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Protein
& Peptide Letters
ISSN: 0929-8665
Protein
& Peptide Letters
Volume 17, Number 1, 2010
Contents
Regular Papers
NMR Structure/Function Relationships of Peptides
Corresponding to the C1B1 Region of PKCγ
Pp. 1-10
J. Lauer, D. Banerjee, D. Shanks, H. Dai, Y.-X. Gong, O. Prakash
and D. Takemoto
[Abstract] [Supplementary
Material] [Full
Text Article]
Identification and Characterization of Molten Globule-Like
State of Hen Egg-White Lysozyme in Presence of Salts Under
Alkaline Conditions Pp. 11-17
M.A. Ansari, S. Zubair, S.M. Atif, M. Kashif, N. Khan,
M. Rehan, T. Anwar, A. Iqbal and M. Owais
[Abstract] [Full
Text Article]
Proteome and Metabolome Alterations in Heart and Liver
Indicate Compromised Energy Production During Sepsis
Pp. 18-31
Jochen Hinkelbein, Armin Kalenka, Charlotte Schubert,
Anna Peterka and Robert E. Feldmann, Jr.
[Abstract] [Full
Text Article]
Predicting Subcellular Localization of Gram-Negative
Bacterial Proteins by Linear Dimensionality Reduction Method Pp. 32-37
Tong Wang and Jie Yang
[Abstract] [Full
Text Article]
[PMID:
19508203 PubMed - indexed for MEDLINE]
Isolation of a Mitogenic Agglutinin with Relatively
High Thermostability from Seeds of the Variegated Shell Ginger Pp. 38-43
Jack Ho Wong, T.B. Ng, Kalin Y.B. Zhang, Stephen C.W.
Sze and H.X. Wang
[Abstract] [Full
Text Article]
Effects of Peptidic Antagonists of Grb2-SH2 on Human Breast
Cancer Cells Pp. 44-53
Chiu-Heng Chen, Meng-Kai Chen, Kee-Ching G. Jeng and
Feng-Di T. Lung
[Abstract] [Full
Text Article]
[PMID:
19508206 PubMed - indexed for MEDLINE]
Salt-Assisted Religation of Proteolyzed Glutathione-S-Transferase
Follows Hofmeister Series Pp. 54-63
K.V. Radha Kishan and Amit Sharma
[Abstract] [Full
Text Article]
[PMID:
19508200 PubMed - indexed for MEDLINE]
Evaluation of Protein Phosphorylation Site Predictors Pp. 64-69
Shufu Que, Yongfei Wang, Peixiang Chen, Yu-Rong Tang,
Ziding Zhang, and Huaqin He
[Abstract] [Full
Text Article]
[PMID: 19508198 PubMed - indexed for MEDLINE]
Expression, Purification, Crystallization and Preliminary
X-Ray Crystallographic Analysis of the Resuscitation Promoting
Factor Interacting Protein RipA from M. tuberculosis
Pp. 70-73
Alessia Ruggiero, Flavia Squeglia, Carla Esposito, Daniela
Marasco, Emilia Pedone, Carlo Pedone and Rita Berisio
[Abstract] [Full
Text Article]
[PMID:
19807672 PubMed - indexed for MEDLINE]
Irbesartan Inhibits Albumin-Elicited Proximal Tubular
Cell Apoptosis and Injury In Vitro Pp. 74-77
Takanori Matsui, Sho-ichi Yamagishi, Seiji Ueda, Kei Fukami
and Seiya Okuda
[Abstract] [Full
Text Article]
Identification of a Cell-Bound Extracellular Protease
Overproduced by Sulfolobus solfataricus in Peptide-Rich
Media Pp. 78-85
Raffaele Cannio, Giuliana Catara, Imma Fiume, Marco Balestrieri,
Mosè Rossi and Gianna Palmieri
[Abstract] [Full
Text Article]
[PMID: 19508193 PubMed - indexed for MEDLINE]
Analysis of the Metabolites in Apical Area of Allium
cepa Roots by High Resolution NMR Spectroscopy Method
Pp. 86-91
Arkady Yu. Budantsev, Vladimir N. Uversky and Victor
P. Kutyshenko
[Abstract] [Full
Text Article]
Two-, Three-, and Four-State Events Occur in the Mechanical
