Lecithinase Activity in the Muscle of Rainbow Trout (Salmo gairdnerii)

1966 ◽  
Vol 23 (2) ◽  
pp. 207-220 ◽  
Author(s):  
E. Bilinski ◽  
R. E. E. Jonas
Keyword(s):  
Rainbow Trout ◽  
Lateral Line ◽  
White Muscle ◽  
Radioactive Tracer ◽  
Enzymic Activity ◽  
The Other ◽  
Level Of Activity ◽  
Hydrolysis Of ◽  
Trout Muscle

A radioactive tracer procedure for determination of the various lecithin hydrolysing enzymes, at a low level of activity, is described. The procedure involves the use of phospholipids labeled with C14in the choline moiety as substrate and the measurement of radioactivity released in the various products of hydrolysis. The pathway of lecithin catabolism in trout muscle is via glycerylphosphorylcholine. Of the other possible routes of breakdown of lecithin, there was no indication for the activity of phospholipase C or D. Greater enzymic activity was present in the lateral line muscle than in the white muscle. The enzyme which is responsible for hydrolysis of lecithin to glycerylphosphorylcholine showed optimum activity in the vicinity of pH 7 did not require Ca++for activity and was partially inhibited by Hg++. A lysolecithinase, showing similar properties, but having a comparatively greater activity, was also present in trout muscle.

Phospholipase A Activity in Rainbow Trout Muscle

1967 ◽  
Vol 24 (12) ◽  
pp. 2555-2562 ◽  
Author(s):  
R. E. E. Jonas ◽  
E. Bilinski
Keyword(s):  
Rainbow Trout ◽  
Lateral Line ◽  
Silicic Acid Column ◽  
Fish Muscle ◽  
Enzymic Activity ◽  
Phospholipase A ◽  
Experimental Conditions ◽  
Optimum Ph ◽  
Layer Chromatography ◽  
Trout Muscle

A sensitive method for assay of phospholipase A activity in the lateral line muscle of rainbow trout is described. 14C labelled lecithin was converted to lysolecithin by the enzyme. Unreacted lecithin was removed by silicic acid column chromatography and the lysolecithin recovered by thin-layer chromatography. The amount of lysolecithin formed was between 43 and 87 mμmoles per gram lateral line muscle per hour under the experimental conditions. The amount formed was directly proportional to time between half an hour and 4 hr and the optimum pH was found to be approximately 7.5. The results are discussed in relation to the enzymic activity previously demonstrated in fish muscle.

Oxidation of Lactate to Carbon Dioxide by Rainbow Trout (Salmo gairdneri) Tissues

1972 ◽  
Vol 29 (10) ◽  
pp. 1467-1471 ◽  
Author(s):  
E. Bilinski ◽  
R. E. E. Jonas
Keyword(s):  
Rainbow Trout ◽  
White Muscle ◽  
Salmo Gairdneri ◽  
Oxidative Decarboxylation ◽  
Complete Oxidation ◽  
Exchange Reactions ◽  
Fish Tissues ◽  
Tissue Slices ◽  
Lactate Oxidation ◽  
Level Of Activity

A comparative study on the ability of various fish tissues to carry out different stages of lactate oxidation was conducted with rainbow trout (Salmo gairdneri). Rate of oxidation of Na-L-lactate-1-14C (5 mM) and Na-L-lactate-3-14C (5 mM) by tissue slices from white muscle, red lateral line muscle, heart, liver, kidney, and gills was determined at 15 C by measuring the formation of 14CO2. In all tissues the liberation of 14CO2 was considerably higher with lactate-1-14C than with lactate-3-14C. Liver was the most active tissue for oxidation of lactate-1-14C (2805 mμmoles/g wet tissue/hr at 15 C) and gills for oxidation of lactate-3-14C (556 mμmoles/g wet tissue/hr at 15 C). With both substrates activity in the white muscle was very limited, whereas other tissues had an intermediate level of activity. The results suggest that, in trout, the catabolism of lactate may take place through oxidative decarboxylation of pyruvate and that liver plays an important role in such a process. It appears also that complete oxidation of lactate may be of significance in supplying energy for the exchange reactions in gills.

