BACKGROUND: Self-monitoring of blood glucose levels is recommended for all diabetic patients who receive insulin treatment, because such monitoring of glucose levels may aid in achieving better control in type II diabetes. Further, the use of point-of-care (POC) blood glucose testing in hospitals has increased substantially. In the present study, we validated the performance of ACCU-CHEK(R) Inform II Blood Glucose Meter and ACCU-CHEK(R) Performa Strip (Roche Diagnostics, Germany). METHODS: We evaluated the precision, accuracy, and maltose interference of the ACCU-CHEK(R) Inform II Blood Glucose Meter and ACCU-CHEK(R) Performa Strip. Further, precision was evaluated using dedicated quality control (QC) and Bio-Rad Whole Blood (WB) QC materials (Meter Trax(TM) Control; Bio-Rad, USA). Forty samples were used to compare the results obtained using the ACCU-CHEK(R) Inform II Blood Glucose Meter and ACCU-CHEK(R) Performa Strip with those obtained using the clinical chemistry analyzer Hitachi 7600 (Hitachi, Japan). Maltose interference was assessed at 2 glucose concentration levels at 3 maltose concentration levels. RESULTS: For each concentration level of control materials, within-run coefficient of variation (CV) and total CV obtained were less than 5%. Good correlation was obtained using the Hitachi 7600 (y = 1.02x - 0.18; r 2 = 0.996; N = 40). Effects of maltose interference were less than 10%. CONCLUSIONS: Thus, the ACCU-CHEK(R) systems show good precision and correlation with the routine clinical chemistry analyzer and allow only minimal effects of maltose interference.
Blood Glucose ; Chemistry, Clinical ; Glucose ; Humans ; Insulin ; Maltose ; Quality Control

α-amylase is an endonucleoside hydrolase that hydrolyzes the α-1, 4-glycosidic bonds inside polysaccharides, such as starch, to generate oligosaccharides, dextrins, maltotriose, maltose and a small amount of glucose. Due to the importance of α-amylase in food industry, human health monitoring and pharmaceuticals, detection of its activity is widely required in the breeding of α-amylase producing strains, in vitro diagnosis, development of diabetes drugs, and the control of food quality. In recent years, many new α-amylase detection methods have been developed with improved speed and sensitivity. This review summarized recent processes in the development and applications of new α-amylase detection methods. The major principle of these detection methods were introduced, and their advantages and disadvantages were compared to facilitate future development and applications of α-amylase detection methods.
Humans ; alpha-Amylases/chemistry* ; Polysaccharides ; Oligosaccharides ; Starch ; Maltose

No abstract available.
Ascorbic Acid/*chemistry ; Blood Chemical Analysis/instrumentation/*methods ; Blood Glucose/*analysis ; Maltose/*chemistry

OBJECTIVE1H-NMR technology was carried out to investigate the chemical difference between 30 batches of Cibotium baronetz decoction pieces and look for new method for quality control of C. baronetz decoction pieces.

METHODSix hundreds MHz H-NMR spectroscopy and principle component analysis (PCA) were used to discriminate between 30 batches of commercially available cibotium samples based on multi-component metabolite profiles.

RESULTSaccharide is the principle component of C. baronetz decoction pieces, and steroid and triterpene were the discriminately chemical component. Protocatechuic acid, protocatechuic aldehyde, cibotiumbaroside A, cibotiumbaroside B and 4-O-caffeoyl-D-glucoside could be used as the marker for controlling the quality of commercial C. baronetz decoction pieces.

CONCLUSIONPattern-recognition techniques applied to proton nuclear magnetic resonance (1H-NMR) spectra of 80% methanol extraction of C. baronetz could correctly discriminate not only the quality, but also the chemical component for batches of commercial C. baronetz decoction pieces.

