CITRATE SYNTHASE

Description

Citrate synthase is a key mitochondrial enzyme that utilizes acetyl-CoA and oxaloacetate to form citrate and is investigated for its role in Alzheimer's disease[1]. Citrate synthase activity was measured in muscle tissue using spectrophotometry to estimate mitochondrial content, and reductions in citrate synthase and citrate can be used to develop an animal model for the silent phase of Alzheimer's disease[1][2].

Chemical Properties

This product is acidic mucopolysaccharide obtained from the cartilage tissue of animals, it is off-white amorphous powder, slightly salty; odorless; moisture-inducing; aqueous solution is viscous, and does not coagulate when heated. Soluble in water, insoluble in ethanol, acetone or glacial acetic acid. The injection solution is a sterilized aqueous solution of chondroitin sulfate sodium salt, which is almost colorless and clear liquid. Chondroitin sulfate is divided into A, B, C, D, E, F, H and so on according to the difference of its chemical composition and structure, among which B, F, H molecules contain L-aidu saccharide.B is not degraded by vitreous acid enzyme, and the color reaction is different from that of A. B is known as dermatophyte sulphate, which is more common in the skin. Medicinal chondroitin sulfate is extracted from animal cartilage, mainly a mixture of A, C and various chondroitin sulfates. It has the function of clarifying lipids and improving the detoxification of the body, and also has the function of diuretic and analgesic, etc. It is effective for collagenous disorders, and also effective for the hearing impairment caused by streptomycin.

Uses

Citrate Synthase from porcine heart has been used:

• to inject newt egg for determining its importance in egg activation at fertilization
• in the preparation of reaction mix to determine pyruvate carboxylase enzyme activity
• to examine whether it can induce a [Ca²⁺]increase and egg activation in unfertilized eggs

Definition

An enzyme that catalyzes the condensation of oxaloacetic acid and acetyl-CoA to yield citric acid and coenzyme A.

Biochem/physiol Actions

Citrate synthase catalyses the conversion of citrate to acetyl-CoA in the presence of coenzyme-A with the release of H2O and oxaloacetate. The enzyme has a molecular weight of 85 kDa and a pI of 6.1-6.6. It is inhibited by fluoroacetyl-CoA, palmitoyl-CoA, and citroyl-CoA. It is also inhibited when it is acetylated by acetic anhydride or iodinated by iodine.

References

[1] Chhimpa, N., Singh, N., Puri, N., & Kayath, H. P. (2023). The Novel Role of Mitochondrial Citrate Synthase and Citrate in the Pathophysiology of Alzheimer's Disease. Journal of Alzheimer's Disease, 94 s1, S453–S472. https://doi.org/10.3233/JAD-220514
[2] Stremming, J., Chang, E. I., Knaub, L. A., Armstrong, M. L., Baker, P. R., Wesolowski, S. R., Reisdorph, N., Reusch, J. E. B., & Brown, L. D. (2022). Lower citrate synthase activity, mitochondrial complex expression, and fewer oxidative myofibers characterize skeletal muscle from growth-restricted fetal sheep. American Journal of Physiology. Regulatory, Integrative and Comparative Physiology, 322 3, R228–R240. https://doi.org/10.1152/ajpregu.00222.2021