46 results about "Peptidoglycan transpeptidase" patented technology

The invention relates to field of biological medicines, in particular to a method for preparing a site specific protein-polyamino acid cyclic conjugate. The method comprises the following steps: (1) using an initiator to initiate N-carboxyl anhydride and glycine N-carboxyl anhydride to be polymerized to obtain block polyamino acid of which the C-terminal has a phenyl thioester structure and the N-terminal has a polyglycine block structure; (2) mixing the obtained block polyamino acid with proteins of which the N-terminal has cysteine and the C-terminal has an LPXaTG sequence, and performing native chemical ligation and transpeptidase reaction continuously to realize cyclization of proteins, wherein Xa is any one of amino acids. The protein-polyamino acid cyclic conjugate prepared by the invention has the characteristics of polypeptide main chain structure, good biocompatibility, low immunogenicity and the like, and is very suitable for modification of protein drugs, thereby being capable of being used for manufacturing the protein drugs.

The invention relates to a method for preparing Nesiritide. In the method, HMPB-AM resin is taken as an initial raw material, amino acids with Fmoc blocking groups are sequentially connected in a solid phase synthesis way under the action of condensing agent and transpeptidase reagent to obtain side chain full-protection linear Nesiritide HMPB-AM resin; linear Nesiritide raw peptides are obtained by schizolysis, Nesiritide raw peptides are obtained by liquid phase oxidation, and Nesiritide fine peptides are obtained by purification, salt transfer and freeze drying. The invention has the advantages of simple operation, easy post treatment, few raw materials, low cost, high yield coefficient, and the like, thereby having considerable economy and utility value and also having extensive application prospect in the polypeptide drug design synthesis field.

The peptidoglycan layer is a vital component of the bacterial cell wall, which comprises 4→3 and 3→3 transpeptide cross-linkages, the formation of which are catalyzed by D,D- and L,D-transpeptidases, respectively. Methods for the treatment of bacterial infections with agents that inhibit L,D-transpeptidases, either alone or in combination with D,D-transpeptidase inhibitors, are provided herein. Also provided are methods for the treatment of chronic stage tuberculosis with agents that inhibit enzyme with L,D-transpeptidase activity.

The invention discloses a preparation method of solid phase peptide synthesis triptorelin, which includes the following steps: with Rink Amide AM resins or Rink Amide MBHA resins as starting materials, amino acids with protective groups are sequentially connected according to solid phase synthesis, so as to obtain protective decapeptide resins, and meanwhile crude products are obtained by sequentially removing Fmoc-protective groups and synchronously removing side-chain protective groups and cutting peptides, and triptorelin elaborate products are prepared after the crude products are separated and purified by C18 (or C8 ) column and freeze-dried. The preparation method is stable in technology, convenient in raw and auxiliary material sources, short in production cycle, high in yield, stable in quality, low in production cost and high in transpeptidase yield. Besides, as the preparation method avoids using poisonous reagents, such as hydrogen fluoride, and the like, the pollution of three wastes is low, purification yield is over 25 percent and each step of transpeptidase yield is above 98 percent; the yield after cutting peptides is 78.8 percent and the total yield is 25.4 percent.

The invention relates to the field of polypeptide synthesis, and in particular relates to a method for preparing sinapultide by combining a solid phase and a liquid phase. The method provided by the invention comprises the following steps of firstly, preparing polypeptide fragments I: Fmoc-Leu-Leu-Leu-Leu-Lys(Boc)-OH, then adopting an Fmoc solid-phase synthesis method to sequentially couple four polypeptide fragments I onto carrier resin, and finally, coupling protected amino acid Lys to prepare the sinapultide through a cleavage reaction. By adopting the method to prepare the sinapultide, only five steps of transpeptidase reactions are needed, the production cycle is short, the crude peptide purity is high, the cost is low, the operation is simple and the method is applicable to industrial production.