Epitope identification of specific naturally occurring human anti-avidin antibodies.

Human serum contains natural antibodies against avidin. Affinity purified natural anti-avidin human IgG exhibits affinity constants comparable to those of antibodies produced by active immunization of rabbits. Using a random hexapeptide library displayed on the filamentous M13 phage, and rabbit anti-avidin purified antibodies as a selector, we searched for epitopes shared by both selector and natural human anti-avidin IgG.

A sensitive colorimetric determination of cyanuric chloride and its activated agarose immobilization resins.

A colorimetric method for determining cyanuric chloride (CC) and for monitoring its polysaccharide gel activation, before and after ligand binding, was developed. The method is based on the reaction of CC or its activated gel with pyridine and barbituric acid or dimethylbarbituric acid. The product formed yields a purple red color with λ max at 595 nm, and an E value of approximately 300,000 after 1 h at room temperature.

Mussel-inspired new approach for polymerization and cross-linking of peptides and proteins containing tyrosines by Fremy's salt oxidation.

Our objective was to develop a method mimicking the natural process of coherence in marine mollusks, by direct chemical conversion of protein tyrosine residues to DOPA-o-quinones, which consequently generates polymerization and cross-linking. Fremy's salt, (ON(SO3K)2, was used to convert tyrosine residues in peptides and proteins to reactive o-quinones. The conversion of tyrosines to DOPA-o-quinones, and their ability to polymerize or cross-link, was tested on tyramine, peptides, and proteins.

Analysis of protein expression profile of oral squamous cell carcinoma by MALDI-TOF-MS.

In this study, two-dimensional gel electrophoresis (2-DE) and matrix-assisted laser desorption/ionisation-time of flight mass spectrometry (MALDI-TOF-MS) technology was used to examine differentially expressed proteins in oral squamous cell carcinoma (OSCC) tissues from Norway (n=15) and the UK (n=45). Twenty-nine proteins were found to be significantly overexpressed in the OSCCs examined compared to the normal controls. Identified proteins included, family of annexin proteins that play important roles in signal transduction pathways and regulation of cellular growth, keratin-1, heat-shock proteins (HSP), squamous cell carcinoma antigen (SCC-Ag), cytoskeleton proteins, and proteins involved in mitochondrial and intracellular signalling pathways.

S-allyl derivatives of 6-mercaptopurine are highly potent drugs against human B-CLL through synergism between 6-mercaptopurine and allicin.

S-allylthio-6-mercaptopurine and its ribose derivative were tested for anti-leukemic activity, using a human- mouse B-CLL model. The novel prodrugs contain two components, a purine analog, which interferes with DNA synthesis, and an S-allylthio, readily engaging in thiol-disulfide exchange reactions. The latter component targets the redox homeostasis which is more sensitive in leukemic cells, than in normal B-cells.

Reaction mechanisms of allicin and allyl-mixed disulfides with proteins and small thiol molecules.

Allylsulfides from garlic are chemopreventive agents. Entering cells they are expected to initially interact with glutathione. Accordingly, reaction mechanisms of the product, S-allylthio-glutathione, with model proteins and thiols were analyzed in cell free systems.

Thiol-disulfide organization in alliin lyase (alliinase) from garlic (Allium sativum).

Alliinase, an enzyme found in garlic, catalyzes the synthesis of the well-known chemically and therapeutically active compound allicin (diallyl thiosulfinate). The enzyme is a homodimeric glycoprotein that belongs to the fold-type I family of pyridoxal-5'-phosphate-dependent enzymes. There are 10 cysteine residues per alliinase monomer, eight of which form four disulfide bridges and two are free thiols.

Allicin up-regulates cellular glutathione level in vascular endothelial cells.

Background: Allicin in garlic is the primary active compound known to rapidly interact with free thiols.

Aims Of The Study: To examine the effect of allicin on gene expression and glutathione cellular level in vascular endothelial cells.

Methods: Cultured endothelial cells were exposed to allicin; mRNA was prepared and subjected to Micro-array and Real-Time PCR.

Allicin inhibits cell growth and induces apoptosis through the mitochondrial pathway in HL60 and U937 cells.

In this article, the effects of allicin, a biological active compound of garlic, on HL60 and U937 cell lines were examined. Allicin induced growth inhibition and elicited apoptotic events such as blebbing, mitochondrial membrane depolarization, cytochrome c release into the cytosol, activation of caspase 9 and caspase 3 and DNA fragmentation. Pretreatment of HL60 cells with cyclosporine A, an inhibitor of the mitochondrial permeability transition pore (mPTP), inhibited allicin-treated cell death.

Two structures of alliinase from Alliium sativum L.: apo form and ternary complex with aminoacrylate reaction intermediate covalently bound to the PLP cofactor.

Alliinase (alliin lyase EC 4.4.1.

The antiatherogenic effect of allicin: possible mode of action.

Objective: Garlic (Allium sativum) has been suggested to affect several cardiovascular risk factors. Its antiatherosclerotic properties are mainly attributed to allicin that is produced upon crushing of the garlic clove. Most previous studies used various garlic preparations in which allicin levels were not well defined.

The effects of S-allylmercaptocaptopril, the synthetic product of allicin and captopril, on cardiovascular risk factors associated with the metabolic syndrome.

