EurekaMag.com logo
+ Site Statistics
References:
48,253,228
Abstracts:
22,798,842
+ Resolve Accession
+ Subscribe to Site Feeds
EurekaMag Most Shared ContentMost Shared
EurekaMag PDF Full Text ContentPDF Full Text
+ PDF Full Text
Request PDF Full TextRequest PDF Full Text
Submit PDF Full TextSubmit PDF Full Text
+ Follow Us
Follow on FacebookFollow on Facebook
Follow on TwitterFollow on Twitter
Follow on Google+Follow on Google+
Follow on LinkedInFollow on LinkedIn

+ Translate

Tri acyl glycerol synthesis in isolated fat cells studies on the microsomal di acyl glycerol acyl transferase ec 2.3.1.20 activity using ethanol dispersed di acyl glycerols


, : Tri acyl glycerol synthesis in isolated fat cells studies on the microsomal di acyl glycerol acyl transferase ec 2.3.1.20 activity using ethanol dispersed di acyl glycerols. Journal of Biological Chemistry 251(15): 4537-4543

The acyl-CoA:1,2-diacylglycerol acyltransferase (EC 2.3.1.20) activity of isolated fat cells [rat] was predominantly (89%) localized to the microsomal subcellular fraction by assays based on the conversion of 1,2-[3H]diacyl-sn-glycerol to triacylglycerol using 1 to 4 .mu.g of protein. A complementary assay based on the conversion of [3H]palmitoyl-CoA to triacylglycerol was developed. These methods, 100 to 1000 times more sensitive than those previously employed, were used to characterize the microsomal activity. The choice of dispersing agent for addition of diacylglycerol to the reaction mixture was crucial. Addition of diacylglycerol in ethanol resulted in the highest diacylglycerol acyltransferase activity of the methods tested. Tween 20, which was previously employed as the dispersing agent, severely inhibited the activity. A broad pH optimum from 7.4 to 8.0 was noted and several salts stimulated the activity more than 2-fold. The activity was unstable at temperatures of 28.degree. and above. Dependences of acyl-CoAs containing 6-18 C atoms were investigated using bacterial diacylglycerol. Acetyl- and butyryl-CoA were not substrates. Highest diacylglycerol acyltransferase activities were observed with decanoyl-CoA and lower activities were noted with longer and shorter saturated chains. Maximal activity with oleoyl-CoA was only 34% of that seen with stearoyl-CoA. No simple relationship between the critical micellar concentrations of the acyl-CoAs employed and diacylglycerol acyltransferase activity was observed. The dependences of diacylglycerols containing fatty acids 6-18 C atoms in length were investigated with [3H]palmitoyl-CoA. While all the 1,2-diacyl-sn-glycerols tested were substrates, diacylglycerol acyltransferase activity was highest with 1,2-dioleoylglycerol. Maximum activity with the bacterial diacylglycerol was 86% that with 1,2-dioleoylglycerol. The diacylglycerol concentrations required for half-maximal velocity were 20-40 .mu.M for long chain diacylglycerols and 2-3 .mu.M for short chain diacylglycerols; these were 75 and 750-fold lower than previously reported. Microsomal diacylglycerol acyltransferase specific activities from isolated cells around 50 nmol/min per mg, 10 to 50-fold higher than previously reported from adipose tissue, were typical using dioleoylglycerol and palmitoyl-CoA as substrates. Diacylglycerol acyltransferase specific activities were 17-fold higher in microsomes from isolated fat cells than any other tissues examined. The diacylglycerol acyltransferase appears to have specificity with respect to acyl-CoAs and diacylglycerols, but a definitive interpretation is limited by the lack of data on the physical properties of these substrates in solution under the conditions employed.

(PDF 0-2 workdays service)

Order PDF Full Text

Close
Close

Click here to order any other PDF Full Text


Accession: 006839855

PDF Full Text: Submit


Submit PDF Full Text

No spam - Every submission is manually reviewed

Due to poor quality, we do not accept files from Researchgate

Submitted PDF Full Texts will always be free for everyone
(We only charge for PDFs that we need to acquire)

Select a PDF file:
Close
Close

Other references

Semenova, L.M.; Sharipova, D.D., 1977: Health education work with the parents of preschool children. Gigiena i Sanitariia 0(1): 51-53

Ptashekas, R.S.; Martsinkiavichus, A.M.; Pikelite, R.L.; Paliushchinskaia, N.A.; Kibarskite, N.Kh., 1977: Clinical anatomical basis of the pathogenesis of fatal complications in the late periods after heart valve prosthesis. On the basis of clinico-anatomical analysis of the causes of death in 35 patients following valve prosthetics for rheumatic valvular disease, it was established that cardiac failure was the most frequent cause. Cardiac failure was due to exacerbat...

Ding, Y.X.; Chen, J.L., 1995: Effect of continuous plantation of Chinese fir on soil fertility. Changes in soil fertility under continuous stands of Chinese fir (Cunninghamia lanceolata) were studied by comparing soil samples from first and second plantations of Chinese fir, evergreen broad-leaved forests (Castanopsis fargesii, C. fabris, C....

Aggarwal, A.; Gurka, J., 1995: Probable ciprofloxacin induced cholestasis. Australian and New Zealand Journal of Medicine 25(5): 541-542

Lombrail, P., 2014: Reviewing the shared strategy health bill: further measures to meet the structural challenges of the health system. This article reviews the draft health bill entitled "Federate health professionals around a shared strategy", currently submitted for consultation in the context of the national health strategy in France. This bill comprises innovative m...

Wilson Monte D.; Otto Bruce R., 1984: Holocene glacial and periglacial features of the Borah Peak area, Lost River Range, Idaho. Abstracts with Programs - Geological Society of America 16(4): 260

Clements R.S.Jr; Diethelm A.G., 1979: The metabolism of myo inositol by the human kidney. The metabolism of myo-inositol was evaluated in control subjects and in patients with chronic renal failure before and after successful renal transplantation. The fasting plasma myo-inositol concentration and myo-inositol pool size were increased...

Levenshteyn M.L.; Zarits kiy O.I.; Mishchenko S.N.; Yurchenko V.F., 1969: Fluorite-bearing zones in the Donets basin, Ukrainian shield. Geologicheskiy Zhurnal (Kiev, 1968) 29(1): 96-99

BRADY.R.O.; LUKENS.F.D.W.; GURIN.S., 1951: Synthesis of radioactive fatty acids in vitro and its hormonal control. The present investigations demonstrate that hepatic lipogenesis occurs at a nearly normal rate in depancreatized-hypophysectomized cats and at considerable, though variable, rates in depancreatized-adrenalectomized animals. Hypophysectomy produces...

Pleskachevskaya G.A., 1981: Experience with sanitary surveillance of rural planning and construction practices. Gigiena i Sanitariya (4): 60-61