A molecular probe for use in imaging of pancreatic islets is provided. The molecular probe comprises a polypeptide represented by the following formula (1), (2), or (3), or a polypeptide having homology with the foregoing polypeptide,
Z-HGEGTFTSDLSXQMEEEAVRLFIEWLKNGGPSSGAPPPS-NH2 (1) (SEQ ID NO. 1)
Z-HGEGTFTSDLSKQMEEEAVRLFIEWLXNGGPSSGAPPPS-NH2 (2) (SEQ ID NO. 2)
B-HGEGTFTSDLSKQMEEEAVRLFIEWLKNGGPSSGAPPPS-NH2 (3) (SEQ ID NO. 3)
where, in formulae (1) and (2), "X" represents a lysine residue, the amino group of the side chain of the lysine residue being labeled with a radioactive nuclide, and "Z-" indicates that the α-amino group at the N-terminus is not modified, or is modified with a modifying group having no electric charge; in formula (3), "B-" indicates that the α-amino group at the N-terminus is labeled with a radioactive nuclide; and in formulae (1), (2), and (3), "-NH2" indicates that the carboxyl group at the C-terminus is amidated.
提供了一种用于胰岛成像的分子探针。该分子探针包括下式(1)、(2)或(3)所代表的
多肽,或与前述
多肽具有同源性的
多肽、
Z-
HGEGTFT
SDLSXQMEEEAVRLFIEWLKNGGPSSGAPPS-NH2 (1) (
SEQ ID NO. 1)
z-
HGEGtft
SDlskqmeeeavrlfiewlxnggPSsgappPS-nh2 (2) (
SEQ ID NO. 2)
B-
HGEGTFT
SDLLSKQMEEEAVRLFIEWLKNGGPSSGAPPS-NH2 (3) (
SEQ ID NO. 3)
其中,在式(1)和(2)中,"X "表示赖
氨酸残基,赖
氨酸残基侧链的
氨基用放射性核素标记,"Z-"表示 N 端的 α-
氨基未修饰或用不带电荷的修饰基修饰;在式(3)中,"B-"表示 N-末端的α-
氨基用放射性核素标记;在式(1)、(2)和(3)中,"-NH2 "表示 C-末端的羧基被酰胺化。