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Protein & Peptide Letters, Volume 10, No. 5, 2003

 

Contents

 

Synthesis of Retro Acyl Carrier Protein (74-65) Fragment on a New Glycerol Based Polystyrene Support Pp.427-433

P.G. Sasikumar, K.S. Kumar and V.N. Rajasekharan Pillai

[Abstract]

 

A Sequence Function Reveals New Features in b-Protein Folding Pp.435-439

Hui Shao and Zong-Hao Zeng

[Abstract]

 

Multiple Roles of Glutathione Binding-Site Residues of Glutathione S-Transferase Pp.441-448

Ardcharaporn Vararattanavech and Albert J. Ketterman

[Abstract]

 

A New Dehydrogenase Specific Towards Aromatic Aldehydes from a Halophilic Bacterium Pp.449-457

F. La Cara , L. Alves , F. Girio , A. Di Salle , A. Capasso  and M. Rossi

[Abstract]

 

Direct Screening of Libraries of Yeast Clones for a-Amylase Activity on Raw Starch Hydrolysis Pp.459-468

Dominic W.S. Wong, Sarah B. Batt, Charles C. Lee and George H. Robertson

[Abstract]

 

In Vivo Lipoprotein Binding Assay of the Insect Exchangeable Apolipoprotein, Apolipophorin-III Pp.469-473

Palaniappan S. Chetty, Estela L. Arrese and Jose L. Soulages

[Abstract]

 

Anticonvulsant Activity of Benzylamides of Some Amino Acids and Heterocyclic Acids Pp.475-482

Ryszard Paruszewski, Marzanna Strupinska, Grazyna Rostafinska-Suchar and James P. Stables

[Abstract]

 

Extracellular Domain of Myelin Oligodendrocyte Glycoprotein (MOG) Exhibits Solvent-Dependent Conformational Transitions Pp.483-490

Maria Ngu-Schwemlein, Michele Corzett, Kevin H. Thornton, Rod Balhorn  and Monique Cosman

[Abstract]

 

Regulation of in Vitro Fibril Formation of Synuclein Mutant Proteins by hsp104p Pp.491-495

Byungmoon Kong, Young Kee Chae and Kyunghee Lee

[Abstract]

 

Factors Determining the Efficacy of Alphahelical Antimicrobial Peptides Pp.497-502

Sarah R. Dennison, Frederick Harris and David A. Phoenix

[Abstract]

 

The Role of Tyrosine Residues in the RNA N-Glycosidase Activity of Cinnamomin A-Chain Pp.503-509

Hong Xu and Wang-Yi Liu

[Abstract]

 

Crystallization and Preliminary X-Ray Analysis of Class II Fructose-1,6-Bisphosphate Aldolase from Thermus Caldophilus Pp.511-515

Jun Hyuck Lee, Young Jun Im, Seong-Hwan Rho, Seong Ho Park, Mun-Kyoung Kim, Su Jin Cho, Tae-Yeon Kim, Jin Hwan Oh, Hyun-Jae Shin, Dae-Sil Lee and Soo Hyun Eom

[Abstract]

 

Crystallization and Preliminary X-Ray Diffraction Analysis of Phosphoglucose Isomerase from Pyrococcus Furiosus Pp.517-520

Michael K. Swan, Thomas Hansen, Peter Schonheit  and Christopher Davies

[Abstract]

 

Purification, Crystallization and Preliminary X-Ray Studies of a p- Nitrophenylphosphatase from Bacillus Stearothermophilus Pp.521-524

Chao-Neng Ji, Liang Tian, Cong-Jing Feng, Gang Yin, Guang Shu, Ji-Xi Li, Wei-Ming Gong, Hai Pang, Yi Xie  and Yu-Min Mao

[Abstract]

 

Initiating Structural Studies of Lys49-PLA2 Homologues Complexed with an Anionic Detergent, a Fatty Acid and a Natural Lipid Pp.525-530

