Extracted tomato polygalacturonase was purified by cation-exchange chromatography (and gel filtration) and characterized for molar mass, isoelectric point, as well as optimal pH for polygalacturonase activity. The enzymatic reaction of purified tomato polygalacturonase on polygalacturonic acid as substrate was investigated during a combined high-pressure/temperature treatment in a temperature r...

We report a novel method for simultaneous determination of cyromazine and melamine based on a molecularly imprinted monolith on-line coupled with high performance liquid chromatography (HPLC). The imprinted monolith was prepared by in situ polymerization using 2,4-diamino-6-undecyl-1,3,5-triazine (DAUTA) as a mimic template. Due to the better solubility of DAUTA in chloroform, hydrogen bonds we...

Two procedures are reported for the purification of lysyl hydroxylase, both procedures involving (NH4)2SO4 fractionation, affinity chromatography on concanavalin A-agarose and elution of the column with ethylene glycol. The additional steps in procedure A consist of gel filtration and chromatography on a hydroxyapatite column, and in procedure B of affinity chromatography on collagen linked to ...

The tryptophan residues on cholera toxin and its A and B protomers have been modified by reaction with 2-nitrophenylsulfenyl chloride and 2,4-dinitrophenylsulfenyl chloride. Modification of the tryptophan residues of cholera toxin results in complete loss of toxicity measured in a skin permeability assay. Modification of cholera toxin and its B protomer results in the complete loss of binding a...

Gas phase polymerization of propylene was carried out in a semi-batch minireactor using a commercially supported Ziegler–Natta (ZN) catalyst. The influence of variables including monomer partial pressure, external electron donor, reaction temperature and time on the particle morphology and size distribution was investigated. Generally, more uniform fragmentation and particle densities were obta...

Nisin is an antimicrobial peptide produced and secreted by several L. lactis strains and is specifically active against Gram-positive bacteria. In previous studies, nisin was purified via cation exchange chromatography at low pH employing a single-step elution using 1 M NaCl. Here, we describe an optimized purification protocol using a five-step NaCl elution to remove contaminants. The obtained...

Concentration dependence of elution volume was determined for Blue Dextran 2000, Dextran 500, Dextran sulphate 500 and bovine serum albumin on columns of Sephadex G-100 equilibrated with sodium phosphate buffer, I 0.1, pH6.8. From the results for Dextran 500, it was shown that a linear relation exists between elution volume and the corresponding osmotic pressure calculated for the same concentr...

cGMP-dependent protein kinase from bovine lung has been purified to homogeneity using 8-(2-aminoethyl)-amino adenosine 3':5'-monophosphate/Sepharose. Conditions for adsorption of holoenzyme to the affinity chromatography media followed by competitive ligand elution with cGMP have been determined. The holoenzyme of 150,000 molecular weight is composed of two 74,000 molecular weight subunits whic...