Pure allicin, prepared biosynthetically by reacting synthetic alliin with an immobilized alliinase enzyme, is known to possess cardioprotective effects. However, in its pure form, allicin is pharmacologically unstable. S-allylmercaptocaptopril (CPSSA) is a new stable synthetic compound produced by chemical reaction between allicin and the angiotensin converting enzyme inhibitor captopril.

Tumour-associated Proteins in Oral Squamous Cell Carcinomas by Proteomics.

Antibody microarrays, two-dimensional electrophoresis and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (2-DE/MALDI-TOF-MS) were used to examine protein changes in 56 oral cancers (OCs)/normal controls (NCs) from Sudanese (41 OCs vs. 31 NCs) and Sri Lankan (15 OCs vs. 15 NCs) patients.

Apoptotic killing of B-chronic lymphocytic leukemia tumor cells by allicin generated in situ using a rituximab-alliinase conjugate.

Allicin, a highly active component from freshly crushed garlic, is produced upon the reaction of the small molecular weight molecule alliin, with the enzyme alliinase (EC 4.4.1.

Allicin inhibits SDF-1alpha-induced T cell interactions with fibronectin and endothelial cells by down-regulating cytoskeleton rearrangement, Pyk-2 phosphorylation and VLA-4 expression.

Allicin, a major ingredient of fresh garlic extract that is produced during the crushing of garlic cloves, exerts various beneficial biological effects, including a broad spectrum of antimicrobial activity, antihyperlipidaemic and antihypertensive effects. However, how allicin affects the immune system is less well known, and its effect on human T cells has never been studied. Here, we examined the in-vitro effects of allicin on the functioning of T cells related to their entry to inflamed extravascular sites.

Efficacy of allicin, the reactive molecule of garlic, in inhibiting Aspergillus spp. in vitro, and in a murine model of disseminated aspergillosis.

Objectives: The evaluation of allicin, the biologically active compound responsible for the antimicrobial activities of freshly crushed garlic cloves, in inhibiting Aspergillus spp. in vitro and in a murine model of disseminated aspergillosis.

Methods: Pure allicin was prepared by reacting synthetic alliin with a stabilized preparation of the garlic enzyme alliinase.

Allicin stimulates lymphocytes and elicits an antitumor effect: a possible role of p21ras.

Allicin, the main organic allyl sulfur component in garlic, exhibits immune-stimulatory and antitumor properties. Allicin stimulated [(3)H]thymidine incorporation in mouse splenocytes and enhanced cell-mediated cytotoxicity in human peripheral mononuclear cells. Multiple administration (i.

Inhibition of tumor growth by a novel approach: in situ allicin generation using targeted alliinase delivery.

Allicin (diallyl thiosulfinate), a highly active component in extracts of freshly crushed garlic, is the interaction product of non-protein amino acid alliin (S-allyl-L-cysteine sulfoxide) with the enzyme alliinase (alliin lyase; EC 4.4.1.

Allylmercaptocaptopril: a new antihypertensive drug.

Allylmercaptocaptopril (CPSSA) was synthesized by reacting captopril with pure allicin. Fructose-induced hypertensive groups of rats were fed a fructose-rich diet for 3 weeks, and then received the diet plus either CPSSA (40 to 56 mg or 138 to 194 micromol/L/kg/d) or captopril (80 mg or 369 micromol/L/kg/d) for 2 more weeks. CPSSA (both doses) significantly lowered blood pressure (BP) from 153.

The effects of allicin on weight in fructose-induced hyperinsulinemic, hyperlipidemic, hypertensive rats.

Background: Commercially available garlic preparations in the form of garlic oil, garlic powder and pills are widely used for certain therapeutic purposes, including lowering blood pressure and improving lipid profile. Despite the impressive effects of garlic most studies are limited by lack of controlled methods and suitable double-blinding, and by the use of preparations with unknown amounts and chemical identification of the active ingredient. Allicin, a synthetic preparation of an active constituent of garlic, was found to lower blood pressure, insulin, and triglycerides levels in fructose-fed rats.

Oriented versus random protein immobilization.

Immobilization of proteins on solid surfaces plays an important role in all the fields of modern biology. Two approaches are used in the immobilization of proteins: a random and an oriented mode of binding to solid matrices. In this note, we show that there is not much difference in using either mode of immobilization, since proteins usually bind to a matrix through only one or two bonds.

A spectrophotometric assay for allicin, alliin, and alliinase (alliin lyase) with a chromogenic thiol: reaction of 4-mercaptopyridine with thiosulfinates.

Allicin (diallylthiosulfinate) is the best known active compound of garlic. It is generated upon the interaction of the nonprotein amino acid alliin with the enzyme alliinase (alliin lyase, EC 4.4.

Alliin lyase (alliinase) from garlic (Allium sativum): crystallization and preliminary X-ray characterization.

The enzyme alliinase has been isolated from garlic bulbs and crystallized. The crystals belong to space group P2(1), with unit-cell parameters a = 70.191, b = 127.

Modification of histidine (B10) is the causative agent for a superactive form of insulin.

The site of modification that is responsible for the formation of superactive insulin (ILM) was determined. The insulin derivative was prepared by treatment of insulin-Sepharose with ammonium bicarbonate. It was found that the insulin was bound to the resin through histidine B10, His (B10), and its ammonium bicarbonate-mediated release resulted in an insulin analog in which His (B10) was modified on the imidazole ring.