Biomedical subjects

Yizheng Zhang

Publications and source records attributed to Yizheng Zhang.

7 recordsLinked to original sources

PubMed2005

Microbial fibrinolytic enzymes: an overview of source, production, properties, and thrombolytic activity in vivo.

Accumulation of fibrin in the blood vessels usually results in thrombosis, leading to myocardial infarction and other cardiovascular diseases. For thrombolytic therapy, microbial fibrinolytic enzymes have now attracted much more attention than typical thrombolytic agents because of the expensive prices and the undesirable side effects of the latter. The fibrinolytic enzymes were successively discovered from different microorganisms, the most important among which is the genus Bacillus from traditional fermented foods. The physiochemical properties of these enzymes have been characterized, and their effectiveness in thrombolysis in vivo has been further identified. Therefore, microbial fibrinolytic enzymes, especially those from food-grade microorganisms, have the potential to be developed as functional food additives and drugs to prevent or cure thrombosis and other related diseases.

Animals↗

PubMed2005

Isolation and characterization of microsatellite loci from forest musk deer (Moschus berezovskii).

This study reported the isolation and characterization of eight polymorphic microsatellite loci in endangered forest musk deer Moschus berezovskii. An improved enrichment protocol was used to isolate microsatellites, and polymorphism was explored with samples from wild musk deer population collected in Miyalo of Sichuan Province in China. Approximately 70% of clones from the genomic library constructed in current study contained dinucleotide (AC) repeats. Eight microsatellite loci amplified were highly polymorphic within forest musk deer population. The number of alleles per locus ranged from 6 to 14, and the observed and expected heterozygosities ranged from 0.41 approximately 1.0 and from 0.8 approximately 0.9, respectively. The average polymorphic information content (PIC) value for these markers was 0.82. This demonstrated that the eight microsatellite loci developed here are highly polymorphic, and can be used as genetic markers for further investigation of musk deer. Also, the results showed that the musk deer distributed in Miyalo had a relatively higher level of genetic variation.

Alleles↗

PubMed2004

Production of lignocellulolytic enzymes by Trametes gallica and detection of polysaccharide hydrolase and laccase activities in polyacrylamide gels.

White rot fungus Trametes gallica was studied for the production of lignocellulolytic enzymes: cellulase, xylanase, laccase, manganese-dependent peroxidase (MnP), and lignin peroxidase (LiP). The results demonstrated that low-nitrogen (2.2 mM N) and surface stationary cultivation favored production of extracellular MnP. MnP activity reached 118.1 UL(-1) while T. gallica was grown in a low-nitrogen culture containing phenylalanine. However, laccase levels observed in high-nitrogen (22 mM N) agitated cultures were much greater than those seen in low-nitrogen. The N source experiments seemed to reveal that NH4+ plays an important role in inducing MnP and laccase of the fungus. Results showed that T. gallica produces a series of the lignocellulolytic enzymes, and needs high N to produce all the enzymes during solid-state fermentation of wheat straw. This paper also presents a modified zymogram procedure to detect xylanase and laccase of T. gallica in polyacrylamide gel. Xylanase in crude enzyme of T. gallica was displayed by contacting protein gel strips with xylan substrate gels and by staining with iodine. By immersing the protein gel strips in o-tolidine solution, the blue-green zones representing laccase activity were visualized against a colorless background.

Basidiomycota↗

PubMed2003

Purification and characterization of an extracellular alkaline serine protease with dehairing function from Bacillus pumilus.

An extracellular alkaline serine protease (called DHAP), produced by a Bacillus pumilus strain, demonstrates significant dehairing function. This protease is purified by hydrophobic interaction chromatography, ion exchange, and gel filtration. DHAP had a pI of 9.0 and a molecular weight of approximately 32,000 Dalton. It shows maximal activity at pH 10 and with a temperature of 55 degrees C; the enzyme activity can be completely inhibited by phenylmethylsulfonyl fluoride (PMSF) and diisopropyl fluorophosphates (DFP). The first 20 amino acid residues of the purified DHAP have been determined with a sequence of AQTVPYGIPQIKAPAVHAQG. Alignment of this sequence with other alkaline protease demonstrates its high homology with protease from another B. pumilus strain.

Amino Acid Sequence↗

PubMed2003

Bioinformatics data distribution and integration via Web Services and XML.

It is widely recognized that exchange, distribution, and integration of biological data are the keys to improve bioinformatics and genome biology in post-genomic era. However, the problem of exchanging and integrating biology data is not solved satisfactorily. The eXtensible Markup Language (XML) is rapidly spreading as an emerging standard for structuring documents to exchange and integrate data on the World Wide Web (WWW). Web service is the next generation of WWW and is founded upon the open standards of W3C (World Wide Web Consortium) and IETF (Internet Engineering Task Force). This paper presents XML and Web Services technologies and their use for an appropriate solution to the problem of bioinformatics data exchange and integration.

Computational Biology↗

PubMed2003

[Cloning and sequence analysis of active fragments of human thrombospondin-1].

OBJECTIVE: To lay a foundation for researches on the expression of gene engineering anti-tumor drugs. METHODS: On the basis of mRNA sequence of human thrombospondin-1(TSP-1), two pairs of primers were designed and synthesized. Two active fragments TSP-1, called TSP-1-I and TSP-1-III, were obtained by using reverse transcription-polymerase chain reaction(RT-PCR). The sizes of those two fragments were found to be 728 bp and 257 bp respectively. They were purified and then cloned into pMDT vector after transformation into Escherichia coli with recombined DNAs. RESULTS: Plasmid DNAs were isolated from transformants and digested with restriction enzyme. The results from agarose gel electrophorasis showed that these two fragments had been inserted into vector and their sizes were in accord with the expected values. Sequence analysis demonstrated that TSP-1-I is 728 bp in size and encodes a peptide containing 212 amino acid residues with relative molecular mass of 23.6 x 10(3) and the TSP-I III is 257 bp in size and encodes a peptide containing 86 amino acid residues with relative molecular mass of 9.5 x 10(3). CONCLUSION: The results from homology analysis indicate that the sequence of these two fragments is identified with that of TSP-1 of Genbank.

Adenocarcinoma↗

PubMed2003

[RT--PCR analysis of Phanerochaete chrysosporium lip genes in colonized fir wood].

Expression of Phanerochaete chrysosporium lip A2 (GLG3) lip C1 (GLG2) lip C2 (GLGS) lipD2( GLG1), lipE (LP0811) genes were analyzed by RT-PCR method. It was showed that some genes were expressed in special colonized period. Only lip A2 (GLG3) transcription occured in the 2nd week and the 8th week, both lip C1 (GLG2) and lip D2 (GLG1) gene transcription was checked out in the period of 6 weeks. However, no lip genes were expressed in the time of 4 weeks. These results indicated that lip gene expression is relied on the colonized period and transcript patterns are re dramatically different from those in previous studies with defined media.

Abies↗