Native Rat Transferrin Protein, CAS No.11096-37-0

CAS: 11096-37-0 Cat. No.: np001009

등급 & 순도 Carrier Free, ≥95%(SDS-PAGE), from Rat serum; Protein concentration: See COA

Accession #

P12346

개요

Transferrin is a single polypeptide chain glycoprotein and is a member of the iron binding family of proteins. It has a molecular weight of 77 kDa and a serum concentration range of 1800 to 2700 mg/L. It is synthesized in the liver and consists of two domains each having a high affinity reversible binding site for Fe³⁺. Iron is transported in blood and interstitial fluids to sites of use and disposal. Iron/transferrin is essential in hemoglobin synthesis and for certain types of cell division. Serum concentration rises in iron deficiency and pregnancy and falls in iron overload, infection and inflammatory conditions. The function of transferrin is to transport iron from the intestine, reticuloendothelial system, and liver parenchymal cells to all proliferating cells in the body. In addition to its function in iron transport, this protein may also have a physiologic role as granulocyte/pollen binding protein (GPBP) involved in the removal of certain organic matter/allergens from serum.

사양

Product Name

Native Rat Transferrin Protein, CAS No.11096-37-0

동의어

Rat Transferrin | Transferrin, Rat | Transferrin from Rat serum | Serotransferrin | Beta-1 metal-binding globulin | Siderophilin | Tf | Tfn | Trf

등급

Carrier Free

사양 및 순도

Carrier Free,≥95%(SDS-PAGE),from Rat serum; Protein concentration: See COA

생화학 및 생리적 메커니즘

Transferrins are iron binding transport proteins which can bind two Fe3+ ions in association with the binding of an anion, usually bicarbonate. It is responsible for the transport of iron from sites of absorption and heme degradation to those of storage a

가입 번호

P12346

예상 분자량

77 kDa

CAS

11096-37-0

분자 유형

Protein

Product Line

생물 제품

제품 특성

ALogP

-2.5

보관 및 배송

모양

Lyophilized

집중력

from Rat serum; Protein concentration: See COA

보관 조건

Store at -20°C,Avoid repeated freezing and thawing

배송

Ice chest + Ice pads

안정성 및 스토리지

Store at -20°C or -80°C long term (6 months). Upon receipt, it is recommended to aliquot.

Application Protocols

The following example workflows are provided as general literature guidance; optimize for your system. Item-specific validated applications are not provided.

1. Preparation of holo-transferrin

• Dissolve apo-transferrin in HEPES-buffered saline (pH 7.4) at 2–5 mg/mL.
• Prepare Fe(III)-NTA (molar ratio Fe:NTA ~1:2) and add with 10–25 mM NaHCO3 to protein at 1.5–2 mol Fe per mol protein.
• Incubate 30–60 min at RT; remove excess reagents by desalting. Verify iron loading by A465/A280 ratio or ICP-MS.

2. TfR1 binding ELISA (ligand-coated)

• Coat plates with recombinant TfR1 ectodomain (1–5 µg/mL) overnight at 4°C in carbonate buffer.
• Block with 3% BSA in PBS (or carrier-free alternative if avoiding animal proteins).
• Add serial dilutions of transferrin (holo and apo as controls) in PBS.
• Detect bound transferrin with anti-transferrin antibody and HRP-conjugated secondary; develop and fit binding curves.

3. Fluorescent uptake assay in cultured cells

• Label transferrin with NHS–Alexa Fluor dye (DOL 1–3) and purify.
• Incubate cells at 4°C with labeled transferrin to bind surface TfR1, wash, then shift to 37°C to allow internalization.
• Fix cells at time points; quantify uptake by flow cytometry or confocal microscopy.

Notes:

• Maintain defined iron state (apo vs holo) throughout.
• Include chelator controls to demonstrate iron-dependent effects.

Biological Roles

Transferrin is the principal extracellular iron(III) transporter in vertebrates, maintaining iron solubility and delivering it to cells via receptor-mediated endocytosis.

Key functions (literature):

• Iron binding/transport: Each transferrin molecule binds up to two Fe(III) ions with a synergistic carbonate anion, preventing Fenton chemistry and controlling iron availability.
• Receptor interaction: Holo-transferrin binds transferrin receptor 1 (TfR1) on the cell surface; the complex is endocytosed, iron is released in acidified endosomes (pH ~5–6), and apotransferrin recycles to the surface to dissociate at neutral pH.
• Homeostasis: Regulates systemic iron distribution between liver, erythroid precursors, and other tissues; impacts ferritin storage and hepcidin signaling indirectly through iron flux (systems-level context).
• Glycosylation: N-linked glycans influence serum half-life and receptor affinity.

