In vitro Degradation of b-Amyloid[25-35] Peptide Pp.423-428
Krisztina
Jost, József Varga, Botond Penke and
Márta Zarándi
An Efficient,
Flexible-Model Program for the Analysis of Differential Scanning Calorimetry
Protein Denaturation Data Pp.429-436
Sasha B.
Grek, John K. Davis and Michael Blaber
Modeling the Hierarchical
Protein Folding Using Clustering Monte-Carlo Algorithm Pp.437-442
Semen O.
Yesylevskyy and Alexander P. Demchenko
Synthesis and
Characterization of New Temporin A Analogs and A Hybrid Peptide Pp.443-450
David Wade,
Tomas Bergman, Jerzy Silberring and Hilkka Lankinen
Interaction of An
Amphipathic Peptide Corresponding to Residues 417-434 of Escherichia coli
Haemolysin with Phospholipid Bilayers Pp.451-460
Georgina
Verza, Félix M. Gońi and Laura S. Bakás
Syntheses of Neurotensin
(NT) Analogues and Their Comparative Anorectic Effect on Food Intake in Rats
Pp.461-468
T. Abiko and Y. Takamura
CDNA Cloning and
Expression of Acutin II, A Native Mutant of Thrombin-Like Enzyme from
Agkistrodon acutus Pp.469-475
Hua Pan, Jiewu Liu, Xiaoyan Du, Yuancong
Zhou and Xiangfu Wu
Renal Effects of the
Lectin from Canavalia brasiliensis Seeds Pp.477-484
Edson H. Teixeira, Alexandre Havt, Paulo
S.F. Barbosa, Dalgimar B. Meneses,
Manassés C. Fonteles, Helena S.A. Monteiro, Alexandre H. Sampaio and Benildo S. Cavada
Serine Protease Inhibitors
from Amazon Leguminosae Seeds: Purification and Preliminary Characterization of
Two Chymotrypsin Inhibitors from Inga umbratica Pp.485-493
Calderon,
L.A., Teles, R.C.L., Leite, J.R.S.A., Bloch, C. Jr., Astolfi-Filho, S. and Freitas,
S.M.
Crystallization Reports
Crystallization and
Preliminary X-Ray Studies of A Thermostable DNA Photolyase from Thermus
thermophilus HB8 Pp.495-498
Hirofumi
Komori, Hiroshi Tsujiuchi, Ryoji Masui, Seiki Kuramitsu, Shigeyuki Yokoyama,
Takehiko Shibata, Yorinao Inoue and Kunio Miki
Preliminary X-Ray
Crystallographic Studies of the Mycobacterium tuberculosis HSP16.3 Molecular
Chaperone Pp.499-502
Chen Y., An
J., Ding Y. Dai H., Mao Q., Feng L., Liu B., Chang Y., Chen F., He H., Tang H.,
Chang Z. and Rao Z.
Crystallization and
Preliminary X-Ray Crystallographic Studies of Staphylokinase Variant S41G Pp.503-507
Chen Y., An
J., Song G., Feng L., Ding Y., Chang Y., Chen F., Liu B., He H., Tang H., Song
H. and Rao Z.
Abstracts
[Back to top] In vitro Degradation of b-Amyloid[25-35] Peptide
Krisztina Jost, József Varga, Botond Penke and Márta Zarándi
Some
amyloid-derived peptides show their toxic effects only after a long “aging”
period performed several days at pH 7.4 and 37 °C for cluster formation.
Our experiments show that long aging of b-amyloid[25-35] under
physiological conditions results in peptide bond cleavage between Asn27 and
Lys28. Relatively short incubation time (24 hours) and absence of Ca2+ ions
prevent peptide cleavage and results in good aggregation of b-amyloids.
[Back to
top] An Efficient, Flexible-Model Program for the Analysis of Differential
Scanning Calorimetry Protein Denaturation Data
Sasha
B. Grek, John K. Davis and Michael Blaber
Although
thermodynamic formalisms for protein denaturation have been established for
some time, available software programs for deconvolution of DSC data exhibit
various limitations. These include enforcing a constant DCp(T), linear heat
capacity functions, and so on. We have developed a Windows™ based program that
allows greater flexibility, speed and accuracy than previously available
programs for the analysis of DSC data.
