The given protein, Protein X, is a heterotrimer - meaning it is a multimeric protein consisting of different polypeptide chains. Its molecular weight is 200 kDa. Using SDS-PAGE, the protein was...

The given protein, Protein X, is a heterotrimer - meaning it is a multimeric protein consisting of different polypeptide chains. Its molecular weight is 200 kDa.  Using SDS-PAGE, the protein was characterized and the following profile is the result (attached in the picture).

1: Standard Protein Ladder

2: Protein X solution

3: Protein X solution + β-mercaptoethanol

Based on the given gel profile in the picture,

• can it be concluded that the solution of Protein X is pure? Explain.


• can it be concluded that disulfide bonds hold together Protein X's quaternary structure? Explain.