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Protein & Peptide Letters, Volume 9, No. 5, 2002

 

Contents

 

Protein Structure to Function via Dynamics Pp.367-377

Neeti Sinha , and Sandra J. Smith-Gill

[Abstract]

 

The use of DODT as a non-malodorous scavenger in Fmoc-based peptide synthesis Pp.379-385

A. Teixeira, W.E. Benckhuijsen, P.E. de Koning, A.R.P.M. Valentijn and J.W. Drijfhout

[Abstract]

 

Kinetic Analysis of the Cleavage of Human Protease-Activated Receptor-1 / 2 / 3 and 4 Using Quenched-Fluorescent Peptide Substrates Pp.387-393

Mark T. Fox , Brett Greer, Jill Lawson, Adrienne Healy and Patrick Harriott.

[Abstract]

 

Antibiotic Activity of Reversed Peptides of a-Helical Antimicrobial Peptide, P18 Pp.395-402

Si-Hyung Lee , Dong Gun Lee , Sung-Tae Yang , Yangmee Kim ,Jae Il Kim , Kyung-Soo Hahm  & Song Yub Shin

[Abstract]

 

Conformational Analysis of Sea Cucumber (Caudina arenicola) C Globin 94-97 Fragment , Pro-Glu-Leu-Leu Pp.403-409

Sunil Kumar, P. N., Devaky, K. S., 1Sadasivan, C. and Haridas, M.

[Abstract]

 

A Synthetic Strategy for ON-Resin Amino Acidspecific Multiple Fatty Acid Acylation of Peptides Pp.411-417

Avaronnan Harishchandran, Bhattaram Pallavi, Ramakrishnan Nagaraj

[Abstract]

 

Cloning and High-Level Expression of Scorpion Toxin BmKITa1 in Escherichia coli and Insect Cells Pp.419-426

Zhen Liu, Guan-Zhen Yang, Cheng-Wu Chi, Xiang-Fu Wu

[Abstract]

 

Functionally Important Residues for the Anticoagulant Activity of a Basic Phospholipase A2 from the Agkistrodon halys pallas Pp.427-434

Xiaoyan Zhong, Haomang Jiao, Liang Fan, Xiangfu  Wu and Yuancong Zhou

[Abstract]

 

Effects of Stereochemistry of Sugars on Protein Stabilities Pp.435-439

Kiyonari Masumoto, Tadashi Ueda , Makiko Nagata, Yuko Yamada,Yuichiro Yoshida, Yoshio Hashimoto, and Taiji Imoto

[Abstract]

 

Purification, Crystallization and Initial Structural Solution of a New a-Like Toxin with Cardiac Toxicity from Scorpion Buthus martensii Karsch Pp.441-449

Rong-Jin Guan, Xiao-Lin He, Miao Wang, Ye-Xiang, Gen-Pei Li and Da-Cheng Wang

[Abstract]

 

Binding Potency of Peptide Fragments of Type 1 Collagen Cross-Linked N-Telopeptide Measured by an Enzyme-Linked Immunosorbant Assay Pp.451-457

Feng-Di T. Lung , Chiu-Heng Chen1, Heuy-Yi Chen , Chien-Chung Liou , and Yen-Meng Liou

[Abstract]

 

Crystallization and preliminary X-ray diffraction analysis of FKBP12 complexed with a novel neurotrophic ligand Pp.459-463

Pengyun Li , Liwei Wang , Yi Ding  , Beili Wu , Cuiling Shu , Aihua Nie , Song Li , Beifen Shen  & Zihe Rao

[Abstract]

 

Abstracts

 

[Back to top] Protein Structure to Function via Dynamics

Neeti Sinha , and Sandra J. Smith-Gill

 

Protein folding, binding, catalytic activity and molecular recognition all involve molecular movements, with varying extents. The molecular movements are brought upon via flexible regions. Stemming from sequence, a fine tuning of electrostatic and hydrophobic properties of the protein fold determine flexible and rigid regions. Studies show flexible regions usually lack electrostatic interactions, such as salt-bridges and hydrogen-bonds, while the rigid regions often have larger number of such electrostatic interactions. Protein flexible regions are not simply an outcome of looser packing or instability, rather they are evolutionally selected. In this review article we highlight the significance of protein flexibilities in folding, binding and function, and their structural and thermodynamic determinants. Our electrostatic calculations and molecular dynamic simulations on an antibody-antigen complex further illustrate the importance of protein flexibilities in binding and function.

