OBJECTIVETo establish a method for the expression of glycogen synthase kinase 3β with high purity and biological activity.

METHODSE.coli expression system and baculovirus-insect cell expression system were used to produce the kinase, followed by purification using His-tag and GST-tag and determination of its purity and activity by SDS-PAGE and kinase reaction, respectively.

RESULTSGlycogen synthase kinase 3β produced from E.coli represented 54% of the total bacterial protein, as compared with 96% of the total protein from the insect cell system .Glycogen synthase kinase 3β produced from insect cell exhibited an one-fold higher biological activity than the protein obtained from E.coli.

CONCLUSIONSCompared with the protein from E.coli system, glycogen synthase kinase 3β from the insect cell expression system is endowed with a higher purity and bioactivity.

Animals ; Baculoviridae ; metabolism ; Escherichia coli ; metabolism ; Genetic Vectors ; Glycogen Synthase Kinase 3 ; biosynthesis ; isolation & purification ; Insecta ; cytology

Saccharomycopsis fibuligera possesses high alpha-amylase and glucoamylase activities that enable it to utilize raw starch as a carbon source. A expression cassette containing the promoter sequence of 3-phosphogylycerate kinase gene (PGK1p), the alpha factor signal sequence from Saccharomyces cerevisiae and the alpha-amylase coding sequence of S. fibuligera was constructed. The alpha-amylase expression cassette was inserted in the ILV2 locus of industrial brewer's yeast strain YSF-5 encoding alpha-acetolactate synthase (AHAS) by homologous recombination. The transformed yeast strain was selected on the media with starch as the sole carbon source and verified by PCR. The transformant exhibited secretive alpha-amylase activity, low AHAS activity and reduced diacetyl production. Effects of temperature, pH, and metal ions on the activity of the alpha-amylase expressed by the transformant were examined. The fermentation performance of host strain YSF-5 and the transformant was also examined.
Beer ; microbiology ; Diacetyl ; metabolism ; Glycogen Synthase Kinase 3 ; genetics ; Recombinant Proteins ; biosynthesis ; genetics ; Recombination, Genetic ; Saccharomyces cerevisiae ; genetics ; metabolism ; Saccharomycopsis ; enzymology ; genetics ; alpha-Amylases ; biosynthesis ; genetics ; metabolism

LPS stimulation of macrophages production of IFN-beta plays a key role in innate immunity defending the microbial invasion. In this study, the effect of S632A3 promoting LPS-induced IFN-beta production and the underlying mechanism were investigated, mRNA level was measured by real-time PCR, cytokine production was determined by ELISA, GSK-3beta activity was investigated by kinase assay, protein phosphorylation and expression were evaluated by Western blotting. The results revealed that S632A3 significantly augmented IFN-beta production by LPS-stimulated macrophages. S632A3 inhibition of the activation of GSK-3beta, reduced the threonine 239 phosphorylation of transcription factor c-Jun but increased the total level of c-Jun in LPS-stimulated macrophages. Moreover, small interfering RNA-mediated knockdown of c-Jun level abrogated the ability of S632A3 to augment IFN-beta. The study thus demonstrates S632A3 being a new anti-inflammation lead compound and provides a molecular mechanism by which S632A3 promoted LPS-induced IFN-beta production in macrophages through inhibiting the activation of GSK-3beta.
Animals ; Anti-Bacterial Agents ; pharmacology ; Cell Line ; Enzyme Activation ; drug effects ; Glycogen Synthase Kinase 3 ; metabolism ; Glycogen Synthase Kinase 3 beta ; Interferon-beta ; biosynthesis ; genetics ; Lipopolysaccharides ; pharmacology ; Macrophages ; cytology ; metabolism ; Mice ; Phosphorylation ; Piperidones ; pharmacology ; Proto-Oncogene Proteins c-jun ; metabolism ; RNA, Messenger ; metabolism ; RNA, Small Interfering ; genetics ; Transfection

OBJECTIVETo investigate effect of inhibiting melatonin biosynthesis on activities of protein kinase A (PKA), glycogen synthase kinase-3 (GSK-3) and tau phosphorylation at PS214 and M4 epitopes using haloperidol, a specific inhibitor of 5-hydroxyindole-O-methyltransferase.