L. Watanabe , M.R.M. Fontes , A.M. Soares , J.R. Giglio  and R.K. Arni

[Abstract]

 

Abstracts

 

[Back to top] Synthesis of Retro Acyl Carrier Protein (74-65) Fragment on a New Glycerol Based Polystyrene Support Pp.427-433

P.G. Sasikumar, K.S. Kumar and V.N. Rajasekharan Pillai

 

Retro-ACP (74-65) fragment was synthesized on a novel 4% tri-(propylene glycol) glycerolate diacrylate cross-linked polystyrene (PS-TRPGGDA) support. The peptide is grown from the functional site present in the cross-linker, which makes it unique and cost-effective among other styrene based polymer supports. A comparative study with Merrifield resin indicates high yield and purity of the peptide synthesized on the novel support.

 

[Back to top] A Sequence Function Reveals New Features in b-Protein Folding

Hui Shao and Zong-Hao Zeng

 

When amino acid residues are represented by parameters describing their side chain lengths and polarities, a sequence function defined as the sum of the first two sequence autocorrelation functions is found to be negatively and linearly correlated with the logarithms of folding rates of b-proteins. The new function reveals new features in b-protein folding: larger residues slow down the folding while alternative distribution of polar-non-polar residues accelerates the folding.

 

[Back to top] Multiple Roles of Glutathione Binding-Site Residues of Glutathione S-Transferase

Ardcharaporn Vararattanavech and Albert J. Ketterman

 

This study was designed to characterize residues in the glutathione binding site of AdGSTD4-4 from the mosquito malaria vector Anopheles dirus. The data revealed that Leu33, His38 and His50 each play a role in enzyme catalysis and glutathione binding. The mutants of these three residues also displayed differences in hydrophobic substrate specificity, suggesting that changes in the active site conformation occurred. Differences in conformations was also suggested by protein stability changes. These results indicate that residues in the glutathione binding site are not only important in the catalytic function but also play a role in the structural integrity of the enzyme.

 

[Back to top] A New Dehydrogenase Specific Towards Aromatic Aldehydes from a Halophilic Bacterium

F. La Cara , L. Alves , F. Girio , A. Di Salle , A. Capasso  and M. Rossi

 

A new enzyme showing a dehydrogenase activity towards aromatic aldehydes was isolated, purified and characterized from a halophilic strain isolated from saline environment. The enzyme is a monomer of 54 kDa; it is rather thermostable (optimal temperature: 50°C) showing a broad spectrum of activity in a large pH range with the maximum at pH 9.5. The substrate specificity and the effect of ions were evaluated and compared with analogous described proteins.

 

[Back to top] Direct Screening of Libraries of Yeast Clones for a-Amylase Activity on Raw Starch Hydrolysis

Dominic W.S. Wong, Sarah B. Batt, Charles C. Lee and George H. Robertson

 

High-throughput screening for high-activity barley a-amylase mutants expressed in Saccharomyces cerevisiae is hampered by the interference of reducing agents, particularly the glucose used in yeast growth media. The present investigation employed colorimetric and chemiluminescent detection systems that enable direct and rapid screening of activities on raw starch substrate. Active clones could be separated into two groups, based on high total activity or high specific activity.

 

[Back to top] In Vivo Lipoprotein Binding Assay of the Insect Exchangeable Apolipoprotein, Apolipophorin-III

Palaniappan S. Chetty, Estela L. Arrese and Jose L. Soulages

 

An original method for the study of the lipid binding properties of exchangeable apolipoproteins is reported. Binding of Locusta migratoria apolipophorin-III to Manduca sexta low-density lipophorin (LDLp) and high-density lipophorin (HDLp) was studied in vivo. This assay could be used useful to investigate the effect of mutations in the lipid binding properties of exchangeable apolipoproteins under physiological conditions.

