Thermoprecipitation of lysozyme from egg white using copolymers of N-isopropylacrylamide and acidic monomers.
Thermoprecipitation of lysozyme from egg white was demonstrated using copolymers of N-isopropylacrylamide with acrylic acid, methacrylic acid, 2-acryloylamido-2-methylpropane-sulfonic acid and itaconic acid, respectively. Polymers synthesized using molar feed ratio of N-isopropylacrylamide:acidic monomers of 98:2 exhibited lower critical solution temperatures in the range of 33--35 degrees C. These polymers exhibited electrostatic interactions with lysozyme and inhibited its bacteriolytic activity. The concentration of acidic groups required to attain 50% relative inhibition of lysozyme by the polymers, was 10(4)--10(5) times lower than that required for the corresponding monomers. This was attributed to the multimeric nature of polymer-lysozyme binding. More than 90% lysozyme activity was recovered from egg white. Polymers exhibited reusability up to at least 16 cycles with retention of >85% recovery of specific activity from aqueous solution. In contrast, copolymer comprising natural inhibitor of lysozyme i.e. poly (N-isopropylacrylamide-co-O-acryloyl N-acetylglucosamine) lost 50% recovery of specific activity. Thermoprecipitation using these copolymers, which enables very high recovery of lysozyme from egg white, would be advantageous over pH sensitive polymers, which generally exhibit lower recovery.
Vaidya
A A
AA
Chemical Engineering Division, National Chemical Laboratory, Polymer Science and Engineering Group, Pune 411 008, India.
Lele
B S
BS
Kulkarni
M G
MG
Mashelkar
R A
RA
D000117:Acetylglucosamine / Q000737:chemistry; D000178:Acrylamides / Q000737:chemistry*; D000179:Acrylates / Q000737:chemistry*; D000818:Animals; D001665:Binding Sites; D011232:Chemical Precipitation; D004529:Egg White; D006863:Hydrogen-Ion Concentration; D007477:Ions; D008689:Methacrylates / Q000737:chemistry; D009113:Muramidase / Q000037:antagonists & inhibitors / Q000302:isolation & purification* / Q000378:metabolism; D009994:Osmolar Concentration; D011108:Polymers / Q000737:chemistry*; D012996:Solutions; D013386:Succinates / Q000737:chemistry
D000178:Acrylamides; D000179:Acrylates; D007477:Ions; D008689:Methacrylates; C090629:N-isopropylacrylamide-acrylic acid copolymer; D011108:Polymers; D012996:Solutions; D013386:Succinates; C008384:methacrylic acid; C067295:N-isopropylacrylamide; D009113:Muramidase; C036658:acrylic acid; C005229:itaconic acid; D000117:Acetylglucosamine