TY  - JOUR
A1  - Einarsson, Jon M.
A1  - Bahrke, Sven
A1  - Sigurdsson, Bjarni Thor
A1  - Ng, Chuen-How
A1  - Petersen, Petur Henry
A1  - Sigurjonsson, Olafur E.
A1  - Jonsson, Halldor
A1  - Gislason, Johannes
A1  - Thormodsson, Finnbogi R.
A1  - Peter, Martin G.
T1  - Partially acetylated chitooligosaccharides bind to YKL-40 and stimulate growth of human osteoarthritic chondrocytes
JF  - Biochemical and biophysical research communications
N2  - Recent evidences indicating that cellular kinase signaling cascades are triggered by oligomers of N-acetylglucosamine (ChOS) and that condrocytes of human osteoarthritic cartilage secrete the inflammation associated chitolectin YKL-40, prompted us to study the binding affinity of partially acetylated ChOS to YKL-40 and their effect on primary chondrocytes in culture. Extensive chitinase digestion and filtration of partially deacetylated chitin yielded a mixture of ChOS (Oligomin(TM)) and further ultrafiltration produced T-ChOS(TM), with substantially smaller fraction of the smallest sugars. YKL-40 binding affinity was determined for the different sized homologues, revealing micromolar affinities of the larger homologues to YKL-40. The response of osteoarthritic chondrocytes to Oligomin(TM) and T-ChOS(TM) was determined, revealing 2- to 3-fold increases in cell number. About 500 mu g/ml was needed for Oligomin(TM) and around five times lower concentration for T-ChOS(TM), higher concentrations abolished this effect for both products. Addition of chitotriose inhibited cellular responses mediated by larger oligosaccharides. These results, and the fact that the partially acetylated T-ChOS(TM) homologues should resist hydrolysis, point towards a new therapeutic concept for treating inflammatory joint diseases.
KW  - Cell culture
KW  - Chitolectin
KW  - Chitooligosaccharides
KW  - Chondrocytes
KW  - High affinity binding
KW  - Rheumatoid arthritis
KW  - YKL-40
Y1  - 2013
U6  - https://doi.org/10.1016/j.bbrc.2013.02.122
SN  - 0006-291X
VL  - 434
IS  - 2
SP  - 298
EP  - 304
PB  - Elsevier
CY  - San Diego
ER  - 
TY  - JOUR
A1  - Mengibar, M.
A1  - Ganan, M.
A1  - Miralles, B.
A1  - Carrascosa, A. V.
A1  - Martinez-Rodriguez, Adolfo J.
A1  - Peter, Martin G.
A1  - Heras, A.
T1  - Antibacterial activity of products of depolymerization of chitosans with lysozyme and chitosanase against Campylobacter jejuni
JF  - Carbohydrate polymers : an international journal devoted to scientific and technological aspects of industrially important polysaccharides
N2  - Chitosan has several biological properties useful for the food industry, but the most attractive is its potential use as a food preservative of natural origin due to its antimicrobial activity against a wide range of food-borne microorganisms. Among food-borne pathogens, Campylobacter jejuni and related species are recognised as the most common causes of bacterial food-borne diarrhoeal disease throughout the world. Recently, it has been demonstrated that campylobacters are highly sensitive to chitosan. Even though chitosan is known to have important functional activities, poor solubility makes them difficult to use in food and biomedical applications. Unlike chitosan, the low viscosity and good solubility of chitosan oligosaccharides (COS) make them especially attractive in an important number of useful applications. In the present work, the effect of different COS on C. jejuni was investigated. Variables such as the physicochemical characteristics of chitosan and the enzyme used in COS preparation were studied. The COS had been fractioned using ultrafiltration membranes and each fraction was characterized regarding its FA and molecular weight distribution. It has been demonstrated that the biological properties of COS on Campylobacter depend on the composition of the fraction analysed. COS prepared by enzymatic hydrolysis with chitosanase were more active against Campylobacter that lysozyme-derived COS, and this behaviour seems to be related with the acetylation of the chains. On the other hand. the 10-30 kDa fraction was the most active COS fraction, independently of the enzyme used for the hydrolysis. These results have shown that COS could be useful as antimicrobial in the control of C. jejuni.
KW  - Campylobacter jejuni
KW  - Chitooligosaccharides
KW  - Chitosanase
KW  - Lysozyme
KW  - Depolymerization
Y1  - 2011
U6  - https://doi.org/10.1016/j.carbpol.2010.04.042
SN  - 0144-8617
VL  - 84
IS  - 2
SP  - 844
EP  - 848
PB  - Elsevier
CY  - Oxford
ER  -