SNCA 61-140 Human
Description
Domain Organization
α-Synuclein is divided into three domains:
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N-terminal lipid-binding domain (1–60): Contains KXKEGV repeats for membrane interaction.
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Non-Amyloid Component (NAC) domain (61–95): Central to amyloidogenesis, with a GAV motif (Gly-Ala-Val) critical for fibrillation.
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C-terminal acidic domain (96–140): Regulates solubility and inhibits aggregation.
The SNCA 61-140 fragment includes the NAC domain (61–95) and part of the C-terminal domain (96–140), excluding the N-terminal lipid-binding region .
Sequence and Production
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Amino Acid Sequence:
MEQVTNVGGAV VTGVTAVAQK TVEGAGSIAA ATGFVKKDQL GKNEEGAPQE GILEDMPVDP DNEAYEMPSE EGYQDYEPEA. -
Additional Met Residue: A methionine is appended at the N-terminus during recombinant production in E. coli .
Aggregation and Fibrillation Studies
SNCA 61-140 is used to model α-synuclein’s amyloidogenic behavior. The NAC domain drives fibril formation, while the C-terminal domain modulates aggregation kinetics .
Epitope Mapping and Antibody Development
Epitope mapping studies reveal that antibodies targeting SNCA 61-140 often bind the central region (61–108), which includes the NAC domain. These antibodies are used to detect α-synuclein pathology in PD models .
| Target Region | Epitope Type | Clinical Relevance |
|---|---|---|
| 61–108 | Central Domain | Linked to neuroinflammation and Lewy body formation . |
| 109–140 | C-terminal Acidic | Regulates protein-membrane interactions and solubility . |
Buffer and Stability
Molecular Weight and SDS-PAGE
| Parameter | Value | Notes |
|---|---|---|
| Theoretical MW | 8.4 kDa | Apparent MW on SDS-PAGE appears higher due to hydrophobicity . |
| Purity | >95% | Verified by SDS-PAGE and chromatography . |
Comparative Product Data
Role in Neurodegeneration
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Aggregation Propensity:
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Metal Ion Interactions:
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Epitope-Specific Antibodies:
Product Specs
Recombinant Human A-Synuclein 61-140, produced in E. coli, is a truncated form of the alpha-synuclein protein, encompassing amino acids 61-140. This non-glycosylated polypeptide chain consists of 81 amino acids, resulting in a molecular weight of 8.4 kDa. However, its apparent size on SDS-PAGE may appear larger due to an additional methionine residue at the N-terminus. Purification of this recombinant protein is achieved through proprietary chromatographic techniques.
MEQVTNVGGAV VTGVTAVAQK TVEGAGSIAA ATGFVKKDQL GKNEEGAPQE GILEDMPVDP DNEAYEMPSE EGYQDYEPEA.
Q&A
What structural characteristics make SNCA 61-140 suitable for studying alpha-synuclein aggregation?
SNCA 61-140 corresponds to the non-amyloid-β component (NAC) domain of human alpha-synuclein, spanning residues 61–140. This region contains the KVKEGV repeat motif (residues 69–79) critical for membrane binding and β-sheet formation . The recombinant protein's utility arises from:
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High solubility: Maintains stability in Tris-HCl/NaCl buffer (pH 7.5) at 1 mg/ml concentrations
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Purity: >95% homogeneity via SDS-PAGE ensures reproducible aggregation kinetics
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Post-translational modification mimicry: Lacks phosphorylation sites present in full-length protein, enabling isolation of NAC-driven aggregation mechanisms
Table 1: Key Structural Features of SNCA 61-140
How does SNCA 61-140 expression differ between in vitro and transgenic models?
