Abstract: Provided are a method for the modification of a polypeptide and uses. The method comprises the following steps: (1) introducing an X into the N-terminus of a polypeptide, thereby obtaining X-polypeptide; (2) oxidizing the X into an aldehyde group; (3) adding a reducing agent, and covalently coupling the oxidation product obtained in step (2) with PEG, thereby obtaining a PEG-modified polypeptide, wherein X is threonine or serine. In the present application, a single component of PEG-modified polypeptide is obtained by introducing a threonine or serine into the N-terminus of the polypeptide, and deriving the amino alcohol structure at the ortho-position of the N-terminus of the polypeptide as an aldehyde group by using a high-specificity oxidation method and covalently coupling the aldehyde group with PEG.

Abstract: Related is use of fumaric acid esters or pharmaceutically acceptable salts thereof in preparing a pharmaceutical for treating ferroptosis-related diseases. The fumaric acid esters includes dimethyl fumarate and/or monomethyl fumarate. The present application reveals, for the first time, the effect of fumaric acid ester and its pharmaceutically acceptable salt on a protein level of a ferroptosis key regulatory gene GPX4, provides a theoretical basis for the research of treatment strategies for the ferroptosis-related diseases, and provides a new outlet for preparing pharmaceuticals used for the ferroptosis-related diseases.