RESUMO
An antifungal protein with a molecular mass of 11 kDa and a lysine-rich N-terminal sequence was isolated from the seeds of the pea Pisum sativum var. arvense Poir. The antifungal protein was unadsorbed on DEAE-cellulose but adsorbed on Affi-gel blue gel and CM-cellulose. It exerted antifungal activity against Physalospora piricola with an IC50 of 0.62 microM, and also antifungal activity against Fusarium oxysporum and Mycosphaerella arachidicola. It inhibited human immunodeficiency virus type 1 reverse transcriptase with an IC50 of 4.7 microM.
Assuntos
Antifúngicos/farmacologia , Peptídeos/química , Pisum sativum/metabolismo , Extratos Vegetais/metabolismo , Aminoácidos/química , Sistema Livre de Células , Celulose/química , Etanolaminas/química , Fusarium/metabolismo , Transcriptase Reversa do HIV/metabolismo , Concentração Inibidora 50 , Testes de Sensibilidade Microbiana , Extratos Vegetais/farmacologia , Biossíntese de Proteínas , Tripsina/farmacologiaRESUMO
A laccase with a novel N-terminal sequence, a low molecular mass of 43 kDa smaller than those of previously reported laccases, a pH optimum of 4, and a temperature optimum at 70 degrees C was isolated from fresh fruiting bodies of the mushroom Tricholoma giganteum. The activity of the enzyme rose steadily from 20 to 50 degrees C, increased very slowly from 50 to 70 degrees C, and fell slightly when the temperature was further increased to 80 degrees C. The activity of the laccase underwent little changes over the pH range 3.0-5.0. However, the enzyme activity dwindled to nothing after exposure to 100 degrees C for 10 min and when the ambient pH was 7 or above. The procedure used for purifying the enzyme included ion exchange chromatography on DEAE-cellulose, affinity chromatography on Affi-gel blue gel, ion exchange chromatography on CM-cellulose, and FPLC-gel filtration on Superdex 75. The laccase was unadsorbed on DEAE-cellulose and adsorbed on Affi-gel blue gel and CM-cellulose. It inhibited HIV-1 reverse transcriptase with an IC(50) of 2.2 microM.
Assuntos
Agaricales/metabolismo , HIV-1/enzimologia , Lacase/isolamento & purificação , Extratos Vegetais , Inibidores da Transcriptase Reversa/farmacologia , Celulose/química , Cromatografia de Afinidade , Cromatografia em Gel , Cromatografia por Troca Iônica , Eletroforese em Gel de Poliacrilamida , Concentração de Íons de Hidrogênio , Concentração Inibidora 50 , Lacase/química , Estrutura Terciária de Proteína , TemperaturaRESUMO
A ribonuclease, with a molecular mass of 30 kDa and a potent inhibitory activity toward HIV-1 reverse transcriptase (IC50=300 nM), was isolated from dried fruiting bodies of the edible wild mushroom Thelephora ganbajun. The ribonuclease exhibited a unique polyhomoribonucleotide specificity, with the highest activity toward poly(U), about 50% and 25% as much activity toward poly(A) and poly(C), respectively, and minimal activity toward poly(G). Unlike other mushroom RNases, the ribonuclease was adsorbed on DEAE-cellulose and Q-Sepharose, and unadsorbed on CM-cellulose. A temperature of 40 degrees C and a pH of 6-7 were required for maximal activity of the enzyme. The enzyme was characterized by an N-terminal sequence without any homology to known proteins.
Assuntos
Basidiomycota/enzimologia , Ribonucleases/química , Ribonucleases/isolamento & purificação , Agaricales/enzimologia , Celulose/química , Cromatografia em Gel/métodos , Cromatografia por Troca Iônica , DEAE-Celulose/química , Eletroforese em Gel de Poliacrilamida , Transcriptase Reversa do HIV/antagonistas & inibidores , Concentração de Íons de Hidrogênio , Concentração Inibidora 50 , Peso Molecular , Poli A/química , Poli C/química , Poli G/química , Ribonucleotídeos/química , TemperaturaRESUMO
An improved method for the removal of polyphenolic compounds from aqueous extracts of plants is presented. The method removes > 99% polyphenolic compounds from 5 mg of extract. The method is simple, robust and reproducible. We examined the removal of polyphenolics from 5 different aqueous extracts of Chinese medicinal herbs.