 

[Back to top] Anticonvulsant Activity of Benzylamides of Some Amino Acids and Heterocyclic Acids

Ryszard Paruszewski, Marzanna Strupinska, Grazyna Rostafinska-Suchar and James P. Stables

 

A series of new potential anticonvulsants have been synthesized. They are N-methyl benzylamides of N-methyl Asp and N-methyl Glu (R and S), benzylamides of some heterocyclic acids and their Noxides and benzylamides of two heteroalicyclic acids. The obtained compounds were evaluated in the Anticonvulsant Screening Project (ASP) of Antiepileptic Drug Development Program (ADDP) of NIH.

 

[Back to top] Extracellular Domain of Myelin Oligodendrocyte Glycoprotein (MOG) Exhibits Solvent-Dependent Conformational Transitions

Maria Ngu-Schwemlein, Michele Corzett, Kevin H. Thornton, Rod Balhorn  and Monique Cosman

 

The conformation of the non-glycosylated recombinant form of the extracellar domain of rat MOG (rMOG(1-125)) dissolved in different solvent conditions was studied by CD spectroscopy. The results show that rMOG(1-125) exhibits a predominantly b sheet conformation in aqueous buffer solution at pH 7.5 and that this 'b-form' is stabilized by zwitterionic phospholipids, DPC and LPCP. The a helical content of the protein can increase from 9% to up to 20% when TFE or anionic detergent LPAP and SDS are added.

 

[Back to top] Regulation of in Vitro Fibril Formation of Synuclein Mutant Proteins by hsp104p

Byungmoon Kong, Young Kee Chae and Kyunghee Lee

 

Hsp104p, as an anti-oxidative protector of ROS generation, was examined to inquire if it prevents aggregation of synuclein mutants, A30P or A53T upon aging, in vitro. The role of Hsp104p was also addressed in dissociation of pre-formed aggregates of synuclein mutants. Significant protection in fibril formation was observed by wild-type Hsp104p regardless of ATP presence, not by mutant Hsp104p. To a lesser extent, the dissociation effect of wild-type Hsp104p was observed only in the presence of ATP. These results will be discussed in relation to the development of an antioxidant approach to prevent amyloid fibril formation in several neurodegenerative diseases.

 

[Back to top] Factors Determining the Efficacy of Alphahelical Antimicrobial Peptides

Sarah R. Dennison, Frederick Harris and David A. Phoenix

 

A database of a-helical antimicrobial peptides (AMP) was established and their minimum inhibitory concentrations (MIC) were compared with their physiochemical characteristics in an attempt to establish those features that determine efficacy. There is no significant difference in AMP sensitivity between Gram-positive and Gram-negative bacteria but fungi did require higher concentrations to achieve the same degree of growth inhibition. For antibacterial peptides there appears to be a positive correlation between MIC and hydrophobic arc size and a negative correlation between MIC and net charge.

 

[Back to top] The Role of Tyrosine Residues in the RNA N-Glycosidase Activity of Cinnamomin A-Chain

Hong Xu and Wang-Yi Liu

 

Cinnamomin is a type II ribosome-inactivating protein (RIP) and its A-chain (CTA) is a RNA Nglycosidase. It is observed that modification of tyrosine residues by N-acetylimidazole (N-AI) causes almost complete loss of CTA activity. Adenine partially protects tyrosine residues from modification by NAI. It is proposed that tyrosine residues are involved in the active site of CTA and they are crucial in recognition and binding of ribosomal RNA. Tryptophan residues of CTA are also studied by NBS modification.

 

[Back to top] Crystallization and Preliminary X-Ray Analysis of Class II Fructose-1,6-Bisphosphate Aldolase from Thermus Caldophilus

Jun Hyuck Lee, Young Jun Im, Seong-Hwan Rho, Seong Ho Park, Mun-Kyoung Kim, Su Jin Cho, Tae-Yeon Kim, Jin Hwan Oh, Hyun-Jae Shin, Dae-Sil Lee and Soo Hyun Eom

 

In this study, we have crystallized class II fructose-1,6-bisphosphate aldolase (FBA) from Thermus caldophilus (Tca). Purified Tca FBA is a tetrameric enzyme of 305 residues, which crystallizes in the space group P212121 (cell dimensions a = 98.9, b = 113.1, c = 115.7 Å), with four molecules in the asymmetric unit. A complete diffraction data set was obtained from orthorhombic crystals at resolution of 2.2 Å.

