A newly isolated gene from Ralstonia sp. M1, encoding an esterase, was cloned in Escherichia coli and its nucleotide sequence determined. The 1.6kb insert revealed one complete open reading frame, predicted to encode an esterase (320 aa, 34.1kDa) with a pI of 9.86. EstR contained a putative oxyanion hole H36G37, a conserved pentapeptide G103HSLG107 and a conserved catalytic His265 and Asp237. The EstR sequence shared 64-70 and 44-48% identity with the hydrolases/acyltransferases from Burkholderia strains and from Ralstonia strains, respectively, 44 and 38% identity with the lactone-specific esterase from Pseudomonas fluorescens and Mesorhizobium loti, respectively. The esterase EstR was expressed with a high level of 41mg/g wet cells. The Ni-NTA-purified esterase EstR showed an optimal activity in the temperature range 60-65 degrees C and pH range 7.5-9.0 towards p-nitrophenyl caproate. The enzyme was found to be highly resistant to many organic solvents especially induced by ethanolamine. Metal ions showed slight effect on esterase activity. The inhibitor phenylmethanesulfonyl fluoride inhibited strongly the esterase. Triton X-45 induced the activation of EstR, but other detergents slightly to strongly decreased or completely inhibited. Among tested p-NP esters, caproate was the most preferential substrate of this esterase.
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http://dx.doi.org/10.1016/j.pep.2006.06.009 | DOI Listing |
Mar Biotechnol (NY)
January 2025
School of Marine Science and Technology, Harbin Institute of Technology (Weihai), Wenhua West Road, 2#, Weihai, 264209, People's Republic of China.
Recently, the scale and frequency of harmful algae blooms (HABs) have gradually increased, posing a serious threat to human health, marine ecosystems and economic development. For early warning, a method is required that can quickly detect and monitor microalgae. It is proposed to use aptamer targeted to Prorocentrum minimum, along with exonuclease III (Exo III), gold nanoparticles, target single-stranded DNA and hairpin structure probe to construct a new method, i.
View Article and Find Full Text PDFFood Sci Nutr
January 2025
Modern-day consumers are interested in highly nutritious and safe foods with corresponding organoleptic qualities. Such foods are increasingly subjected to various processing techniques which include the use of enzymes. These enzymes like amylases, lipases, proteases, xylanases, laccases, pullulanase, chitinases, pectinases, esterases, isomerases, and dehydrogenases could be derived from extremophilic organisms such as thermophiles, psychrophiles, acidophiles, alkaliphiles, and halophiles.
View Article and Find Full Text PDFToxicol Rep
June 2025
Department of Zoology, University of Kalyani, Nadia, Kalyani, West Bengal 741235, India.
After being exposed, microplastics mostly bioaccumulated in guts and gills of fish, then, through circulation, spread and bioaccumulated in other tissues. Circulatory system of fish is impacted by the microplastic bioaccumulation in their tissues, influencing a number of hematological indices that are connected with immunity, osmotic pressure, blood clotting, molecular transport and fat metabolism. Variables like size, dose, duration, food consumption and species, all affect the bioaccumulation and toxicity of the microplastic, rather than the exposure routes.
View Article and Find Full Text PDFInt J Nanomedicine
January 2025
Hospital of Stomatology, Guanghua School of Stomatology, Sun Yat-sen University, Guangzhou, People's Republic of China.
Introduction: Acute respiratory distress syndrome (ARDS) is a life-threatening type of acute lung injury (ALI) characterized by elevated mortality rates and long-term effects. To date, no pharmacological treatment has proven effective for ARDS. Mesenchymal stem cell-derived apoptotic vesicles (apoVs) were recently found to have excellent therapeutic potential for inflammatory diseases.
View Article and Find Full Text PDFArch Pharm (Weinheim)
January 2025
N. N. Vorozhtsov Novosibirsk Institute of Organic Chemistry, Siberian Branch Russian Academy of Sciences, Novosibirsk, Russian Federation.
Tyrosyl DNA phosphodiesterases 1 and 2 (TDP1 and TDP2), which are enzymes involved in the repair of DNA, are regarded as promising targets for the development of new anticancer drugs. In this study, a series of imidazolidine-2,4-diones, 2,4,5-triones, and 2-thioxoimidazolidine-4,5-diones based on dehydroabietylamine (DHAAm) were synthesized. The inhibitory activity of the new compounds against TDP1 and TDP2, as well as their cytotoxic characteristics, were evaluated.
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