Protein and Peptide Letters - Volume 13, Issue 2, 2006

The etiology of multiple sclerosis (MS) remains unclear. To determine if autoantibodies to myelin basic protein (MBP) are produced during parvovirus B19 infection, A competitive ELISA was performed using plasma from MS patients exhibiting high IgG titers for parvovirus. Our results showed the addition of MBP decreased the binding of IgG to B19 antigen in A dose dependent fashion suggesting A possible link betwee Read More

Thermal unfolding kinetics of β-glucosidase B from Paenibacillus polymyxa and its thermoresistant mutant H62R were determined from far-UV circular dichroism (CD) measurements at different temperatures. The unfolding of both enzymes followed simple two-state kinetics. The new ionic pair formed between Arg62 and Glu429 in the H62R variant did not change substantially the enzyme structure as judged by far-UV CD a Read More

We studied the processing of amyloid β-peptides (Aβs) including Aβ1-40, Aβ1-42 and pAβ3-42 by rat neutral cysteine protease bleomycin hydrolase (BH) according to the methods of SDS-PAGE, HPLC and matrix-assisted laser desorption/inonization time-of-flight mass spectrometry (MALDI-TOF MS). BH significantly processed them by novel features of its diverse activities. It initially cleaved at two sites, His14-Gln15 and Phe19-Ph Read More

A simple nonradioactive assay, which was based on the specific shift of the absorbance maximum of methylene blue induced by its intercalation into poly(A) molecules, was developed for poly(A)-specific ribonuclease (PARN). A good linear relationship was found between the absorbance at 662 nm and the poly(A) concentration. The assay conditions, including the concentration of methylene blue, the incubation temperature Read More

(DIPP-L-Leu)2-L-LysOCH3 is A diisopropylphosphoryl dipeptide which is known to induce apoptosis of human leukemia K562 cells. The molecular and cellular mechanisms involved in this process remain to be clarified. Herein, we show that (DIPP-L-Leu)2-L-LysOCH3-induced apoptosis is associated with cytosolic accumulation of cytochrome c, sustained loss of mitochondrial transmembrane potential (MMP), transient generation of r Read More

A novel chemically-modified insulin, ε-NB29-lipoyl insulin, was selectively prepared by the covalent linkage of α-lipoic acid (LA) to the ε-amino group of LysB29 of insulin without any protecting agent and analyzed by PAGE, HPLC, MALDI-TOF-MS. Monolipoyl- insulin maintained the glucose-lowering effect as well as native insulin and showed A longer duration of action than native insulin and an inhibitory effect towards trypsin degradation.

In this study, we calculated the amino-acid distribution rank of 1201 hemagglutinins from influenza A viruses dated from 1918 to 2004 in order to compare them with respect to subtypes, species and years. After noticing fluctuations in distribution rank along the time course, we used the fast Fourier transform to determine the mutation periodicity of the hemagglutinins. Then we estimated our position at the current cycle of h Read More

The recombinant chimeric enzyme, AnsB-TTP-CETPC, comprising asparaginase, tetanus toxin helper T cell epitope and human CETP B cell epitope was expressed as A soluble protein in Escherichia coli. The purified chimeric enzyme exhibited approximate 83% activity of the native asparaginase. After immunization with three doses of chimeric enzyme, high titers of anti-CETP antibodies were induced and lasted mor Read More

Human β-defensin-2 (hBD2) is A small cationic peptide with A broad range of antimicrobial activity. An E. coli cell-free system was employed to express the hBD2 fusion protein by using the hBD2 gene with 14 rare codons. The results showed that the expression level of trxA-hBD2 fusion protein was 0.35 mg/ml, which is the same as that obtained with A synthetic codon-optimized gene. By using another fusion partner (GF Read More

Quinolinate phosphoribosyltransferase was examined for susceptibility to different chemical modification reagents. Loss of enzyme activity with trinitrobenzenesulfonate (TNBS) occurred when 1.1 lysines per subunit were modified. Tryptic digestion of the modified enzyme followed by HPLC-MS analysis of the peptides showed Lys70 reacts with TNBS. Based on x-ray studies, this amino acid participates in A conformational cha Read More

Using radio-receptor analysis, it has been demonstrated that human ε-casomorphin-7 (Tyr-Pro-Phe-Val- Glu-Pro-Ile) displaces 3H-spiperone from 5-HT2-receptors of rat brain frontal cortex. IC50 of human β-casomorphin-7 was 8 μM. These data suggest that one of the mechanisms of neurotropic action of β-casomorphin-7 is might be associated with its influence on the serotoninergic system.

We report A new prohormone convertase gene of insect origin, Trichoplusia ni furin, which was cloned from BTI-Tn-5B-4 (Tn5) insect cells. We constructed A truncated mutant that lacked Cys-rich repeated segments. Using baculovirus expression system and standard enzymatic assay, we obtained recombinant Tn furin and evaluated aspects of its function.

The modeled structure of penicillin acylase from Alcaligenes faecali (AFPGA) was constructed by comparative modeling with the Modeller program. Candidate positions that could be replaced with cysteine were estimated by scanning the modeled structure of AFPGA with the program MODIP (modeling disulfide bond in protein). The mutant Q3C/P751C had A higher optimum temperature by three degrees than that of the wild t Read More

Electric field stimulation (EFS) causes excitatory non adrenergic-non cholinergic (eNANC) and cholinergic constrictions in the guinea pig isolated bronchus, the activation of eNANC and cholinergic nerves respectively. We investigated the effects of [Nphe1]nociceptin(1-13)NH2 ([Nphe1]NC(1-13)NH2), [Phe1(CH2-NH)Gly2]nociceptin(1- 13)NH2 ([F/G] NC(1-13)NH2), and nocistatin (NST) on nociceptin (NC) inhibited constrictions in Read More

Solid phase peptide synthesis requires large amounts of organic solvents, the safe disposal of which is an important environmental issue. Peptide synthesis, if performed in water and using less or nontoxic reagents, circumvents the disposal problem. Our ultimate aim is to develop an "environment-friendly" solid phase peptide synthesis (SPPS) methodology. Previously, we showed that SPPS in water is feasible. To perfor Read More

There is an urgent need for high purity, single chain, fully functional Eph/ephrin membrane proteins. This report outlines the pTIg-BOS-Fc vector and purification approach resulting in rapid increased production of fully functional single chain extracellular proteins that were isolated with high purity and used in structure-function analysis and pre-clinical studies.

Production of GST-fused WW domains of FBP proteins was increased using the bubbling cultivation method for E. coli. Purified WW domains of FBP11 and FBP28 bound A PL motif peptide with dissociation constants (KD) of 248 ± 27 and 1880 ± 280 μM, respectively.

Human spindlin1 is A newly screened and identified gene product related to ovarian carcinomas and is highly homologous to mouse spindlin. It is an abundant maternal transcript expressed in the mouse during the transition from oocyte to embryo. Here, the recombinant human spindlin1 has been overexpressed in Escherichia coli BL21, purified and crystallized using the hanging-drop vapour-diffusion method. Crystals diffracti Read More

Purified malate dehydrogenase (MDH) of Streptomyces aureofaciens was crystallized either in the absence or in the presence of NADH or NADPH coenzymes by hanging-drop vapour-diffusion method. An X-ray study has shown, that MDH crystals belong to space group C2221 with unit-cell parameters A = 53.2 Å, b = 104.6 Å, c = 520.0 Å, α = β = γ = 90° , MDH-NADH crystals to space group C2 with unit-cell parameters A = Read More