Principles of Protein Structure - G. Schultz 1982

Structural basis of the mechanism, action, and function of proteins
Biological and medical aspects of protein action and function
Proteins as functional components of the organism

Proteins in situ must possess a wide range of properties that enable them to function within a highly complex environment [586]. These properties include rapid spontaneous folding, necessary physicochemical characteristics such as solubility and isoelectric point, as well as “good behavior” (intracellular proteins must not interact with the vast majority of cellular components) (Sec. 10.1).

Many proteins in situ are present at concentrations significantly higher than those typically required to perform their specific Functions, such as catalyzing certain Chemical Reactions. This suggests that proteins may serve as a storage form for Amino Acids and/or perform functions yet unknown to us. For instance, the high concentration of creatine kinase in Muscle (20 mg per 1 g of tissue [751]) remained unexplained until it was discovered that this Protein Functions not only as an enzyme, but also as a structural component of the M-band that Supports the contractile apparatus [752].

One of the challenges in studying biological function is that it can go unnoticed as long as it operates normally. Therefore, the identification of a function often relies on The Study of diseases and Mutations, as well as the effects of poisons, toxins, and drugs. Deficient or impaired function can generally be linked to incomplete, inadequate, or altered Cell/13.html">Protein Structure. This demonstrates that in protein function, the details of molecular architecture are vividly and directly reflected in The activity of an entire organ or Organism [753].