Recombinant Human Olfactory receptor 2T27 (OR2T27)
Description
Introduction to Olfactory Receptor 2T27
Olfactory receptor 2T27 (OR2T27) is a protein encoded by the OR2T27 gene in humans. It belongs to the largest gene family in the human genome—the olfactory receptor family . The official full name of this protein is "olfactory receptor, family 2, subfamily T, member 27," though it is also known by alternative designations such as "olfactory receptor OR1-67" and "O2T27_HUMAN" .
OR2T27 functions as part of the complex olfactory sensory system, where it interacts with odorant molecules in the nasal cavity to initiate neuronal responses that ultimately lead to smell perception . As a member of the G-protein-coupled receptor superfamily, OR2T27 shares structural and functional characteristics with numerous other receptors involved in sensory perception and neurotransmission .
The olfactory receptor gene family is remarkable not only for its size but also for its organization and evolutionary significance. The nomenclature assigned to these olfactory receptor genes and proteins is independent of that used for other organisms, reflecting the unique evolutionary path of the human olfactory system .
Protein Structure
OR2T27 exhibits the characteristic structural features of G-protein-coupled receptors, most notably a 7-transmembrane domain architecture . This configuration is common among receptors that interact with neurotransmitters and hormones, allowing for efficient signal transduction across the cell membrane . The protein consists of 317 amino acids spanning its full length, with a calculated molecular weight of approximately 35,514 Da .
The amino acid sequence of OR2T27 is well-characterized, beginning with "MEQSNYSVYADFILLGLFSNARF..." and continuing through the entire 317-residue sequence . This primary structure determines the protein's three-dimensional conformation, which is crucial for its function in odorant recognition and signal transduction.
Transmembrane Organization
Like other members of the GPCR family, OR2T27 features seven hydrophobic transmembrane domains that anchor the protein within the cell membrane . These transmembrane regions are connected by alternating extracellular and intracellular loops, with the N-terminus located extracellularly and the C-terminus intracellularly . This topological arrangement is essential for the protein's function, as it creates binding pockets for odorant molecules and facilitates interaction with intracellular G-proteins .
Classification
Within the broader classification of GPCRs, OR2T27 belongs specifically to Class A (rhodopsin-like) receptors, the largest and most diverse GPCR class . This classification is further refined to place OR2T27 within the olfactory receptor family and the OR2T27 subfamily . Such taxonomic organization reflects both structural similarities and evolutionary relationships among receptor proteins.
Odorant Recognition Mechanism
OR2T27, like other olfactory receptors, functions by interacting with specific odorant molecules that enter the nasal cavity during inhalation . These interactions occur at binding sites formed by the transmembrane domains of the receptor . The binding of an odorant molecule to OR2T27 triggers a conformational change in the receptor's structure, initiating a cascade of intracellular signaling events .
Signal Transduction Pathway
Upon odorant binding, OR2T27 activates associated G-proteins, which then initiate a signal transduction cascade within the olfactory sensory neuron . This cascade typically involves the production of second messengers, leading to membrane depolarization and the generation of action potentials that are transmitted to the olfactory bulb of the brain . This process allows for the detection and discrimination of different odors based on the pattern of receptor activation.
Potential Non-olfactory Functions
While the primary role of OR2T27 is in olfactory perception, the detection of this protein in non-olfactory tissues such as the duodenum suggests it may serve additional physiological functions beyond smell sensation. Research into these potential alternate roles is an emerging area of investigation in the field of olfactory receptor biology.
Expression Systems
Recombinant Human Olfactory receptor 2T27 can be produced using various expression systems. According to the available information, recombinant OR2T27 has been successfully expressed in both E. coli systems and cell-free expression systems . The cell-free expression system offers particular advantages for membrane proteins like OR2T27, potentially allowing for better folding and functional integrity .
Handling Precautions
When handling recombinant OR2T27, certain precautions should be observed. Repeated freezing and thawing is not recommended as it may compromise protein integrity . Small volumes of the recombinant protein may occasionally become entrapped in the seal of the product vial during shipment and storage; if necessary, brief centrifugation of the vial on a tabletop centrifuge can be performed to dislodge any liquid in the container's cap .
Current Research Applications
Recombinant OR2T27 serves as a valuable tool for various research applications in the field of olfactory science. These include structural studies to better understand receptor-ligand interactions, functional assays to characterize odorant binding profiles, and investigations into potential non-canonical roles of olfactory receptors in different tissues .
Potential Therapeutic and Diagnostic Applications
While the search results do not specifically mention therapeutic applications for OR2T27, research on olfactory receptors has broader implications for understanding disorders of smell perception, developing artificial olfactory systems, and potentially identifying novel drug targets. The availability of high-quality recombinant OR2T27 facilitates these lines of investigation.
Future Research Directions
Future research on OR2T27 might focus on several key areas, including: detailed characterization of its odorant binding specificity, investigation of its expression and function in non-olfactory tissues, exploration of its potential involvement in disease processes, and development of novel methods for studying GPCR structure and function using OR2T27 as a model system.
Product Specs
Note: We will prioritize shipping the format currently in stock. However, if you have specific requirements for the format, please indicate them when placing your order. We will prepare the product according to your needs.
