ACO4 Antibody

Biochemical Characteristics of ACO4 Antibody

The ACO4 antibody (AS18 4240) is a polyclonal antibody raised in rabbits against a KLH-conjugated peptide derived from Arabidopsis thaliana ACO4 (UniProt: Q06588, TAIR: AT1G05010) . Key properties include:

Ethylene Biosynthesis in Arabidopsis thaliana

• Role in Seedling Growth: ACO4 overexpression (35S–ACO4) increases ethylene production, leading to reduced hypocotyl elongation in seedlings. This phenotype is reversible with Co²⁺ ions, confirming ACO4’s enzymatic activity .

• Light-Dependent Expression: ProACO4–GUS assays show strong ACO4 expression in shoots under light, with ACC (ethylene precursor) upregulating and Co²⁺ downregulating its activity .

• Brassinosteroid (BR) Regulation: BR signaling via the transcription factor BZR1 suppresses ACO4 expression. BR-deficient mutants (det2) exhibit elevated ACO4 levels, restored by brassinolide (BL) treatment .

Role in Fruit Ripening (Tomato Studies)

• Protein Dynamics: Western blotting using a cross-reactive antibody revealed ACO protein (including ACO4) peaks during tomato fruit ripening (breaker to pink stage), correlating with ethylene production .

• Activity Correlation: ACO protein abundance aligns with enzymatic activity, confirming its role in climacteric ethylene bursts .

Experimental Use Cases

Limitations and Cross-Reactivity

• The antibody’s epitope (a consensus peptide for ACO1–ACO4 in tomatoes) may limit isoform-specific detection .

• Low signal intensity in ACS Western blots suggests affinity challenges for related enzymes .