Patent ID: 8287850

Claim:
A method for preparing a conjugate comprising a protein and a polymer derivative, wherein the polymer is a hydroxyalkyl starch (HAS), said method comprising (a)(1) reacting the polymer at its optionally oxidized reducing end with an at least bifunctional compound, said compound comprising two functional groups M and Q, functional group M being reacted with the optionally oxidized reducing end of the polymer, and functional group Q being an aldehyde group or keto group or hemiacetal group, to give an aldehyde or keto or hemiacetal functionalized polymer derivative; or (a)(2) reacting the polymer at its optionally oxidized reducing end with an at least bifunctional compound, said compound comprising two functional groups M and Q, functional group M being reacted with the optionally oxidized reducing end of the polymer to give a polymer derivative comprising a free functional group Q, the method further comprising reacting said polymer derivative with a further at least bifunctional compound comprising a functional group capable of being reacted with the functional group Q, and an aldehyde group or keto group or hemiacetal group, to give an aldehyde or keto or hemiacetal functionalized polymer derivative; and (b) covalently linking the aldehyde group or keto group or hemiacetal group of the aldehyde or keto or hemiacetal functionalized polymer derivative to at least one amino group of the protein by reductive amination.