Meltrin beta (ADAM19) mediates ectodomain shedding of Neuregulin beta1 in the Golgi apparatus: fluorescence correlation spectroscopic observation of the dynamics of ectodomain shedding in living cells.

Membrane-anchored Neuregulin beta1 sheds its ectodomain as soluble factors. Two proteases that belong to a disintegrin and metalloprotease (ADAM) family are known to cleave Neuregulin beta1. One is tumor necrosis factor-alpha converting enzyme (TACE/ADAM17).

An optimized homogeneous noncompetitive immunoassay based on the antigen-driven enzymatic complementation.

We describe an optimized noncompetitive and homogeneous immunoassay based on the antigen-dependent reassociation of antibody variable domains and beta-galactosidase (beta-gal) complementation (open sandwich enzymatic complementation immunoassay, OS-ECIA). The reassociation of two fusion proteins, an antibody heavy chain variable region fragment tethered to an N-terminal deletion mutant of beta-gal, V(H)Deltaalpha, and the light chain variable region fragment tethered to a C-terminal deletion mutant of beta-gal, V(L)Deltaomega, was monitored by the enzymatic complementation between the two. With the use of anti-hen egg lysozyme (HEL) antibody HyHEL10, an antigen-dependent enhancement in the enzymatic activity was clearly observed.

A homogeneous noncompetitive immunoassay for the detection of small haptens.

We describe a noncompetitive homogeneous immunoassay for small haptens based on the antigen-dependent reassociation of antibody variable domains and beta-galactosidase (beta-gal) complementation (open sandwich enzymatic complementation immunoassay). As a model system, the reassociation of two fusion proteins, an anti 4-hydroxy-3-nitrophenylacetyl (NP) antibody heavy-chain variable-region fragment fused to an N-terminal deletion mutant of beta-gal (V(H)delta alpha) and the light-chain variable-region fragment fused to a C-terminal deletion mutant of beta-gal (V(L)delta omega), was monitored by the enzymatic complementation between the two. Upon simple mixing of the reagents with the sample, an antigen (NP)-dependent increase in enzymatic activity was observed.