| 摘要 |
PURPOSE: To obtain the subject ligand as, a compound having a specific molecular weight, positive in Coomassie staining reaction and PAS staining reaction in color reactions, bonding to a polypeptide containing a specific amino acid sequence and stimulating the proliferation of undifferentiated blood cells. CONSTITUTION: A new lagand to a receptor type tyrosine kinase contains a part or the whole of a polypeptide having an amino acid sequence containing an amino acid sequence of formula I, has at least a molecular weight of 23,500±1,500 dalton, is positive in Coomassie staining reaction and PAS staining reaction in color reactions, bonds to a polypeptide having an amino acid sequence containing an amino acid of formula II and stimulates the proliferation of undifferentiated blood cells. The compound is obtained by separating a receptor type tyrosine kinase gene participating to the differentiation and proliferation of a hemato poietic stem cell from a human megakaryoblast leukemia cell, cloning a human placenta cDNA library by using the tyrosine kinase as a probe and manifesting a DNA of a positive clone in a host. |
