Construction and analysis of high-complexity ribosome display random peptide libraries.

Random peptide libraries displayed on the ribosome are becoming a new tool for the in vitro selection of biologically relevant macromolecules, including epitopes, antagonists, enzymes, and cell-surface receptors. Ribosome display is a cell-free system of coupling individual nascent proteins (phenotypes) to their corresponding mRNA (genotypes) by the formation of stable protein-ribosome-mRNA complexes and permitting the selection of a functional nascent protein by iterative cycles of panning and reverse transcription-polymerase chain reaction (RT-PCR) amplification in vitro. The complexity of the random peptide library is critical for the success of a panning experiment; greater the diversity of sequences within the library, the more likely it is that the library comprises sequences that can bind a given target with specific affinity.

[Expression of functional human STK11 protein in Escherichia coli].

STK11 (serine/threonine kinase 11 ), a multi-functional protein reported recently, possibly participates in a broad range of cellular processes, including regulation of cell cycle, p53-mediated apoptosis, ras-induced cell transformation and cell polarization. An efficient expression of functional STK11 in Escherichia coli will promote the study on its structure and function. Inducible prokaryotic expression vector pET-Nus-STK11 (with Nus fusion tag) was constructed with pET-44a( + ) and the cDNA of STK11 gene cloned in our lab.

[Polymorphism of CYP1A1 gene Msp I site in the Mongolian and Han nationality populations of Inner Mongolia of China].

Objective: To study the polymorphism of CYP1A1 gene Msp I site in the Mongolian and Han nationality populations of Inner Mongolia.

Methods: The PCR-restriction fragment length polymorphism(PCR-RFLP) technique was used to analyze the genotypes of CYP1A1 gene Msp I site in 80 subjects of Mongolian nationality and 120 subjects of Han nationality among whom there is no blood relationship each other.

Results: The genotype frequency of CYP1A1 gene Msp I site showed that the wild-type, heterozygote, homozygous variants were 35.

[Influence of smoke tar on mRNA expression of aromatic hydrocarbon receptor and cytochrome P4501A1 gene of mice lungs].

Objective: To investigate the influence of the smoke tar on the expression of aromatic hydrocarbon receptor (AHR) and the cytochrome P4501Al (CYP1A1) gene of mice lungs.

Methods: The smoke tar of 5.29, 10.

[Prokaryotic expression of functional PTEN in Escherichia coli and preparation of polyclonal antibody].

PTEN, a dual-specificity phosphatase, exerts its tumor-suppressive effects through the inhibition of cell cycle progression and cell immigration, therefore could be an important candidate for tumor-suppression. As study on prokaryotic expression of PTEN and its anti-tumor functions has not been reported, the present study aims at an efficient expression of functional PTEN in Escherichia coli and the investigation of its tumor-suppression activity. PTEN cDNA cloned in our lab previously was recombined into prokaryotic expression vector pET-44a(+) to construct pET-PTEN (pEP) and pET-Nus-PTEN (pENP).

[Studies of effects of lipid on rat fetal neural stem cells].

Rat fetal neural stem cells (rFNSCs) was separated from embryo about 14.5-16.5 days, and cultured in DMEM/F12 media with additives and epidermal growth factor (EGF) and basic fibroblast growth factor (bFGF).

[Cloning and analysis of six full-length cDNA similar to sheep KAP6-1 from cashmere goat].

Cashmere is the fiber of kings, produced from the cashmere goat (Capra hircus). Cashmere fabric has little squama. Due to its lightness cashmere feels smooth and silky.

[HPRT gene knock-out from rat fetal neural stem cells].

The 3.0 kb 5' arm (long arm, LA) of rat HPRT gene knock-out vector was cut by Sal I from rat HPRT gene genomic bacterial artificial chromosome (BAC) , and the 1.7 kb 3' arm (short arm, SA) was proliferated by PCR.

Abrin-a A chain expressed as soluble form in Escherichia coli from a PCR-synthesized gene is catalytically and functionally active.

Abrin-a A chain (ABRaA) is a potent plant toxin, which possesses N-glycosylase activity toward eukaryotic 28S rRNA, and may have potential use in cancer therapy. To improve levels of expression in Escherichia coli, the gene encoding ABRaA was optimized by replacing rare codons with high-frequency ones, and synthesized using two-step PCR. The optimized ABRaA was cloned into the pET-His vector, and highly expressed in cytoplasm of E.