System and method for is used to all float on the preliminary placement of a water level, after they are sowed and/or are extracted water before them

摘要

The present invention provides the method and compound for modifying protein, the peptides and organic compound of the free amino of an imidate derivative with PEG or relevant water-soluble organic polymer. The novel imidate derived product of PEG and other water-soluble polymers is provided for. Also the water-soluble polymer butterfly agent of the subject invention of the imidate including polyethylene glycol, polypropylene glycol, polyoxyethylated polyalcohols, heparin, heparin fragment, dextran, polysaccharide, polyaminoacid, polyvinyl alcohol and other water-soluble organic polymer. One advantage of PEG- imidates is reacted in the amino groups with protein like that, and gained derivative still retains positive charge and shifts positive charge far from water-soluble polymer backbone. It is same to provide with then passing through polypeptide of interest derived from water-soluble polymer imidate.