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911.
Timofey V. Malyarenko Alla A. Kicha Natalia V. Ivanchina Anatoly I. Kalinovsky Pavel S. Dmitrenok Svetlana P. Ermakova Valentin A. Stonik 《Steroids》2011,76(12):1280-1287
Six new steroidal biglycosides, cariniferosides A–F (1–6), were isolated along with six previously known glycosides, 7–12, from the alcoholic extract of the starfish Asteropsis carinifera. The structures of 1–6 were determined by extensive NMR and ESIMS techniques. The isolated compounds did not show any apparent cytotoxicity in cancer cell lines HCT-116, RPMI-7951, and T-47D, but sulfated compounds 6, 11, and 12 demonstrated a significant inhibition of RPMI-7951 and T-47D cell colony formation in a soft agar clonogenic assay. 相似文献
912.
Alla O. Badyakina Natalia V. Vasil’eva Yulia A. Koryakina Elena V. Anisimova Natalia E. Suzina Marina A. Nesmeyanova 《Central European Journal of Biology》2007,2(3):385-404
Secretion of periplasmic alkaline phosphatase (PhoA) encoded by the gene constituent of plasmids and the peculiar properties
of cell envelope biogenesis in Escherichia coli strains with controlled synthesis of individual membrane phospholipids have been studied. Alkaline phosphatase secretion
across the cytoplasmic membrane declines, while secretion into the culture medium intensifies under changed metabolism. The
composition of anionic membrane phospholipids changes due to inactivation of the pgsA gene or regulation of its expression by environmental factor, as well as in the absence of the pssA gene which is responsible for the synthesis of the precursor for zwitter-ionic phospholipid — phosphatidylethanolamine. This
correlates with intensified secretion of exopolysaccharides and lower content of lipopolysaccharide and lipoprotein which
are responsible for barrier properties of the outer membrane. The results suggest a possible coupling of protein secretion
with biogenesis of cell envelope components at a level of phospholipid metabolism. 相似文献
913.
E Luchter-Wasylewska J Dulińska W S Ostrowski V P Torchilin V S Trubetskoy 《Biotechnology and applied biochemistry》1991,13(1):36-47
Human prostatic acid phosphatase (PAP) (EC 3.1.3.2) was covalently linked to chondroitin sulfate A from whale cartilage. In order to bind the protein amino groups with the preactivated carboxyl groups of chondroitin sulfate, 1-ethyl-3-(3'-dimethylaminepropyl)carbodiimide and N-hydroxysulfosuccinimide were used as coupling agents. The product was soluble and enzymatically active. The activity was on average 25% higher than that of the free enzyme. The product was heterogeneous in respect to charge and Mr (50-1500) kDa, as determined by chromatography on Sephacryl S 300 and polyacrylamide gel electrophoresis. The resulting polymers contained covalently bound chondroitin sulfate, as shown by the biotin-avidin test. The modified enzyme is more resistant against various denaturing agents, e.g., urea, ethanol, and heat. Thus covalent modification of PAP by cross-linking to chondroitin sulfate could be the preferred method for stabilization of its biological activity. 相似文献