Biodiesel from most agricultural feedstocks has flow properties that are prone to startup and operability problems during cold weather. Biodiesel from soybean oil is generally a mixture of long-chain fatty acid alkyl esters composed of 0.15–0.20 mass fraction saturated esters (melting point [MP] 0 C) mixed with unsaturated esters (MP \ 0 C). This work investigates the crystallization properties...

Exposure of insulin-producing cells to elevated levels of the free fatty acid (FFA) palmitate results in the loss of β-cell function and induction of apoptosis. The induction of endoplasmic reticulum (ER) stress is one mechanism proposed to be responsible for the loss of β-cell viability in response to palmitate treatment; however, the pathways responsible for the induction of ER stress by palm...

Dispersions of pure, spin-label phosphatidylcholines in aqueous buffer have been investigated with the Privalov high-sensitivity differential scanning calorimeter. The lipids studied are mixed-chain ones in which C-2 of glycerol bears a spin-label derivative of stearic acid and the fatty acid group at C-1 is palmitate. A well-defined phase transition is observed at 30.3-30.7 degrees C for the p...

The absence of peroxisomes in patients with the cerebrohepatorenal syndrome of Zellweger leads to several biochemical abnormalities, including deficient synthesis of plasmalogens as well as accumulation of very long-chain fatty acids and intermediates in bile acid biosynthesis. Accumulation of very long-chain fatty acids in serum and fibroblasts has hitherto been used most extensively for diagn...

The hypothesis that substrate availability can alter contractile function in reperfused myocardium after global ischemia was investigated in this study. Isolated rabbit hearts were placed in a dual tuned (31P/13C) NMR probe with a 9.4-T magnet and perfused with the following substrates given individually or in combination: 10 mM glucose, 2 mM palmitate, and 2.5 mM [3-13C]pyruvate. Glucose was t...

In the eye, hydrolysis of stored retinyl esters is catalyzed by retinyl ester hydrolase (REH) activities in retinal pigment epithelium (RPE) membranes. In the present study, biochemical analyses were conducted to determine the substrate specificity of these activities. Specific activities determined for hydrolysis of various retinol isomers of retinyl palmitate (9-cis-, 11-cis-, 13-cis-, and al...

Exposure to high fatty acids (FAs) induces whole body and skeletal muscle insulin resistance. The globular form of the adipokine, adiponectin (gAd), stimulates FA oxidation and improves insulin sensitivity; however, its ability to prevent lipid-induced insulin resistance in humans has not been tested. The purpose of this study was to determine 1) whether acute (4 h) exposure to 2 mM palmitate w...

Determination of the BSA-palmitate high-affinity binding constant ( K a) traditionally relied on the heptane-water partitioning technique. We used this technique to calculate K a for the BSA-[3H]palmitate complex, to determine if K a was independent of protein concentration, and to determine if the unbound [3H]palmitate concentration is constant at different BSA concentrations using constant BS...