Unfolding of Small Protein L Using Molecular Dynamics Simulations Pp. 92-103
Anna V. Glyakina, Nikolay K. Balabaev and Oxana
V. Galzitskaya
[Abstract] [Full
Text Article]
Cells with Minimal Expression of the JAK/STAT Pathway
Related Proteins STAT5a and the Prolactin Receptor: Evidence
of an Alternate Prolactin Receptor Isoform in Breast Disease Pp. 104-108
G.L. Bratthauer, M.D. Stamatakos and T.N. Vinh
[Abstract] [Full
Text Article]
The Malarial Drug Target Plasmodium falciparum
1–Deoxy–D–Xylulose–5–Phosphate
Reductoisomerase (PfDXR): Development of a 3–D
Model for Identification of Novel, Structural and Functional
Features and for Inhibitor Screening Pp. 109-120
Jessica L. Goble, Matthew R. Adendorff, Tjaart A.P. de
Beer, Linda L. Stephens and Gregory L. Blatch
[Abstract]
[Supplementary
Material] [Full
Text Article]
Synthesis and Anti-Angiogenic Effect of Conjugates
Between Serum Albumin and Non-Steroidal Anti-Inflammatory
Drugs Pp. 121-130
B. Kjær, C. Struve, T. Friis, A.-M. Engel, N.H.
Beyer, P. Højrup and G. Houen
[Abstract] [Full
Text Article]
Location of MBL-Associated Serine Proteases Binding
Motifs on Human Mannan-Binding Lectin (MBL) Pp.
132-136
Daming Zuo, Xuemin Cai, Na Zhao, Liyun Zhang and
Zhengliang Chen
[Abstract] [Full
Text Article]
Sequence-Based Prediction of Protein-Protein Interactions
by Means of Rotation Forest and Autocorrelation Descriptor
Pp. 137-145
Jun-Feng Xia, Kyungsook Han and De-Shuang Huang
[Abstract] [Full
Text Article]
Abstracts
[Back to top] [Full
Text Article]
NMR Structure/Function Relationships of Peptides
Corresponding to the C1B1 Region of PKCγ
J. Lauer, D. Banerjee, D. Shanks, H. Dai, Y.-X. Gong, O. Prakash
and D. Takemoto
[Supplementary
Material]
The region (101-112) of C1B domain in PKCγ
plays a crucial role in the activation of the enzyme and subsequent
gap junction inhibition. Substitution studies on peptides
correlating to the C1B region show that a flexible structure
and ability to be phosphorylated on serine 109 are critical
for this purpose.
[Back to top]
[Full
Text Article]
Identification and Characterization of Molten Globule-Like
State of Hen Egg-White Lysozyme in Presence of Salts Under
Alkaline Conditions
M.A. Ansari, S. Zubair, S.M. Atif, M. Kashif, N. Khan,
M. Rehan, T. Anwar, A. Iqbal and M. Owais
In the present study, we elucidated the effect of potassium
salts on alkali denatured hen egg white lysozyme (EC 3.2.1.17)
using intrinsic/extrinsic fluorescence as well circular dichroism
(CD) spectroscopic methods. Intrinsic fluorescence studies
revealed that various potassium salts mediate stabilization
of lysozyme against alkali denaturation. Far and near UV CD
spectrum studies, showed that 2M KCl induced appreciable amount
of secondary structure with minimum tertiary contacts in lysozyme
at pH 12.6. Acrylamide quenching studies suggest that at pH
12.6, the presence of 2M KCl causes reduced accessibility
of the quencher to tryptophan residues of the protein presumably
because of its compact conformation. In summary, the results
of present study suggest that lysozyme attains a compact folded
intermediate with molten globule like characteristics at alkaline
pH in presence of potassium chloride.
