BGN16.3, a novel acidic beta-1,6-glucanase from mycoparasitic fungus Trichoderma harzianum CECT 2413.
A new component of the beta-1,6-glucanase (EC 3.2.1.75) multienzymatic complex secreted by Trichoderma harzianum has been identified and fully characterized. The protein, namely BGN16.3, is the third isozyme displaying endo-beta-1,6-glucanase activity described up to now in T. harzianum CECT 2413. BGN16.3 is an acidic beta-1,6-glucanase that is specifically induced by the presence of fungal cell walls in T. harzianum growth media. The protein was purified to electrophoretical homogenity using its affinity to beta-1,6-glucan as first purification step, followed by chomatofocusing and gel filtration. BGN16.3 has a molecular mass of 46 kDa in SDS/PAGE and a pI of 4.5. The enzyme only showed activity against substrates with beta-1,6-glycosidic linkages, and it has an endohydrolytic mode of action as shown by HPLC analysis of the products of pustulan hydrolysis. The expression profile analysis of BGN16.3 showed a carbon source control of the accumulation of the enzyme, which is fast and strongly induced by fungal cell walls, a condition often regarded as mycoparasitic simulation. The likely involvement beta-1,6-glucanases in this process is discussed.
Montero
Manuel
M
Centro Hispano-Luso de Investigaciones Agrarias, Universidad de Salamanca, Spain. manuel.montero@sainsbury-laboratory.ac.uk
Sanz
Luis
L
Rey
Manuel
M
Monte
Enrique
E
Llobell
Antonio
A
D000818:Animals; D002473:Cell Wall / Q000378:metabolism*; D002686:Chitin / Q000378:metabolism; D002851:Chromatography, High Pressure Liquid; D003001:Cloning, Molecular; D015966:Gene Expression Regulation, Fungal; D006026:Glycoside Hydrolases / Q000276:immunology / Q000302:isolation & purification / Q000378:metabolism*; D007074:Immunoglobulin G / Q000276:immunology; D011817:Rabbits; D013379:Substrate Specificity; D014242:Trichoderma / Q000201:enzymology*; D047071:beta-Glucans / Q000378:metabolism*
D007074:Immunoglobulin G; D047071:beta-Glucans; D002686:Chitin; C064197:beta-1,6-glucan; D006026:Glycoside Hydrolases; C020105:endo-1,6-beta-glucanase