In the Thy1-aSyn line 61 mouse model, human SNCA-140 overexpression shows:
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Gender-dependent phenotypes: Male mice exhibit earlier dopaminergic neuron loss (14 months vs. 18 months in females)
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Transcript splicing artifacts: Endogenous mouse α-synuclein splice variants (e.g., SNCA-126, -112) complicate interpretation of human transgene effects
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Regional specificity: Ventral midbrain shows 3.8-fold higher SNCA-140 accumulation than cortex in aged mice
Methodological Recommendation:
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Use RNase-free tissue dissection protocols with McIlwain choppers (750 μm slices) to preserve transcript integrity
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Validate species specificity via primers spanning human exon 3 (e.g., hSNCA ex3 fwd: 5′-AAA ACC AAG GAG GGA GTG GT)
How can researchers resolve contradictory findings between SNCA 61-140 in vitro aggregation and in vivo pathology?
Discrepancies often arise from:
Table 2: Key Experimental Variables
Resolution Strategies:
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Dose-response calibration: Match in vitro concentrations to ventricular CSF levels (2.7–4.1 ng/ml in PD patients)
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Dynamic light scattering: Monitor oligomer size distributions during prolonged incubation (14–28 days)
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Cross-validate with transcript analysis: Use mutually exclusive primers (e.g., hSNCA ex2/4 fwd + ex5 rev) to discriminate endogenous vs. transgenic expression
Required Controls:
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Scrambled primer validation: Prevents false-positive splicing detection (Fig. 1C SC/B SC in )
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Gender-matched cohorts: Account for X-chromosome transgene expression in Thy1-aSyn models
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Housekeeping gene normalization: GAPDH amplification with hGAPDH fwd/rev primers (60.5°C annealing)
Example Workflow:
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Perfuse mice with heparinized saline (4°C) to inhibit RNase activity
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Extract RNA with RNeasy Lipid Tissue Mini Kit + DNase digestion
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Perform RT-PCR with:
How to optimize detection of low-abundance SNCA splice variants?
The half-scrambled primer technique (Fig. 1C in ) enhances specificity:
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Design primers with:
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≤15 bp overlap at exon junctions
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Tm differential >2°C between target and off-target binding
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Validate with:
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Quantify using:
How to reconcile transcript vs. protein-level discrepancies in SNCA 61-140 studies?
Key considerations:
Integrative Approach:
Product Science Overview
Alpha-synuclein is a small, soluble protein composed of 140 amino acids. It is natively unfolded, meaning it does not adopt a fixed three-dimensional structure under physiological conditions. This intrinsic disorder allows alpha-synuclein to interact with a variety of other proteins and cellular components. The 61-140 segment of alpha-synuclein retains many of the protein’s functional properties and is often used in research to study its behavior in isolation.
Alpha-synuclein is primarily found in the brain, particularly in the presynaptic terminals of neurons, where it is believed to play a role in synaptic vesicle regulation and neurotransmitter release. It is also involved in the maintenance of synaptic plasticity and the regulation of dopamine neurotransmission .
The pathological aggregation of alpha-synuclein is a hallmark of several neurodegenerative diseases collectively known as synucleinopathies. These include Parkinson’s disease, dementia with Lewy bodies (DLB), and multiple system atrophy (MSA). In these conditions, alpha-synuclein aggregates to form insoluble fibrils that are deposited in the brain, leading to neuronal dysfunction and cell death .
In Parkinson’s disease, alpha-synuclein aggregates are found in Lewy bodies and Lewy neurites, which are characteristic pathological features of the disease. The presence of these aggregates is associated with the loss of dopaminergic neurons in the substantia nigra, a brain region critical for motor control. This neuronal loss leads to the motor symptoms of Parkinson’s disease, such as tremors, rigidity, and bradykinesia .
The study of recombinant alpha-synuclein, including the 61-140 segment, has provided valuable insights into the mechanisms of protein aggregation and its role in disease. Researchers use recombinant alpha-synuclein to investigate how mutations, post-translational modifications, and environmental factors influence its aggregation propensity and toxicity .
Understanding the behavior of alpha-synuclein is crucial for developing therapeutic strategies aimed at preventing or reversing its aggregation. Potential therapeutic approaches include small molecules that inhibit aggregation, immunotherapies that target alpha-synuclein, and gene therapies that modulate its expression .