[Back to top]
[Full
Text Article]
Proteome and Metabolome Alterations in Heart and Liver
Indicate Compromised Energy Production During Sepsis
Jochen Hinkelbein, Armin Kalenka, Charlotte Schubert,
Anna Peterka and Robert E. Feldmann, Jr.
During the course of sepsis, heart and liver dysfunction occurs
in 20-30 % of patients. Both septic cardiomyopathy and septic
liver dysfunction have a high mortality and the underlying
molecular pathophysiology remains unclear. The present study
investigated changes in both cardiac and liver protein expression
after cecal ligature and puncture (CLP) in a model of rat
sepsis during a post-induction time course of 12, 24, and
48 hours.
After approval by the local institutional review board, 62
male Wistar rats were investigated and assigned to three sham
groups (n=16) and three sepsis groups (n=46). Rats of the
sepsis groups and control groups were analyzed at specific
time points after sepsis induction. Sepsis was induced by
CLP and both heart and liver were removed after decapitation
and prepared for proteomics. 2D-gel electrophoresis (2D-GE)
and mass spectrometry (MS) as well as bioinformatic network
pathway analysis (Ingenuity Pathways Analysis, IPA) were used
to identify changes in protein expression between septic and
non-septic samples.
N=27 rats of the sepsis group died (mortality 59 %) and no
rat of the sham group died. More than 1,100 proteins could
be discriminated with the proteomic method in both organs,
of which 12 and 13 proteins were significantly regulated in
heart and liver, respectively. 82 % of the cardiac proteins
could be associated with mitochondrial function. Both heart
and liver proteins were primarily down-regulated in the course
of sepsis. IPA associated the sets of differentially regulated
proteins with proteins of heart and liver with compromised
energy production.
Sepsis induced significant alterations in the cardiac and
liver proteome at 12, 24, and 48 hours after sepsis induction.
Differentially regulated proteins of both organs mainly play
a role in energy production. The diverse protein regulation
indicates metabolic derangement and severely compromised cellular
energy production following sepsis. Here, protein alterations
may reflect septic organ dysfunction.
[Back to top]
[Full
Text Article] [PMID:
19508203 PubMed - indexed for MEDLINE]
Predicting Subcellular Localization of Gram-Negative
Bacterial Proteins by Linear Dimensionality Reduction Method
Tong Wang and Jie Yang
With the rapid increase of protein sequences in the post-genomic
age, the need for an automated and accurate tool to predict
protein subcellular localization becomes increasingly important.
Many efforts have been tried. Most of them aim to find the
optimal classification scheme and less of them take the simplifying
the complexity of biological system into consideration. This
work shows how to decrease the complexity of biological system
with linear DR (Dimensionality Reduction) method by transforming
the original high-dimensional feature vectors into the low-dimensional
feature vectors. A powerful sequence encoding scheme by fusing
PSSM (Position-Specific Score Matrix) and Chou’s PseAA
(Pseudo Amino Acid) composition is proposed to represent the
protein samples. Then, the K-NN (K-Nearest Neighbor) classifier
is employed to identify the subcellular localization based
on their reduced low-dimensional feature vectors. Ex-perimental
results thus obtained are quite encouraging, indicating that
the aforementioned linear DR method is quite promising in
dealing with complicated biological problems, such as predicting
the subcellular localization of Gram-negative bacterial proteins.
[Back to top]
[Full
Text Article]
Isolation of a Mitogenic Agglutinin with Relatively
High Thermostability from Seeds of the Variegated Shell Ginger
Jack Ho Wong, T.B. Ng, Kalin Y.B. Zhang, Stephen C.W.
Sze and H.X. Wang
An agglutinin with a molecular mass of 130 kDa has been isolated
from the seeds of Alpinia zerumbet cv.’Variegata’.
