Document Detail


Mode of action of a family 75 chitosanase from Streptomyces avermitilis.
MedLine Citation:
PMID:  22376136     Owner:  NLM     Status:  Publisher    
Abstract/OtherAbstract:
Chitooligosaccharides (CHOS) are oligomers composed of glucosamine and N-acetylglucosamine with several interesting bioactivities that can be produced from enzymatic cleavage of chitosans. By controlling the degree of acetylation of the substrate chitosan, the enzyme, and the extent of enzyme degradation, CHOS preparations with limited variation in length and sequence can be produced. We here report on the degradation of chitosans with a novel family 75 chitosanase, SaCsn75A from Streptomyces avermitilis . By characterizing the CHOS preparations, we have obtained insight into the mode of action and subsite specificities of the enzyme. The degradation of a fully deacetylated and a 31% acetylated chitosan revealed that the enzyme degrade these substrates according to a non-processive, endo mode of action. With the 31% acetylated chitosan as substrate, the kinetics of the degradation showed an initial rapid phase, followed by a second slower phase. In the initial faster phase, an acetylated unit (A) is productively bound in subsite -1, whereas deacetylated units (D) are bound in the -2 subsite and the +1 subsite. In the slower second phase, D-units bind productively in the -1 subsite, probably with both acetylated and deacetylated units in the -2 subsite, but still with an absolute preference for deacetylated units in the +1 subsite. Chitooligosaccharides produced in the initial phase are composed of deacetylated units with an acetylated reducing end. In the slower second phase, higher amounts of low DP fully deacetylated oligomers (dimer and trimer) are produced, while the higher DP oligomers are dominated by compounds with acetylated reducing ends containing increasing amounts of internal acetylated units. The degradation of chitosans with varying degrees of acetylation to maximum extents of degradation showed that increasingly longer oligomers are produced with increasing degree of acetylation, and that the longer oligomers contain sequences of consecutive acetylated units interspaced by single deacetylated units. The catalytic properties of SaCsn75A differ from the properties of a previously characterized family 46 chitosanase from S. coelicolor (ScCsn46A).
Authors:
Ellinor Bœvre Heggset; Tina R Tuveng; Ingunn Alne Hoell; Zhanliang Liu; Vincent G H Eijsink; Kjell Morten Varum
Related Documents :
2478196 - Purification and characterization of a phosphotyrosyl-protein phosphatase from wheat se...
1695086 - Choline derivatives increase two different acid phosphatases in rhizobium meliloti and ...
3301386 - Hymenolepis diminuta: interactions of the isolated brush border membrane with proteolyt...
3905306 - Physiological factors controlling release of enterokinase from rat enterocytes.
20047516 - Evaluation of various ions and compounds on nitrilase produced from streptomyces sp.
6434506 - Fungal glucoamylases.
Publication Detail:
Type:  JOURNAL ARTICLE     Date:  2012-2-29
Journal Detail:
Title:  Biomacromolecules     Volume:  -     ISSN:  1526-4602     ISO Abbreviation:  -     Publication Date:  2012 Feb 
Date Detail:
Created Date:  2012-3-1     Completed Date:  -     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  100892849     Medline TA:  Biomacromolecules     Country:  -    
Other Details:
Languages:  ENG     Pagination:  -     Citation Subset:  -    
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Descriptor/Qualifier:

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


Previous Document:  WOMAC-pf as a measure of physical function in patients with Parkinson's disease and late-onset seque...
Next Document:  Genome-wide analysis of the MADS-box gene family in cucumber.