dc.description.abstract | The antibiotics are substances that kill or inhibit the growth of
bacteria. Most antibiotics are modified chemically from original
compounds found in nature. The antibiotics were frequently used for
antimicrobial therapy. The main objective of this study was to
determination of the effects of some antibiotics such as ceftazidime
pentahydrate, prednisolone, amikacin sulfate, ceftriaxone sodium and
teicoplanin on bovine milk lactoperoxidase activity were investigated in
this study. Lactoperoxidase was purified using Amberlite-CG-50 resin, CM
Sephadex-C-50 ion-exchange and Sephadex-G-100 gel filtration
chromatographies from bovine milk.
2,2'-Azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) was used as a
chromogenic substrate for spectrophotometric determination of
lactoperoxidase activity. Lactoperoxidase was purified 19 fold with a
yield of 24.5\%. All of the used antibiotics exhibited inhibitory
effects on the enzyme and displayed competitive type of inhibition
mechanism. IC(50) values of ceftazidime pentahydrate, prednisolone,
amikacin sulfate, ceftriaxone sodium and teicoplanin were 0.048, 0.053,
0.26, 0.29 and 1.016 mM, respectively. K(i) constants were calculated as
0.018 +/- 0.0035 mM, 0.019 +/- 0.0005 mM, 0.04 +/- 0.015 mM, 0.10 +/-
0.055 mM and 0.13 +/- 0.022 mM for ceftazidime pentahydrate,
prednisolone, amikacin sulfate, ceftriaxone sodium and teicoplanin,
respectively. Present study showed that ceflazidime pentahydrate
exhibited much higher inhibitory effect at lower concentrations compared
to other antibiotics used. | |