The isolation procedure involved anion exchange chromatography
on DEAE-cellulose, affinity chromatography on Affi-gel blue
gel, and gel filtration by fast protein liquid chromatography
on Superdex 75. The agglutinin exhibited hemagglutinating
activity toward rabbit erythrocytes which could not be inhibited
by simple sugars. It was composed of four identical 32-kDa
subunits with substantial N-terminal sequence similarity to
chitinase and yieldin. The hemagglutinating activity of A.
zerumbet agglutinin was stable up to 80ºC
and not affected by presence of a variety of salts. The agglutinin
stimulated [methyl-3H]-thymidine
uptake by mouse splenocytes. It did not exhibit antifungal
activity.
[Back to top]
[Full
Text Article]
[PMID:
19508206 PubMed - indexed for MEDLINE]
Effects of Peptidic Antagonists of Grb2-SH2 on Human
Breast Cancer Cells
Chiu-Heng Chen, Meng-Kai Chen, Kee-Ching G. Jeng and
Feng-Di T. Lung
The growth factor receptor-bound protein Src homology
2 (Grb2-SH2) plays an important role in the oncogenic Ras
signaling pathway, which involves in cell proliferation and
differentiation. Therefore, the antagonist of Grb2-SH2 has
become a potential target for developing anticancer agents.
Recently, we discovered the peptide 1 (Fmoc-Glu-Tyr-Aib-Asn-NH2)
with high affinity for the Grb2-SH2 domain by using surface
plasmon resonance (SPR)-biosensor technology. Herein, we report
the further design of the lead peptide 1
by addition of an Arg-Gly-Asp sequence to 1
to enhance its binding to Grb2-SH2 and to induce apoptosis
in cancer cells. Both the linear and cyclic analogs of the
newly designed compounds were prepared along with an analog
in which the Nα-Fmoc
group was removed. These peptide analogs were assayed for
their affinity for the Grb2-SH2, their antiproliferative effect
on human breast cancer cells, their specificity for cancer
cells, and their effects on cytotoxicity and the cell cycle.
MCF-7 and MDA-MB-453 breast cancer cells were treated with
various concentrations of each peptide. The cell viability
and cytotoxicity of peptide-treated cells were determined
by using the cell proliferation kit (3-[4, 5-dimethyl-2-thiazolyl]-2,
5-diphenyl-tetrazolium bromide, MTT) and cytotoxicity kit
(lactate dehydrogenase, LDH), respectively. Effects of peptides
on the cell cycle progression of cancer cells and apoptosis
were analyzed by using flow cytometry. Results demonstrated
that the peptide analog 2 (H-Arg-Gly-Asp-Glu-Tyr-Aib-Asn-Arg-Gly-Asp-NH2)
had anti-proliferative effects on MCF-7 and MDA-MB-453 cells
with the IC50 of 45.7 µM
and 47.4 µM,
respectively. The cytotoxicity and percentage of sub-G1 in
the cell cycle were increased in these cancer cells when cells
were treated with higher concentration of the Arg-Gly-Asp-containing
peptide 2. These results provide important
information for the development of anti-cancer agents.
[Back to top]
[Full
Text Article]
[PMID: 19508200 PubMed - indexed for MEDLINE]
Salt-Assisted Religation of Proteolyzed Glutathione-S-Transferase
Follows Hofmeister Series
K.V. Radha Kishan and Amit Sharma
Proteases have been used not only for proteolysis but also
in organic solvent-assisted religation processes. Here, we
demonstrated the effect of salts on peptide bond resynthesis
in Glutathione-S-transferase (GST) and have found it to be
in the purview of the Hofmeister phenomena. Our results show
that the efficiency and ease of religation increases with
an increase in the surface charge densities of the cations
used in the study. Thus, the yield of religated GST follows
the order: Mg2+>Li+>Na+>K+.
