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E Storm

Publications and source records attributed to E Storm.

At least 19 recordsLinked to original sources
PubMed1984

The nutritive value of rumen micro-organisms in ruminants. 4. The limiting amino acids of microbial protein in growing sheep determined by a new approach.

Four experiments were carried out to identify and quantify the limiting amino acids (AA) in rumen microbial protein (RMP). A method was developed which involved first, an assessment of the efficiency of utilization of absorbed AA-nitrogen (U) of RMP, defined as the retention of AA-N from RMP absorbed from the small intestine, and second, addition of a mixture of AA similar to the absorbed AA profile in a quantity defined by the U of RMP and equal to (1-U)/U. Third, it involved removal of each AA in turn and measurement of the resultant N retention. Using this approach it was possible to calculate both the order and extent of AA limitations in RMP. Apart from methionine which was found to be the most limiting AA, only lysine, arginine and histidine reduced N retention when omitted, and accordingly only these AA were limiting in RMP. The method is discussed in detail and the amount of supplementary AA required to utilize RMP fully is calculated.

Amino Acids↗
PubMed1983

The nutritive value of rumen micro-organisms in ruminants. 1. Large-scale isolation and chemical composition of rumen micro-organisms.

A method is described whereby a large quantity of rumen microbial dry matter of high purity was isolated from whole rumen contents obtained from abattoirs, by means of a continuous process of one filtration through four sieves followed by three differential centrifugations. The contents of ash, carbohydrate, lipid, nitrogen, RNA, DNA and individual amino acids of the three centrifugal fractions are given and compared with values summarized from more than sixty published reports on the chemical composition of rumen micro-organisms isolated from both whole rumen contents and pure cultures. The amino acid composition of isolated rumen micro-organisms, in particular that of the bacteria, was found to be remarkably constant.

Amino Acids↗
PubMed1983

The nutritive value of rumen micro-organisms in ruminants. 2. The apparent digestibility and net utilization of microbial N for growing lambs.

Four experiments were conducted with eighteen lambs sustained entirely by intragastric nutrition at gross energy inputs varying from 430 to 860 kJ/kg live weight0.75 (W0.75). Isolated rumen micro-organisms (RMO) were infused into the abomasum in quantities varying from 0 to 2 g digestible N/kg W0.75 to assess the increase in N balance as a result of increasing RMO input when N was limiting. The over-all utilization of N from RMO (RMO-N) could be described by the equation y = 0.543 X -0.457, residual SD = 0.037, where y is the N balance and X is the abomasal input of RMO-N, both expressed in g/kg W0.75. Thus the coefficient of efficiency of utilization of infused RMO-N was 0.543 (SE 0.008). The coefficient of efficiency of utilization of RMO-N truly digested (i.e. the biological value) was 0.659 (SE 0.015). The RMO-N input (mean with SE) at N equilibrium was 0.843 (0.009) g/kg W0.75. The true digestibility of RMO-N was 0.813 (0.004). The urinary N excretion when no N was infused was 0.329 (0.008) g/kg W0.75 and the N excreted via the faeces with zero N input was 0.036 (0.009) g/kg W0.75.

Amino Acids↗
PubMed1983

The nutritive value of rumen micro-organisms in ruminants. 3. The digestion of microbial amino and nucleic acids in, and losses of endogenous nitrogen from, the small intestine of sheep.

An experiment was conducted with three sheep maintained entirely by intragastric nutrition to estimate the digestibility of isolated individual constituents and amino acids (AA) of rumen micro-organisms (RMO) in the small intestine. Five levels of RMO were infused into the abomasum. The apparent and true disappearance of the individual components were measured by regression of abomasal input on the passage at the ileum. The true digestibility values of N, AA-N, DNA and RNA were 0.82, 0.85, 0.81 and 0.87, respectively. The digestibility of individual AA varied between 0.80 and 0.88, the only exceptions being diaminopimelic acid (0.37), histidine (0.68) and cystine (0.73), which were significantly lower than the average (0.847). The endogenous components in the ileal fluid in sheep given protein-free infusions, expressed in mg/kg live weight0.75 per d, were total N 42 and AA-N 20.

Amino Acids↗
PubMed1977

Purification and some properties of the protein component of tissue thromboplastin from human brain.