Benzaldehydes ; chemistry ; Caffeic Acids ; chemistry ; Catechols ; chemistry ; Drugs, Chinese Herbal ; chemistry ; standards ; Ferns ; chemistry ; Furans ; chemistry ; Glucose ; chemistry ; Glucosides ; chemistry ; Glycosides ; chemistry ; Hydroxybenzoates ; chemistry ; Magnetic Resonance Spectroscopy ; methods ; Maltose ; chemistry ; Quality Control ; Steroids ; chemistry ; Sucrose ; chemistry ; Triterpenes ; chemistry

Pulldown assay is an in vitro method for studies of protein-protein interactions, in which tagged proteins are usually expressed as the bait to enrich other proteins that could bind to them. In this technology, the GST tag is broadest used for its modest size and hydrophilic property. In most cases, the GST tag could increase the hydrophility of the fusion protein and help to avoid the formation of inclusion bodies. However, in the other few cases, the target protein may be strongly hydrophobic or have complicated structures that were hard to fold and assemble in correct conformations without champerons, and even the existence of GST tag could not make them soluble. These proteins were always expressed as inclusion bodies and had no functions. LMO2 was a small molecular weight and insoluble protein, in this study, GST system and MBP system were used to express GST-LMO2 and MBP-LMO2 fusion proteins, respectively. We found that GST-LMO2 fusion protein was expressed as inclusion bodies whereas MBP-LMO2 fusion protein was expressed in soluble form. Moreover, the production rate of MBP-LMO2 was also much higher than GST-LMO2. Then MBP-LMO2 fusion proteins and renatured GST-LMO2 fusion proteins were used as bait in pulldown assay to study the interaction between LMO2 and endogenous GATA1 in K562 cells. Western blot analyses showed that both of these proteins could bind to endogenous GATA1 in K562 cells, but recovered GATA1 protein by MBP-LMO2 fusion protein was much more than GST-LMO2 fusion protein. These results suggest that using of MBP system is a helpful attempt in the case of studying small molecular weight, strong hydrophobic proteins.
Adaptor Proteins, Signal Transducing ; Carrier Proteins ; chemistry ; Chemical Precipitation ; DNA-Binding Proteins ; chemistry ; GATA1 Transcription Factor ; chemistry ; Genetic Vectors ; Glutathione Transferase ; chemistry ; Humans ; K562 Cells ; LIM Domain Proteins ; Maltose-Binding Proteins ; Metalloproteins ; chemistry ; Protein Binding ; Protein Interaction Domains and Motifs ; Protein Renaturation ; Proto-Oncogene Proteins ; chemistry ; Recombinant Fusion Proteins ; genetics ; metabolism

Human maltase-glucoamylase (MGAM) hydrolyzes linear alpha-1,4-linked oligosaccharide substrates, playing a crucial role in the production of glucose in the human lumen and acting as an efficient drug target for type 2 diabetes and obesity. The amino- and carboxyl-terminal portions of MGAM (MGAM-N and MGAM-C) carry out the same catalytic reaction but have different substrate specificities. In this study, we report crystal structures of MGAM-C alone at a resolution of 3.1 Å, and in complex with its inhibitor acarbose at a resolution of 2.9 Å. Structural studies, combined with biochemical analysis, revealed that a segment of 21 amino acids in the active site of MGAM-C forms additional sugar subsites (+ 2 and + 3 subsites), accounting for the preference for longer substrates of MAGM-C compared with that of MGAM-N. Moreover, we discovered that a single mutation of Trp1251 to tyrosine in MGAM-C imparts a novel catalytic ability to digest branched alpha-1,6-linked oligosaccharides. These results provide important information for understanding the substrate specificity of alpha-glucosidases during the process of terminal starch digestion, and for designing more efficient drugs to control type 2 diabetes or obesity.
Acarbose ; chemistry ; Amino Acid Sequence ; Catalytic Domain ; Crystallography, X-Ray ; Glycoside Hydrolase Inhibitors ; Humans ; Hydrogen Bonding ; Intestines ; enzymology ; Kinetics ; Maltose ; chemistry ; Molecular Sequence Data ; Mutagenesis, Site-Directed ; Mutation, Missense ; Oligosaccharides ; chemistry ; Pichia ; Protein Binding ; Recombinant Proteins ; antagonists & inhibitors ; chemistry ; genetics ; Substrate Specificity ; Surface Properties ; alpha-Glucosidases ; chemistry ; genetics