[Chemical modification of epsilon-amino lysine groups in horseradish peroxidase. Its effect on catalytic properties and spatial structure of the enzyme].
Effect of chemical modification of horseradish peroxidase lysine epsilon-amino groups by propionic, butyric, valeric, succinic anhydrides and trinitrobenzolsulfonic acid (TNBS) on catalytic properties of the enzyme is investigated. All the preparations of modified peroxidase have 100% peroxidase activity for o-dianizidine at pH 7.0, which indicates the absence of lysine epsilon-amino group in the enzyme active site. pH-dependencies of modified peroxidase relative activity are studied; modification by anhydrides of monobasic acids is not found to result in changes of the relative activity pH-profile, while modification by succinic anhydride widens it. Absorption and circular dichoism spectra of native and modified peroxidase within 260--270 nm are obtained, some changes in the enzyme tertiary structure after its epsilon-amino groups modification are observed. Modification of four epsilon-amino groups by buturic and succinic anhydrides and of three epsilon-amino groups by TNBS is found to increase the regidity of protein surrounding of heme, and modification of six epsilon-amino groups by TNBS results in more unwrapped enzyme structure as compared with its native molecule.
D002087:Butyrates; D006735:Horseradish Peroxidase / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D008239:Lysine / Q000031:analogs & derivatives; D010544:Peroxidases / Q000378:metabolism*; D011422:Propionates; D011487:Protein Conformation; D013056:Spectrophotometry, Ultraviolet; D013387:Succinic Anhydrides; D014302:Trinitrobenzenesulfonic Acid; D014631:Valerates
D002087:Butyrates; D011422:Propionates; D013387:Succinic Anhydrides; D014631:Valerates; D014302:Trinitrobenzenesulfonic Acid; D006735:Horseradish Peroxidase; D010544:Peroxidases; D008239:Lysine
Khimicheskaia modifikatsiia epsilon-NH2-grupp lizina v peroksidaze khrena. Vliianie ee na kataliticheskie svoĭstva i prostranstvennyiu struktury fermenta.