Kinetics of reaction of Escherichia coli ribosomal proteins toward N-ethylmaleimide.

The kinetics of reaction of the exposed ribosomal proteins from Escherichia coli toward N-ethylmaleimide (NEM) have been studied. While most of the proteins from the 30S subunit react rapidly with NEM and plateau levels can be reached, most of the proteins from the 50S subunit show biphasic uptake kinetics. Furthermore, differences have been observed in the reactivity of proteins toward NEM depending on whether the protein is in the free subunit or in the 70S ribosome.