Characteristics of the salt-religated GST were studied using
size exclusion chromatography, CD spectroscopy, mass spectrometry
and CDNB activity assay. Results show that the properties
of salt-religated GST are in close agreement with those of
the native GST. Additionally, we also assessed the specific
activity of the protease, Subtilisin Carlsberg, used in this
study. Contrary, to aqueous-organic systems, wherein there
is a remarkable decrease in the proteolytic activity, the
activity in the presence of salts is only minimally changed.
Our studies suggest that salt-assisted peptide bond formation
is favoured primarily due to changes in the ionic environment
of the nicked termini of GST, and that there is no role played
by the protease.
[Back to top]
[Full
Text Article]
[PMID:
19508198 PubMed - indexed for MEDLINE]
Evaluation of Protein Phosphorylation Site Predictors
Shufu Que, Yongfei Wang, Peixiang Chen, Yu-Rong Tang,
Ziding Zhang, and Huaqin He
A series of elegant phosphorylation site prediction methods
have been developed, which are playing an increasingly important
role in accelerating the experimental characterization of
phosphorylation sites in phosphoproteins. In this study, we
selected six recently published methods (DISPHOS, NetPhosK,
PPSP, KinasePhos, Scansite and PredPhospho) to evaluate their
performance. First, we compiled three testing datasets containing
experimentally verified phosphorylation sites for mammalian,
Arabidopsis and rice proteins. Then, we present the
prediction performance of the tested methods on these three
independent datasets. Rather than quantitatively ranking the
performance of these methods, we focused on providing an understanding
of the overall performance of the predictors. Based on this
evaluation, we found the following results: i) current phosphorylation
site predictors are not effective for practical use and there
is substantial need to improve phosphorylation site prediction;
ii) current predictors perform poorly when used to predict
phosphorylation sites in plant phosphoproteins, suggesting
that a rice-specific predictor will be required to obtain
confident computational annotation of phosphorylation sites
in rice proteomics research; and iii) the tested predictors
are complementary to some extent, implying that establishment
of a meta-server might be a promising approach to developing
an improved prediction system.
[Back to top]
[Full
Text Article]
[PMID:
19807672 PubMed - indexed for MEDLINE]
Expression, Purification, Crystallization and Preliminary
X-Ray Crystallographic Analysis of the Resuscitation Promoting
Factor Interacting Protein RipA from M. tuberculosis
Alessia Ruggiero, Flavia Squeglia, Carla Esposito, Daniela
Marasco, Emilia Pedone, Carlo Pedone and Rita Berisio
RipA is an important growth factor of M. tuberculosis.
Its depletion produces decreasing bacterial growth and abnormal
phenotype. RipA C-terminal fragment (263-472), containing
its predicted catalytic domain has been successfully crystallized
using vapor-diffusion methods. The structure has been solved
by Multiwavelength Anomalous Dispersion and atomic resolution
refinement is in progress.
[Back to top]
[Full
Text Article]
Irbesartan Inhibits Albumin-Elicited Proximal Tubular
Cell Apoptosis and Injury In Vitro
Takanori Matsui, Sho-ichi Yamagishi, Seiji Ueda, Kei Fukami
and Seiya Okuda
There is accumulating evidence that proteinuria is not merely
a biomarker for the progression of chronic kidney disease
(CKD), but also a mediator of this devastating disorder. Indeed,
albumin, one of the major components found in proteinuria,
causes proinflammatory and profibrotic changes in cultured
proximal tubular cells. Further, numerous studies have demonstrated
the active participation of the renin-angiotensin system (RAS)
in the pathogenesis of CKD as well. However, the role of the
RAS in albumin-elicited tubular cell damage remains to be
elucidated. Therefore, in this study, we studied whether and
how irbesartan, an angiotensin II type 1 receptor blocker,
could inhibit albumin-elicited proximal tubular cell apoptosis
and injury in vitro. Bovine serum albumin (BSA) increased
oxidative stress generation in human cultured proximal tubular
cells, which was blocked by the treatment with irbesartan.
