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Protein and Peptide Letters, Vol. 5, No. 5, 1998

Contents

Microscale Isolation of Blocked N-Terminal Pepfides and Sequence Analysis by Mass Spectrometry. Pp. 243-250.
Kuo-Liang Hsi, Lydia Nuwaysir, Dave Dupont and Pau-Miau Yuan
[Abstract]

Carboxyl-Terminal Sequencing: New C-Terminal Peptidyl-Thiohydantoins Formation Conditions. Pp. 251-256.
Patricia D. Ribeiro, Ronaldo S.M. Borges, Paulo R.R. Costa, Elias W. Alves and Olga L T. Machado
[Abstract]

Sodium Iodide as a Novel, Neutral and Facile Deprotecting Reagent of N-tert-Butyloxycarbonyl Groups in Peptide Chemistry. Pp. 257-258.
Jungyeob Ham, Kyungseok Choi, Jaeyoung Ko, Hanwon Lee and Mankil Jung
[Abstract]

Designing b-Hairpin Forming Short Peptide. Pp. 259-264.
Sha Yinlin, Huang Yongliang, Wang Qi and Lai Luhua
[Abstract]

Compression Refolding of Cytochrome C. Pp. 265-268.
Masashi Dewa, Masato Tayauchi, Masao Sakurai and Katsutoshi Nitta
[Abstract]

New Synthetic Peptides on Nuclear Localization Signal Derived from Jun by Single Amino Acid Substitutions. Pp. 269-272.
Kazuhiro Chida, Tomoko Tagawa, Shushi Nagamori and Toshio Kuroki
[Abstract]

Soluble Expression and One-Step Purification of Recombinant Bacillus anthracis Protective Antigen. Pp. 273-278.
David C. Willhite and Steven R. Blanke
[Abstract]

Effect of Alcohol on Aggregation of Human Neuronal Tau Protein. Pp. 279-286.
Rong-Qiao He, Jian-Ying Luo and Wei Li
[Abstract]

In Vitro Effects of a Novel Tetrapeptide in Human Neutrophils and in a Rat Model of Osteoarthritis. Pp. 287-294.
Satish Devadas, C. V. Ramesh and R. Puvanakrishnan
[Abstract]

a-Fetoprotein Structure Depends on the Protein Purification Procedure: Further Evidence on the Structure Forming Role of the Ligands. Pp. 295-301.
Andrey Yu Tomashevski, Natalya V. Narishneva, Tatyana N. Melnik and Vladimir N. Uversky
[Abstract]


Abstracts

[Back to top] Microscale Isolation of Blocked N-Terminal Pepfides and Sequence Analysis by Mass Spectrometry. Kuo-Liang Hsi, Lydia Nuwaysir, Dave Dupont and Pau-Miau Yuan.
An improved procedure for selectively isolating a blocked N-terminal is described to work with low microgram amounts of protein. Additionally, the scope of this method is expanded to include selective isolation of free and blocked N-termini. Proteins modified with succinic anhydride are purified by SDS-PAGE, digested in situ with chymotrypsin and treated with cyanogen bromide-activated Sepharose 4B. The isolated N-terminal peptide from proteins are analyzed utilizing mass spectrometer. Both amino acid sequence information and the nature of the blocking group can be determined.

[Back to top] Carboxyl-Terminal Sequencing: New C-Terminal Peptidyl-Thiohydantoins Formation Conditions. Patricia D. Ribeiro, Ronaldo S.M. Borges, Paulo R.R. Costa, Elias W. Alves and Olga L T. Machado.
The present study explores conditions to activate the carboxyl group before the coupling of C-terminus-AA with TMS-ITC. N-tert-butoxy-carbonyl amino acids (Boc-AAs) and Leucine Enkephalin were used as models and isobutyl chloroformate was used as a C-terminal activator. The reaction coupling activated AA with TMS-ITC was temperature dependent. We also report here a new, efficient, economical and ecological technique to separate the mixture of amino acids thiohydantoins (TH-AA).

[Back to top] Sodium Iodide as a Novel, Neutral and Facile Deprotecting Reagent of N-tert-Butyloxycarbonyl Groups in Peptide Chemistry. Jungyeob Ham, Kyungseok Choi, Jaeyoung Ko, Hanwon Lee and Mankil Jung.
The N-tert-butyloxycarbonyl (N-t-Boc) protecting groups of amino acids were cleanly and easily removed by treatment with sodium iodide under neutral conditions.