Glycerylphosphorylcholine and Related Compounds in Rainbow Trout Muscle Stored at −4 C

1967 ◽  
Vol 24 (2) ◽  
pp. 273-280 ◽  
Author(s):  
R. E. E. Jonas ◽  
E. Bilinski
Keyword(s):  
Fatty Acids ◽  
Rainbow Trout ◽  
General Trend ◽  
Fish Muscle ◽  
Enzymic Activity ◽  
Salmo Gairdneri ◽  
Threefold Increase ◽  
Free Choline ◽  
Related Compounds ◽  
Trout Muscle

Glycerylphosphorylcholine in rainbow trout (Salmo gairdneri) muscle stored at −4 C showed an increase from 36 μmoles/100 g in fresh muscle to 46 μmoles/100 g after 2 weeks. During longer periods of storage an approximately threefold increase in concentration took place, reaching 123 and 105 μmoles/100 g muscle after 9 and 17 weeks. Liberation of free choline was found to take place after 6 weeks of storage. There was very little change in the concentration of choline after 6 weeks storage when the value was approximately 100 μmoles/100 g. The release of free fatty acid during cold storage showed a general trend, which was similar to the formation of glycerylphosphorylcholine, but quantitatively the changes were more pronounced. Free fatty acids amounted to 45 μmoles/100 g in fresh muscle and rose to a plateau of approximately 1200 μmoles/100 g after 9 weeks of storage. The results are discussed in relation to the enzymic activity present in fish muscle.

Lysosomal Triglyceride Lipase from the Lateral Line Tissue of Rainbow Trout (Salmo gairdneri)

1971 ◽  
Vol 28 (7) ◽  
pp. 1015-1018 ◽  
Author(s):  
E. Bilinski ◽  
R. E. E. Jonas ◽  
Y. C. Lau
Keyword(s):  
Rainbow Trout ◽  
Lateral Line ◽  
Lysosomal Enzymes ◽  
Lipolytic Activity ◽  
Mitochondrial Fraction ◽  
Maximum Activity ◽  
Salmo Gairdneri ◽  
Acid Lipase ◽  
Triton X ◽  
Hydrolysis Of

An acid lipase active toward tripalmitin and having the characteristics of lysosomal enzymes was shown to occur in the red lateral line tissue of rainbow trout (Salmo gairdneri). The enzyme showed maximum activity at pH 4–4.5. Triton X-100 (0.2–2.0%) strongly stimulated the activity of the acid lipase, but it inhibited markedly the lipolytic activity above pH 7. NaF (20 mM) and Na-p-chloromercuriphenyl-sulfonate (1 mM) partially inhibited the acid lipase. Fractionation of the total homogenate by differential centrifugation in 0.25 M sucrose showed that the acid lipase was present at highest concentration in the light mitochondrial fraction. Palmitic acid and dipalmitin were the two main products of hydrolysis of tripalmitin.

A micromethod for quantitative determination of iodoamino acids in thyroglobulin

1997 ◽  
Vol 153 (1) ◽  
pp. 99-104 ◽  
Author(s):  
N Baudry ◽  
B Mallet ◽  
P J Lejeune ◽  
L Vinet ◽  
J L Franc
Keyword(s):  
Acetic Acid ◽  
Enzymatic Hydrolysis ◽  
Mobile Phase ◽  
High Sensitivity ◽  
The Other ◽  
Reverse Phase Hplc ◽  
Reverse Phase ◽  
Spectrophotometric Detection ◽  
Hydrolysis Of