METHODSBrain ventricular and intraperitoneal injections were used for haloperidol administration, Western blots for tau phosphorylation, 32P-labeling for PKA and GSK-3 activity, and high performance liquid chromatograph for detection of serum melatonin levels.

RESULTSHaloperidol injection through the lateral ventricle and intraperitoneal reinforcement significantly stimulated PKA activity with a concurrent hyperphosphorylation of tau at M4 (Thr231/Ser235) and PS214 (Ser214) sites. Prior treatment of the rats using melatonin supplement for one week and reinforcement during the haloperidol administration arrested PKA activity and attenuated tau hyperphosphorylation. GSK-3 activity showed no obvious change after haloperidol injection, however, melatonin supplements and reinforcements during haloperidol infusion inactivated basal activity of GSK-3.

CONCLUSIONDecreased melatonin may be involved in Alzheimer-like tau hyperphosphorylation, and overactivation of PKA may play a crucial role in this process.

Animals ; Cyclic AMP-Dependent Protein Kinases ; metabolism ; Epitopes ; Glycogen Synthase Kinase 3 ; metabolism ; Haloperidol ; administration & dosage ; pharmacology ; Hippocampus ; enzymology ; metabolism ; Injections, Intraperitoneal ; Injections, Intraventricular ; Male ; Melatonin ; biosynthesis ; blood ; Phosphorylation ; drug effects ; Rats ; Rats, Wistar ; tau Proteins ; metabolism

The mature cyst of Acanthamoeba is highly resistant to various antibiotics and therapeutic agents. Cyst wall of Acanthamoeba are composed of cellulose, acid-resistant proteins, lipids, and unidentified materials. Because cellulose is one of the primary components of the inner cyst wall, cellulose synthesis is essential to the process of cyst formation in Acanthamoeba. In this study, we hypothesized the key and short-step process in synthesis of cellulose from glycogen in encysting Acanthamoeba castellanii, and confirmed it by comparing the expression pattern of enzymes involving glycogenolysis and cellulose synthesis. The genes of 3 enzymes, glycogen phosphorylase, UDP-glucose pyrophosphorylase, and cellulose synthase, which are involved in the cellulose synthesis, were expressed high at the 1st and 2nd day of encystation. However, the phosphoglucomutase that facilitates the interconversion of glucose 1-phosphate and glucose 6-phosphate expressed low during encystation. This report identified the short-cut pathway of cellulose synthesis required for construction of the cyst wall during the encystation process in Acanthamoeba. This study provides important information to understand cyst wall formation in encysting Acanthamoeba.
Acanthamoeba castellanii/*enzymology/genetics/growth & development ; Amebiasis/*parasitology ; Cell Wall/*metabolism ; Cellulose/*biosynthesis/genetics ; Glucosyltransferases/genetics/metabolism ; Glycogen Phosphorylase/genetics/metabolism ; Protozoan Proteins/genetics/*metabolism ; UTP-Glucose-1-Phosphate Uridylyltransferase/genetics/metabolism

Estimation of the postmortem interval (PMI) is a practical task in daily forensic casework. Researches on PMI is an important practical project in forensic field. Estimation of the time since death is influenced by internal and external, antemortem and postmortem factors, thus the old methods have limitations. Fourier transform infrared (FTIR) spectroscopy has been applied to study the pure protein, nucleic acid and carbohydrate and to detect the changes in complex cells and tissues. At present because the powerful software has could be used to achieve the spectrum transformation, smoothing, baseline correction and normalization, it is possible to analyze the samples quantitatively with the FTIR which has been applied in the biology and clinical medicine. This paper has reviewed the mechanism of FTIR and its application in biomedicine. The postmortem FTIR spectral changes were also discussed, which showed its potential for estimating PMI.
Animals ; Forensic Pathology/methods* ; Glycogen/biosynthesis* ; Humans ; Kidney Cortex/metabolism* ; Lung/metabolism* ; Muscle, Skeletal/metabolism* ; Myocardium/metabolism* ; Nucleic Acids/metabolism* ; Postmortem Changes ; Rats ; Spectroscopy, Fourier Transform Infrared/methods* ; Spleen/metabolism* ; Temperature ; Time Factors