Exotoxins are classified as which type of biologic molecules?

Exotoxins are classified as proteins, which is a key characteristic that distinguishes them from other types of biologically active molecules. These proteins are secreted by certain bacteria, and they serve a variety of purposes, such as disrupting host cell function, damaging tissues, or provoking an immune response. The protein nature of exotoxins enables them to have specific modes of action, often targeting particular receptors or cellular processes within the host.

Their classification as proteins is significant in the context of their structure and function. Unlike lipopolysaccharides, which are components of bacterial cell membranes, or mucopolysaccharides, which are polysaccharide structures found in connective tissues, exotoxins are enzymatically active and can elicit strong immune responses due to their ability to be recognized as foreign by the host’s immune system.

Understanding that exotoxins are proteins helps to comprehend how they can be neutralized by specific antibodies, leading to treatments such as antitoxins in cases of toxin exposure. This attribute also helps in developing vaccines that target these proteins, providing protective immunity against certain bacterial infections.