PMID: 2505757Jul 1, 1989Paper

Chemical modification of a xylanase from a thermotolerant Streptomyces. Evidence for essential tryptophan and cysteine residues at the active site

The Biochemical Journal
S S KeskarV Deshpande

Abstract

Extracellular xylanase produced in submerged culture by a thermotolerant Streptomyces T7 growing at 37-50 degrees C was purified to homogeneity by chromatography on DEAE-cellulose and gel filtration on Sephadex G-50. The purified enzyme has an Mr of 20,463 and a pI of 7.8. The pH and temperature optima for the activity were 4.5-5.5 and 60 degrees C respectively. The enzyme retained 100% of its original activity on incubation at pH 5.0 for 6 days at 50 degrees C and for 11 days at 37 degrees C. The Km and Vmax. values, as determined with soluble larch-wood xylan, were 10 mg/ml and 7.6 x 10(3) mumol/min per mg of enzyme respectively. The xylanase was devoid of cellulase activity. It was completely inhibited by Hg2+ (2 x 10(-6) M). The enzyme degraded xylan, producing xylobiose, xylo-oligosaccharides and a small amount of xylose as end products, indicating that it is an endoxylanase. Chemical modification of xylanase with N-bromosuccinimide, 2-hydroxy-5-nitrobenzyl bromide and p-hydroxymercuribenzoate (PHMB) revealed that 1 mol each of tryptophan and cysteine per mol of enzyme were essential for the activity. Xylan completely protected the enzyme from inactivation by the above reagents, suggesting the presence of tryptophan and cy...Continue Reading

Citations

Jan 1, 1997·Critical Reviews in Biotechnology·A Sunna, G Antranikian
Mar 19, 2003·Letters in Applied Microbiology·A DíazT G Villa
Jul 1, 1992·World Journal of Microbiology & Biotechnology·K B Bastawde
Apr 18, 2002·Critical Reviews in Biotechnology·S Subramaniyan, P Prema
Mar 1, 1991·World Journal of Microbiology & Biotechnology·M C SrinivasanM V Deshpande
Dec 1, 2007·World Journal of Microbiology & Biotechnology·Krutika Desai, Subramanian Sivakami
Nov 1, 1992·World Journal of Microbiology & Biotechnology·H BalakrishnanM V Rele
Sep 4, 2009·Applied Biochemistry and Biotechnology·Dhananjay SorenAnil K Ghosh
Jun 16, 2010·Journal of Industrial Microbiology & Biotechnology·Ricardo Sposina Sobral TeixeiraElba Pinto da Silva Bon
Sep 1, 1991·Bulletin of Environmental Contamination and Toxicology·R G DankaH F Morris
May 12, 2019·Journal of Applied Microbiology·M M BadonE M Woolridge
Nov 21, 2007·Applied Biochemistry and Biotechnology·Ahmed Jawaard AfzalKhawar Sohail Siddiqui
Jan 1, 1994·FEMS Microbiology Letters·M T Fernández-EspinarS Vallés
Jul 28, 1999·FEMS Microbiology Reviews·N KulkarniM Rao
Jun 1, 1993·Applied and Environmental Microbiology·A KhasinY Shoham
Jun 1, 1994·Applied and Environmental Microbiology·O GatY Shoham
Dec 1, 1995·Applied and Environmental Microbiology·A BlancoF I Pastor

❮ Previous
Next ❯

Related Concepts

Trending Feeds

COVID-19

Coronaviruses encompass a large family of viruses that cause the common cold as well as more serious diseases, such as the ongoing outbreak of coronavirus disease 2019 (COVID-19; formally known as 2019-nCoV). Coronaviruses can spread from animals to humans; symptoms include fever, cough, shortness of breath, and breathing difficulties; in more severe cases, infection can lead to death. This feed covers recent research on COVID-19.

Blastomycosis

Blastomycosis fungal infections spread through inhaling Blastomyces dermatitidis spores. Discover the latest research on blastomycosis fungal infections here.

Nuclear Pore Complex in ALS/FTD

Alterations in nucleocytoplasmic transport, controlled by the nuclear pore complex, may be involved in the pathomechanism underlying multiple neurodegenerative diseases including Amyotrophic Lateral Sclerosis and Frontotemporal Dementia. Here is the latest research on the nuclear pore complex in ALS and FTD.

Applications of Molecular Barcoding

The concept of molecular barcoding is that each original DNA or RNA molecule is attached to a unique sequence barcode. Sequence reads having different barcodes represent different original molecules, while sequence reads having the same barcode are results of PCR duplication from one original molecule. Discover the latest research on molecular barcoding here.

Chronic Fatigue Syndrome

Chronic fatigue syndrome is a disease characterized by unexplained disabling fatigue; the pathology of which is incompletely understood. Discover the latest research on chronic fatigue syndrome here.

Evolution of Pluripotency

Pluripotency refers to the ability of a cell to develop into three primary germ cell layers of the embryo. This feed focuses on the mechanisms that underlie the evolution of pluripotency. Here is the latest research.

Position Effect Variegation

Position Effect Variagation occurs when a gene is inactivated due to its positioning near heterochromatic regions within a chromosome. Discover the latest research on Position Effect Variagation here.

STING Receptor Agonists

Stimulator of IFN genes (STING) are a group of transmembrane proteins that are involved in the induction of type I interferon that is important in the innate immune response. The stimulation of STING has been an active area of research in the treatment of cancer and infectious diseases. Here is the latest research on STING receptor agonists.

Microbicide

Microbicides are products that can be applied to vaginal or rectal mucosal surfaces with the goal of preventing, or at least significantly reducing, the transmission of sexually transmitted infections. Here is the latest research on microbicides.