Irbesartan was also found to block the BSA-induced apoptotic
cell death as well as up-regulation of plasminogen activator
inhibitor-1 and transforming growth factor-β
mRNA levels in tubular cells. The present study suggests that
there could exist a pathophysiological crosstalk between the
RAS and albumin overload in proximal tubular cell apoptosis
and damage. Blockade of the RAS by irbesartan may play a protective
role against tubular cell injury by attenuating the deleterious
effects of albumin.
[Back to top]
[Full
Text Article]
[PMID:
19508193 PubMed - indexed for MEDLINE]
Identification of a Cell-Bound Extracellular Protease
Overproduced by Sulfolobus solfataricus in Peptide-Rich
Media
Raffaele Cannio, Giuliana Catara, Imma Fiume, Marco Balestrieri,
Mosè Rossi and Gianna Palmieri
A new protease, named SsMTP was identified from the archeon
Sulfolobus solfataricus. The enzyme is associated
to the cell-membrane and over-produced in response to the
peptide-enriched media. SsMTP has a molecular mass of 120
kDa showing optimal activity at pH 2.0 in the temperature
range 70 – 90 °C, and a half-life of 20 days at
80 °C. Primary structure analysis revealed that SsMTP
represents a novel type of multi-domain thermopsin-like protease
containing the catalytic domain followed by two distinct domains,
PKD and Y_Y_Y, which are usually involved in a range of protein-protein
interactions among the extracellular proteins.
[Back to top]
[Full
Text Article]
Analysis of the Metabolites in Apical Area of Allium
cepa Roots by High Resolution NMR Spectroscopy Method
Arkady Yu. Budantsev, Vladimir N. Uversky and Victor
P. Kutyshenko
Elucidation of the molecular mechanisms determining the formation
of various tissues and organs is one of the central problems
of cell biology. High-resolution NMR spectroscopy was applied
for the analysis of the metabolites produced at the various
areas of the apical part of the onion Allium cepa
roots. To this end, three samples were extracted from the
root apex (the root cap, the meristem region and the cell
elongation zone). These samples were noticeably different
in the number of mitoses and the sets of metabolites. Furthermore,
the complete stasis of the plant roots and tops growth was
registered in heavy water. Comparison of the morphological
and NMR data revealed their perfect agreement with the cellular
processes occurring in the root apex. The root cap sample
was characterized by the greatest mitotic activity reflected
in the great variability of the chemical compounds extracted
from this area, the high level of energy consumption, and
the increased synthesis of the phosphocholines needed for
the cell fission. Sample containing the cell elongation zone
possessed the high sugar content, which is required for the
cell-wall growth. Therefore, our data show that high-resolution
NMR spectroscopy can be used for the identification of chemical
compounds in the various regions of the onion root apical
area.
[Back to top]
[Full
Text Article]
Two-, Three-, and Four-State Events Occur in the Mechanical
Unfolding of Small Protein L Using Molecular Dynamics Simulations
Anna V. Glyakina, Nikolay K. Balabaev and Oxana
V. Galzitskaya
Mechanical properties of (protein L)5
have been recently investigated by single-molecule force spectroscopy.
It has been demonstrated that the unfolding of individual
domains proceeds through a two-state mechanism. Here, we study
mechanical properties of protein L at the atomic level under
stretching at constant velocity using molecular dynamics simulations.
We have found that the unfolding process of protein L can
occur either in a single step or through short living and
quite native like intermediate states, which was not observed
in previous studies. Analysis of the 24 trajectories from
molecular dynamics simulations with explicit water showed
that the mechanical unfolding of protein L occurs through
at least two pathways. These pathways coincide in two- and
multi-state events and at different extension velocities studied
(0.125, 0.0625 and 0.005 Å.ps-1).
[Back to top]
[Full
Text Article]
Cells with Minimal Expression of the JAK/STAT Pathway
Related Proteins STAT5a and the Prolactin Receptor: Evidence
of an Alternate Prolactin Receptor Isoform in Breast Disease
G.L. Bratthauer, M.D. Stamatakos and T.N. Vinh
Usually, wherever breast STAT5a is present, PRLR is reduced;
without STAT5a PRLR becomes abundant. Five breast lesions
essentially lacking both were tested immunohistochemically
for PRLR isoforms. The intermediate isoform was essentially
only detected in these lesions. In some breast lesions PRLR
isoforms may be involved in JAK/STAT pathway disturbances.
