Datasheet

生物学的記述

Specificity	A2M Antibody (Rabbit mAb) [N15F12] detects endogenous levels of total A2M proteins.
Background	Alpha-2-macroglobulin (A2M) is an abundant plasma protease inhibitor that uses a unique physical trapping mechanism to neutralize proteases, rather than the active-site blocking mechanism used by classical serpin-type inhibitors, allowing A2M to inhibit proteases from all four major catalytic classes despite lacking specificity for any particular active site sequence. This trapping mechanism is triggered by cleavage within an exposed, unstructured 39-residue "bait region" that is highly susceptible to proteolysis by nearly any protease; engineering the bait region entirely into glycine-serine repeats leaves A2M fully functional and no longer cleavable by any tested protease, demonstrating that the specific bait region sequence itself is dispensable for A2M's overall inhibitory architecture and that its role is simply to present an easily cleaved site regardless of composition. Structural analysis using this glycine-serine "tabula rasa" bait region shows that the C-terminal portion of the bait region normally threads through a central channel within native A2M, and cleavage retracts this segment out of the channel, abolishing the plug-in-channel arrangement; elongating disulfide-looped versions of the bait region by chemically reducing the disulfide bonds keeps A2M in its native conformation, and cleavage occurring within an intact disulfide loop fails to trigger the conformational change until the disulfide bond is also reduced, together demonstrating that introducing a physical discontinuity into the bait region, rather than cleavage of any single peptide bond alone, is the specific trigger for A2M's large-scale conformational rearrangement. This conformational collapse physically encages the trapped protease within A2M's structure, and in many A2M homologs the collapse also exposes an internal, highly reactive thioester bond that covalently conjugates the enzyme to A2M, further stabilizing the complex; the trapped protease remains catalytically active against small peptide substrates but is sterically prevented from accessing large protein substrates, and the resulting protease-A2M complex is subsequently recognized and cleared by macrophage receptors. Because this trapping mechanism accommodates a broad and structurally diverse range of proteases, A2M functions as a general regulator of extracellular proteolysis relevant to processes including blood clotting, inflammation and tissue remodeling, and dysregulated A2M activity has been implicated in conditions ranging from sepsis to neurodegenerative amyloid disease.

Specificity

A2M Antibody (Rabbit mAb) [N15F12] detects endogenous levels of total A2M proteins.

Background

Alpha-2-macroglobulin (A2M) is an abundant plasma protease inhibitor that uses a unique physical trapping mechanism to neutralize proteases, rather than the active-site blocking mechanism used by classical serpin-type inhibitors, allowing A2M to inhibit proteases from all four major catalytic classes despite lacking specificity for any particular active site sequence. This trapping mechanism is triggered by cleavage within an exposed, unstructured 39-residue "bait region" that is highly susceptible to proteolysis by nearly any protease; engineering the bait region entirely into glycine-serine repeats leaves A2M fully functional and no longer cleavable by any tested protease, demonstrating that the specific bait region sequence itself is dispensable for A2M's overall inhibitory architecture and that its role is simply to present an easily cleaved site regardless of composition. Structural analysis using this glycine-serine "tabula rasa" bait region shows that the C-terminal portion of the bait region normally threads through a central channel within native A2M, and cleavage retracts this segment out of the channel, abolishing the plug-in-channel arrangement; elongating disulfide-looped versions of the bait region by chemically reducing the disulfide bonds keeps A2M in its native conformation, and cleavage occurring within an intact disulfide loop fails to trigger the conformational change until the disulfide bond is also reduced, together demonstrating that introducing a physical discontinuity into the bait region, rather than cleavage of any single peptide bond alone, is the specific trigger for A2M's large-scale conformational rearrangement. This conformational collapse physically encages the trapped protease within A2M's structure, and in many A2M homologs the collapse also exposes an internal, highly reactive thioester bond that covalently conjugates the enzyme to A2M, further stabilizing the complex; the trapped protease remains catalytically active against small peptide substrates but is sterically prevented from accessing large protein substrates, and the resulting protease-A2M complex is subsequently recognized and cleared by macrophage receptors. Because this trapping mechanism accommodates a broad and structurally diverse range of proteases, A2M functions as a general regulator of extracellular proteolysis relevant to processes including blood clotting, inflammation and tissue remodeling, and dysregulated A2M activity has been implicated in conditions ranging from sepsis to neurodegenerative amyloid disease.

使用情報

Application

WB, IHC, ELISA, ChIP

Dilution

WB	IHC	CHIP
1:500	1:200-1:2000	1:50-1:100

Reactivity

Human, Mouse, Rat

Source

Rabbit Monoclonal Antibody

MW

163 kDa

Storage Buffer

PBS, pH 7.2+50% Glycerol+0.05% BSA+0.01% NaN3

Storage
(from the date of receipt)

-20°C (avoid freeze-thaw cycles), 2 years

プロトコール

References

https://pubmed.ncbi.nlm.nih.gov/34139236/
https://pubmed.ncbi.nlm.nih.gov/35787371/

Application Data

WB

Validated by Selleck

Lane 1: HepG2