Nucleotides

Biological role of nucleotides

Nucleotides participate in nearly all biochemical processes important for growth: ATP is an universal energy currency in all biological systems particularly abundant in muscles. Adenine nucleotides are components of three major coenzymes, NAD+, FAD, and CoA. Being building blocks of the nucleic acids (DNA and RNA), nucleotides are particularly required for actively proliferating cells of the immune system or intestinal epithelium.

PROLIFERATION

dNTPs are building blocks of DNA, required for rapidly proliferating cells of the immune system, intestinal epithelium and unicellular microorganisms.

PROTEIN SYNTHESIS

NTPs are building blocks of tRNA, rRNA and mRNA involved in protein synthesis and cell growth.

ENERGY

ATP is an universal energy currency in all biological systems particularly abundant in muscles.

COENZYME

Adenine nucleotides are components of three major coenzymes, NAD+, FAD, and CoA involved in numerous biosynthesis pathways.

NEOGLYCOGENESIS

UDP-activated glucose is required for glycogen synthesis in liver and skeletal muscles.

PHOSPHOLIPIDS

CDP-activated choline is involved in the biosynthesis of phospholipids particularly in the neuronal membranes.

TASTE

GMP and IMP nucleotides are flavor compounds that drastically enhance the umami taste of glutamate and improve the palatability of the food with reduced salt.

LIGHT REFLECTANCE

Multilayer stacks of guanine crystals are responsible for the metallic luster of fish skin.

Nucleotides: 'conditionally essential' nutrients

Since nucleotides can be synthesized de novo and recycled through salvage pathways, they are considered as semi-essential nutrients.

De novo pathway of AMP and GMP biosynthesis is long and energy consuming process (6 moles of ATP per each mole of nucleotide produced).

Purine salvage produces GMP or AMP directly from nucleosides and bases in one step.

However, rapidly growing tissues or proliferating immune cells during infection have higher requirements for nucleotides that cannot be met only through de novo synthesis. In these cases, nucleotides become "essential" nutrients that can be provided with aliments and assimilated through shorter salvage pathways (2 steps) compared to de novo synthesis (9 steps for purines). Because of the fundamental importance of nucleotides for growth, development and immune health nucleotides are now widely recognized as “conditionally essential” nutrients.

DIETARY NUCLEOTIDES : EFFECT OF SUPPLEMENTATION

INFANT FORMULA

After being identified as one of the components of human milk enhancing immune function, 5’ NMP have been added to infant formulas and have beneficial effects on early infant growth, small intestinal growth and development, intestinal microflora, and immune function.

AQUACULTURE

Nucleotides supplementation of aquafeed has been shown to improve growth performance of fish at early stages of development; to enhance fish immune response and resistance against pathogens; by improving osmoregulation.

PETFOOD

Dietary nucleotides supports the natural growth process and improve the immune response of puppies and young animals at weaning.

DIETARY NUCLEOTIDES : SOURCES

YEAST EXTRACT

Yeasts are naturally rich in RNA and are known as an excellent source of both purine and pyrimidine nucleotides for decades. Prior to RNA hydrolysis to NMP, yeast phosphatases must be inactivated or separated from RNA. Palatability of yeast extracts can be further improved by enzymatic conversion of AMP to IMP.

FISHMEAL

Fish meal is a natural source of nucleotides IMP, inosines and hypoxanthine issued from post-mortem breakdown of fish muscle ATP. Since fishmeal is a limited natural resource, considerable efforts are done toward its replacement by alternative products.

SCP producers:

Edible unicellular microorganisms, used in the production of single-cell proteins are also rich in RNA and can be used also excellent source of nucleotides.