Biochemical and catalytic properties of an endoxylanase purified from the culture filtrate of Thermomyces lanuginosus ATCC 46882
Φόρτωση...
Ημερομηνία
Συγγραφείς
Bennett, N. A.
Ryan, J.
Biely, P.
Vrsanska, M.
Kremnicky, L.
Macris, B. J.
Kekos, D.
Christakopoulos, P.
Katapodis, P.
Claeyssens, M.
Τίτλος Εφημερίδας
Περιοδικό ISSN
Τίτλος τόμου
Εκδότης
Περίληψη
Τύπος
Είδος δημοσίευσης σε συνέδριο
Είδος περιοδικού
peer reviewed
Είδος εκπαιδευτικού υλικού
Όνομα συνεδρίου
Όνομα περιοδικού
Carbohydr Res
Όνομα βιβλίου
Σειρά βιβλίου
Έκδοση βιβλίου
Συμπληρωματικός/δευτερεύων τίτλος
Περιγραφή
An endoxylanase (1,4-beta-D-xylan xylanohydrolase, EC 3.2.1.8) from the culture filtrates of T. lanuginosus ATCC 46882 was purified to homogeneity by DEAE-Sepharose and Bio-Gel P-30 column chromatographies. The purified endoxylanase had a specific activity of 888.8 mumol min-1 mg-1 protein and accounted for approximately 30% of the total protein secreted by this fungus. The molecular mass of native (non-denatured) and denatured endoxylanase were 26.3 and 25.7 kD as, respectively. Endoxylanase had a pI of 3.7 and was optimally active between pH 6.0-6.5 and at 75 degrees C. The enzyme showed > 50% of its original activity between pH 5.5-9.0 and at 85 degrees C. The pH and temperature stability studies revealed that this endoxylanase was almost completely stable between pH 5.0-9.0 and up to 60 degrees C for 5 h and at pH 10.0 up to 55 degrees C for 5 h. Thin-layer chromatography (TLC) analysis showed that endoxylanase released mainly xylose (Xyl) and xylobiose (Xyl2) from beechwood 4-O-methyl-D-glucuronoxylan, O-acetyl-4-O-methyl-D-glucuronoxylan and rhodymenan (a beta-(1-->3)-beta(1-->4)-xylan). Also, the enzyme released an acidic xylo-oligosaccharide from 4-O-methyl-D-glucuronoxylan, and an isomeric xylotetraose and an isomeric xylopentaose from rhodymenan. The enzyme hydrolysed [1-3H]-xylo-oligosaccharides in an endofashion, but the hydrolysis of [1-3H]-xylotriose appeared to proceed via transglycosylation. since the xylobiose was the predominant product. Endoxylanase was not active on pNPX and pNPC at 40 and 100 mM for up to 6 h, but showed some activity toward pNPX at 100 mM after 20-24 h. The results suggested that the endoxylanase from T. lanuginosus belongs to family 11.
Περιγραφή
Λέξεις-κλειδιά
Disaccharides/metabolism, Endo-1,4-beta Xylanases, Enzyme Stability, Fungal Proteins/chemistry, Hydrogen-Ion Concentration, Isoelectric Point, Mitosporic Fungi/*enzymology, Oligosaccharides/metabolism, Substrate Specificity, Temperature, Xylans/metaboli
Θεματική κατηγορία
Παραπομπή
Σύνδεσμος
http://www.ncbi.nlm.nih.gov/pubmed/9648252
http://ac.els-cdn.com/S0008621597100763/1-s2.0-S0008621597100763-main.pdf?_tid=0998d7f0-c389-11e2-9e50-00000aacb361&acdnat=1369300591_3b8208b967e26d2bf0b2751c1914c8e9
http://ac.els-cdn.com/S0008621597100763/1-s2.0-S0008621597100763-main.pdf?_tid=0998d7f0-c389-11e2-9e50-00000aacb361&acdnat=1369300591_3b8208b967e26d2bf0b2751c1914c8e9
Γλώσσα
en
Εκδίδον τμήμα/τομέας
Όνομα επιβλέποντος
Εξεταστική επιτροπή
Γενική Περιγραφή / Σχόλια
Ίδρυμα και Σχολή/Τμήμα του υποβάλλοντος
Πανεπιστήμιο Ιωαννίνων. Σχολή Επιστημών και Τεχνολογιών. Τμήμα Βιολογικών Εφαρμογών και Τεχνολογιών