Purification and characterization of two cellulases from auxin-treated pea epicotyls.

摘要: Two forms of beta-1,4-glucan 4-glucanohydrolase (EC 3.2.1.4) were extracted from growing regions Pisum sativum epicotyls which had been treated with the auxin, (2,4-dichlorophenoxy)acetic acid. One cellulase is buffer-soluble, other buffer-insoluble but extractable high salt concentrations. Both enzymes catalyze endohydrolysis carboxymethylcellulose same pH optimum (5.5 to 6.0). They purified use DEAE-cellulose chromatography, Sephadex gel filtration, and ultrafiltration. are distinct proteins as characterized by: electrofocusing disc electrophoresis (pI values = 5.2 6.9, respectively); mobility in sodium dodecyl sulfate polyacrylamide gels, fractionation on Sephadex, sedimentation ultracentrifuge (mol wt approximately 20,000 70,000, S 2.63 3.73); immunological properties. The buffer-soluble enzyme tends dimerize purification. Amino acid analyses show that relatively rich glycine, alanine, valine deficient cystine, tryosine, phenylalanine compared enzyme. two activities generated equal amounts after auxin treatment. Within 5 days their levels increased at least 100-fold they constituted about 0.1% total cellular protein. Present data indicate one not derived other.