10 research outputs found
Urinary biomarker values for mine site employees.<sup>Ī±</sup>
Ī±<p>Values are means<u>Ā±</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 ā¼20 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 (1ā¶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 ā¼20 kDa band excised from the SDS-PAGE gel is a fragment of perlecan.
<p>Mascot search results.</p>Ī±<p>Ions score is ā10*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 ā¼20 kDa by SDS-PAGE (<b>arrow)</b> suggesting that the bands at ā¼20 kDa in the gel were the proteins which constituted m/z 16881 in the spectra. <b>c</b>) The protein at ā¼20 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 ā¼20 kDa band was the feature originally detected at m/z 16881.</p
Summary of physical exposure relative to different postures and activity.
*<p>
<b>ā=āp<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
UVāNIRāIR 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 rheniumĀ(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)Ā°
between the terminal C1 and C12 atoms and the centroid of the central
CāC bond, with the most acute distortion at the point where
the polyyne chain pushes against the ReĀ(CO)<sub>3</sub>Cl 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
(Ļ = 3.0 ps), whereas in the rhenium-rotaxane there is triplet
EET, from the macrocycle complex <sup>3</sup>MLCT state to the hexayne
(Ļ = 1.5 ns). This study revealed detailed information on the
short-lived higher excited state of the hexayne (lifetime ā¼1
ps) and on structural reorganization and cooling of hot polyyne chains,
following internal conversion (over ā¼5 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 41ā47 Ā°C where the GS aggregates/oligomers
disassemble and at Tm2 = 57 Ā± 2 Ā°C
where there is significant change involving GS Ī²-sheet-type
hydrogen bonds, whereby it is proposed that there is loss of interpeptide
hydrogen bonds and we are left with mainly intrapeptide Ī²-sheet
and Ī²-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 proteināligand
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 āfoldedā
and āunfoldedā 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 moleculeāprotein
interactions, but its relevance to small moleculeāDNA 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 ligandāDNA 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