PMID: 727027Jan 1, 1978Paper

A method for improving the nutritional value of food proteins: covalent attachment of amino acids

Advances in Experimental Medicine and Biology
A PuigserverJ R Whitaker


Casein was modified by use of a series of active N-hydroxy-succinimide esters of amino acids in order to study the effects of new covalently linked hydrophobic or hydrophilic groups on its physical and nutritional properties. Tryptophan was used to determine the best conditions for the chemical reaction and to study the stability of the newly formed amide linkage (isopeptide bond). Casein was also modified with glycine, alanine, methionine, N-acetyl-methionine and aspartic acid. In vitro hydrolysis studies using bovine chymotrypsin, pancreatine and rat bile-pancreatic juice indicated that digestibility of the modified casein derivatives was lower than that of the untreated protein. Since solubility was not significantly changed (except for tryptophyl-casein), the decreased in vitro digestibility is probably due to other factors such as steric hindrance as well as decrease in lysine residues available to trypsin in pancreatin and rat pancreatic juice. Plasma amino acid patterns for rats fed a 10% protein diet of highly modified glycyl-casein or methionyl-casein suggest that the epsilon-aminolysyl derivatives are readily hydrolyzed in vivo. This was confirmed by the growth response of rats fed the following isonitrogenous diets (...Continue Reading


Sep 30, 2000·European Journal of Biochemistry·T GiardinaA Puigserver
Oct 1, 1995·International Journal of Biological Macromolecules·M SitohyT Haertlé

Related Concepts

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.

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.

Chronic Fatigue Syndrome

Chronic fatigue syndrome is a disease characterized by unexplained disabling fatigue; the pathology of which is incompletely understood. Discover the latest research on chronic fatigue syndrome here.

Hereditary Sensory Autonomic Neuropathy

Hereditary Sensory Autonomic Neuropathies are a group of inherited neurodegenerative disorders characterized clinically by loss of sensation and autonomic dysfunction. Here is the latest research on these neuropathies.

Spatio-Temporal Regulation of DNA Repair

DNA repair is a complex process regulated by several different classes of enzymes, including ligases, endonucleases, and polymerases. This feed focuses on the spatial and temporal regulation that accompanies DNA damage signaling and repair enzymes and processes.

Glut1 Deficiency

Glut1 deficiency, an autosomal dominant, genetic metabolic disorder associated with a deficiency of GLUT1, the protein that transports glucose across the blood brain barrier, is characterized by mental and motor developmental delays and infantile seizures. Follow the latest research on Glut1 deficiency with this feed.

Separation Anxiety

Separation anxiety is a type of anxiety disorder that involves excessive distress and anxiety with separation. This may include separation from places or people to which they have a strong emotional connection with. It often affects children more than adults. Here is the latest research on separation anxiety.

KIF1A Associated Neurological Disorder

KIF1A associated neurological disorder (KAND) is a rare neurodegenerative condition caused by mutations in the KIF1A gene. KAND may present with a wide range and severity of symptoms including stiff or weak leg muscles, low muscle tone, a lack of muscle coordination and balance, and intellectual disability. Find the latest research on KAND here.

Regulation of Vocal-Motor Plasticity

Dopaminergic projections to the basal ganglia and nucleus accumbens shape the learning and plasticity of motivated behaviors across species including the regulation of vocal-motor plasticity and performance in songbirds. Discover the latest research on the regulation of vocal-motor plasticity here.