Protein and Peptide Letters - Volume 10, Issue 6, 2003

Scaffolded peptides, in which fragments of the sequence are presented through a molecular scaffold in a discontinuous and nonlinear fashion, are promising candidates for the mimicry of discontinuous protein binding sites. Twelve scaffold molecules based on cyclic peptides with ring sizes ranging from 13 to 30 were generated. Up to three different peptide fragments were attached to the scaffolds in a site-selective manne Read More

We have performed a systematic investigation of the structural features of the peptides Int (a sequence able to cross cell membranes) and Int-H1(S6A,F8A) (which shows interesting antitumoral properties). After screening in aqueous solution at different ionic strength and pH values, we analyzed the structures of the peptides in different water / trifluoroethanol mixtures by Circular Dichroism and Nuclear Magnetic Resona Read More

Crystal structure of hemoglobin isolated from the Brazilian maned wolf (Chrysocyon brachyurus) was determined using standard molecular replacement technique and refined using maximumlikelihood and simulated annealing protocols to 1.87Å resolution. Structural and functional comparisons between hemoglobins from the Chrysocyon brachyurus and Homo sapiens are discussed, in order to provide further insigh Read More

The mutation had dramatic effect on the kinetic and thermodynamic parameters inferring thermostability of endo-glucanase from Cellulomonas biazotea mutant 51 SMr .The denaturation activation energies of native and mutated enzymes were 73.3 and 68.8 kJ / mol respectively. They showed compensation effect at 55°C. Both enthalpy and entropy values of irreversible thermal inactivation for mutated enzyme were d Read More

Kinetic behavior of aggregation of amyloid-β-protein (Aβ) is represented by a stretched exponential function, F=A{1-exp(-Btn)}. Differences in temperature-dependence of A, B and n are studied for Aβ 1-40 and Aβ 1-42. As the temperature is lowered, parameter A is increased, parameter B is decreased and parameter n is increased in Aβ 1-40, while these parameters are less sensitive to temperature in a more hydrophobic Read More

Previously we reported that halobacterial nucleoside diphosphate kinase can be refolded in the presence of concentrated trimethylamine N-oxide (TMAO) as well as NaCl, indicating that enhancement of compact structure formation by TMAO is sufficient for folding. Here we showed that the refolding effect of MgCl2 is maximal at 1 M and declines to zero at 2 M, indicating that charge shielding effect of MgCl2 is offset by its sal Read More

A new coding sequence of the procarboxypeptidase B gene was obtained from SD rat fresh pancreas by RT-PCR and highly expressed in Escherichia coli in inclusion bodies. The folded procarboxypeptidase B was subjected to trypsin enzymatic cleavage to produce active carboxypeptidase B, subsequently, carboxypeptidase B was effectively purified with anion exchange chromatography DEAE-FF and hydr Read More

An analysis of hydrogen bonding patterns of cyclic decapeptide (CDP) β-sheet structures has resulted in a 'non-intuitive' design of cyclic decapeptides wherein their β-turns and residue positions can be fixed by choosing 2 of the 10 residues, i.e. positions i and i+4, to be Prolines or N-substituted residues. This sequence relationship between the two Pro or N-substituted residues is shown to uniquely define the conforma Read More

Gastrodia anti-fungal protein (GAFP) displays strong inhibitory activity against certain fungal pathogens. Five GAFP analogues with different mutations at mannose-binding sites and the wild-type one were expressed and purified in Escherichia coli. The inhibitory analysis of the purified various GAFPs against the growth of Trichoderma viride indicates that single amino acid mutated-type GAFPs have inhibitory activity, but Read More

A glucose / mannose lectin was purified by affinity chromatography from Pisum arvense seeds (PAL) and the 50 kDa molecular mass in solution determined by size exclusion chromatography. SDS-PAGE and electrospray ionization mass spectrometry showed two distinct polypeptide chains: α (Mr. 5,591 Da) and β (19,986 Da). The lectin was extensively characterized in terms of its biochemical and biological aspects. The amino Read More

Lipases are versatile enzymes regarding the range of reactions they catalyse and substrates on which they act. They are as well important as catalyst in organic synthesis. Their immobilization on appropriate supports confer them greater stability besides the possibility of operating in continuous reactors. In order to explore these abilities, the reactions involving hydrolysis of p-nitrophenyl acetate (PNPA) and transesteri Read More