 

[Back to top] The use of DODT as a non-malodorous scavenger in Fmoc-based peptide synthesis

A. Teixeira, W.E. Benckhuijsen, P.E. de Koning, A.R.P.M. Valentijn and J.W. Drijfhout

 

We have synthesized a random group of peptides and performed cleavages using various cleavage cocktails including 3,6-dioxa-1,8-octanedithiol (DODT). Purity of the peptides was compared to that obtained with standard protocols for cleavage using RP-HPLC and Maldi-Tof mass spectrometry. We show that stinking thiols can  be replaced by the almost odourless (DODT) without negatively affecting the purity of the end product.

 

[Back to top] Kinetic Analysis of the Cleavage of Human Protease-Activated Receptor-1 / 2 / 3 and 4 Using Quenched-Fluorescent Peptide Substrates

Mark T. Fox , Brett Greer, Jill Lawson, Adrienne Healy and Patrick Harriott.

 

Protease-activated receptors [PARs] are a family of G-protein-coupled seven-transmembrane domain receptors that are activated by proteolytic cleavage of their amino-terminal exodomain. To characterize the cleavage rate of human PAR-1 / 2 / 3 and 4 by trypsin and thrombin, four synthetic quenched-fluorescent peptide substrates have been synthesized. Each substrate consisted of a ten-residue peptide spanning the receptor activation cleavage site and using progress-curve kinetics, kcat / Km values were determined.

 

[Back to top] Antibiotic Activity of Reversed Peptides of a-Helical Antimicrobial Peptide, P18

Si-Hyung Lee , Dong Gun Lee , Sung-Tae Yang , Yangmee Kim ,Jae Il Kim , Kyung-Soo Hahm  & Song Yub Shin

 

P18 (KWKLFKKIPKFLHLAKKF-NH2), an a-helical antimicrobial peptide designed from cecropin Amagainin 2 hybrid, was known to have potent antimicrobial activity against bacteria as well as fungi without hemolytic activity. To find the peptides comparable or superior to the antimicrobial activity of P18, the two reversed peptides (Rev-1 and Rev-2) of P18 were designed and synthesized. These peptides were found to have similar antimicrobial activity against bacterial and fungal cells without hemolytic activity as compared with P18. Furthermore, a reversed peptide, Rev-2 was shown to have a two-fold higher activity in killing some bacterial cells than P18. Therefore, these results suggested that Rev-2 peptide seems to be an excellent candidate for developing novel peptide antibiotics.

 

[Back to top] Conformational Analysis of Sea Cucumber (Caudina arenicola) C Globin 94-97 Fragment , Pro-Glu-Leu-Leu

Sunil Kumar, P. N., Devaky, K. S., 1Sadasivan, C. and 1Haridas, M.

 

The tetrapeptide Pro-Glu-Leu-Leu forms the 94-97 fragment of C globin in sea cucumber. 2% Butanediol dimethacrylate-cross linked polystyrene (2% BDDMA-PS), which had been optimized, was used for the synthesis of the tetrapeptide Pro-Glu-Leu-Leu. The peptide was synthesized by using Boc-amino acid strategy. The peptide purity was checked by RP-HPLC and the peptide was characterized by 1H NMR spectroscopy and amino acid analysis. Conformation of the peptide was studied by 1D- and 2D- homonuclear 1H NMR, in DMSO-d6 at 300K. The conformation of the synthetic tetrapeptide (extended backbone conformation) is not in agreement with that in C globin.

 

[Back to top] A Synthetic Strategy for ON-Resin Amino Acidspecific Multiple Fatty Acid Acylation of Peptides

Avaronnan Harishchandran1, Bhattaram Pallavi1, Ramakrishnan Nagaraj

 

Covalent modification with fatty acids is observed in several proteins that play crucial roles in cellular physiology. In this paper, a convenient method for the generation of multiple fatty acylated synthetic peptides is described. Peptides were synthesized using solid phase procedures with fluorenylmethoxycarbonyl a-amino protected amino acids. Acetamidomethyl protected cysteines were employed. The thiol protecting group was selectively deprotected and acylation was carried out on the resin-bound peptides. The strategy described in this report is applicable to any peptide sequence.

 

[Back to top] Cloning and High-Level Expression of Scorpion Toxin BmKITa1 in Escherichia coli and Insect Cells

Zhen Liu, Guan-Zhen Yang, Cheng-Wu Chi, Xiang-Fu Wu

 

BmK ITa1 cDNA was cloned and highly expressed in E. coli and insect cell. SDS-PAGE and western blot analysis revealed that subunit molecular weight of expression products is about 40 kDa and 10 kDa respectively. The expression product purified by a Ni2+-IDA-sepharose 6B column was toxic for insect, which indicated that it was biologically activity. Furthermore, Quantitative estimation show that the biological activity of recombinant BmK ITa1 from Tn cells was more powerful than from E. coli.

