Analysis of WCID-cIEF Spectrogram of Recombinant Interleukin-15 Fusion Protein / 中国药学杂志

OBJECTIVE: To analyze the glycosylated chains of recombinant interleukin-15 fusion protein using capillary isoelectric focusing-whole column imaging detection (WCID-cIEF) spectrograms. METHODS: Using established corresponding mathematical models and the least square method, the WCID-cIEF spectrograms of whole protein, de-salicylic-acid protein and de-N-glycosylation-chain protein were analyzed. Among the mathematical models, the interval-1-peak model was selected. And according to the model, the relationship between isoform peak-areas and isoelectric points was listed. RESULTS: The rationality of the interval-1-peak model was confirmed and a series of basic data was obtained according to the model as follows:the apparent m value of the protein was 25.53 reference(R), the apparent n value of the protein was 28.83R, the apparent m value of sialic acid was 0.86 (0.855) R, the apparent n value was 0.12 (0.119) R, the apparent n value of N-acetylglucosamine (undifferentiated from N-acetylgalactosamine) was 0.06(0.061) R, and the apparent m value of formed carboxyl after N-chain removal was 0.19 (0.186) R. Some information of protein sugar composition was also obtained: the sialylation degree was about 1.83 mol•mol-1, the percentage of prototype protein was about 8.3%, the percentage of single N-glycosated modification protein was about 19.8%, the percentage of double N-glycosated modification protein was about 28.4%, the percentage of triple N-glycosated modification protein was about 23.7%, and the percentage of O-glycosated modification (with sialic acid) protein was about 19.8%. The main sugar types should be G0 (F), G1 (F), G2 (F), G1A1 (F), and G2A1 (F). CONCLUSION: The structure of sugar chain is complex, but it also has some repeatability and regularity. We hope that through this study, the glycoprotein sugar chain can be quickly outlined, the understanding of glycoprotein and the study of protein interaction can be improved.

Comparison of several common methods for measuring the biological activity of recombinant human granulocyte colony stimulating factor / 中国药学杂志

OBJECTIVE: To compare several common staining and detection methods using NFS-60 cells for biological activity test of recombinant human granulocyte colony stimulating factor (rhG-CSF). METHODS: The biological activity of rhG-CSF was detected using some common methods, named NFS-60 cells/MTT staining, NFS-60 cells/MTS staining, NFS-60 cells/CCK-8 staining, and NFS-60 cells/fluorescence staining. The biological activity was detected using the NFS-60 cells/MTT method using dual wavelength (570 nm detection, 630 nm reference) and single wavelength (570nm detection and 630nm detection). The biological activity was detected using NFS-60 cells/MTS dynamic detection method and NFS-60 cell/CCK-8 dynamic method. Then, the results were analyzed and compared. RESULTS: The different methods were not significantly different (P>0.05); the difference between the dual wavelength detection and single wavelength detection of NFS-60 cells/MTT was not significant (P>0.05). The results from NFS-60 cells/MTS dynamic detection method, NFS-60 cells/CCK-8 dynamic method and NFS-60 cells/MTT method had not significant difference (P>0.05). CONCLUSION: The biological activity determination results of the tested methods using NFS-60 cells are consistent. This study provides basis for utilization of results from different laboratories using different methods, support for expansion of the biological activity detection method of rhG-CSF in Chinese Pharmacopoeia, and reference for expansion of the biological activity detection method of other cytokines.

The effect of cold-light-activated bleaching treatment on enamel surfaces in vitro / 国际口腔科学杂志·英文版

This in vitro study aims to evaluate the crystal and surface microstructure of dental enamel after cold-light bleaching treatment. Twelve sound human premolars were cross-split into four specimens, namely, mesio-buccal (Group LP), disto-buccal (Group P), mesio-lingual (Group NP) and disto-lingual (Group L) specimens. These four groups were treated using the standard cold-light bleaching procedure, a bleaching agent, a peroxide-free bleaching agent and cold-light, respectively. Before and after treatment, all specimens were analyzed by high-resolution, micro-area X-ray diffraction and scanning electron microscopy. Using a spectrometer, tooth color of all specimens was measured before and after treatment. The phase of the enamel crystals was identified as hydroxyapatite and carbonated hydroxyapatite. After treatment, specimens in Groups LP and P showed significantly weaker X-ray diffraction peaks, significant reduction in crystal size and crystallinity, significant increase in L* but decrease in a* and b*, and obvious alterations in the surface morphology. However, specimens in Groups NP and L did not show any significant changes. The cold-light bleaching treatment leads to demineralization in the enamel surface. The acidic peroxide-containing bleaching agent was the major cause of demineralization, whereas cold-light did not exhibit significant increase or decrease effect on this demineralization.

