PROTEIN

• Proteins are large, complex molecules that play many critical roles in the body. They are made up of long chains of amino acids, which are organic compounds composed of carbon, hydrogen, oxygen, nitrogen, and sometimes sulfur
• Life, as we understand it, depends on proteins, which are composed of amino acids. Although numerous amino acids exist in nature, just 20 of them, combined in various ways, form all the proteins present in the human body and most living organisms.
• Amino acids play essential roles in providing structural support in tissues, acting as catalysts in biochemical reactions, transporting molecules across biological membranes, regulating muscle contractions that enable movement and heartbeat, and facilitating communication between cells to carry out their functions

• The protein-folding problem refers to the challenge of predicting a protein's three-dimensional (3D) structure based solely on its amino acid sequence.
• A protein possesses multiple identities, one of which is determined by the arrangement of its amino acids in three-dimensional space—its 3D structure. In 1962, researchers John Kendrew and Max Perutz from the University of Cambridge were awarded the Nobel Prize in Chemistry for creating the first 3D models of hemoglobin and myoglobin, both proteins, through X-ray crystallography.
• A significant breakthrough occurred in 1969 when scientists discovered that a protein does not attempt to adopt various shapes; instead, it inherently knows the specific shape it needs to achieve and swiftly folds itself accordingly. This enigmatic ability of the protein is referred to as the protein-folding problem.
• By the late 2010s, scientists had determined the structures of approximately 170,000 proteins—an impressive number, yet still a fraction compared to the estimated 200 million proteins found in nature. However, this scenario dramatically changed around 2018.
• Proteins: These are long chains of amino acids that fold into specific shapes, which determine their functions. The sequence of amino acids (the primary structure) dictates how the protein folds into its secondary, tertiary, and quaternary structures
• Proteins can have hundreds or thousands of amino acids, leading to an enormous number of possible configurations.
• The process of folding involves many interactions (hydrogen bonds, hydrophobic interactions, ionic bonds, etc.) and is influenced by the protein's environment
• Proteins do not fold randomly; they often follow specific pathways to reach their final functional form.
• Understanding these pathways is crucial for predicting the folded structure from the amino acid sequence.
• Improper folding can lead to non-functional proteins or proteins that aggregate, which can cause diseases such as Alzheimer’s, Parkinson’s, and certain types of cancer.
• Understanding how proteins fold correctly is essential for developing treatments for these conditions.