 

[Back to top] Functionally Important Residues for the Anticoagulant Activity of a Basic Phospholipase A2 from the Agkistrodon halys pallas

Xiaoyan Zhong, Haomang Jiao, Liang Fan, Xiangfu  Wu and Yuancong Zhou

 

To identify the anticoagulant region of the phospholipase A2 (PLA2) from the Agkistrodon halys Pallas (class II), four mutants E53G, W70M, T56K, and D67K were produced according to the prediction from the crystal structure and the sequence comparison of the strong, weak and non-anticoagulant PLA2s. A test of blood clotting revealed that E53G and W70M had lost their effects on the blood clotting, while T56K and D67K had enhanced activity. The four residues are located on the same face in the tertiary structure of this enzyme. The result supported the prediction that there exists an anticoagulant region that is composed of some residues that are close to each other in tertiary structure to form a functional face.

 

[Back to top] Effects of Stereochemistry of Sugars on Protein Stabilities

Kiyonari Masumoto, Tadashi Ueda , Makiko Nagata, Yuko Yamada,Yuichiro Yoshida, Yoshio Hashimoto, and Taiji Imoto

 

We investigated thermal stabilities of four proteins in the presence of four kinds of sugars to analyze the mechanism of stabilization of proteins by additives. These proteins were stabilized by the addition of sugars, and the degree of stabilization correlated to the partial molar isentropic compressibility of the sugar.

 

[Back to top] Purification, Crystallization and Initial Structural Solution of a New a-Like Toxin with Cardiac Toxicity from Scorpion Buthus martensii Karsch

Rong-Jin Guan, Xiao-Lin He, Miao Wang, Ye-Xiang, Gen-Pei Li and Da-Cheng Wang

 

An a-like toxin named BmK M7 active on both mammals and insects has been purified from the venom of scorpion Buthus martensii Karsch (BmK) recently. The electrophysiological experiments showed that M7 can bind to human cardiac Na+-channel and modify its normal properties, hence can be considered as a cardiotoxin. Single crystals of M7 have been obtained by hanging-drop vapor diffusion method using ammonium sulfate as precipitant in Tris-HCl buffer at pH 8.5. A data set to 1.40 Å resolution was collected using synchrotron radiation and CCD detector in Photon Factory in Japan. Data analysis showed that the crystals belonged to space group P3121/P3221, with cell dimensions a=b=32.76 Å, c=176.82 Å. Assuming two molecules per asymmetric unit, the Vm value is 1.92 Å3/Da. The initial structural analysis was carried out by molecular replacement, which showed the correct space group (P3121), and the orientations and positions of the two molecules in the asymmetric unit.

 

[Back to top] Binding Potency of Peptide Fragments of Type 1 Collagen Cross-Linked N-Telopeptide Measured by an Enzyme-Linked Immunosorbant Assay

Feng-Di T. Lung , Chiu-Heng Chen1, Heuy-Yi Chen , Chien-Chung Liou , and Yen-Meng Liou

 

Osteoporosis represents a major healthcare problem affecting elderly person. Urinary level of the crosslinked N-telopeptide of type I collagen is a sensitive marker of bone resorption. Ten overlapping peptides covering the N-telopeptide of alpha-2 type I collagen were synthesized, purified, and assayed for their relative binding response to anti-type I collagen cross-linked N-telopeptide (NTX) antibody by using a competitive-inhibition enzyme-linked immunosorbent assay (ELISA). Peptides 1, 2, and 3, containing the N-terminal sequence of Ntelopeptide, showed higher binding potency than peptides 4-10, suggesting that these peptides may contain binding sites for anti-NTX antibodies, and can serve as the lead for further preparation of their antibodies in order to develop novel bioassays for monitoring the bone loss in humans.

 

[Back to top] Crystallization and preliminary X-ray diffraction analysis of FKBP12 complexed with a novel neurotrophic ligand

Pengyun Li , Liwei Wang , Yi Ding  , Beili Wu , Cuiling Shu , Aihua Nie , Song Li , Beifen Shen  & Zihe Rao

 

A novel neurotrophic ligand, (3R)-4-(p-Toluenesulfonyl)-1,4-thiazane-3-carboxylic acid-L-Leucine ethyl ester, has been complexed with FKBP12 and crystallized using the hanging-drop vapor-diffusion method. Crystals belong to P21 space group, with unit cell parameters a=41.2, b=29.6, c=41.5Å, b=114.0°. The crystals diffract to 1.8 Å resolution limit.