48 results about "Beta-galactosidase" patented technology

Short enzyme donor fragments of β-galactosidase are provided of not more than 40 amino acids, where the short fragments are used as a label and may be substituted with a wide variety of organic compounds, particularly polypeptides having independent functional activity. The enzyme donor finds use in competitive and non-competitive assays, monitoring intracellular events, or other processes where a sensitive non-interfering label is desired.

The invention discloses a method for resisting human mesenchymal stem cell aging and enhancing stem characteristics of human mesenchymal stem cells. According to the method, immune cells in human peripheral blood and aged human mesenchymal stem cells are cultured in a cell-to-cell contact mode, the aging characteristics of the aged human mesenchymal stem cells can be remarkably reversed, the expression of cell aging markers such as beta galactosidase, P21 and P16 proteins is reduced, and meanwhile, the cell cycle of the aged human mesenchymal stem cells can be obviously adjusted, specifically,the number of cells in the G1 stage is reduced, and the number of cells in the S stage is increased. More importantly, the method can remarkably enhance the stem characteristics of the aged human mesenchymal stem cells, such as self-renewal capacity, multiplication capacity and multi-directional differentiation potential, and the cells obtained by the culture mode are used for treating disease models and are safe and effective. The method can be directly applied to long-term in-vitro amplification of the human mesenchymal stem cells, the problem of cell aging in the amplification process is solved, the cell activity is recovered, and the clinical application effect is improved.

The invention provides a Lactobacillus plantarum (L.plantarum) CZ401 strain producing exopolysaccharides and β-galactosidase, which was preserved in the China Type Culture Collection Center on March 7, 2016, and the address is: Wuhan University, Wuchang District, Wuhan City, Hubei Province, the preservation number is CCTCC NO: M2016092, and the 16S rDNA sequence of the strain is shown in SEQ ID NO.1. The bacterial colonies observed on MRS solid medium were light yellow, smooth, round, and raised in the center; microscopic observation showed that the strains were Gram-positive, rod-shaped, without flagella, and without spores. The above-mentioned CZ401 strain provided by the present invention not only has higher exopolysaccharide-producing ability and β-galactosidase activity, but also can ferment milk to produce lactic acid drinks, and has wide application value.

The invention provides a system of heavy metal sequestration by bacteria. The bacteria expresses the ppk, mt, and / or β-galactosidase (lacZ) genes and can tolerate at least 25 μM mercury, 1,000 μM zinc, 250 μM cadmium, and 3,000 μM Pb. The system allows for facile determination of the presence of heavy metal contaminants in a liquid and the facile collection of the bacteria that has sequestered large amounts of heavy metal. Further provided is a system of gene expression in bacteria that comprises phage and plastid gene expression elements and delivers a particularly high level of protein expression and heavy metal resistance.

A method for determining ligand activation of receptors using cells expressing genetic constructs of a fusion protein of at least a binding domain of an auxiliary protein and a fragment of β-galactosidase, a fusion protein of an endosome-associated protein and a complementary fragment of β-galactosidase, and a wild-type receptor. The receptors are characterized by binding to the auxiliary protein-binding domain upon activation by an agonist and then endocytosing associated with an endosome to which the endosome-associated protein binds. Cells are incubated with a candidate ligand followed by lysis with a lysing medium comprising a substrate for the β-galactosidase. The enzyme product is then detected as a measure of the activation of the receptor.