39 results about "Double mutation" patented technology

The invention is based on the reaction of recombinagenic oligonucleotides in a cell-free system containing a cytoplasmic cell extract and a test duplex DNA on a plasmid. The reaction specifically converts a mutant kanr gene to recover the resistant phenotype in transformed MutS, RecA deficient bacteria and allows for the rapid and quantitative comparison of recombinagenic oligonucleobases. Using this system a type of Duplex Mutational Vector termed a Heteroduplex Mutational Vector, was shown to be more active in than the types of mutational vectors heretofore tested. Further improvements in activity were obtained by replacement of a tetrathymidine linker by a nuclease resistant oligonucleotide, such as tetra-2'-O-methyl-uridine, to link the two strands of the Duplex Mutational Vector and removal of the DNA-containing intervening segment. The claims concern Duplex Mutational Vectors that contain the above improvements. In an alternative embodiment the claims concern a reaction mixture containing a recombinagenic oligonucleobase, a cell-free enzyme mixture and a duplex DNA containing a target sequence. In yet an alternative embodiment, the invention concerns the use of such mixture to test improvements in recombinagenic oligonucleobases, as well as to test the effects of compounds on the activity of the cell-free enzyme mixture and also to make specific changes in the target DNA sequence.

Modified polypeptides based on the botulinum neurotoxin A heavy chain containing the double mutation Trp-Tyr->Leu-Ser in the ganglioside binding motif Ser-X-Trp-Tyr do not bind polysialogangliosides and nerve endings. The polypeptides are useful in the preparation of nontoxic vaccines against the effects of C. botulinum infection. The modified polypeptides are also useful as vehicles for the transepithelial delivery of diagnostic and therapeutic entities, through formation of conjugates between the polypeptides and the diagnostic or therapeutic entities.

We disclose a cell having double mutations of the hERG gene that lead to charge reversal amino acid substitutions at residues 466 and 534 of the wild type Kv11.1 channel protein. These double charge reversal mutations result in cells having constitutively open Kv11.1 channels. Such cells could be used in a method of testing development-stage drugs and other compounds for Kv11.1 channel block activity.

Disclosed is a new use of ibrutinib (PCI-32765). In particular, the present invention has found that ibrutinib can treat non-small cell lung cancer carrying EGFR T790M mutations and / or EGFR L858R mutations and / or EGFR delE746_A750 mutations, especially non-small cell lung cancer carrying EGFR L858R and EGFR T790M double mutations.

The present invention provides a mutant of Perakine reductase and its application. The mutant is obtained by the following single mutation or combined double mutation of 126 and 127 in the amino acid sequence of wild-type Perakine reductase at position 126 or 127: H126G / R / I / C / P / K / N / W / A / Y, R127M / P / N / S / F, where " / " stands for "or". Based on the three-dimensional crystal structure and sequence comparison, the present invention adopts the point-saturation mutation technology to carry out molecular transformation on Perakine reductase, and screens to obtain the mutant capable of selectively reducing the enone double bond. The method of the present invention as a catalyst for selectively reducing enone double bonds has the advantages of simple reaction steps, mild reaction conditions, environmental friendliness, high catalytic efficiency, simple enzyme purification, good stability, and strong stereoselectivity. Bond reduction and the synthesis of related saturated ketone drugs have good application prospects.

The invention discloses a linoleate isomerase mutant and application thereof, and the linoleate isomerase mutant is obtained by mutation of 62th-site methionine of linoleate isomerase with an amino acid sequence as shown in SEQIDNO:1 into alanine or glycine, and mutation of 295th-site serine into alanine, leucine or valine. The enzyme activity for catalysis of linoleic acid for preparation of trans-10,cis-12 conjugated linoleic acid of the linoleate isomerase mutant can be greatly improved compared with that of a wild-type enzyme, especially during double mutation such as M62A / S295L, M62A / S295A, M62A / S295V, M62G / S295L, M62G / S295A and M62G / S295V, the enzyme activity can be increased by about 10 times, and the linoleate isomerase mutant has good prospects for industrial application.

The invention discloses a mutant for trehalose synthase as well as a preparation method and an application of the mutant and belongs to the fields of genetic engineering and enzyme engineering. The mutant is prepared by the following steps: mutating 289th bp glutamate near the active center of the trehalose synthase of Thermobifida fusca YX into glycine to obtain a mutant E289G; mutating 295th bp histidine into an asparagine mutant H295N; mutating 344th bp methionine into a lysine mutant M344K; and mutating 367th bp methionine into a leucine mutant M367L, and carrying out double mutations on the basis of the H295N to obtain mutants H295N / E289G, H295N / M344K, H295N / M367L and H295N / M344K / M367L. According to the mutant disclosed by the invention, although a substrate contains a certain quantity of glucose, the transformation efficiency of preparing trehalose by virtue of the trehalose synthase can not be greatly influenced still, and the mutant has very high industrial value.