Microcomplement fixation was employed to compare the immunological differences that occur between purified inhibitor I from potato tubers, the four purified protomers that comprise it, and inhibitor I from tuber and leaf extracts. Total inhibitors of chymotrypsin and trypsin in leaves of seven genera of the Solanaceae were identified by enzymatic assay. In leaves of three genera, Solanum, Lycop...

The direct-writing technique laser-induced forward transfer has been employed for the micro-array printing of liquid solutions of the enzyme horseradish peroxidase and the protein Titin on nitrocellulose solid surfaces. The effect of two UV laser pulse lengths, femtosecond and nanosecond has been studied in relation with maintaining the activity of the transferred biomolecules. The quantificati...

An enzymatic assay system for nitrate employing the membrane-bound nitrate reductase (EC 1.7.99.4) of E. coli is described. Contrary to previous enzymatic assay systems, the present method is a kinetic one, i.e. the substrate, nitrate, is assayed by measuring the reaction rate of the nitrate reductase-catalyzed reaction. Based on the observation that the nitrate reductase-catalyzed reaction obe...

The wheat dehydrin DHN-5 has been previously shown to exhibit heat protecting effect on enzymatic activities. In order to understand the molecular mechanism by which DHN-5 exerts its protective function, we performed an approach to dissect the functional domains of DHN-5 responsible for this feature. In two distinct enzymatic assays, we found that the truncated forms of DHN-5 containing only on...

The use of microfluidic devices to control drops of water in a carrier oil is a promising means of performing biological and chemical assays. An essential requirement for this is the controlled coalescence of pairs of drops to mix reagents together. We show that this can be accomplished through electrocoalescence of drops synchronized by size-dependent flow in microfluidic channels. Smaller dro...

In the present study, we assessed the treatment effects of PBDE-209 administration on the immune function in rats during pregnancy and lactation. We harvested the blood and organs for flow cytometry, viability assay, enzyme-linked immunosorbent assay, and histological evaluation. The results of this study were the PBDE-209 exposure during pregnancy and lactation impairs immune function in rats....

Wheat α-amylase, a multi-domain protein with immense industrial applications, belongs to α+β class of proteins with native molecular mass of 32 kDa. In the present study, the pathways leading to denaturation and the relevant unfolded states of this multi-domain, robust enzyme from wheat were discerned under the influence of temperature, pH and chemical denaturants. The structural and functional...

The single, uncross-linked polypeptide chain of the zymogen of the streptococcal proteinase is unfolded to a random structure in 6 M guanidinium chloride. When the denaturing agent is removed by dialysis, the potential enzymatic activity after tryptic hydrolysis and reduction is recoverable in 90% yield. Data on the unfolding process have been obtained by enzymatic assays and by optical rotator...

A p-nitrophenolate-sensitive membrane electrode was constructed by using tetraheptylammonium chloride as an ion-exchanger and o-nitrophenyl phenyl ether as a membrane solvent. The electrode responded to p-nitrophenolate down to 1 ,ƒÊM in a buffer solution of 0.1 M Na2CO3NaHCO3 (pH 10). The selectivity coefficients of the electrode to typical anions increased in the following order: Cl-<NO3< SCN...

Hydrogen peroxide (H2O2) detection is of high importance as it is a versatile (bio)marker whose detection can indicate the presence of explosives, enzyme activity and cell signalling pathways. Herein, we demonstrate the rapid and accurate ratiometric electrochemical detection of H2O2 using disposable screen-printed electrodes through a reaction-based indicator assay. Ferrocene derivatives equip...