One novel feature of the program is the inclusion of, and ability to
refine, a concentration-dependent term.
[Back to
top] Modeling the Hierarchical
Protein Folding Using Clustering Monte-Carlo Algorithm
Semen O. Yesylevskyy and Alexander P. Demchenko
A
new modification of Monte-Carlo algorithm was suggested for the simulation of
hierarchical protein folding. When applied to 2D lattice model of 12-member
peptide this method allows observing complex kinetic folding behavior with the
formation of clustered intermediates.
[Back to
top] Synthesis and
Characterization of New Temporin A Analogs and A Hybrid Peptide
David
Wade, Tomas Bergman, Jerzy Silberring
and Hilkka Lankinen
Temporin A is one of a group of 31 structurally similar antibiotic peptides isolated from the skins of anurans, 10 of which were isolated from the European red frog, Rana temporaria. The synthesis and bacteriological study of temporin A and 8 analogs were reported previously, and this article describes the synthesis and analyses of 11 new temporin A analogs, and a cecropin A-temporin A hybrid peptide
[Back to
top] Interaction of An Amphipathic Peptide Corresponding to Residues of
Escherichia coli Haemolysin with Phospholipid Bilayers
Georgina
Verza, Félix M. Gońi and Laura S. Bakás
a-Haemolysin is an extracellular protein toxin (107KDa) produced by certain pathogenic strains of Escherichia coli. It can bind to lipid bilayers and produce membrane disruption in cell and model membranes. Protein secondary structure predictions suggest an amphipathic helix conformation for the membrane-interacting domain of HlyA, and no potential transmembrane segments. In this paper, we investigated the lipid associating properties of the chemically synthesized peptide H9 (MFEHVASKMADVIAEWEK) corresponding to residues 417-434 of HlyA. Changes in the intrinsic fluorescence and fluorescence anisotropy of the single Trp residue after the addition of DMPC-LUV reveal that the peptide-membrane interaction is optimum at or above the gel-liquid crystalline transition temperature of the lipid. Moreover, the peptide induces vesicle aggregation, as detected through changes in light scattering by the vesicle suspension. However, under comparable conditions, H9 has no hemolytic activity against sheep erythrocytes, nor does it induce leakage of vesicular aqueous contents. These data suggest that HlyA binds the membrane surface through amphipathic helices, though cooperativity among neighbouring helices is probably necessary to explain the lytic effect of the toxin.
[Back to
top] Syntheses of Neurotensin
(NT) Analogues and Their Comparative Anorectic Effect on Food Intake in Rats
T. Abiko and Y. Takamura
Five
analogues of neurotensin (NT: Pyr-Leu-Tyr-Glu-Asn-Lys-Pro-Arg-Arg-Pro-Tyr-Ile-Leu)
were prepared by the solid-phase method and their comparative anorectic effects
on food intake in rats were examined. Among them, [Phe(NO2)3,11]-NT and
[Phe(4F)3,11]-NT showed stronger anorectic activity than that of the parent
peptide but [Tyr(Me)3,11]-NT was less active than the parent peptide. On the
contrary, the other two analogues, [Sar7,10]-NT and [βAla7,10]-NT had no
anorectic activity.
[Back to
top] CDNA Cloning and
Expression of Acutin II, A Native Mutant of Thrombin-Like Enzyme from
Agkistrodon acutus
Hua Pan, Jiewu Liu, Xiaoyan Du, Yuancong Zhou and Xiangfu Wu
One
cDNA of a thrombin-like enzyme named acutinII was amplified by RT-PCR from
the venom gland of the Agkistrodon acutus snake. AcutinII shows high similarity to
acutin, the other thrombin-like enzyme from Agkistrodon acutus snake in
nucleotide and amino acid sequences except it is shorter by 16 amino acid at
the C-terminus. The catalytic residues and disulfide bridges of acutinII were deduced. AcutinII was expressed in E. coli .The
expressed protein was detected by western blotting and the yield was up to 32%
of the total proteins.
