Polymerization enzymatic cross-linking

Waxes, in particular cutin and suberin, are polymerized and cross linked structures of hydroxy fatty acids that are resistant to oxidation and to microbial and enzymatic attack. Cutin is found on the outer surface of plant tissue while suberin is mainly associated with roots and bark of plants. Both contain an even number of carbons in the range from C, to C,(,. Cutan and suberan are also highly aliphatic polymers lacking ester cross linkages. They are linked by carbohydrate structures to form glycolipids that are integral parts of microbial cell walls (De Leeuw and Largeau, 1993). 

A copolymer of this monomer with N,N melhylenebis (acrylamide) imbibed 100 times its weight of water. This swelling was not affected by sodium chloride in the water. Most super-slurpers swell less in the presence of dissolved salts. Thus, the new copolymer may be of use in collecting urine in diapers. Another polymeric hydrogel was made by polymerization of sucrose-l -acrylate using sucrose-6,1 -diacrylate (prepared by enzymatic transesterification of sucrose and vinyl acrylate) as the cross-linking agent.155... 

The main classes of Maillard reaction end products of practical interest inelude volatile heterocyclic molecules responsible for aromas of thermally processed foods colored oligomeric and polymeric molecules that determine non-enzymatic browning of thermally processed foods protein and lipid cross-linking and other advanced glycation end products in vivo, which are implicated in pathogenesis of comphcations in diabetes and aging. Here we only consider the contribution of D-finctosamines implicated in the formation of these end products. A number of reviews containing detailed considerations of the formation of volatiles, melanoidins, and... 

Novel photoinitiated mechanisms of polymerization have also been developed to pattern cellular behavior within bulk hydrogel constmcts. For example, a sequential cross-linking technique was used to pattern MSG spreading within adhesive and enzymatically degradable HA... 

OmpF was successfully reconstituted into Upid vesicles (186,218), which could be demonstrated using an encapsulated enzyme, -lactamase, which is able to hydrolyze the antibiotic ampicillin. The hydrolysis product, ampicillinoic acid, can reduce iodine to iodide, which can be monitored by iodometry, ie via the decol-orization of a starch/iodine complex in the exterior solution. The enzyme and the membrane channel have been shown to preserve their activity in the presence of hydrophobic methacrylate monomers before and after their cross-linking polymerization. Polymerization of hydrophobic iV-butylmethacrylate and ethylene glycol dimethacrylate (186) lead to partial expulsion of some reconstituted channels during the cross-linking reaction, thereby decreasing the enzymatic activity. 

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