1. A method for conjugating a water-soluble polymer with an oxidized carbohydrate portion of (1) a glycoprotein other than a blood coagulation protein, (2) a ganglioside or (3) a drug delivery system containing a carbohydrate group, comprising contacting the oxidized carbohydrate portion with water-soluble polymer under conditions that allow conjugation, wherein said water-soluble polymer contains an aminooxy group, and an oxime is formed between the oxidized carbohydrate moiety and the aminooxy group on the water-soluble polymer a bond, or where said water-soluble polymer contains a hydrazide group, and a hydrazone bond forms between the oxidized carbohydrate moiety and the hydrazide group on the water-soluble polymer. 2. The method of claim 1, wherein the water soluble polymer is polyethylene glycol (PEG), hydroxyethyl cellulose (HEC), dextrin, or polyoxazoline. The method of claim 1, wherein the water soluble polymer is polysialic acid (PSA) or a modified PSA (mPSA). The method of claim 3, wherein the PSA or mPSA is colominic acid or a modified colominic acid. The method according to claim 3 or 4, where the PSA or mPSA contains 2-500 units of sialic acid. The method according to any one of claims 1 to 4, wherein the ganglioside comprises a glycosphingolipid (ceramide and oligosaccharide), wherein one or more sialic acids are attached to a sugar chain. The method according to any one of claims 1 to 4, wherein the ganglioside contains ceramide bound to glucose, which is bound to the first galactose, which is bound to N-acetylgalactosamine, which is bound to the second galactose. The method according to any one of claims 1 to 4, where the system for drug delivery includes m1. Способ конъюгации растворимого в воде полимера с окисленной углеводной частью (1) гликопротеина, отличного от белка свертывания крови, (2) ганглиозида или (3) системы для доставки лекарственного средства, содержащей углеводную группу, включающий контактирование окисленной углеводной части с рас
