PubMed Health⌕ Search

Biomedical subjects

J R Couch

Publications and source records attributed to J R Couch.

25 records · Page 2Linked to original sources
PubMed1975

Distribution studies of glycine and serine enzymes in chicks.

Day-old broiler type chicks were fed a practical starter ration for three weeks, sacrificed and the D-3-phosphoglycerate dehydrogenase (E.C.1.1.1.s), phosphoserine phosphatase (E.C.3.1.3.3.), glycerate dehydrogenase (E.C.1.1.1.29), hydroxypyruvate-P: glutamate transaminase, serine transhydroxymethylase (E.C.2.1.2.1), and serine dehydratase (E.C.4.2.1.13) enzyme activities were determined in liver, kidney, heart, spleen and brain tissue in evaluating glycine and serine metabolism. The distribution of the various glycine and serine biosynthetic enzymes in the chick tissues studied show that the major portion of glycine and serine synthesis occurs in hepatic tissue via the "phosphorylated pathway".

Alcohol Oxidoreductases↗
PubMed1975

Effect of various concentrations of protein in chick diet upon the metabolic enzymes of glycine and serine.

The effect of feeding low protein diets with and without 2% glycine or 2% L-serine to chicks upon the enzymes concerned in the matabolism of glycine and serine has been determined. D-3-phosphoglycerate dehydrogenase (EC 1.1.1.s), hosphoserine phosphatase (EC 3.1.3.3), and serine hydroxymethyltransferase (EC 2.1.2.1) activities were significantly increased in livers from chicks fed 75% protein diets as compared to liver enzyme activities from chicks fed either 24% chick starter, 2% or 25% protein diets. Phosphoserine phosphatase activity was significantly higher in kidney tissue of chicks fed 75% protein diets. Livers from chicks fed 25% protein diets had a higher activity for D-3-phosphoglycerate dehydrogenase and phosphoserine phosphatase than did those fed chick starter or 2% protein diets. D-3-phosphoglycerate dehydrogenase and phosphoserine phosphatase activities were higher in livers from chicks fed 2% protein, 2% protein + 2% glycine, and 2% protein + 2% L-serine diets when compared to those from chicks fed low protein diets with supplemental methionine or cysteine. Serine dehydratase (EC 4.2.1.13), glycerate dehydrogenase (EC 1.1.1.29) and hydroxypyruvate-P: L-glutamate transaminase activities remained constant in livers from chicks fed all experimental diets. The uric acid concentration was significantly increased in plasma from chicks fed the high protein diets which suggests that D-3-phosphoglycerate dehydrogenase, phosphoserine phosphatase and serine hydroxymethyltransferase activities were increased because of the high requirement for glycine in uric acid formation. The 75% protein diet provided three times as much glycine as the 25% protein diet which may have met the increased need for glycine for uric acid formation.

Alcohol Oxidoreductases↗
PubMed1975

Collaborative study of the determination of available lysine in proteins and feeds.

In the proposed method 1-fluoro-2,4-dinitrobenzene (DNFB) is reacted with the free epsilon-amino groups in protein of form DNFB-epsilon-amino lysine which is stable to acid hydrolysis. The sample is acid hydrolyzed and unavailable lysine is determined with an amino acid analyzer; total lysine is determined on the untreated sample. The available lysine, which was bound by DNFB, is determined by difference. The available lysine has been determined in 3 samples of 44% protein soybean meal by 5 collaborators, following the method outlined. The range for available lysine in reference standard 1 was 2.02-2.14%, in reference standard 2, 2.59-2.73% and in reference standard 3, 0.55-0.91%. The method has been adopted as official first action.

Animal Feed↗