 

[Back to top] Crystallization and Preliminary X-Ray Diffraction Analysis of Phosphoglucose Isomerase from Pyrococcus Furiosus

Michael K. Swan, Thomas Hansen, Peter Schonheit  and Christopher Davies

 

In several euryarchaeota, phosphoglucose isomerase (PGI) activity is catalyzed by an enzyme unrelated to the well-known family of PGI enzymes found in prokaryotes, eukaryotes and some archaea. In order to understand the mechanistic differences between the two families of enzymes we have crystallized PGI from the archaeon Pyrococcus furiosus. The crystals belong to the space group P21 and a complete dataset extending to 1.9 Å resolution has been collected.

 

[Back to top] Purification, Crystallization and Preliminary X-Ray Studies of a p- Nitrophenylphosphatase from Bacillus Stearothermophilus

Chao-Neng Ji, Liang Tian, Cong-Jing Feng, Gang Yin, Guang Shu, Ji-Xi Li, Wei-Ming Gong, Hai Pang, Yi Xie  and Yu-Min Mao

 

Thermostable p-nitrophenylphosphatase from Bacillus stearothermophilus has been expressed in Escherichia coli, purified and crystallized. The crystals belong to space group C2, with unit-cell parameters a = 67.17 Å, b = 57.84 Å, c = 62.49 Å and a = 90.0º, b = 95.4º, g = 90.0º. Diffraction data were collected to 1.40 Å resolution with a completeness of 94.7% (96.6% for the last shell), an Rfac value of 0.074 (0.341) and an I/s (I) value of 30.1 (2.67).

 

[Back to top] Initiating Structural Studies of Lys49-PLA2 Homologues Complexed with an Anionic Detergent, a Fatty Acid and a Natural Lipid

L. Watanabe , M.R.M. Fontes , A.M. Soares , J.R. Giglio  and R.K. Arni

 

Lys49-Phospholipase A2 (Lys49-PLA2 - EC 3.1.1.4) homologues damage membranes by a Ca2+- independent mechanism which does not involve catalytic activity. Both MjTX-II from Bothrops moojeni and BthTX-I from Bothrops jararacussu are dimeric in solution and in the crystalline states, and a model for the Ca2+-independent membrane damaging mechanism has been suggested in which flexibility at the dimer interface region permits quaternary structural transitions between “open” and “closed” membrane bound dimer conformations which results in the perturbation of membrane phospholipids and disruption of the bilayer structure [1]. With the aim of gaining insights into the structural determinants involved in protein/lipid association, we report here the crystallization and preliminary X-ray analysis of the (i) MjTXII/ SDS complex at a resolution of 2.78Å, (ii ) MjTX-II/STE complex at a resolution of 1.8 Å and (iii) BthTXI/ DMPC complex at 2.72Å. These complexes were crystallized by the hanging drop vapour-diffusion technique in (i) HEPES buffer (pH 7.5) 1.8M ammonium sulfate with 2% (w/v) polyethyleneglycol 400, in (ii ) 0.6-0.8 M sodium citrate as the precipitant (pH 6.0-6.5) and in (iii) sodium citrate buffer (pH 5.8) and PEG 4000 and 20% isopropanol, respectively. Single crystals of these complexes have been obtained and Xray diffraction data have been collected at room temperature using a R-AXIS IV imaging plate system and graphite monochromated Cu Ka X-ray radiation generated by a Rigaku RU300 rotating anode generator for (i) and (iii) and using using a Synchrotron Radiation Source (Laboratório Nacional de Luz Sincrotron, LNLS, Campinas, Brazil) for (ii ).