Dec 1, 1975

Spin-labelled phosphofructokinase. A simple and direct approach to the study of allosteric equilibria under near-physiological conditions

European Journal of Biochemistry
R JonesI O Walker


Rabbit muscle phosphofructokinase, spin-labelled at its most reactive thiol group, has an electron spin resonance spectrum which is very sensitive to the binding of substrates and allosteric effectors. The spectral changes have been interpreted in terms of a concerted allosteric transition between two conformational states with non-exclusive binding of effectors. On this basis MgATP, fructose 6-phosphate plus ATP, and NH+4ions behave as potent positive effectors, inorganic phosphate, sulphate, AMP, fructose 6-phosphate and fructose 1,6-bisphosphate are less potent activators, and free ATP and H+ions are negative effectors, in agreement with the kinetic behaviour, but citrate behaves anomalously. In addition, the allosteric equilibrium can be displaced towards the inhibited state by selectively modifying two further thiol groups. Strong positive cooperativity occurs under suitable conditions with ATP, metal-ATP and fructose 6-phosphate. Biphasic changes of conformation, attributed to binding at the catalytic and inhibitory sites, have been observed in titrations with ATP. The differentiation of the two ATP binding sites arises in the presence of fructose 6-phosphate because of a distinct concerted effect on conformation between ...Continue Reading

  • References23
  • Citations6


Mentioned in this Paper

Allosteric Site
Adenosine Triphosphate, Magnesium Salt
Citrate Measurement
Phosphate Measurement
Sulfhydryl Compounds
Plasma Protein Binding Capacity
Cell Differentiation Process

About this Paper

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.

Synthetic Genetic Array Analysis

Synthetic genetic arrays allow the systematic examination of genetic interactions. Here is the latest research focusing on synthetic genetic arrays and their analyses.

Autism: Motor Learning

A common feature of autism spectrum disorder (ASD) is the impairment of motor control and learning, consistent with perturbation in cerebellar function. Find the latest research on ASD and motor learning here.

Position Effect Variegation

Position Effect Variagation occurs when a gene is inactivated due to its positioning near heterochromatic regions within a chromosome. Discover the latest research on Position Effect Variagation here.

Sexual Dimorphism in Neurodegeneration

There exist sex differences in neurodevelopmental and neurodegenerative disorders. For instance, multiple sclerosis is more common in women, whereas Parkinson’s disease is more common in men. Here is the latest research on sexual dimorphism in neurodegeneration

Protein Localization in Disease & Therapy

Localization of proteins is critical for ensuring the correct location for physiological functioning. If an error occurs, diseases such as cardiovascular, neurodegenerative disorders and cancers can present. Therapies are being explored to target this mislocalization. Here is the latest research on protein localization in disease and therapy.

Genetic Screens in Bacteria

Genetic screens can provide important information on gene function as well as the molecular events that underlie a biological process or pathway. Here is the latest research on genetic screens in bacteria.

Head And Neck Squamous Cell Carcinoma

Squamous cell carcinomas account for >90% of all tumors in the head and neck region. Head and neck squamous cell carcinoma incidence has increased dramatically recently with little improvement in patient outcomes. Here is the latest research on this aggressive malignancy.

Artificial Intelligence in Cardiac Imaging

Artificial intelligence (ai) techniques are increasingly applied to cardiovascular (cv) medicine in cardiac imaging analysis. Here is the latest research.