Structure verification of a recombinant chimeric anti-CD20 IgG1 monoclonal antibody / 药学学报

Structure of a recombinant chimeric anti-CD20 IgG1 monoclonal antibody was verified by the application of high-performance liquid chromatography-mass spectrometry (HPLC-MS)and N-terminal sequencer. Molecular masses, N-terminal sequences and peptide maps of the antibody treated with different reagents and enzymes were measured. Results indicate that the amino acid sequences of light and heavy chains and 10 disulfide bonds were consistent with theoretical structure. By comparison of molecular masses and peptide maps for the fully glycosylated and deglycosylated samples, the N-linked glycosylation site was identified. The method is simple, rapid, precise, and could be referred to the quality control and structure determination of other IgG1 products.

Effect of cold-light bleaching technique on human permanent teeth enamel surface / 华西口腔医学杂志

<p><b>OBJECTIVE</b>To study the effects of the cold-light bleaching technique on crystals and microstructure of the dental enamel.</p><p><b>METHODS</b>The human premolars extracted for orthodontic reasons were treated by a standard cold-light bleaching procedure. After the treatment, all samples were detected by high resolution micro-area X-ray diffractometer, Fourier transform infrared spectroscope and scanning electron microscope.</p><p><b>RESULTS</b>After the permanent teeth were treated with cold-light bleaching technique, the enamels' crystal dimension, crystallinity decreased and irregular surfaces and shallow disk pits appeared.</p><p><b>CONCLUSION</b>The cold-light bleaching technique could lead to the changes of crystals and microstructure in the surface layer of dental enamel.</p>

The preparation and characterization of sol-gel derived zinc modified carbonated hydroxyapatite / 华西口腔医学杂志

<p><b>OBJECTIVE</b>To prepare zinc-modified carbonated hydroxyapatite (Zn-CHA) coating material via sol-gel method and explore the influence of zinc substitution on physical and chemical properties of biomaterial samples.</p><p><b>METHODS</b>Two kinds of samples with different zinc content and Ca/P molar ratio were prepared. One was fabricated with 4% zinc and the Ca/P molar ratio was 1.67. Another was prepared with 8% zinc and the (Ca+Zn)/P molar ratio was 1.67. The coating samples were characterized by X-ray diffraction (XRD), Fourier transformed infrared spectroscopy (FTIR), scanning electron microscopy (SEM). Furthermore, the zinc ions releasing ability of the coating samples were investigated by atomic absorption spectroscopy (AAS).</p><p><b>RESULTS</b>XRD results revealed that the coating samples contained hydroxyapatite phase. After determination by FTIR, the biomaterial samples were found to contain carbonate and resemble biological apatites. High homogeneous and porous surfaces of coating samples were observed in SEM micrographs. According to the results of dissolution test, zinc was incorporated into hydroxyapatite lattice structure or surface absorbed when calcium was insufficient or sufficient respectively.</p><p><b>CONCLUSION</b>The results demonstrate that phase-pure zinc-modified carbonated hydroxyapatite might be prepared through simple sol-gel method and have favorable antibacterial effect.</p>

Activity Study of Ciliary Neurotrophic Factor(CNTF)Mutant / 中国生物工程杂志

To study still further the activity of CNTF mutant designed by computer molecular modling,the methods of dissociated cultures of chick dorsal root ganglion、TF-1 prolification and the normal mice'weight loss tests weve used.The results indicated that the mutant protein promoted the survival of dorsal root ganglion、induced TF-1 prolification and made the normal mice lose weight,decrease appetite and reduce fat index.The weight loss effect was dependant with its administration dosage,ED50 was 150.986?g/kg/d.To TF-1,the specific activity reached 2.0?106U/mg against international reference reagent.In a word,CNTF mutant had excel bioactivity.So it provided clues for its development and application.