Related Experiment Video
Updated: Aug 17, 2026

Modifying Levels of Maternal Dietary Folic Acid or Choline to Study the Impact of Deficiencies on Offspring Health Outcomes
Published on: June 28, 2024
Dietary S-methylmethionine, a component of foods, has choline-sparing activity in chickens
Nathan R Augspurger1, Colleen S Scherer, Timothy A Garrow
1Department of Animal Sciences, Division of Nutritional Sciences, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA.
Abstract:
Acid hydrolysis of dehulled soybean meal (SBM) and corn gluten meal (CGM) followed by chromatographic amino acid analysis (ninhydrin detection) revealed substantial quantities of S-methylmethionine (SMM) in both ingredients (1.65 g SMM/kg SBM; 0.5 g SMM/kg CGM). Young chicks were used to quantify the methionine- (Met) and choline-sparing bioactivity of crystalline L-SMM, relative to L-Met and choline chloride standards in 3 assays. A soy isolate basal diet was developed that could be made markedly deficient in Met, choline, or both. When singly deficient in choline or in both choline and Met, dietary SMM addition produced a significant (P < 0.01) growth response. In Assay 2, dietary SMM did not affect (P > 0.10) growth of chicks fed a Met-deficient, choline-adequate diet. A standard-curve growth assay revealed choline bioactivity values (wt:wt) of 14.2 +/- 0.8 and 25.9 +/- 5.1 g/100 g SMM based on weight gain and gain:food responses, respectively. A fourth assay, using standard-curve procedures, showed choline bioactivity values of 20.1 +/- 1.1 and 22.9 +/- 1.7 g/100 g SMM based on weight gain and gain:food responses, respectively. It is apparent that SMM in foods and feeds has methylation bioactivity, and this has implications for proper assessment of dietary Met and choline requirements as well as their bioavailability in foods and feeds.
Related Concept Videos
Direct-Acting Cholinergic Agonists: Pharmacokinetics
Cholinesterases: Distribution and Function
Direct-Acting Cholinergic Agonists: Therapeutic Uses
Indirect-Acting Cholinergic Agonists: Mechanism of Action
Reversible inhibitors like edrophonium bind to a specific part of the enzyme called the anionic catalytic site. They form noncovalent bonds, which means they are not strongly attached to the enzyme. This creates a temporary and less stable enzyme–inhibitor complex, leading to...
Synthesis of Phosphatidylcholine in the ER Membrane
The major components of all eukaryotic cell...
Direct-Acting Cholinergic Agonists: Chemistry and Structure-Activity Relationship
The direct-acting...

