66 results about "Bifunctional reagent" patented technology

The invention provides a method for preparing an enzyme labelling antibody. The method comprises the following steps of: concentrating a colloidal gold solution, and then adjusting the pH value of the concentrated colloidal gold solution to be slightly greater than the pH value of an isoelectric point of an enzyme for labelling; adding an aqueous solution of the enzyme for labelling into the colloidal gold solution, mixing the solutions, and then connecting the antibody to molecules of the enzyme on the surface of colloidal gold by a bifunctional reagent; and carrying out centrifugation to obtain an enzyme labelling colloid gold compound antibody. In the method, enzyme labelling on the colloidal gold is accomplished in a direct-absorption simple mode; the separation of the enzyme and a coupling agent and separation purification after connection of the antibody can be finished only by the simple centrifugation without the complicated and high-loss expensive steps of gel filtration, dialysis or affinity chromatography; by concentration operation prior to enzyme absorption by the colloid gold, the connection amount of a connected reagent can be increased, and the concentration of gold colloid particles in the enzyme labelling colloid gold compound antibody can be increased simultaneously; and the enzyme labelling colloid gold compound antibody is accordant with the characteristic.

The present invention provides one kind of nanometer bacterial magnetic corpuscle carrying primary amino group medicine and its preparation process. The nanometer bacterial magnetic corpuscle consists of three structural units, including homotype double-function reagent, primary amino group medicine and nanometer bacterial magnetic corpuscle. The nanometer bacterial magnetic corpuscle carrying primary amino group medicine has high medicine carrying capacity, less aggregation, easy separation and purification, anticancer and antitumor effect similar to that of pure primary amino group medicine, but much lower toxicity.

Methods and reagents for site-selective functionalization of peptides and proteins. The methods most generally involve the reaction of a thioester with hydrazine. Reagents include bifunctional reagents of formula:H2N—NH—CH2-M-L-FGand salts thereof where M is a single bond or a chemical group carrying a non-bonding electron pair, such as —C(O)NR′—, where R′ is H, or an alkyl or aryl group; L is an optional linker group as described above; and FG is a functional group having reactivity that is orthongonal to that of the hydrazine group. FG can, among others, be an azide, alkenyl, alkynyl, nitrile (—CN) or triazole group and is preferably an azide group (—N3). Methods and reagents can, for example, be combined with intein-mediated protein splicing to link proteins or fragments thereof to various chemical species or to a surface. Surface immobilization of proteins via the methods herein results in immobilized proteins which substantially retain biological activity and is thus useful for the generation of peptide or protein microarrays. Kits for functionalization and / or immobilization of peptides and proteins are provided as well as microarrays of peptides, proteins or both.

The invention provides a preparation method of a novel polysaccharide conjugate vaccine treating a PEG heterobifunctional reagent as a conjugation bridge. A meningococcal polysaccharide conjugate vaccine is exploited through the method. The method has the following advantages: 1, the respective self-crosslinking of polysaccharides and proteins in traditional methods is avoided, the yield is improved, and the quality control is benefited; and 2, a long PEG chain can increase the distance between the polysaccharides and the proteins, reduce the mutual space shield effect between the polysaccharides and the proteins, and improve the immunogenicity of the polysaccharide conjugate vaccine.

The invention provides an immobilization method of xylanase and immobilized xylanase. In the invention, xylanase is immobilized on the surface of a 3-aminopropyltriethoxysilane-modified Fe3O4@SiO2 nanoparticle carrier by a covalent bond (peptide bond) through the binding function of a bifunctional reagent to obtain immobilized xylanase, which limits the spatial configuration transformation of xylanase, so as to realize the heat tolerance, acid and alkali resistance, and resistance to interference of metal ions and inhibitors of xylanase; and the immobilized xylanase has relatively high tolerance to heat (40-70 DEG C), relatively wide adaptability to extreme pH values (3.0-8.0), relatively high tolerance to metal ions (Ba<2+>, Fe<2+>, Mn<2+>, Ca<2+>) and interfering agents (blue moon hand sanitizer, Triton X-100, Tween 20, EDTA solution, ethanol), and excellent operational stability. The activity of the immobilized xylanase can still be maintained at 73% or higher after being repeatedly used for 9 times.

A polysialic acid compound is reacted with a hetero-bifunctional reagent to introduce a pendant functional group for site-specific conjugation to sulfhydryl groups, for instance side chains of cysteine units in drugs, drug delivery systems, proteins or peptides. The functional group is, for instance, an N-maleimide group.

The invention discloses a preparation method of a cross-linked beta-lactamase aggregate for treating pharmaceutical wastewater. The preparation method comprises the following steps: transferring a recombinant beta-lactamase gene sequence into a host cell E.coli Top10 to obtain recombined bacteria; carrying out induced expression, ultrasonic crushing and centrifugal treatment and taking supernatant to obtain rough enzyme liquid; adding bovine serum albumin into the rough enzyme liquid as an aggregation agent and a protection agent; precipitating and aggregating to form an enzyme aggregate; crossly linking the obtained enzyme aggregate through a bidirectional reagent so as to prepare the cross-linked beta-lactamase aggregate. After a test, the cross-linked beta-lactamase aggregate prepared by the invention is high in enzyme activity and good in stability, can be repeatedly utilized and is used for treating antibiotic wastewater; the chemical oxygen demand is reduced by 72.9 percent; the cross-linked beta-lactamase aggregate has an important application value in the treatment of the antibiotic wastewater in a pharmaceutical industry.