What is a characteristic feature of integral membrane proteins?

Integral membrane proteins are characterized by their embedding within the lipid bilayer of cellular membranes. This embedding is due to their hydrophobic regions that interact with the fatty acid tails of the membrane lipids. Because they are integrated into the membrane, these proteins are not fully soluble in water, which distinguishes them from some other types of proteins. Their structure often allows them to span the membrane, maintaining both extracellular and intracellular domains, which can be crucial for various functions such as transport, signaling, and cell recognition.

The characteristic nature of integral membrane proteins means they can play roles in forming channels or pores; however, the option indicating that they cannot do so is incorrect. While purification techniques for integral membrane proteins can be challenging, they typically require specific detergents to solubilize them without disrupting their functional state, rather than 'mild conditions.' Therefore, being embedded in the bilayer is indeed the defining trait of integral membrane proteins.