and Two Dimensions

The development of multidimensional spectroscopic tools capable of resolving site-specific information about proteins and enzymes in the solution phase is an important aid to our understanding of biomolecular mechanisms, structure, and dynamics. Nicotinamide adenine dinucleotide (NAD) is a common biological substrate and so offers significant potential as an intrinsic vibrational probe of protein–ligand interactions but its complex molecular structure and incompletely characterized infrared spectrum currently limit its usefulness. Here, we report the FTIR spectroscopy of the oxidized and reduced forms of NAD at a range of pD values that relate to the “folded” and “unfolded” forms of the molecules that exist in solution. Comparisons with structural analogs and the use of density functional theory simulations provide a full assignment of the observed modes and their complex pD dependencies. Finally, ultrafast two-dimensional infrared spectra of the oxidized and reduced forms of NAD are reported and their usefulness as biomolecular probes is discussed

2D-IR Spectroscopy Shows that Optimized DNA Minor Groove Binding of Hoechst33258 Follows an Induced Fit Model

The induced fit binding model describes a conformational change occurring when a small molecule binds to its biomacromolecular target. The result is enhanced noncovalent interactions between the ligand and biomolecule. Induced fit is well-established for small molecule–protein interactions, but its relevance to small molecule–DNA binding is less clear. We investigate the molecular determinants of Hoechst33258 binding to its preferred A-tract sequence relative to a suboptimal alternating A-T sequence. Results from two-dimensional infrared spectroscopy, which is sensitive to H-bonding and molecular structure changes, show that Hoechst33258 binding results in loss of the minor groove spine of hydration in both sequences, but an additional perturbation of the base propeller twists occurs in the A-tract binding region. This induced fit maximizes favorable ligand–DNA enthalpic contributions in the optimal binding case and demonstrates that controlling the molecular details that induce subtle changes in DNA structure may hold the key to designing next-generation DNA-binding molecules