GBSS1 Antibody
Description
Definition and Overview of GBSS1 Antibody
The GBSS1 Antibody is a polyclonal antibody targeting Granule-Bound Starch Synthase 1 (GBSS1), a key enzyme in starch biosynthesis. It is primarily used in research to detect and quantify GBSS1 in plant and algal systems, particularly in studies involving starch granule formation, amylose synthesis, and carbohydrate metabolism. The antibody is produced in rabbits and is validated for Western blotting (WB) and enzyme-linked immunosorbent assay (ELISA) applications .
Western Blotting (WB)
GBSS1 Antibody is employed to detect GBSS1 in starch granules isolated from tissues such as endosperm, tubers, or seeds. For example:
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Banana Fruit Development: GBSS1 protein levels were monitored via SDS-PAGE and WB during fruit ripening, showing increased expression correlated with amylose accumulation .
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Chlamydomonas Starch Synthesis: WB confirmed the presence of GBSS1 in starch granules and its interaction with periplastidial starch-targeting proteins (PTST) .
ELISA
While ELISA data is less frequently reported, protocols recommend starting concentrations of ~1 µg/mL for antigen detection .
Comparative Studies
In Panicum miliaceum, GBSS1 antibodies identified genetic variants (e.g., S₀ vs. S-15) linked to starch phenotypes, demonstrating its utility in resolving isoform-specific differences .
Cross-Reactivity and Specificity
The antibody exhibits broad reactivity across plant species, as evidenced by immunoblotting and peptide mapping studies:
Role in Starch Synthesis
GBSS1 is the primary enzyme responsible for amylose synthesis in starch granules. Antibody-based studies reveal:
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Protein Localization: GBSS1 is tightly bound to starch granules, as shown by immunoblotting of purified granules .
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Functional Interactions: PTST (a starch-targeting protein) co-purifies with GBSS1, suggesting a cooperative role in granule formation .
Genetic and Environmental Influences
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Fruit Ripening: GBSS1 expression peaks during banana fruit development, correlating with amylose accumulation .
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Storage Effects: Mature banana fruits show reduced GBSS1 activity post-harvest, impacting starch quality .
Evolutionary Insights
Phylogenetic studies using GBSS1 antibodies identified conserved motifs (e.g., K.EALQAAAGLPVDR.K) and divergent regions (e.g., a 15-bp indel in Panicum miliaceum) critical for isoform-specific function .
Product Specs
Target Background
- Plays a role in photoperiod-mediated flowering induction. (PMID: 26039474)
- AtCCR4a and AtCCR4b, localized to cytoplasmic P-bodies (processing bodies), are involved in sucrose and starch metabolism. They also regulate the poly(A) tail length of the Granule-bound starch synthase 1 (GBSS1) transcript. (PMID: 25630334)
- The PROTEIN TARGETING TO STARCH (PTST) protein is necessary for GBSS localization to starch granules and for proper amylose synthesis in Arabidopsis. (PMID: 25710501)
Q&A
Here’s a structured collection of FAQs tailored for researchers working with GBSS1 antibodies, incorporating methodological insights and data-driven analysis from peer-reviewed studies:
Advanced Research Questions
How to resolve contradictions in GBSS1 detection across studies?
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Troubleshooting steps:
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Compare extraction buffers: SDS-containing buffers improve solubility of granule-bound proteins .
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Re-evaluate antibody clonality: Polyclonal sera may recognize diverse epitopes, while monoclonals offer higher specificity .
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Assess species compatibility: For example, rice OsGBSS1 antibodies may not cross-react with barley HvGBSS1 due to sequence divergence .
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What molecular mechanisms explain reduced GBSS1 binding in mutant lines?
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Findings from structural studies:
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Amino acid deletions (e.g., ΔG218/E219 in barley) disrupt β-sheet domains, reducing starch-binding capacity (p < 0.01) .
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Mutations distant from the active site (e.g., C487 in rice) still impair starch adsorption .
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Experimental validation: Use recombinant protein binding assays (Figure 3C in ) to quantify starch affinity.
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How to engineer antibodies for improved GBSS1 detection in non-model species?
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Strategies:
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Species switching: Reformat variable regions into a host-compatible backbone (e.g., mouse→human) to reduce immunogenicity .
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Epitope mapping: Identify conserved regions across orthologs (e.g., ADPG-binding domains in GT5 glycosyltransferases) .
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Avidity optimization: Use bispecific formats to enhance signal in low-abundance samples .
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