[Back to top]
[Full
Text Article]
The Malarial Drug Target Plasmodium falciparum
1–Deoxy–D–Xylulose–5–Phosphate
Reductoisomerase (PfDXR): Development of a 3–D
Model for Identification of Novel, Structural and Functional
Features and for Inhibitor Screening
Jessica L. Goble, Matthew R. Adendorff, Tjaart A.P. de
Beer, Linda L. Stephens and Gregory L. Blatch
[Supplementary
Material]
A three–dimensional model of the malarial drug target
protein PfDXR was generated, and validated using
structure–checking programs and protein docking studies.
Structural and functional features unique to PfDXR
were identified using the model and comparative sequence analyses
with apicomplexan and non–apicomplexan DXR proteins.
Furthermore, we have used the model to develop an efficient
approach to screen for potential tool compounds for use in
the rational design of novel DXR inhibitors.
[Back to top]
[Full
Text Article]
Synthesis and Anti-Angiogenic Effect of Conjugates
Between Serum Albumin and Non-Steroidal Anti-Inflammatory
Drugs
B. Kjær, C. Struve, T. Friis, A.-M. Engel, N.H.
Beyer, P. Højrup and G. Houen
Non-steroidal anti-inflammatory drugs (NSAIDs) inhibit tumor
growth and angiogenesis. Covalent linkage of naproxen to human
serum albumin (HSA) has been shown to target it efficiently
to the liver and this may potentially be exploited for liver-selective
inhibition of angiogenesis. With the aim of investigating
the anti-angiogenic efficiency of NSAID-HSA conjugates in
vitro, three NSAIDs, aspirin, ibuprofen, and naproxen
were conjugated to HSA using different concentrations of their
N-hydroxysuccinimide esters. Conjugation ratios from
10 to 50 were achieved and the conjugates retained a growth
inhibitory effect on endothelial cells at or above the level
of the non-conjugated NSAIDs in an in vitro angiogenesis
assay.
[Back to top]
[Full
Text Article]
Location of MBL-Associated Serine Proteases Binding
Motifs on Human Mannan-Binding Lectin (MBL)
Daming Zuo, Xuemin Cai, Na Zhao, Liyun Zhang and
Zhengliang Chen
The lectin pathway provides an antibody independent route
of complement activation. Mannan-binding lectin (MBL) can
form compound with MBL-associated serine proteases (MASPs)
through its collagen-like region (CLR) to initiate complement
fixation. In this study, we designed and synthesized a range
of peptides according to the sequence of CLR in human MBL,
which were assumed to block the MBL-MASP interaction, in order
to locate the serine protease binding motifs on human MBL.
It was demonstrated that MASPs bind on the C-terminal side
of the hinge region formed by an interruption in the Gly-X-Y
repeat pattern of the collagen-like domain. In addition, Arg32Cys,
Gly35Asp and Gly37Glu mutant proteins have the similar serine
protease binding characteristic with wild type MBL, but the
binding between mutated MBL proteins and MASPs is much weaker
than that between wild type MBL protein and MASPs.
[Back to top]
[Full
Text Article]
Sequence-Based Prediction of Protein-Protein Interactions
by Means of Rotation Forest and Autocorrelation Descriptor
Jun-Feng Xia, Kyungsook Han and De-Shuang Huang
We propose a sequence-based multiple classifier system, i.e.,
rotation forest, to infer protein-protein interactions (PPIs).
Moreover, Moran autocorrelation descriptor is used to code
an interaction protein pair. Experimental results on Saccharomyces
cerevisiae and Helicobacter pylori datasets
show that our approach outperforms those previously published
in literature, which demonstrates the effectiveness of the
proposed method.
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