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Showing papers on "Penicillin amidase published in 1979"


Journal ArticleDOI
TL;DR: Two types of bead‐form macroporous carriers based on glycidyl methacrylate with ethylene dimethacrylated copolymers were used for the immobilization of penicillin amidase either directly or after chemical modificaton.
Abstract: Two types of bead-form macroporous carriers based on glycidyl methacrylate with ethylene dimethacrylate copolymers were used for the immobilization of penicillin amidase either directly or after chemical modification. Direct binding through oxirane groups, which is equally efficient at pH 4.2 and 7, is relatively slow and brings about an activity loss at low enzyme concentrations. The most efficient immobilization was achieved on glutaraldehyde-activated amino carrier, irrespective of whether the amino groups were formed by ammonia or 1,6-diaminohexane treatment of the original oxirane carrier. Hydrazine treatment gave lower immobilization yields. The same is true of the azide method independent of the length of the spacer. Most enzyme activity was preserved by coupling the carbodiimide-activated enzyme to the carrier with alkyl or arylamino groups at the end of a longer substituent. Immobilization on diazo-modified carrier gave average results. Rapid immobilization by a lysine-modified phosgene-treated carrier resulted in an activity loss. It is suggested that multipoint and very tight attachment of the enzyme molecule to the matrix decreased the activity. The immobilized activity is quite stable in solution and very stable upon lyophilization with sucrose.

44 citations


Journal ArticleDOI
TL;DR: An enzyme preparation in a spherical granule form was obtained by copolymerization of penicillin amidase and acrylamide via a crosslinking agent, and immobilized amidase is more resistant to heating, has a lower affinity to benzylpenicillin, and is less inhibited by phenylacetate.
Abstract: An enzyme preparation in a spherical granule form was obtained by copolymerization of penicillin amidase (EC 3.5.1.11) (previously modified with maleic anhydride) and acrylamide via a crosslinking agent. As compared with the native enzyme, immobilized amidase is more resistant to heating, has a lower affinity to benzylpenicillin, and is less inhibited by phenylacetate. Its substrate specificity and optimum pH remain unchanged.

16 citations


Journal ArticleDOI
TL;DR: Some biochemical properties of whole-cell penicillin amidohydrolase from Micrococcus luteus have been studied and this enzyme showed first-order decay at 36 degrees C and had synthetic activity for semisynthetic penicillins or cephalosporins from D-(--)-alpha-phenylglycine methyl ester and 6-alpha-aminopenicillanic acid.
Abstract: Some biochemical properties of whole-cell penicillin amidohydrolase from Micrococcus luteus have been studied This whole-cell enzyme showed its maximal activity at 36 degrees C at pH 75 It was found that the activation energy of this enzyme was 803 kcal (ca 336 kJ) per mol, and this amidohydrolase showed first-order decay at 36 degrees C The penicillin amidohydrolase was deactivated rapidly at temperatures above 50 degrees C during storage or preincubation for 24 h The Michaelis constant, Km, for penicillin G was determined as 226 mM, and the substrate inhibition constant, Kis, was 155 mM The whole-cell penicillin amidohydrolase from M luteus was capable of hydrolyzing penicillin G, penicillin V, ampicillin, and cephalexin, but not cephalosporin C and cloxacillin This whole-cell enzyme also had synthetic activity for semisynthetic penicillins or cephalosporins from D-(--)-alpha-phenylglycine methyl ester and 6-alpha-aminopenicillanic acid or 7-amino-3-deacetoxycephalosporanic acid

4 citations