Protein and Peptide Letters - Volume 10, Issue 5, 2003

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.

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 β-proteins. The new function reveals new features in β-protein folding: larger residues slow down the folding while alternative distribution Read More

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. Differe Read More

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 an Read More

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 Read More

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.

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.

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 β sheet conformation in aqueous buffer solution at pH 7.5 and that this 'β-form' is stabilized by zwitterionic phospholipids, DPC and LPCP. The a helical content of the protein can Read More

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 dissoc Read More

A database of α-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 i Read More

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 ribosom Read More

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.

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 exten Read More

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 α = 90.0°, β = 95.4°, γ = 90.0°. 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 Read More

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 Read More