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Polyphenol oxidase (PPO) belongs to the oxidoreductase enzyme family.Here, PPO was purified from potato using Sepharose 4B-L-tyrosine-p-aminobenzoic acid affinity chromatography. It determined the interactions between some phenolic acids and the In the literature, the polyphenol oxidase (PPO) enzyme has been purified a many times via Sepharose 4B-l-tyrosine-p-aminobenzoic acid affinity column. In order to study PPO purification efficiency, 2-aminophenol and 4-aminophenol were applied as a spacer arm to CNBr-activated Sepharose 4B. The
l-Phenylalanine ammonia-lyase (E.C. 4.3.1.5) from maize is active with l-tyrosine and l-phenylalanine and exhibits atypical Michaelis-Menten kinetics with both substrates. With phenylalanine as a substrate, the pH optimum is 8.7 and with tyrosine, 7.7. The estimated Km at high substrate
p-Coumaroyl-D-glucose hydroxylase in sweet potato (Ipomoea batatas Lam.) has been purified to apparent electrophoretic homogeneity using a combination of anion-and cation-exchange, hydrophobic and gel filtration chromatography. The purified enzyme was a monomer with a molecular weight of 33,000 and
L-Phenylalanine ammonia-lyase (PAL) activity was developed in response to cut injury in sweet potato root tissue. The enzyme was purified from tissue incubated for 1 day after slicing by ammonium sulfate fractionation, column chromatographies on L-phenylalanyl Sepharose 4B, phosphocellulose.
Several vegetative tissues of potato plants were screened for proteinase activity. Both endopeptidase and exopeptidase activities were investigated using gelatin and L-amino acid-4-nitroanilides (benzoyl-L-arginine-4-nitroanilide/BAPA, glutaryl-L-phenyl-alanine-4-nitroanilide/GLUPHEPA,
Potato scab, caused by several plant pathogenic Streptomyces species, is known to occur in potato-planting areas worldwide. Symptoms of disease on potato tubers are shallow, raised, or pitted corky lesions (2). In 1998, Streptomyces turgidiscabies was reported as a new potato scab pathogen from
L-Tyrosine beta-naphthylamide, a synthetic substrate designed to measure tyrosine aminopeptidase activity, is a potent inhibitor of hydroxycinnamoyl-CoA:tyramine N-(hydroxycinnamoyl)transferase (THT) purified from elicited tobacco cell-suspension cultures. The inhibition is competitive, with the
Potato tuber disks, when treated with laminarin, a beta-1,3-glucooligosaccharide from Laminaria digitata, accumulate a hydroxycinnamoyl amide compound, N-p-coumaroyloctopamine (p-CO). The biosynthesis of p-CO was investigated by feeding experiments, in order to show that the precursors of
The major acid phosphatase (APase) from potato (Solanum tuberosom L. cv Chiefton) tubers has been purified 2289-fold to near homogeneity and a final O-phospho-L-tyrosine (P-Tyr) hydrolyzing specific activity of 1917 [mu]mol Pi produced min-1 mg-1 of protein. Nondenaturing polyacrylamide gel
A high affinity cyclic nucleotide binding phosphatase was purified to homogeneity from potato tubers by a rapid procedure involving batchwise elution from carboxymethylcellulose and gel filtration. The phosphatase has a molecular weight of 28,000 as estimated from both SDS-PAGE and gel filtration.
The present study deals with the transformation of L-tyrosine to L-dopa by Acremonium rutilum, a fungal tyrosinase producer, isolated from decomposed banana stud. This appears to be the first report on A. rutilum as a polyphenoloxidase producer with both cresolase and catecholase activity. Enriched
From initial velocity studies a sequential mechanism for the reactions catalysed by phenoloxidase from potatoes is indicated. The data are in accordance with an ordered addition of oxygen and phenolic substrate to the enzyme, with oxygen being the first substrate bound at thermodynamic equilibrium.
The inhibition of Helix pomatia arylsulfatase by the synergistic combination of N-acetyl-l-tyrosine ethyl ester and vanadate has been extended to affinity chromatography for purification. In the presence of vanadate, l-tyrosine ethyl ester (TEE), immobilized on CH-Sepharose 4B retained arylsulfatase
Tyrosinase, the rate-limiting enzyme of melanin synthesis, is a di-copper metalloprotein that catalyzes the conversion of L-tyrosine to L-DOPAquinone. Phenylthiourea (PTU) is a well-known inhibitor of tyrosinase and melanin synthesis and is known to interact with sweet potato catechol oxidase, an