The lipid raft-bound alkaline phosphatase activity increases and the level of transcripts remains unaffected in liver of merosin-deficient LAMA2dy mouse.

Alkaline phosphatase (AP) and other proteins add glycosylphosphatidylinositol (GPI) before addressing to raft domains of the cell membrane. Our previous report showing an increased density of lipid rafts in muscle of dystrophic Lama2dy mice prompted us to compare livers of normal (NL) and dystrophic mice (DL) for their levels of rafts. With this aim, hepatic rafts were isolated as Triton X-100 resistant membranes, and identified by their abundance of flotillin-2, alkaline phosphatase (AP) and other raft markers.

Expression of cholinesterases in human kidney and its variation in renal cell carcinoma types.

Despite the aberrant expression of cholinesterases in tumours, the question of their possible contribution to tumorigenesis remains unsolved. The identification in kidney of a cholinergic system has paved the way to functional studies, but details on renal cholinesterases are still lacking. To fill the gap and to determine whether cholinesterases are abnormally expressed in renal tumours, paired pieces of normal kidney and renal cell carcinomas (RCCs) were compared for cholinesterase activity and mRNA levels.

The levels of both lipid rafts and raft-located acetylcholinesterase dimers increase in muscle of mice with muscular dystrophy by merosin deficiency.

Wild type and dystrophic (merosin-deficient) Lama2dy mice muscles were compared for their density of lipid rafts. The 5-fold higher level of caveolin-3 and the 2-3 times higher level of ecto-5'-nucleotidase activity in raft preparations (Triton X-100-resistant membranes) of dystrophic muscle supported expansion of caveolar and non-caveolar lipid rafts. The presence in rafts of glycosylphosphatidylinositol (GPI)-linked acetylcholinesterase (AChE) dimers, which did not arise from erythrocyte or nerve, not only revealed for the first time the capacity of the myofibre for translating the AChE-H mRNA but also an unrecognized pathway for targeting AChE-H to specialized membrane domains of the sarcolemma.

Hydrolysis of acetylthiocoline, o-nitroacetanilide and o-nitrotrifluoroacetanilide by fetal bovine serum acetylcholinesterase.

Besides esterase activity, acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) hydrolyze o-nitroacetanilides through aryl acylamidase activity. We have reported that BuChE tetramers and monomers of human blood plasma differ in o-nitroacetanilide (ONA) hydrolysis. The homology in quaternary structure and folding of subunits in the prevalent BuChE species (G4(H)) of human plasma and AChE forms of fetal bovine serum prompted us to study the esterase and amidase activities of fetal bovine serum AChE.

Human butyrylcholinesterase components differ in aryl acylamidase activity.

Apart from its esterase activity, butyrylcholinesterase (BuChE) displays aryl acylamidase (AAA) activity able to hydrolyze o-nitroacetanilide (ONA) and its trifluoro-derivative (F-ONA). We report here that, despite amidase and esterase sites residing in the same protein, in human samples depleted of acetylcholinesterase the ratio of amidase to esterase activity varied depending on the source of BuChE. The much faster degradation of ONA and F-ONA by BuChE monomers (G1) of colon and kidney than by the tetramers (G4) suggests aggregation-driven differences in the AAA site between single and polymerized subunits.

Molecular properties of acetylcholinesterase in mouse spleen.

The presence of acetylcholinesterase (AChE) mRNA and activity in the tissues and cells involved in immune responses prompted us to investigate the level and pattern of AChE components in spleen. AChE activity was higher in mouse spleen (0.46 +/- 0.

Muscular dystrophy with laminin deficiency decreases the content of butyrylcholinesterase tetramers in sciatic nerves of Lama2dy mice.

The Lama2dy mouse, a model of congenital muscular dystrophy (CMD) by merosin deficiency (MCMD), shows muscle degeneration and dysmyelination of peripheral nerves. Although it has been reported that MCMD reduces acetylcholinesterase (AChE) activity of mouse sciatic nerve, no information is available regarding its action on butyrylcholinesterase (BuChE). Amphiphilic BuChE monomers (G(1)(A), 39%), dimers (G(2)(A), 18%), and tetramers (G(4)(A), 33%), along with hydrophilic tetramers (G(4)(H), 10%), were identified in mouse sciatic nerve.