Ovine bones are the major by-products after slaughtered. The present study was conducted to extract and characterize acid soluble collagens （ASC） and pepsin soluble collagens （PSC） from ovine bones （Ujumuqin shee...Ovine bones are the major by-products after slaughtered. The present study was conducted to extract and characterize acid soluble collagens （ASC） and pepsin soluble collagens （PSC） from ovine bones （Ujumuqin sheep）. Ovine bones collagen were identified by sodium dodecyl sulfate-polyacrylamide gel electrophoresis （SDS-PAGE） and liquid chromatography-tan- dem mass spectrometry （LC-MS/MS） as type I collagen. The results of Fourier transform infrared （FTIR） spectra analysis testified the existence of triple superhelical structure in both ASC and PSC, showing pepsin did not disrupt the triple helical structure of ovine bones collagen. Glycine, accounting for one-third of total amino acids, was the major amino acid for ovine bones collagen. Higher imino acid content was responsible for higher thermal denaturation temperature of ovine bones collagen compared to fish collagens. The isoelectric point of ASC was lower than PSC due to the higher content of acidic amino acids. Therefore, this study provides the potential reference for collagen extraction and application of ovine bones by-procduct.展开更多
Hepatitis B virus(HBV) is an important human pathogen belonging to the Hepadnaviridae family, Orthohepadnavirus genus. Over 240 million people are infected with HBV worldwide. The reverse transcription during its geno...Hepatitis B virus(HBV) is an important human pathogen belonging to the Hepadnaviridae family, Orthohepadnavirus genus. Over 240 million people are infected with HBV worldwide. The reverse transcription during its genome replication leads to low fidelity DNA synthesis, which is the source of variability in the viral proteins. To investigate the variability quantitatively, we retrieved amino acid sequences of 5,167 records of all available HBV genotypes(A–J) from the Genbank database. The amino acid sequences encoded by the open reading frames(ORF) S/C/P/X in the HBV genome were extracted and subjected to alignment. We analyzed the variability of the lengths and the sequences of proteins as well as the frequencies of amino acids. It comprehensively characterized the variability and conservation of HBV proteins at the level of amino acids. Especially for the structural proteins, hepatitis B surface antigens(HBsAg), there are potential sites critical for virus assembly and immune recognition. Interestingly, the preS1 domains in HBsAg were variable at some positions of amino acid residues, which provides a potential mechanism of immune-escape for HBV, while the preS2 and S domains were conserved in the lengths of protein sequences. In the S domain, the cysteine residues and the secondary structures of the alpha-helix and beta-sheet were likely critical for the stable folding of all HBsAg components. Also, the preC domain and C-terminal domain of the core protein are highly conserved. However, the polymerases(HBpol) and the HBx were highly variable at the amino acid level. Our research provides a basis for understanding the conserved and important domains of HBV viral proteins, which could be potential targets for anti-virus therapy.展开更多
The amino acid tailed porphyrin and their zinc complexes were firstly synthesized. They were characterized by FAB-MS, IR, UV-Vis, elemental analysis and chemical analysis.
熊果酸属于五环三萜类配合物,在自然界中分布广泛,并显示出多种生物活性,如保肝、抗炎、抗病毒、抗癌等多种药理作用.为寻找高效、低毒的熊果酸衍生物,以具有一定生物活性的熊果酸为先导配合物,通过对其C-28位进行结构修饰及C-3位引入...熊果酸属于五环三萜类配合物,在自然界中分布广泛,并显示出多种生物活性,如保肝、抗炎、抗病毒、抗癌等多种药理作用.为寻找高效、低毒的熊果酸衍生物,以具有一定生物活性的熊果酸为先导配合物,通过对其C-28位进行结构修饰及C-3位引入氨基酸,共设计合成了10种未见报道的熊果酸衍生物.目标配合物的结构经1 H NMR、IR和HRMS表征确证,并以其对培养于高铁血红蛋白的金黄色葡萄球菌、耐甲氧西林金黄色葡萄球菌、耐喹诺酮金黄色葡萄球菌和培养于脑心浸液培养基中的大肠杆菌进行抑菌活性测试.结果表明,经修饰后的熊果酸衍生物对金黄色葡萄球菌、耐甲氧西林金黄色葡萄球菌、耐喹诺酮金黄色葡萄球菌的抗菌活性较母体配合物有不同程度的提升.展开更多
对蜡状芽孢杆菌Bc-05菌株的发酵上清液经硫酸铵分级沉淀、DEAE Sepharose Fast Flow阴离子交换层析所获得的纤溶酶进行性质研究.结果表明:经纤维蛋白平板法检测该酶有直接水解纤维蛋白和激活纤溶酶原的双重作用,最适作用温度37℃,最适pH...对蜡状芽孢杆菌Bc-05菌株的发酵上清液经硫酸铵分级沉淀、DEAE Sepharose Fast Flow阴离子交换层析所获得的纤溶酶进行性质研究.结果表明:经纤维蛋白平板法检测该酶有直接水解纤维蛋白和激活纤溶酶原的双重作用,最适作用温度37℃,最适pH=8.0,在pH=8.0条件下25℃和37℃放置24 h酶活力仍保持77.52%和78.96%,该酶体外对兔血凝块有明显的溶解作用;Ca2+,Mn2+离子对该酶具有激活作用,而Cu2+,Fe3+完全抑制其纤溶活性,PMSF,EDTA和DTT对该酶有抑制作用,说明活性中心含有二硫键、金属离子和丝氨酸;测其N端10个氨基酸序列为NH2-Val-Thr-Pro-Thr-Asn-Ala-Val-Asn-Thr-Gly,与其他生物来源的纤溶酶相比较没有同源性.展开更多
基金funded by the emarked fund for China Agriculture Research System (CARS-39)the National Agricultural Science and Technology Innovation Program
文摘Ovine bones are the major by-products after slaughtered. The present study was conducted to extract and characterize acid soluble collagens （ASC） and pepsin soluble collagens （PSC） from ovine bones （Ujumuqin sheep）. Ovine bones collagen were identified by sodium dodecyl sulfate-polyacrylamide gel electrophoresis （SDS-PAGE） and liquid chromatography-tan- dem mass spectrometry （LC-MS/MS） as type I collagen. The results of Fourier transform infrared （FTIR） spectra analysis testified the existence of triple superhelical structure in both ASC and PSC, showing pepsin did not disrupt the triple helical structure of ovine bones collagen. Glycine, accounting for one-third of total amino acids, was the major amino acid for ovine bones collagen. Higher imino acid content was responsible for higher thermal denaturation temperature of ovine bones collagen compared to fish collagens. The isoelectric point of ASC was lower than PSC due to the higher content of acidic amino acids. Therefore, this study provides the potential reference for collagen extraction and application of ovine bones by-procduct.
