An object of the present invention is to provide an oligosaccharide chain added GLP-1 peptide that has higher stability in blood than that of GLP-1 and, preferably, exhibits higher activity of controlling blood-sugar levels than that of GLP-1. The present invention provides an oligosaccharide chain added GLP-1 peptide having GLP-1 activity, wherein at least two amino acids are each substituted with an oligosaccharide chain added amino acid, in (a) GLP-1 (b) a peptide having the amino acid sequence of GLP-1 with deletion, substitution or addition of one or several amino acids or (c) a GLP-1 analog. The present invention also provides an oligosaccharide chain added GLP-1 peptide having GLP-1 activity, wherein at least one amino acid is substituted with an oligosaccharide chain added amino acid, in the (a), (b) or (c) and the oligosaccharide chain is an oligosaccharide chain comprising oligo hyaluronic acid. In the oligosaccharide chain added amino acid, the oligosaccharide chain may be linked to the amino acid via a linker.本發明之課題係提供一種與GLP-1較之血中半衰期長、且最好顯示出具有高血糖值抑制活性之附加糖鏈GLP-1胜肽。本發明提供一種具有GLP-1活性之附加糖鏈GLP-1胜肽,係在(a)GLP-1;(b)GLP-1中,係為被缺失、置換或附加1個或數個胺基酸之胜肽;或(c)GLP-1之同系物;之中,其特徵為以附加糖鏈胺基酸來置換至少2個之胺基酸者。本發明又在前述(a)、(b)或(c)中,至少1個胺基酸以附加糖鏈胺基酸置換之具有GLP-1活性之附加糖鏈GLP-1胜肽,其中係提供該糖鏈含有寡聚透明質酸之糖鏈之附加糖鏈GLP-1胜肽,附加糖鏈胺基酸亦可藉由結合子來連結糖鏈和胺基酸。
