| Field | Specification |
|---|---|
| Mfr No | |
| Activity | |
| Alternative Names | Cry2Cryptochrome-2 |
| Conjugate | |
| Endotoxin Level | |
| Expression System | |
| Form | Liquid or Lyophilized powder |
| Function | |
| Molecular Weight | |
| Product Type | |
| Protein Length | |
| Purity | |
| Reconstitution | |
| Species | |
| Storage | |
| Target | |
| UniProt # |
Overview
Recombinant Rat Cryptochrome-2 (Cry2) is a recombinant protein reagent for research-use applications such as assay development, binding studies, and mechanistic experiments. It corresponds to Cry2 (Rattus norvegicus (Rat)) and is intended for RUO workflows where a defined protein standard or functional input is needed.
Key elements and design rationale
- Expression system: E.coli (expression context can influence folding and PTMs).
- Expression region: 1-594aa (region choice can affect activity and binding readouts).
- Conjugate(s)/tag: N-terminal 10xHis-SUMO-tagged and C-terminal Myc-tagged (can support detection or purification depending on format).
- Molecular weight: 87.2 kDa (useful for interpreting gel migration and size-exclusion profiles).
When comparing results across assays, consider that expression system and expressed region can alter glycosylation, disulfide formation, and oligomerization state, which may shift apparent potency or binding behavior in vitro.
Biological background
Transcriptional repressor which forms a core component of the circadian clock. The circadian clock, an internal time-keeping system, regulates various physiological processes through the generation of approximately 24 hour circadian rhythms in gene expression, which are translated into rhythms in metabolism and behavior. It is derived from the Latin roots 'circa' (about) and 'diem' (day) and acts as an important regulator of a wide array of physiological functions including metabolism, sleep, body temperature, blood pressure, endocrine, immune, cardiovascular, and renal function. Consists of two major components: the central clock, residing in the suprachiasmatic nucleus (SCN) of the brain, and the peripheral clocks that are present in nearly every tissue and organ system. Both the central and peripheral clocks can be reset by environmental cues, also known as Zeitgebers (German for 'timegivers'). The predominant Zeitgeber for the central clock is light, which is sensed by retina and signals directly to the SCN. The central clock entrains the peripheral clocks through neuronal and hormonal signals, body temperature and feeding-related cues, aligning all clocks with the external light/dark cycle. Circadian rhythms allow an organism to achieve temporal homeostasis with its environment at the molecular level by regulating gene expression to create a peak of protein expression once every 24 hours to control when a particular physiological process is most active with respect to the solar day. Transcription and translation of core clock components (CLOCK, NPAS2, ARNTL/BMAL1, ARNTL2/BMAL2, PER1, PER2, PER3, CRY1 and CRY2) plays a critical role in rhythm generation, whereas delays imposed by post-translational modifications (PTMs) are important for determining the period (tau) of the rhythms (tau refers to the period of a rhythm and is the length, in time, of one complete cycle). A diurnal rhythm is synchronized with the day/night cycle, while the ultradian and infradian rhythms have a period shorter and longer than 24 hours, respectively. Disruptions in the circadian rhythms contribute to the pathology of cardiovascular diseases, cancer, metabolic syndromes and aging. A transcription/translation feedback loop (TTFL) forms the core of the molecular circadian clock mechanism. Transcription factors, CLOCK or NPAS2 and ARNTL/BMAL1 or ARNTL2/BMAL2, form the positive limb of the feedback loop, act in the form of a heterodimer and activate the transcription of core clock genes and clock-controlled genes (involved in key metabolic processes), harboring E-box elements (5'-CACGTG-3') within their promoters. The core clock genes: PER1/2/3 and CRY1/2 which are transcriptional repressors form the negative limb of the feedback loop and interact with the CLOCK|NPAS2-ARNTL/BMAL1|ARNTL2/BMAL2 heterodimer inhibiting its activity and thereby negatively regulating their own expression. This heterodimer also activates nuclear receptors NR1D1/2 and RORA/B/G, which form a second feedback loop and which activate and repress ARNTL/BMAL1 transcription, respectively. CRY1 and CRY2 have redundant functions but also differential and selective contributions at least in defining the pace of the SCN circadian clock and its circadian transcriptional outputs. Less potent transcriptional repressor in cerebellum and liver than CRY1, though less effective in lengthening the period of the SCN oscillator. Seems to play a critical role in tuning SCN circadian period by opposing the action of CRY1. With CRY1, dispensable for circadian rhythm generation but necessary for the development of intercellular networks for rhythm synchrony. May mediate circadian regulation of cAMP signaling and gluconeogenesis by blocking glucagon-mediated increases in intracellular cAMP concentrations and in CREB1 phosphorylation. Besides its role in the maintenance of the circadian clock, is also involved in the regulation of other processes. Plays a key role in glucose and lipid metabolism modulation, in part, through the transcriptional regulation of genes involved in these pathways, such as LEP or ACSL4. Represses glucocorticoid receptor NR3C1/GR-induced transcriptional activity by binding to glucocorticoid response elements (GREs). Represses the CLOCK-ARNTL/BMAL1 induced transcription of BHLHE40/DEC1 and NAMPT.
Research relevance and current trends
- Reagent standardization: using recombinant proteins as reference materials for quantitative calibration and cross-study comparability.
- Interaction-focused studies: mapping binding partners, affinity changes, and structure–function relationships across variants or domains.
- Multi-omic readouts: combining recombinant perturbations with transcript, protein, and functional endpoints to connect mechanism to phenotype.
Common research applications
- Assay development and validation: use as a defined input or standard where protein identity is required.
- Binding studies: evaluate interaction strength and specificity using plate-based or biophysical formats.
