Globulins are a diverse class of globular proteins found in blood plasma, egg white, and other biological fluids. They include alpha, beta, and gamma globulins, with gamma globulins functioning as antibodies (immunoglobulins). Unlike albumins, globulins are generally insoluble in pure water but soluble in dilute salt solutions. They play roles in transport, immune response, and enzymatic functions. As macromolecules, they lack fixed small-molecule properties such as boiling or melting points and instead denature at elevated temperatures. Molecular weights vary widely (e.g., 150 kDa for IgG).