The glycine decarboxylase (GDC), also known as the glycine cleavage system, catalyzes the degradation of glycine. The P protein, utilizing its pyridoxal phosphate cofactor, binds the α-amino group of glycine. Subsequently, carbon dioxide (CO2) is released, and the remaining methylamine moiety is transferred to the lipoamide cofactor of the H protein.
Technical variables: Compare antigen retrieval methods (e.g., pH 6.0 vs. pH 9.0 buffers significantly alter epitope accessibility).
Biological variables: Account for tissue fixation time (under-fixed samples show false nuclear localization).
Analytical solution: Perform meta-analysis of raw data from public repositories (e.g., Human Protein Atlas) using standardized quantification pipelines.
Start with manufacturer’s recommended dilution (typically 1:100–1:500)
Test 3-fold serial dilutions (1:50 to 1:1600) using Fc-blocked cells
Calculate signal-to-noise ratio:
Target S/N >5
Non-linear dilution effects in low-abundance targets
Increased background in CD14+ monocytes due to Fc receptor binding
| Tool | Function | Compatibility |
|---|---|---|
| CPath | Spatial proteomics alignment | IHC/IF + scRNA-seq |
| ANTIGENn | Epitope-phosphosite mapping | Mass spec data |
| COPaKB | Cross-platform knowledge bridging | Array/Sequencing data |
Validate findings with pathway enrichment tools (DAVID, GSEA) using FDR <0.1.
Biological: Isogenic cell lines with GLDP1 promoter mutations
Technical: IgG control + input DNA normalization
Functional: CRISPRi-mediated GLDP1 suppression vs. overexpression
Peak calling: MACS2 with stringent parameters (q-value <0.01)
Motif analysis: Confirm presence of GLDP1-binding consensus sequence (G/C-rich regions)
Fixed intervals (every 24h for cell models, weekly for in vivo)
Multi-omics anchoring: Correlate antibody-derived protein levels with mRNA (RNA-seq) and metabolites (LC-MS)
Use mixed-effects models to account for individual variability:
Where = random intercept per subject
| Artifact indicator | True interaction marker |
|---|---|
| Random spatial distribution | Clustered foci with Voronoi tessellation |
| Temperature-independent | Reduced signal at 37°C vs. 4°C |
| Unchanged by competitor RNA | >50% reduction with target oligos |
Confirm with crosslinking MS showing direct GLDP1-GLDP1 contacts.
CODEX: 60-plex imaging with iterative antibody stripping (<5% signal carryover)
Antibody-oligo conjugates: Allows sequencing-based detection (CITE-seq)
Time-resolved FRET: Distinguish membrane vs. intracellular GLDP1 pools
Compensation controls for spectral overlap
Single-stain reference samples for spillover correction
| Method | Success rate | Risk of damage |
|---|---|---|
| HIER (pH 9.0) | 82% | Moderate |
| Proteinase K (5μg/ml) | 68% | High |
| Microwave antigen retrieval | 91% | Low |
Combine with tyramide amplification (TSA) for >3x signal enhancement.
In vitro: Organoid models with antibody-mediated GLDP1 inhibition
In vivo: Conditional knockout + antibody-based rescue experiments
Clinical correlation: Multiplexed staining of patient cohorts (Cox regression, HR >2 required)
Mitochondrial morphology (electron microscopy)
Redox status (Grx1-roGFP2 biosensors)
Metabolic flux (Seahorse XF analysis)