title: The Transferrins from Amphioxus and the Molecular Evolution of Transferrin.
abstract: An amphioxus transferring was isolated and purified from the Xiamen amphioxus. Its physio-chemical properties are the same as those of Qingdao amphioxus transferrin. It is a glyco-protein with a molecular weight of 26 kD that is about a quarter of that of the transferrin from vertebrates. Its partial amino acid sequence and its C-terminal fragment were determined. By comparison with the sequence of human serum transferrin, it has been found that the sequence of human serum transferrin can be divided into 4 fragments with about equal size as the sequences of the amphioxus transferrin. There is quite a high homology between the sequences of amphioxus transferrin and each of the 4 fragments as well as between the four fragments. The results demonstrate that the current transferrin may be evolved from an ancestor transferrin with one quarter of the molecular weight as a result of twice gene duplication. Amphioxus transferrin may be the representative from of such ancestor transferrin.
authors.affiliation: State Key Laboratory of Molecular Biology, Shanghai Institute of Biochemistry, the Chinese Academy of Sciences, Shanghai 200031, China.
authors.forename: Jian-Guo
authors.initials: JG
authors.lastname: Du
authors.forename: You-Min
authors.initials: YM
authors.lastname: Feng
authors.forename: You-Shang
authors.initials: YS
authors.lastname: Zhang