Amino acids are organic compounds that contain both amino and carboxylic acid functional groups. Although over 500 amino acids exist in nature, by far the most important are the 22 α-amino acids incorporated into proteins. Only these 22 appear in the genetic code of life.
In organic chemistry, a peptide bond is an amide type of covalent chemical bond linking two consecutive alpha-amino acids from C1 of one alpha-amino acid and N2 of another, along a peptide or protein chain.
Cysteine is a semiessential proteinogenic amino acid with the formula HOOC−CH(−NH2)−CH2−SH. The thiol side chain in cysteine often participates in enzymatic reactions as a nucleophile. Cysteine is chiral, but interestingly, both D and L-cysteine are found in nature with D-cysteine having been found in developing brain.
Leroy "Lee" Edward Hood is an American biologist who has served on the faculties at the California Institute of Technology (Caltech) and the University of Washington. Hood has developed ground-breaking scientific instruments which made possible major advances in the biological sciences and the medical sciences. These include the first gas phase protein sequencer (1982), for determining the sequence of amino acids in a given protein; a DNA synthesizer (1983), to synthesize short sections of DNA; a peptide synthesizer (1984), to combine amino acids into longer peptides and short proteins; the first automated DNA sequencer (1986), to identify the order of nucleotides in DNA; ink-jet oligonucleotide technology for synthesizing DNA and nanostring technology for analyzing single molecules of DNA and RNA.
Proteinogenic amino acids are amino acids that are incorporated biosynthetically into proteins during translation. The word "proteinogenic" means "protein creating". Throughout known life, there are 22 genetically encoded (proteinogenic) amino acids, 20 in the standard genetic code and an additional 2 that can be incorporated by special translation mechanisms.
Native Chemical Ligation (NCL) is an important extension of the chemical ligation concept for constructing a larger polypeptide chain by the covalent condensation of two or more unprotected peptides segments. Native chemical ligation is the most effective method for synthesizing native or modified proteins of typical size.
In organic chemistry, peptide synthesis is the production of peptides, compounds where multiple amino acids are linked via amide bonds, also known as peptide bonds. Peptides are chemically synthesized by the condensation reaction of the carboxyl group of one amino acid to the amino group of another. Protecting group strategies are usually necessary to prevent undesirable side reactions with the various amino acid side chains. Chemical peptide synthesis most commonly starts at the carboxyl end of the peptide (C-terminus), and proceeds toward the amino-terminus (N-terminus). Protein biosynthesis in living organisms occurs in the opposite direction.
Chemical biology is a scientific discipline between the fields of chemistry and biology. The discipline involves the application of chemical techniques, analysis, and often small molecules produced through synthetic chemistry, to the study and manipulation of biological systems. Although often confused with biochemistry, which studies the chemistry of biomolecules and regulation of biochemical pathways within and between cells, chemical biology remains distinct by focusing on the application of chemical tools to address biological questions.
Defensins are small cysteine-rich cationic proteins across cellular life, including vertebrate and invertebrate animals, plants, and fungi. They are host defense peptides, with members displaying either direct antimicrobial activity, immune signaling activities, or both. They are variously active against bacteria, fungi and many enveloped and nonenveloped viruses. They are typically 18-45 amino acids in length, with three or four highly conserved disulphide bonds.
Stephen B. H. Kent is a professor at the University of Chicago. While professor at the Scripps Research Institute in the early 1990s he pioneered modern ligation methods for the total chemical synthesis of proteins. He was the inventor of native chemical ligation together with his student Philip Dawson. His laboratory experimentally demonstrated the principle that chemical synthesis of a protein's polypeptide chain using mirror-image amino acids after folding results in a mirror-image protein molecule which, if an enzyme, will catalyze a chemical reaction with mirror-image stereospecificity. At the University of Chicago Kent and his junior colleagues pioneered the elucidation of protein structures by quasi-racemic & racemic crystallography.
Chemical ligation is the chemoselective condensation of unprotected peptide segments enabled by the formation of a non-native bond at the ligation site.
Ronald T. Raines is an American chemical biologist. He is the Roger and Georges Firmenich Professor of Natural Products Chemistry at the Massachusetts Institute of Technology. He is known for using ideas and methods of physical organic chemistry to solve important problems in biology.
Bioconjugation is a chemical strategy to form a stable covalent link between two molecules, at least one of which is a biomolecule.
ADP-ribosylation is the addition of one or more ADP-ribose moieties to a protein. It is a reversible post-translational modification that is involved in many cellular processes, including cell signaling, DNA repair, gene regulation and apoptosis. Improper ADP-ribosylation has been implicated in some forms of cancer. It is also the basis for the toxicity of bacterial compounds such as cholera toxin, diphtheria toxin, and others.
Glycopeptides are peptides that contain carbohydrate moieties (glycans) covalently attached to the side chains of the amino acid residues that constitute the peptide.
Laura Lee Kiessling is an American chemist and the Novartis Professor of Chemistry at the Massachusetts Institute of Technology. Kiessling's research focuses on elucidating and exploiting interactions on the cell surface, especially those mediated by proteins binding to carbohydrates. Multivalent protein-carbohydrate interactions play roles in cell-cell recognition and signal transduction. Understanding and manipulating these interactions provides tools to study biological processes and design therapeutic treatments. Kiessling's interdisciplinary research combines organic synthesis, polymer chemistry, structural biology, and molecular and cell biology.
Elizabeth Marie Nolan is an American chemist and associate professor at Massachusetts Institute of Technology.
Mei Hong is a Chinese-American biophysical chemist and professor of chemistry at the Massachusetts Institute of Technology. She is known for her creative development and application of solid-state nuclear magnetic resonance (ssNMR) spectroscopy to elucidate the structures and mechanisms of membrane proteins, plant cell walls, and amyloid proteins. She has received a number of recognitions for her work, including the American Chemical Society Nakanishi Prize in 2021, Günther Laukien Prize in 2014, the Protein Society Young Investigator award in 2012, and the American Chemical Society’s Pure Chemistry award in 2003.
Yu-Shan Lin is a computational chemist. She is an associate professor of chemistry at Tufts University in the United States. Her research lab uses computational chemistry to understand and design biomolecules, with topics focusing on cyclic peptides, protein folding, and collagen.
Alexander M. Spokoyny is an American chemist and associate professor in chemistry and biochemistry at UCLA and a faculty member of the California NanoSystems Institute (CNSI). He is currently a department chair of Chemistry and Biochemistry at UCLA.
