Hyaluronic acid bacterial type

The second type of material includes spores, which may or may not produce disease symptoms but which can germinate in the insect gut and give rise to vegetative bacterial cells which in turn may produce, and exoenzymes such as phospholipases (lecithinases) or hyaluronidase. The phospholipases may produce direct toxic symptoms owing to their action on nervous or other phospholipid-containing tissue. Hyaluronidase breaks down hyaluronic acid and produces effects on animal tissue which are morphologically similar to the breakdown of insect gut wall in the presence of microbial insecticide preparations. 

The PL-catechin conjugate showed greatly amplified concentration-dependent inhibition activity against bacterial collagenase (ChC) on the basis of the catechin unit, which is considered to be due to effective multivalent interaction between ChC and the catechin unit in the conjugate. The kinetic study suggests that this conjugate is a mixed-type inhibitor for ChC. Hyaluronidase is an enzyme which catalyzes hydrolysis of hyaluronic acid and is often involved in a number... 

Stacey has written an excellent review on the subject of mucopolysaccharides, which he classified on the basis of their containing both hexosamine and hexuronic acid residues, one or the other of these sugar derivatives, or neither. Hyaluronic acid, chondroitinsulfuric acid. Type I pneumococcal polysaccharides, and heparin are members of the first class. Types II, III, and VIII pneumococcal polysaccharides are examples containing hexuronic acid but no hexosamine. Chi tin and Types IV and XIV pneiuno-coccal polysaccharides contain hexosamine but no hexuronic acid and bacterial dextrans, mold polysaccharides, and levans contain neither hexosamine nor hexuronic acid. 

The function of hyaluronic acid was initially confined to the maintenance and sta-bihty of the ECM (96). However, the action of hyaluronic acid varies with its size, which determines its function in a cell-type specific manner (97-101). Hyaluronic acid represents more than 50% of the ECM in the skin. High molecular weight hyaluronic acid (>1,000 kDa) controls tissue water content, ECM lubrication, structural integrity, free oxygen radicals, and distribution of plasma proteins (96,100,101). The synthesis of hyaluronic acid is achieved by hyaluronan synthase-1 to -3 (102,103). The stability of hyaluronic acid varies with its microenvironment, as its half-life is less than 10 min in blood, up to 12 h in the skin, and extends to months in the vitreous gel of the eye (100,101). Hyaluronic acid is the only GAG with a function of its breakdown molecules, as small hyaluronic acid molecules and fragments stimulated the maturation of dentritic cells and the synthesis of proinflammatory IL-lp, IL-12, and TNF-a (103-105). The latter effect seems to be restricted to an interaction of hyaluronic acid fragments with the Toll-like receptor 4 (104,105). The observation that bacterial spreading in the... 

First studied in the 1960s as a medical device, hyaluronic acid is a non-sulfated glycosaminoglycan made by fibroblasts and type B synoviocytes [32]. Five commercially available hyaluronic acid formulations of differing MW and crosslinking are in use clinically. They are purified from rooster combs or produced by bacterial fermentation. It is injected either in the form of sodium hyaluronate or covalently crossUnked hyaluronic acid molecules [56]. The treatment regimen is formulation dependent, administered by 1, 3, or 5 intra-articular weekly injections. 

Bacterial polysaccharides are a very heterogeneous group and are clearly of several biosynthetic types. Many are closely equivalent to the polysaccharide (O-antigenic-type) chains of lipopolysaccharide and have presumably been released by hydrolysis, rather than transferred to lipid A or core structures. Some, such as bacterial hyaluronate, somewhat resemble wall polymers (some teichuronic acids, in this case), but have no exact counterparts. Others, such as bacterial cellulose and colominic acid (polysialic acid) are very different from... 

Type 3. Microbial hyaluronidases (e.g. Streptococcus hyaluronidase). Microbial hyaluronidases hydrolyse p-N-acetylaminoglycoside bonds of a substrate and simultaneously dehydrate the residue of uronic acid at the non-reducing terminus of the molecule. Substrate specificity of bacterial hyaluronate lyases varies considerably in the different species of microbe producers. Hyaluronidase of Streptococcus pneumoniae has the highest substrate specificity it hydrolyses HA alone and does not destroy other glucosami-noglycans [43]. The hyaluronate lyase, when isolated from Streptococcus pneumoniae, reaches optimal activity at pH 6.0 with the Michaelis constant with respect to HA being equal to 3.8x 10" mol/l (in terms of Michaelis-Menten kinetics) [44]. The presence of Cd3 (about 10 mM) is necessary in order to show the maximum enzyme activity. 

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