[Back to top] Designing b-Hairpin Forming Short Peptide. Sha Yinlin, Huang Yongliang, Wang Qi and Lai Luhua.
The short linear peptide sequence H2N-Val-Thr-Leu-D-Pro-Gly-Val-Thr-Val-COOH predicted to form b-hairpin was synthesized by Fmoc/Bu strategy and purified by RP-HPLC. The CD spectra show a minimum at ca. 216nm and a maximum at ca. 194nm, which have been concluded as the common contribution from b-turn and b-sheet, and the structure in water was enhanced by organic reagent, such as TFE, acetonitrile and isopropyl alcohol.

[Back to top] Compression Refolding of Cytochrome C. Masashi Dewa, Masato Tayauchi, Masao Sakurai and Katsutoshi Nitta.
Perturbation of thermal unfolding of cytochrome C with compression was investigated to obtain volumetric quantities of the unfolding.  At pH 2.9-3.2 and around 40-60ºC, cytochrome C does not unfold but refold when compressed.  This phenomenon contradicts to our present understanding that a protein unfolds if high pressure is applied.  The volume change is strongly dependent on temperature and decreases with decreasing temperature.  This ckiange of volume changes its sign around 40ºC and is negative at room temperature.

[Back to top] New Synthetic Peptides on Nuclear Localization Signal Derived from Jun by Single Amino Acid Substitutions. Kazuhiro Chida, Tomoko Tagawa, Shushi Nagamori and Toshio Kuroki.
We examined nuclear transport activities of synthetic peptides on the basis of nuclear localization signal (NLS) of Jun, Arg-Lys-Arg-Lys-Leu, by microinjection into the cytoplasm of NRK cells. Each amino acids of this sequence was replaced by protein or nonprotein amino acids. The four basic amino acids could be replaced by either lysine, arginine or ornithine (Orn). Replacement of the leucine by a methionine enhanced the transport activity. A nonprotein amino acid sequence Orn-Orn-Orn-Orn-Nrv (norvaline) functioned as an NLS.

[Back to top] Soluble Expression and One-Step Purification of Recombinant Bacillus anthracis Protective Antigen. David C. Willhite and Steven R. Blanke.
We have greatly simplified production of the Bacillus anthracis protective antigen (PA), the immunoprotective antigen of the anthrax vaccine.  By varying induction conditions, we have expressed stable, soluble PA in E. coli, affinity-tagged to facilitate rapid, single-step purification. Recombinant PA exhibited identical properties to B. anthracis PA. Our approach is an attractive strategy for generating purified vaccine antigens that are difficult to express recombinantly.

[Back to top] Effect of Alcohol on Aggregation of Human Neuronal Tau Protein. Rong-Qiao He, Jian-Ying Luo and Wei Li.
Effects of alcohol and heparin on aggregation of the recombinant tau have been studied. Alcohol at low concentrations induces tau polymerization distinguishably at room temperature and 37ºC. The effect of heparin on tau's aggregation was cooperative with that of alcohol if both heparin and alcohol were added to tau solutions. It appears that the polymerization of tau might be correlated to the disorder of neuronal transportation of alcoholism.

[Back to top] In Vitro Effects of a Novel Tetrapeptide in Human Neutrophils and in a Rat Model of Osteoarthritis. Satish Devadas, C. V. Ramesh and R. Puvanakrishnan.
PEP1261, a derivative of Lys-Arg-Asp-Ser (KRDS) exhibits an inverse dose response in that it exhibits antioxidant properties at low concentrations and oxidant characteristics at higher concentrations. This study shows that when PEP1261 is tested on neutrophils, it exhibits marked inhibition on myeloperoxidase activity and also decreases the levels of H202 and superoxide. This indicates therapeutic application for PEP1261 in osteoarthritis.

[Back to top] a-Fetoprotein Structure Depends on the Protein Purification Procedure: Further Evidence on the Structure Forming Role of the Ligands. Andrey Yu Tomashevski, Natalya V. Narishneva, Tatyana N. Melnik and Vladimir N. Uversky.
a-Fetoprotein samples isolated from human cord serum by metal affinity chromatography and immunoaffinity method were compared by circular dichroism, fluorescence spectroscopy and scanning microcalorimetry. The isolation procedures were quite distinguished by their influence on native protein structure (and, consequently, by the effectiveness of natural ligand release from a protein molecule). As a result, structural properties and conformational stability of a-fetoprotein in the samples were found to be rather different.