Glycine

Glycine
Name	Glycine
IUPAC name	Aminoethanoic acid
Formula	NH2CH2COOH
Molar mass	75.07 g/mol
Density	1.17 g/cm3 (solid)
Melting point	233–238 °C (decomposes)
PKa1	2.35
PKa2	9.78

Glycine is the smallest proteinogenic amino acid, widely present in Nature and central to biochemistry and molecular biology research. It functions as a building block of proteins and a key metabolite in one-carbon metabolism, neurotransmission, and biosynthetic pathways studied across medicine, pharmacology, and industrial chemistry. Its simple structure and versatile chemistry make it a frequent subject in experimental work at institutions like Harvard University, Max Planck Society, and National Institutes of Health laboratories.

Structure and properties

Glycine's chemical structure is the amino acid backbone NH2–CH2–COOH; crystalline glycine appears in polymorphs studied by researchers at Royal Society-affiliated journals and groups such as American Chemical Society investigators. The zwitterionic form predominates at physiological pH, a topic explored in spectroscopic studies by teams at Massachusetts Institute of Technology, California Institute of Technology, and University of Cambridge. Physical properties (melting point, solubility) are cataloged in databases maintained by IUPAC, NIST, and the European Chemicals Agency, and its conformational preferences inform protein-folding models developed at European Molecular Biology Laboratory and Scripps Research. Crystallography of glycine-containing peptides has been reported by labs at Stanford University, University of Oxford, and ETH Zurich.

Biosynthesis and metabolism

Endogenous glycine synthesis is integrated with pathways investigated by researchers at Rockefeller University and Weizmann Institute of Science, including conversion from serine via serine hydroxymethyltransferase characterized in studies at Johns Hopkins University and Imperial College London. Mitochondrial glycine cleavage system components were elucidated by teams at University of Pennsylvania and University of Tokyo, linking glycine to folate-mediated one-carbon units central to work by Linus Pauling-era biochemical programs and contemporary groups at Karolinska Institutet. Metabolic flux analyses employing techniques from Cold Spring Harbor Laboratory, Lawrence Berkeley National Laboratory, and EMBL-EBI detail glycine’s role in purine biosynthesis, heme synthesis, and creatine pathways investigated at Mayo Clinic and Cleveland Clinic.

Biological functions and physiological roles

Glycine acts as an inhibitory neurotransmitter in the spinal cord and brainstem; electrophysiology studies from labs at University College London, McGill University, and Columbia University have characterized glycine receptors and synaptic clearance mechanisms involving transporters studied at Yale University and Duke University. Its role in collagen structure is central to connective tissue research at Johns Hopkins Hospital, Mount Sinai Hospital, and Karolinska University Hospital; mutations affecting glycine positions underlie hereditary disorders analyzed in clinics at Great Ormond Street Hospital and genetic centers like Broad Institute. Glycine participates in glutathione synthesis, impacting oxidative stress responses studied by investigators at National Cancer Institute and metabolic disease research at NIH Clinical Center. Clinical trials at institutions including University of California, San Francisco, M.D. Anderson Cancer Center, and Vanderbilt University have explored glycine supplementation effects on sleep, schizophrenia, and metabolic syndromes.

Industrial and pharmaceutical applications

Glycine is produced at scale by chemical firms and biotech companies supplying markets tracked by World Health Organization and FDA-regulated industries; manufacturers include multinational corporations with facilities audited by European Medicines Agency and regulatory oversight similar to pharmaceuticals reviewed at EMA and FDA. It serves as a feedstock for herbicide formulation research at Syngenta-adjacent labs, as an intermediate in flavor enhancer production studied by food science programs at Nestlé Research Center and Mondelez International collaborations, and as a buffering agent in bioprocessing at biopharma sites like Pfizer and Roche. Pharmaceutical development involving glycine derivatives has been pursued in clinical pipelines at Johnson & Johnson, Novartis, and academic spinouts from University of Cambridge and MIT.

Analytical methods and detection

Quantification of glycine in biological samples uses chromatographic and spectrometric techniques developed by teams at Thermo Fisher Scientific, Agilent Technologies, and instrument groups at Bruker; methods include HPLC with derivatization protocols refined at University of Michigan, University of Toronto, and Johns Hopkins University Hospital. Mass spectrometry workflows applied in metabolomics are standardized in consortia such as Metabolomics Society with validation efforts from NIH-funded centers and core labs at European Bioinformatics Institute. Nuclear magnetic resonance spectroscopy studies of glycine-containing peptides have been performed at facilities including Bruker Biospin centers, ISIS Neutron and Muon Source, and university NMR cores at UCLA and University of Wisconsin–Madison.

Safety, toxicity, and environmental impact

Glycine has low acute toxicity and is listed in safety data formats used by OSHA and EPA; risk assessments by regulatory bodies such as European Chemicals Agency guide workplace exposure limits employed by industrial sites like BASF and Dow Chemical Company. Environmental fate studies at USGS and EPA laboratories track biodegradation in wastewater treatment plants monitored by municipal agencies including New York City Department of Environmental Protection and Metropolitan Water Reclamation District of Greater Chicago. Clinical safety evaluations conducted at centers such as Cleveland Clinic and Beth Israel Deaconess Medical Center inform therapeutic dosing guidelines reviewed by FDA panels.

Category:Amino acids