基金partially supported by the National Natural Science Foundation of China (Nos. U1611265, 81773271 and 31672536)the Key Projects of Department of Education of Guangdong Province (No. 2017KZDXM088)
文摘Hepatitis B virus(HBV) is an important human pathogen belonging to the Hepadnaviridae family, Orthohepadnavirus genus. Over 240 million people are infected with HBV worldwide. The reverse transcription during its genome replication leads to low fidelity DNA synthesis, which is the source of variability in the viral proteins. To investigate the variability quantitatively, we retrieved amino acid sequences of 5,167 records of all available HBV genotypes(A–J) from the Genbank database. The amino acid sequences encoded by the open reading frames(ORF) S/C/P/X in the HBV genome were extracted and subjected to alignment. We analyzed the variability of the lengths and the sequences of proteins as well as the frequencies of amino acids. It comprehensively characterized the variability and conservation of HBV proteins at the level of amino acids. Especially for the structural proteins, hepatitis B surface antigens(HBsAg), there are potential sites critical for virus assembly and immune recognition. Interestingly, the preS1 domains in HBsAg were variable at some positions of amino acid residues, which provides a potential mechanism of immune-escape for HBV, while the preS2 and S domains were conserved in the lengths of protein sequences. In the S domain, the cysteine residues and the secondary structures of the alpha-helix and beta-sheet were likely critical for the stable folding of all HBsAg components. Also, the preC domain and C-terminal domain of the core protein are highly conserved. However, the polymerases(HBpol) and the HBx were highly variable at the amino acid level. Our research provides a basis for understanding the conserved and important domains of HBV viral proteins, which could be potential targets for anti-virus therapy.
文摘The amino acid tailed porphyrin and their zinc complexes were firstly synthesized. They were characterized by FAB-MS, IR, UV-Vis, elemental analysis and chemical analysis.
文摘熊果酸属于五环三萜类配合物,在自然界中分布广泛,并显示出多种生物活性,如保肝、抗炎、抗病毒、抗癌等多种药理作用.为寻找高效、低毒的熊果酸衍生物,以具有一定生物活性的熊果酸为先导配合物,通过对其C-28位进行结构修饰及C-3位引入氨基酸,共设计合成了10种未见报道的熊果酸衍生物.目标配合物的结构经1 H NMR、IR和HRMS表征确证,并以其对培养于高铁血红蛋白的金黄色葡萄球菌、耐甲氧西林金黄色葡萄球菌、耐喹诺酮金黄色葡萄球菌和培养于脑心浸液培养基中的大肠杆菌进行抑菌活性测试.结果表明,经修饰后的熊果酸衍生物对金黄色葡萄球菌、耐甲氧西林金黄色葡萄球菌、耐喹诺酮金黄色葡萄球菌的抗菌活性较母体配合物有不同程度的提升.
文摘对蜡状芽孢杆菌Bc-05菌株的发酵上清液经硫酸铵分级沉淀、DEAE Sepharose Fast Flow阴离子交换层析所获得的纤溶酶进行性质研究.结果表明:经纤维蛋白平板法检测该酶有直接水解纤维蛋白和激活纤溶酶原的双重作用,最适作用温度37℃,最适pH=8.0,在pH=8.0条件下25℃和37℃放置24 h酶活力仍保持77.52%和78.96%,该酶体外对兔血凝块有明显的溶解作用;Ca2+,Mn2+离子对该酶具有激活作用,而Cu2+,Fe3+完全抑制其纤溶活性,PMSF,EDTA和DTT对该酶有抑制作用,说明活性中心含有二硫键、金属离子和丝氨酸;测其N端10个氨基酸序列为NH2-Val-Thr-Pro-Thr-Asn-Ala-Val-Asn-Thr-Gly,与其他生物来源的纤溶酶相比较没有同源性.