Abstract We describe a new method for quantification of iodoamino acids after enzymatic hydrolysis of thyroglobulin. The procedure involves separation of monoiodotyrosine (MIT), diiodotyrosine, tri-iodothyronine and thyroxine by reverse phase HPLC with a Vydac C18 stationary phase and a mobile phase of water–acetonitrile–acetic acid. The separation is monitored by sensitive spectrophotometric detection through a 96-well microplate system based on the catalytic Sandell–Kolthoff reaction of iodide on the oxidation of arsenic(III) by cerium(IV). This new microassay is particularly convenient because of its high sensitivity and its rapidity (less than 2 h). It can detect 1 pmol MIT and 0·5 pmol of the other three iodoamino acids with a recovery higher than 96%. Moreover, the 96-well microplate system allows many samples to be tested simultaneously and avoids the use of radiolabeled iodine. Journal of Endocrinology (1997) 153, 99–104

scholarly journals The optimum temperature of salicin hydrolysis by enzyme action is independent of the concentrations of substrate and enzyme

1914 ◽  
Vol 87 (594) ◽  
pp. 245-254 ◽  
Keyword(s):  
Enzyme Concentration ◽  
The Other ◽  
Optimum Temperature ◽  
Constant Concentration ◽  
M 10 ◽  
The One ◽  
The Given ◽  
Hydrolysis Of ◽  
Preliminary Determination

The object of the present investigation is to ascertain the influence, if any, on the optimum temperature—temperature of greatest activity—of an enzyme, of the concentration, on the one hand, of the substrate, and, on the other, of the enzyme. The investigation, involving two variables, presents three cases for consideration, according as the concentration of the substrate and the concentration of the enzyme are varied separately or together. An account is given of the results obtained with the enzyme or enzymic function, present in sweet-almond emulsin, which hydrolyses the glucoside salicin with the production of equimolecular quantities of glucose and saligenin. A commercial specimen of Merck’s emulsin was used, while the purity of the salicin employed was ascertained by determining its melting point (200-5°) and its optical activity ([ α ] 21 D = -62·7°). The successive stages in the inquiry may be briefly summarised as follows: (1) a preliminary determination of the activity of the specimen under certain chosen conditions as regards the concentration of the substrate, the temperature, and the duration of the experiment; (2) a preliminary determination of the optimum temperature with the quantity of enzyme found capable of producing 50 per cent, hydrolysis of the substrate under the above conditions; (3) a determination of the activity curves of the enzyme at the temperature thus found, in an action of the same duration for five concentrations of the substrate M/5, M/10, M/15, M/30, and M/50; (4) a determination of the optimum temperature of the enzyme for each of the five concentrations of the substrate in presence of a constant enzyme concentration ; (5) a determination of the optimum temperature of the enzyme for each of the five concentrations of the substrate with quantities of enzyme indicated by the activity curves as capable of producing 70 per cent, hydrolysis of the substrate in the given time: (6) a determination of the optimum temperature of the enzyme for a constant concentration of the substrate in presence of different enzyme concentrations.

Determination of the lattice translation across {110} APBs in GaAs

1988 ◽  
Vol 46 ◽  
pp. 600-601
Author(s):  
D.R. Rasmussen ◽  
N.-H. Cho ◽  
C.B. Carter
Keyword(s):  
Grain Boundaries ◽  
Lower Energy ◽  
Antiphase Boundary ◽  
The Other ◽  
Boundary Structure ◽  
Interface Plane ◽  
Inversion Symmetry ◽  
High Angle ◽  
Equilibrium Distance

Domains in GaAs can exist which are related to one another by the inversion symmetry, i.e., the sites of gallium and arsenic in one domain are interchanged in the other domain. The boundary between these two different domains is known as an antiphase boundary [1], In the terminology used to describe grain boundaries, the grains on either side of this boundary can be regarded as being Σ=1-related. For the {110} interface plane, in particular, there are equal numbers of GaGa and As-As anti-site bonds across the interface. The equilibrium distance between two atoms of the same kind crossing the boundary is expected to be different from the length of normal GaAs bonds in the bulk. Therefore, the relative position of each grain on either side of an APB may be translated such that the boundary can have a lower energy situation. This translation does not affect the perfect Σ=1 coincidence site relationship. Such a lattice translation is expected for all high-angle grain boundaries as a way of relaxation of the boundary structure.

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