The inhibitory effect of cyclodextrin on the degradation of 9 -hydroxyandrost-4-ene-3,17-dione by Mycobacterium sp. VKM Ac-1817D

• Published in: Biocatalysis and biotransformation 2007, Vol.25 (5), p.386-392
• Main Authors: Khomutov, Sergey M., Sukhodolskaya, Galina V., Donova, Marina V.
• Format: Article
• Language: English
• ISSN: 1024-2422; 1029-2446
• DOI: 10.1080/10242420701510510

The inhibitory effect of methylated -cyclodextrin (mCD) on steroid degradation was studied using the degradation of 9 -hydroxyandrost-4-ene-3,17-dione (9-OH-AD) by Mycobacterium sp. VKM Ac-1817D as a model process. The formation of the [9-OH-AD-mCD] complex was shown by 1H NMR-spectroscopy. The biodegradation of 9-OH-AD by whole and disrupted cells was carried out at 30°C in aqueous solutions with or without mCD. Enzyme kinetic parameters were calculated by non-linear regression of the Michaelis-Menten plot. The complexation of 9-OH-AD and mCD was evaluated via the stability constant for the [9-OH-AD-mCD] complex. The Vmax and KM values calculated for the free (non-complex) steroid in mCD solutions corresponded to steroid degradation in the absence of mCD. The inclusion complex [9-OH-AD-mCD] was shown to be resistant to enzymatic degradation. The inference is made that the ''guest-host'' molecular complexation with cyclodextrin can be used for the control of steroid bioconversions.