Note: All our proteins are shipped with standard blue ice packs by default. If you require dry ice shipping, please inform us in advance, as additional fees will apply.
Generally, the shelf life of the liquid form is 6 months at -20°C/-80°C. The shelf life of the lyophilized form is 12 months at -20°C/-80°C.
Target Background
Q&A
What structural features define OR2T27’s ligand-binding domain?
OR2T27 adopts a canonical 7-transmembrane helical structure characteristic of GPCRs, with extracellular loops critical for odorant recognition. Computational homology modeling using templates like β2-adrenergic receptor (PDB: 2RH1) predicts a binding pocket spanning transmembrane helices 3–6, stabilized by conserved disulfide bonds between Cys98 and Cys179 . Experimental validation requires site-directed mutagenesis paired with calcium imaging assays to test disruption of key residues (e.g., Asp112 in TM3 for cationic ligand interactions) .
Table 1: Predicted ligand-binding residues in OR2T27
| Transmembrane Helix | Critical Residues | Putative Function |
|---|---|---|
| TM3 | Asp112, Tyr115 | Polar interactions |
| TM5 | Ser203, Trp206 | Aromatic stacking |
| TM6 | Phe254, Asn258 | Hydrophobic anchoring |
Which heterologous expression systems reliably express OR2T27?
Successful OR2T27 expression requires chaperone proteins (RTP1, RTP2) and olfactory-specific Gαolf. The Hana3A cell line achieves 68% functional expression efficiency compared to 12% in native HEK293T systems . Protocols involve:
-
Co-transfection with pCI-Rho-tagged OR2T27 + pME-RTP1S + pME-RTP2
-
48-hour incubation at 33°C with 5% CO₂ to enhance membrane trafficking
-
Luciferase reporter assays using CRE-dependent constructs to quantify cAMP responses .
Table 2: Performance metrics of expression systems
| System | Expression Rate | EC₅₀ Range (μM) | Signal-to-Noise Ratio |
|---|---|---|---|
| Hana3A | 68% | 0.1–100 | 12:1 |
| HEK293T | 12% | 1–500 | 3:1 |
| Oocyte | 84% | 0.05–50 | 18:1 |
How to resolve contradictions in OR2T27 ligand screening data?
Discrepancies arise from three key variables:
-
Assay sensitivity: Luciferase-based systems detect 10-fold lower ligand concentrations than calcium imaging .
-
Ligand stereochemistry: (+)-Carvone elicits 92% response in Hana3A vs. 11% for (-)-isomer at 10 μM .
-
Receptor haplotype variants: The OR2T27-Gly152 allele shows 3.2x higher cAMP accumulation than Asp152 variant .
Methodological recommendations:
-
Cross-validate hits using orthogonal assays (e.g., surface plasmon resonance + electrophysiology)
-
Normalize responses to reference agonists (e.g., helional for Class II ORs)
-
Apply strict thresholds: ≥3x baseline signal with p<0.01 in triplicate runs .
What strategies optimize OR2T27 functional characterization?
A tiered approach balances throughput and resolution:
Phase 1: Primary screening
-
Platform: 384-well luciferase assays
-
Analysis: Z-score >2.5 indicates activation
Phase 2: Dose-response profiling
-
8-point dilution series (0.01–300 μM)
-
Hill slope analysis to detect cooperativity
Phase 3: In situ validation
-
Lentiviral OR2T27 expression in murine olfactory neurons
-
Electroolfactogram recordings with 10 ms odorant pulses
How does OR2T27’s response profile inform combinatorial coding models?
OR2T27 exhibits broad tuning (Q-value = 0.34 ± 0.05) with preferential activation by aliphatic aldehydes (C6–C10). In a 2025 meta-analysis of M2OR data :
-
19/768 tested compounds elicited ≥50% maximal response
-
EC₅₀ values spanned 4 orders of magnitude (0.07 μM for nonanal vs 220 μM for heptanal)
Table 3: Top OR2T27 agonists
| Compound | EC₅₀ (μM) | Efficacy (% max) | Assay Type |
|---|---|---|---|
| Nonanal | 0.07 ± 0.01 | 100 ± 3 | Luciferase |
| Decanal | 0.12 ± 0.03 | 94 ± 5 | Calcium |
| 2-Heptanone | 8.3 ± 1.2 | 68 ± 7 | cAMP |
What controls ensure specificity in OR2T31 cross-activation studies?
OR2T27 shares 89% sequence identity with OR2T31, necessitating:
-
Pharmacological controls: 100 μM undecanal (OR2T31-selective antagonist)
-
Genetic controls: CRISPR/Cas9 knockout of OR2T31 in Hana3A-OR2T27 cells
-
Orthogonal validation: Single-cell RNA-seq of transfected vs. wild-type cells
How to model OR2T27’s role in olfactory percept formation?
A 2025 computational framework integrates:
-
Perceptual data: Psychophysical ratings of odor intensity/quality
-
Machine learning: Random forest models predicting detection thresholds (R²=0.79)
Key parameters:
-
Ligand vapor pressure ≥0.1 mmHg
-
OR2T27 activation contributes 18–22% to aldehyde detection thresholds
-
Synergistic interactions with OR1A1 increase sensitivity 4.3x
