Die Bildung von Lanthionin- und Lysinoalanin-Querbrücken bei der alkalischen Denaturierung von Rinderserumalbumin

Abstract

The denaturation of bovine serum albumin was studied, using the usual chemical methods of protein analysis. In buffers containing urea, at pH values between 9. 0 and 12.5 lanthionine and lysinoalanine cross linkages are formed. The denaturation product was separated into 3 fractions by gel filtration on Sephadex G-200; each fraction had a different average molecular weight, but the same lanthionine content. Therefore, the newly formed cross linkages cannot all be formed between different polypeptide chains. The formation of the thio-ether bridges of lanthionine and the methyleneaminobutylene bridges of lysinoalanine cause an irreversible change in conformation; the protein cannot be renatured.