The present invention is directed to a method of modifying a spider silk protein and a spider silk protein obtainable by said method. The invention further pertains to a nucleic acid sequence coding for a modified spider silk protein, a vector containing said sequences and host cells transformed with this vector. The invention furthermore is directed to a pharmaceutical or cosmetical composition containing a modified spider silk protein as defined herein and the use of said modified sequences in various fields, in particular in the fields of medicine, cosmetics and technical applications.