[Back to
top] Renal Effects of the
Lectin from Canavalia brasiliensis Seeds
Edson
H. Teixeira, Alexandre Havt, Paulo S.F. Barbosa, Dalgimar B. Meneses, Manassés C. Fonteles, Helena S.A. Monteiro, Alexandre
H. Sampaio and Benildo S. Cavada
The lectin from the seeds of Canavalia brasiliensis (Con Br) was tested for its renal effects using the isolated perfusion rat kidney method. Three different doses were examined (3, 10 and 30 mg/ml), which were compared with a control group. The control group was perfused with only Krebs-Henseleit solution containing 6% BSA. Con Br caused diuresis and natriuresis, with a mild alteration on the perfusion pressure. Probably the lectin is inhibiting the Na+/K+/2Cl- transporter present in the thick ascending limb of the Henle´s loop.
[Back to
top] Serine Protease Inhibitors
from Amazon Leguminosae Seeds: Purification and Preliminary Characterization of
Two Chymotrypsin Inhibitors from Inga umbratica
Calderon,
L.A., Teles, R.C.L., Leite, J.R.S.A., Bloch, C. Jr., Astolfi-Filho, S. and Freitas, S.M.
Nine
species of Leguminosae seeds from Amazon forest have been screened for trypsin
and chymotrypsin inhibitory activity.
The species involved were Cassia basselari, Cassia grandis, Cassia
occidentalis, Dialium guianense, Inga fagifolia, Inga rubiginosa, Inga
umbratica, Inga velutina and Mimosa guillandinae. Extracts from all the
species, except I. umbratica, contained significant activity against trypsin,
chymotrypsin and blood human clotting factors Xa. Two new chymotrypsin
inhibitors (IuCI-1 and IuCI-2) have been purified to homogeneity from I.
umbratica with molecular masses of 20,088.6 and 20,271.2, respectively.
[Back
to top] Crystallization and
Preliminary X-Ray Studies of A Thermostable DNA Photolyase from Thermus
thermophilus HB8
Hirofumi
Komori, Hiroshi Tsujiuchi, Ryoji Masui, Seiki Kuramitsu, Shigeyuki Yokoyama,
Takehiko Shibata, Yorinao Inoue and Kunio Miki
A
thermostable DNA photolyase from an extremely thermophilic bacterium, Thermus
thermophilus HB8 has been crystallized by the hanging drop vapor diffusion
method using NH4H2PO4 as a precipitant.
The hexagonal crystals were grown to a size of 0.4 mm in length. X-ray diffraction experiments show the
crystals to belong to the hexagonal space group P6522 or P6122 with the
unit cell dimensions of a=b=113.6 Ĺ, c=142.0 Ĺ. They diffract X-rays to 2.4 Ĺ resolution with synchrotron
radiation.
[Back
to top] Preliminary X-Ray
Crystallographic Studies of the Mycobacterium tuberculosis HSP16.3 Molecular
Chaperone
Chen
Y., An J., Ding Y. Dai H., Mao Q., Feng L., Liu B., Chang Y., Chen F., He H.,
Tang H., Chang Z. and Rao Z.
Mycobacterium
Tuberculosis HSP16.3 is a major antigen maximally expressed during the
stationary phase. Previous studies showed that HSP16.3 can function as a
molecular chaperone in vitro. Here, crystallization trails of HSP 16.3 were
reported. A kind of crystal can be diffracted to 2.8 Ĺ resolution at the
"Photon Factory", a synchrotron light source in Japan. The crystal
displayed the space group R3 with unit cell parameters a=b=110 Ĺ , c=152 Ĺ and
γ=120˚. Assuming the presence of 9 HSP16.3 molecules in an asymmetric
unit, it gives a Vm= 0.73 Ĺ 3/Da. and solvent content of 35% by volume.
[Back
to top] Crystallization and
Preliminary X-Ray Crystallographic Studies of Staphylokinase Variant S41G
Chen
Y., An J., Song G., Feng L., Ding Y., Chang Y., Chen F., Liu B., He H., Tang H., Song H. and Rao Z.
Staphylokinse (Sak) is a plasminogen activator for the treatment of patients with thrombolitic disorders. However, the highly purified Sak can form dimer in solution, which is believed to be the cause for the increased antigenicity. Here we report a new crystal form with two molecules in an asymmetric unit, suggesting there maybe a dimer packing in crystal. The crystal belongs to the orthorhombic space group P212121 and the unit cell dimensions are a=43.9, b=59.3, c=102.4 Ĺ, a=b=g=90ş. The diffraction data was 99.7% complete to 2.3 Ĺ with an Rmerge of 5.5%.