The protein component of tissue thromboplastib (Factor III) from human brain was purified by extraction of a microsomal fraction with sodium deoxycholate, gel filtration of the extract on Sephadex G-100 and preparative polyacrylamide-gel electrophoresis in the presence of sodium dodecyl sulphate. The product, apoprotein III, was homogeneous by anayltical polyacrylamide-gel electrophoresis, and it induced monospecific antibodies in rabbits and goat as shown by immunodiffusion and immunoelectrophoresis. Amino acid- and carbohydrate-analysis data for apoprotein III are presented. The carbohydrate moiety of the protein consists of fucose, mannose, galactose, N-acetylglucosamine and N-acetylneuraminate, amounting to a total content of 6.3g/100g. The apoprotein alone had no procoagulant activity. When Factor III was reconstituted by combining the pure apoprotein with a purified lipid fraction from the deoxycholate extract of crude Factor III, a high and optimal procoagulant activity was obtained at a phospholipid/protein ratio of 1.1g/g. Phosphatidylethanolamine alone had a weak but significant ability to restore activity, whereas phosphatidylcholine and phosphatidylserine separately had almost none. Two-component mixtures were on average more effective, and three-component mixtures far more effective, than the single phospholipids. The inclusion of a small amount of phosphatidylserine was very important for high activity.

Amino Acids↗
PubMed1977

Localization of tissue thromboplastin in the human brain.

Monospecific antisera against the purified protein component of tissue thromboplastin (apoprotein-III) from human brain have been raised in goats and rabbits. The antisera neutralized tissue thromboplastin prepared from brain, thyroid gland and pulmonary tissue, indicating that apoproteins in the various preparations cross-reacted immunologically and therefore were similar or identical. Comparison of the activities of tissue thromboplastin preparations from 34 different areas of the brain demonstrated a characteristic distribution pattern and a wide range of activities. White and grey matter from the same areas had similar activities. Bulbus and tractus olfactorius, medulla oblongata, corpus pineale, hippocampus and hypothalamus contained 160-270% of the average activity, whereas cerebellum globus pallidus, nucleus ruber and substantia nigra contained 30-60%. The distinct distribution pattern was unrelated to tissue vascularization, and may suggest that apoprotein-III could serve other functions, apart from the coagulation of blood. The predominance in phylogenetically older brain regions would suggest that it represents a primitive or fundamental feature.

Animals↗
PubMed1975

The interaction of the protein and phospholipid components of tissue thromboplastin (factor III) with the factors VII and X.

The protein and phospholipid components of tissue thromboplastin have been isolated and their interactions with factor VII and factor Xa have been studied by gel filtration, centrifugation and heat inactivation. As expected, the phospholipid fraction bound both factors in the presence of Ca2+. No evidence for an interaction of apoprotein III with factor VII or Xa was obtained.

Apoproteins↗
PubMed1969

The adenosine triphosphate inhibition of the pyruvate kinase reaction and its dependence on the total magnesium ion concentration.

1. The effects of ATP, PP(i) and EDTA on the skeletal-muscle pyruvate kinase reaction at various concentrations of magnesium (where ;magnesium' refers to total Mg(2+), both free and in the form of complexes) were investigated. The reaction rate was determined as the amount of pyruvate formed in a recorded time of incubation. 2. At 44mm-magnesium the K(m) values for ADP and phosphoenolpyruvate were unaltered by the presence of ATP up to 6.8mm in systems buffered with either tris-hydrochloric acid or glycylglycine-sodium hydroxide, but the K(m) values were different in these systems. The K(m) for one substrate was independent of the concentration of the second substrate. 3. At 10mm-magnesium in the tris-hydrochloric acid system ATP inhibited the reaction competitively with respect to ADP and phosphoenolpyruvate. In the glycylglycine-sodium hydroxide system the inhibition appeared to be non-competitive. At 10mm-magnesium the K(m) values were lower than at 44mm-magnesium and dependent on the system used. 4. In the tris-hydrochloric acid system the reaction rate rose with increasing magnesium concentration up to a maximum at a concentration 10-20 times that of ADP. Further increase inhibited the reaction and at 44mm-magnesium the rate was 25-50% of its maximum. This inhibition paralleled that produced by increasing trimethylammonium chloride concentrations and was not due to a specific effect of the Mg(2+) ion. 5. In the presence of 6.8mm-ATP no reaction occurred below 4-6mm-magnesium, and further increase apparently abolished the inhibition as the reaction rate increased and became equal to those obtained in the absence of ATP at 10-25mm-magnesium. Further increase in magnesium concentration gave reaction rates that were slightly higher in the presence of ATP than in its absence. The maximal rate in the presence of ATP was distinctly lower than in its absence. When 6.8mm-PP(i) or 6.8mm-EDTA was present the variations in reaction rate with rising magnesium concentration were similar to that obtained in the presence of ATP below 6-8mm-magnesium but further increase in the magnesium concentration resulted in an increase in the rate up to a maximum comparable with that of the control. The effect of pure chelation was thus a displacement of the reaction maximum to higher magnesium concentrations without changing the maximal rate. When correction had been made for this effect, ATP gave inhibition at 44mm-magnesium that was competitive with respect to ADP (K(i) 2.1x10(-2)m). This degree of inhibition is far less than was reported earlier and its importance for the mechanism of the pyruvate kinase reaction is discussed.

Adenine Nucleotides↗