Feb 10, 1976

Synthetic flavinyl peptides related to the active site of mitochondrial monoamine oxidase II. Fluorescence properties

M C Falk, D B McCormick


The fluorescence properties of various 8alpha-sulfur-linked flavinyl peptides and related flavin analogues were investigated as the pH solvent, temperature, and flavin concentration were varied. Substitution in the 8alpha position by a thioether-linked peptide brings about a marked quenching of fluorescence (up to 98% in water), a slight bathochromic shift and broadening of the fluorescence emission spectra, and a slight decrease in the fluorescence lifetimes. Oxidation of the thioether function to a sulfone partially releases this fluorescence quenching without further changes in the fluorescence emission spectra. The primary effect on the fluorescence intensity is due to an interaction between the nonbonding electrons of the thioether, the hydrogen-bonding, polar solvent, and the isoalloxazine ring. Dissolving these flavinyl peptides in nonaqueous solvents increases the fluorescence intensity as much as 20-fold. A secondary effect on flavinyl fluorescence can be attributed to a collisional quenching by the vicinal tyrosyl residue within tyrosine-containing flavinyl peptides. The fluorescence properties provide further confirmation of the identity of the synthetic and naturally obtained flavinyl peptides and of the interactio...Continue Reading

Mentioned in this Paper

Structure-Activity Relationship
Monoamine Oxidase [PK]
Fluorescence Spectroscopy
Plasma Protein Binding Capacity
Sulfone [EPC]
Monoamine Oxidase

Trending Feeds


Coronaviruses encompass a large family of viruses that cause the common cold as well as more serious diseases, such as the ongoing outbreak of coronavirus disease 2019 (COVID-19; formally known as 2019-nCoV). Coronaviruses can spread from animals to humans; symptoms include fever, cough, shortness of breath, and breathing difficulties; in more severe cases, infection can lead to death. This feed covers recent research on COVID-19.

Bone Marrow Neoplasms

Bone Marrow Neoplasms are cancers that occur in the bone marrow. Discover the latest research on Bone Marrow Neoplasms here.

IGA Glomerulonephritis

IgA glomerulonephritis is a chronic form of glomerulonephritis characterized by deposits of predominantly Iimmunoglobin A in the mesangial area. Discover the latest research on IgA glomerulonephritis here.

Cryogenic Electron Microscopy

Cryogenic electron microscopy (Cryo-EM) allows the determination of biological macromolecules and their assemblies at a near-atomic resolution. Here is the latest research.

STING Receptor Agonists

Stimulator of IFN genes (STING) are a group of transmembrane proteins that are involved in the induction of type I interferon that is important in the innate immune response. The stimulation of STING has been an active area of research in the treatment of cancer and infectious diseases. Here is the latest research on STING receptor agonists.

LRRK2 & Immunity During Infection

Mutations in the LRRK2 gene are a risk-factor for developing Parkinson’s disease. However, LRRK2 has been shown to function as a central regulator of vesicular trafficking, infection, immunity, and inflammation. Here is the latest research on the role of this kinase on immunity during infection.

Antiphospholipid Syndrome

Antiphospholipid syndrome or antiphospholipid antibody syndrome (APS or APLS), is an autoimmune, hypercoagulable state caused by the presence of antibodies directed against phospholipids.

Meningococcal Myelitis

Meningococcal myelitis is characterized by inflammation and myelin damage to the meninges and spinal cord. Discover the latest research on meningococcal myelitis here.

Alzheimer's Disease: MS4A

Variants within membrane-spanning 4-domains subfamily A (MS4A) gene cluster have recently been implicated in Alzheimer's disease by recent genome-wide association studies. Here is the latest research.