23 research outputs found
A Study on the Real Estate Mortgage System in China-The Present Conditions and Problems of the Real Estate Mortgage-
本研究は、中国の不動産担保法制度の現状に対して、立法及び学説を検討し、不動産担保法制度のあり方を明らかにすることを目的とする。そのため、中国の不動産担保法制度の歴史変革を概観し、現行法上の不動産抵当権の概念、類型、設定及び公示制度を中心として、中国における不動産抵当権制度の現状と課題について考察する。特に、都市部における未完成建物の抵当権制度、農村における家屋の抵当権制度、抵当物の価値と被担保債権額の関係問題、不動産抵当権の公示制度などの課題を明らかにしたい
Flowering phenology of the diploid <i>Centaurea aspera</i>, the tetraploid <i>C</i>. <i>seridis</i>, and the triploid hybrid <i>C</i>. × <i>subdecurrens</i>.
<p>w1-w52: weeks of field observations; w1: start at January 5th-11th for 2004 and January 3rd-9th for 2005.</p
Number of cypselae, category and ploidy level obtained for each pollination treatment and taxon.
<p>N, number of treated capitula; Se, standard error; Kurt., kurtosis; Intact, cypselae with fully developed embryo; Small, cypselae with small or aborted embryos; Tiss., cypselae filled with nonembryonic tissue; Depr., empty or depredated cypselae; Aberr., percentage of aberrations. In Ploidy, number in parenthesis corresponds to the number of cypsela that has been effectively evaluated.</p><p>*One aneuploid.</p><p>Number of cypselae, category and ploidy level obtained for each pollination treatment and taxon.</p
Predicted values for the tetraploid <i>Centaurea seridis</i> by the Zero inflated Poisson model.
<p>Colors represent the repetitions; red: first repetition; green: second; blue: third and purple: fourth. Selfing: self-pollination; S×S: cross-pollination between individuals of <i>C</i>. <i>seridis</i> (intraploidy); S×A: coss-pollination between mother tetraploid <i>C</i>. <i>seridis</i> and father diploid <i>C</i>. <i>aspera</i>; S×H: coss-pollination between mother tetraploid <i>C</i>. <i>seridis</i> and father triploid <i>C</i>. × <i>subdecurrens</i>; bagged: bagged treatment without brushing. Error bars indicate the standard error for the Poisson model estimates.</p
Correction to “Evaluating the Catalytic Contribution from the Oxyanion Hole in Ketosteroid Isomerase”
Correction
to “Evaluating the Catalytic Contribution
from the Oxyanion Hole in Ketosteroid Isomerase
Correction to “Evaluating the Catalytic Contribution from the Oxyanion Hole in Ketosteroid Isomerase”
Correction
to “Evaluating the Catalytic Contribution
from the Oxyanion Hole in Ketosteroid Isomerase
Correction to “Evaluating the Catalytic Contribution from the Oxyanion Hole in Ketosteroid Isomerase”
Correction
to “Evaluating the Catalytic Contribution
from the Oxyanion Hole in Ketosteroid Isomerase
Uncovering the Determinants of a Highly Perturbed Tyrosine p<i>K</i><sub>a</sub> in the Active Site of Ketosteroid Isomerase
Within
the idiosyncratic enzyme active-site environment, side chain
and ligand p<i>K</i><sub>a</sub> values can be profoundly
perturbed relative to their values in aqueous solution. Whereas structural
inspection of systems has often attributed perturbed p<i>K</i><sub>a</sub> values to dominant contributions from placement near
charged groups or within hydrophobic pockets, Tyr57 of a Pseudomonas putida ketosteroid isomerase (KSI) mutant,
suggested to have a p<i>K</i><sub>a</sub> perturbed by nearly
4 units to 6.3, is situated within a solvent-exposed active site devoid
of cationic side chains, metal ions, or cofactors. Extensive comparisons
among 45 variants with mutations in and around the KSI active site,
along with protein semisynthesis, <sup>13</sup>C NMR spectroscopy,
absorbance spectroscopy, and X-ray crystallography, was used to unravel
the basis for this perturbed Tyr p<i>K</i><sub>a</sub>.
The results suggest that the origin of large energetic perturbations
are more complex than suggested by visual inspection. For example,
the introduction of positively charged residues near Tyr57 raises
its p<i>K</i><sub>a</sub> rather than lowers it; this effect,
and part of the increase in the Tyr p<i>K</i><sub>a</sub> from the introduction of nearby anionic groups, arises from accompanying
active-site structural rearrangements. Other mutations with large
effects also cause structural perturbations or appear to displace
a structured water molecule that is part of a stabilizing hydrogen-bond
network. Our results lead to a model in which three hydrogen bonds
are donated to the stabilized ionized Tyr, with these hydrogen-bond
donors, two Tyr side chains, and a water molecule positioned by other
side chains and by a water-mediated hydrogen-bond network. These results
support the notion that large energetic effects are often the consequence
of multiple stabilizing interactions rather than a single dominant
interaction. Most generally, this work provides a case study for how
extensive and comprehensive comparisons via site-directed mutagenesis
in a tight feedback loop with structural analysis can greatly facilitate
our understanding of enzyme active-site energetics. The extensive
data set provided may also be a valuable resource for those wishing
to extensively test computational approaches for determining enzymatic
p<i>K</i><sub>a</sub> values and energetic effects
MOESM3 of Diffusion tensor imaging with direct cytopathological validation: characterisation of decorin treatment in experimental juvenile communicating hydrocephalus
Additional file 3: Table S1. In the corpus callosum, no significant cytopathological changes were observed in hydrocephalic animals. The mean values ¹ the standard error of the means of GFAP, OX-42, AQP4 and MBP immunostaining in the four different experimental groups are expressed
Ground State Destabilization from a Positioned General Base in the Ketosteroid Isomerase Active Site
We compared the binding affinities of ground state analogues
for
bacterial ketosteroid isomerase (KSI) with a wild-type anionic Asp
general base and with uncharged Asn and Ala in the general base position
to provide a measure of potential ground state destabilization that
could arise from the close juxtaposition of the anionic Asp and hydrophobic
steroid in the reaction’s Michaelis complex. The analogue binding
affinity increased ∼1 order of magnitude for the Asp38Asn mutation
and ∼2 orders of magnitude for the Asp38Ala mutation, relative
to the affinity with Asp38, for KSI from two sources. The increased
level of binding suggests that the abutment of a charged general base
and a hydrophobic steroid is modestly destabilizing, relative to a
standard state in water, and that this destabilization is relieved
in the transition state and intermediate in which the charge on the
general base has been neutralized because of proton abstraction. Stronger
binding also arose from mutation of Pro39, the residue adjacent to
the Asp general base, consistent with an ability of the Asp general
base to now reorient to avoid the destabilizing interaction. Consistent
with this model, the Pro mutants reduced or eliminated the increased
level of binding upon replacement of Asp38 with Asn or Ala. These
results, supported by additional structural observations, suggest
that ground state destabilization from the negatively charged Asp38
general base provides a modest contribution to KSI catalysis. They
also provide a clear illustration of the well-recognized concept that
enzymes evolve for catalytic function and not, in general, to maximize
ground state binding. This ground state destabilization mechanism
may be common to the many enzymes with anionic side chains that deprotonate
carbon acids