- Cell-response profiling: add protein to cultured cells and interpret downstream marker changes with appropriate controls.
Interpretation is most robust when signal changes are evaluated relative to matched controls (buffer-only, unrelated protein controls, or pathway controls) and when readouts are compared across dose and time.
Notes for experimental interpretation
- Isoforms and PTMs can influence binding and activity; ensure the expressed region and expression system match your experimental needs.
- Species differences may affect receptor binding or antibody recognition; confirm species/source alignment with your model.
- Use concept-level controls such as negative controls (no protein), matrix controls, or orthogonal readouts to support conclusions.
What is protein expression and purification?
Why is there no/low protein expression?
b. Rare codons. You should optimize codons, use strains supplementing rare codons, induce at lower temperature or grow in poor media.
c. Protein toxicity. You should use promoters with tighter regulation or lower plasmid copy number. Use pLysS/pLysE bearing strains in T7-based systems or strains that are better for the expression of toxic proteins. Start induction at high OD and shorten induction time. Add glucose when using expression vectors containing lac-based promoters.
How to avoid inclusion bodies and improve soluble expression?
b. Incorrect disulfide bond formation. You should add fusion partners, including thioredoxin, DsbA, DsbC. Clone in a vector containing secretion signal peptide to cell periplasm. Use gamiB (DE3)strains with oxidative cytoplasmic environment. Lower inducer concentration and induction temperature.
c. Incorrect folding. You should use a fusion partner. Co-express with molecular chaperones. Use strains with cold-adapted chaperones. Supplement media with chemical chaperones and cofactors. Reduce the inducer concentration and add fresh media. Induce for a shorter time at low temperature.
Why is the molecular weight of protein smaller than the predicted?
b. Imbalanced translation process of fusion protein. You should change another fusion tag or move fusion tag to C-terminal. You should induce for a shorter time at low temperature or change to poor media.
c. Protein degradation. You should replace specific protease sites. Use protease deficient strains. Induce at high OD. You should induce for a shorter time at low temperature or use protease inhibitors when breaking cells.
Why is the actual band size different from the predicted?
b. Post-translational cleavage. Many proteins are synthesized as pro-proteins, and then cleaved to give the active form.
c. Splice variants. Alternative splicing may create different sized proteins from the same gene.
d. Relative charge. The composition of amino acids have different relative charge which will affect the electrophoretic mobility.
e. Multimers such as dimerisation of a protein. This is usually prevented in reducing conditions, although strong interactions can result in the appearance of higher bands.
f. Protein structure such as disulfide bond, protein secondary structure or protein 3D structure formation.
g. Hydrophobic proteins, such as transmembrane proteins, may have difficulties in migrating into the gel, and thus resulting in different multi-banded patterns.
How to express a protein with bioactivity? Why is the protein inactive?
a. Low solubility of the protein. You should fuse desired protein to a fusion partners and lower temperature.
b. Lack of essential post translational modification. You should change another expression system.
c. Incomplete folding. You should use a fusion partner and use strains with cold-adapted chaperones. Co-express with molecular chaperones at lower temperature. Monitor disulfide bond formation and allow further folding in vitro.
d. Mutations in cDNA. You should sequence plasmid before and after induction or use a recA− strain to ensure plasmid stability. Transform E. coli before each expression round.
Why are our protein products almost invisible in pipes?
Tips: Before opening the lid, we recommend to centrifuge in a small centrifuge for 20-30 seconds firstly to ensure that the contents are on the bottom of the tube. Our quality control steps ensure that the amount of protein contained in each tube is accurate, although sometimes you can’t see the protein powder, but the protein content in the tube is still very accurate.
How is the protein purified? Is the purity guaranteed?
Although we guarantee a minimum purity standard of >85%, some of the proteins we prepared have a purity of 95% or even 97%.
How should I reconstitute and store the products?
As for short-term storage or usage, please use sterile deionized water to completely reconstitute proteins to 0.1-1.0 mg/mL. Aliquot after 10-15 minutes if needed and store at 4℃.
As for long-term storage, the cytokines or recombinant proteins are recommended to add 5-50% of glycerol (final concentration) and aliquot for long-term storage at -20℃/-80℃. Our default final concentration of glycerol is 50%. Customers could use it as reference.
What types of tags do you use for fusion?
What is the impact of a given tag type and any potential biological activity of the protein?
Can you remove the endotoxin?
Can you offer aseptic manufacture processing?
How to determine species cross-reactivity of cytokines?
b. Many mouse cytokines may also have effect on human cells, however, the activity may be lower than the corresponding human cytokines.
c. One of the few human cytokines will be more active than corresponding mouse cytokines when acting on mouse cells, such as IL-7.
d. Interferon, GM-CSF, IL-3 and IL-4 and other cytokines are species-specific and almost have no activity on non-homologous cells.
e. In contrast, fibroblast growth factor (FGF) and neurotrophin are highly conserved and both have good activity on cells of different species.
What is the general preservative? Which kind of preservative do you usually add?
What is the general protectant? What kind of protectant do you usually add?
Can’t Find What You’re Looking For? We can help you source the best match or customize a recombinant protein solution for your study. Options may include species (human/mouse/rat), protein region/domain (full-length vs fragment), tag or label (His/GST/FLAG/biotin/fluorescent), expression system (E. coli/HEK293/insect), purity grade, formulation (buffer, carrier-free, glycerol-free), activity/functional validation (binding or enzymatic assays), endotoxin level (low-endotoxin for cell-based work), mutants/variants (point mutations, isoforms), and bulk or custom packaging. Click Talk to a Scientist to submit a request form, email us at support@biohippo.com, or explore our Research Services for additional support. Our team will be in contact with you shortly.
