ABSTRACT
Reversible lysine acetylation is one of the most widely distributed post-translational modifications; it is involved in a variety of biological processes and can be found in all three domains of life. Acetyltransferases and deacetylases work coordinately to control levels of protein acetylation. In this work, we applied the genetic code expansion strategy to site-specifically incorporate Nε-thioacetyl-l-lysine (TAcK) as an analog of Nε-acetyl-l-lysine (AcK) into green fluorescent protein and malate dehydrogenase in Escherichia coli. We showed that TAcK could serve as an ideal functional mimic for AcK. It could also resist the bacterial sirtuin-type deacetylase CobB. Thus, genetic incorporation of TAcK as a non-deacetylatable analog of AcK into proteins will facilitate in vivo studies of protein acetylation.
ABSTRACT
Two simple and inexpensive UV spectrophotometric methods were developed for the quantification and dissolution studies of meloxicam in tablet dosage forms. Meloxicam was estimated at 365nm and 360nm in Method I and Method II, respectively. The calibration curve was linear over a concentration range from 2.0 to 12.0µg/ml for both methods. The limit of detection and limit of quantitation were found to be 0.12µg/ml and 0.38µg/ml, 0.09µg/ml and 0.27µg/ml for Method I and Method II, respectively. The percentage recoveries of meloxicam were found to be 99.68 to 100.61% and 99.11 to 100.96% for Method I and Method II, respectively. It was concluded that the developed methods are precise, accurate and were successfully applied for the estimation of meloxicam in pharmaceutical formulations and in vitro dissolution studies.
