Disease relevance of CEL

• These viral component presentations were selected to obtain mAbs against specific BLV proteins: located on the cell surface (FOR and CEL), in free virus particles (PV) and intracellular viral proteins (SOC and LYS) [1].
• Pneumonia in pigs caused by experimental infection with Mycoplasma hyopneumoniae resulted in a 25-fold increase in the B-cell population in BAL and lung parenchyma 28 days post infection [2].
• Naive calves infected with Pasteurella multocida had a 5-fold increase in the B-cell blast population in lung parenchyma and BAL, and a greater than 60-fold increase in the draining lymph node at 9 days post infection [2].

High impact information on CEL

• A comparison of the second-order rate constants for the inhibition of cholesterol esterase by compound 1 or 2 indicates that the octyl derivative is the more potent inhibitor [3].
• The inhibition of cholesterol esterase by compound 1 or 2 shows saturation kinetics with increasing inhibitor concentration [3].
• p-Nitrophenyl and cholesteryl-N-alkyl carbamates as inhibitors of cholesterol esterase [3].
• The activity of cholesterol esterase in the presence of compound 1 or 2 can be protected by the competitive inhibitor, phenylboronic acid [3].
• First-order decreases in cholesterol esterase activity effected by compound 1 or 2 are also observed in the presence of taurocholate/phosphatidylcholine micelles [3].

Chemical compound and disease context of CEL

• The five antigen preparations for immunizing BALB/c mice were: live cells (CEL), sonicated and ultracentrifuged cells (SOC), cell lysates (LYS), semi-purified BLV (PV), and formalin-treated cells (FOR) from two cell lines permanently infected with BLV (FLK-BLV and BLV-bat2) [1].

Biological context of CEL

• The high-resolution crystal structure of bovine pancreatic cholesterol esterase (Rcryst = 21.1%; Rfree = 25.0% to 1.6 A resolution) shows an alpha-beta hydrolase fold with an unusual active site environment around the catalytic triad [4].
• Comparison of the N-terminal amino acid sequence of bp-BAL with the deduced amino acid sequence of the latter revealed that they are identical [5].
• Conventional antibody against Nepsilon-(carboxymethyl)lysine (CML) shows cross-reaction to Nepsilon-(carboxyethyl)lysine (CEL): immunochemical quantification of CML with a specific antibody [6].
• In the dark, IFA reversibly inhibited cholesteryl [14C]oleate hydrolysis by purified bovine pancreatic cholesterol esterase with an apparent Ki of 150 microM [7].
• Taken together, these data suggest that pancreatic cholesterol esterase and possibly other proteoglycan-binding extracellular enzymes of neutral lipid metabolism may facilitate movement of neutral lipids into the plasma membrane and direct them into functional intracellular sites [8].

Anatomical context of CEL

• Previously from bovine pancreas a lysophospholipase has been purified and a gene was cloned and sequenced encoding an enzyme with cholesterol esterase/lysophospholipase activity [5].
• This conclusion is further supported by the fact that the N-terminal amino acid sequence of this lipase/esterase is 88% homologous to human milk BAL and human pancreatic BAL [5].
• Cholesterol esterase bound to intestinal brush border membranes does not accelerate incorporation of micellar cholesterol into absorptive cells [9].
• We confirmed that cholesterol esterase accelerated the incorporation of unesterified cholesterol solubilized in bile salt micelles into differentiated Caco-2 cells under various experimental conditions [9].
• Rat pancreatic juice and bovine cholesterol esterase increased the incorporation of micellar cholesterol into rat intestinal brush border membranes [9].

Associations of CEL with chemical compounds

• The structure of pancreatic cholesterol esterase, an enzyme that hydrolyzes a wide variety of dietary lipids, mediates the absorption of cholesterol esters, and is dependent on bile salts for optimal activity, is determined to 1.6 A resolution [4].
• The amphipathic, helical lid found in other triglyceride lipases is truncated in the structure of cholesterol esterase and therefore is not a salient feature of activation of this lipase [4].
• RESULTS: The crystal structures of bovine BAL and its complex with taurocholate have been determined at 2.8 A resolution [10].
• Staining with various lectins showed that bp-BAL is a glycoprotein which contains fucose residues [5].
• The lipase activity increased 42 times in the presence of 10 mM sodium taurocholate, which for the first time provides direct evidence that a bile salt-activated lipase (bp-BAL) was isolated from bovine pancreas [5].

Other interactions of CEL

• Synthesis of tricyclic 1,3-oxazin-4-ones and kinetic analysis of cholesterol esterase and acetylcholinesterase inhibition [11].

Analytical, diagnostic and therapeutic context of CEL

• Furthermore, the molecular weight of the purified bp-BAL of 63,000, as estimated by SDS-PAGE, is very similar to that of the purified lysophospholipase (65,000) and to the theoretical molecular weight of 65,147 of the cholesterol esterase/lysophospholipase [5].
• Radioimmunoassays also showed that the calf pancreas contained at least 100-fold less cholesterol esterase protein [12].
• We developed a procedure for the large scale isolation of bovine bile salt-activated lipase (BAL) for its crystallization [Wang, X., et al. (1997) Structure 5, 1209-1218] and also carried out a study on the molecule's glycosylation profile for a better deduction of the structure of the enzyme [13].

References