Rat-specific context (literature):

• High sequence and structural conservation with human transferrin enables cross-species studies of TfR1 biology; minor sequence and glycosylation differences can modulate receptor affinity and isoelectric focusing patterns.

Experimental considerations:

• Chelation state and carbonate concentration modulate iron occupancy and receptor binding.
• Oxidative modifications or proteolysis reduce function; handle gently at low temperature and avoid metal-catalyzed oxidation.

Buffer Applications

As a protein reagent, performance depends strongly on buffer composition. Item-specific buffer formulation is not provided; tailor to your assay.

General buffer guidance (literature/practice):

• Standard working buffers: PBS (10–50 mM phosphate, 150 mM NaCl, pH 7.2–7.4) or HEPES (10–25 mM, 150 mM NaCl, pH 7.2–7.5) support structural stability.
• Iron state control: For apo-transferrin, include 1–2 mM EDTA or citrate during preparation then dialyze into chelator-free buffer. For holo-transferrin, add Fe(III)-NTA and 10–25 mM NaHCO3; remove excess iron complex by desalting.
• Stabilizers: 5–10% glycerol or 0.2–0.5 M sucrose/trehalose can protect during freezing; avoid if they interfere with downstream assays (e.g., SPR baseline drift).
• Surfactants: 0.005–0.01% Tween-20 may reduce adsorption to plastics; verify compatibility with cell assays and biophysical methods.
• Avoid: Strong acids/bases (pH <5 or >9) for extended periods; high concentrations of denaturants (urea, guanidine) unless intentionally unfolding.

Preparation tips:

• Use metal-clean glassware for iron-binding studies; rinse with dilute acid then copious water to remove trace metals.
• Degas and filter (0.22 µm) buffers for kinetic assays (SPR/BLI) to minimize bubbles and particulates.
• Record buffer carbonate content because it directly affects iron occupancy and spectral signatures.

Green Alternatives

Green chemistry considerations for protein reagents center on buffer selection, waste reduction, and cold-chain efficiency rather than solvent replacement.

Opportunities (general guidance):

• Buffer systems: Prefer Good’s buffers (HEPES, MOPS) prepared with CO2-free water to minimize carbonate variability, reducing experimental repeats. Avoid azide if feasible due to aquatic toxicity; consider short-term storage with sterile filtration and low-temperature handling instead.
• Minimizing hazardous additives: Use low concentrations of preservatives compatible with downstream assays (e.g., thimerosal-/azide-free when possible) to reduce disposal impact.
• Process intensification: Plan aliquots to eliminate repeated freeze–thaw cycles, decreasing material loss and repeat experiments.
• Packaging: Choose recyclable secondary containers and consolidate shipments to reduce dry-ice and coolant use. The item ships cold with ice pads; coordinate receipt to avoid reshipments.

Comparison (illustrative, literature-based):

• Sodium azide vs preservative-free/sterile technique • Azide: Effective antimicrobial but toxic to aquatic life and incompatible with copper plumbing. • Preservative-free + sterile workflow: Requires aseptic handling/filtration and cold storage; lowers hazardous waste footprint.

Trade-offs:

• Removing carrier proteins reduces background but may increase adsorption losses; mitigate with low-bind plastics or benign excipients (e.g., trehalose) rather than adding BSA if animal-free workflows are desired.

Pharmaceutical Uses

No clinical or therapeutic claims are made for this product; it is for research use only.

Relevant formulation/manufacturing contexts (literature/general):

• Media supplementation: Transferrin is widely employed in serum-free and chemically defined cell culture media to supply bioavailable iron under controlled conditions; holo- vs apo-form selection tunes iron delivery rates.
• Conjugation scaffold: Leveraged in research on ligand-directed delivery via TfR1; transferrin can be chemically conjugated to cargos (fluorophores, nanoparticles) to study receptor-mediated endocytosis and intracellular trafficking.
• Analytical standards: Used as a glycoprotein and mass standard in method qualification (e.g., SEC, CE-SDS, LC-MS) and as a system suitability standard for intact protein MS.
• Reference materials: Employed as an isoelectric focusing standard due to distinct sialoform microheterogeneity profiles.

Regulatory/compendial status:

• No pharmacopeial monograph or lot-specific regulatory status is provided for this item. Any cGMP or clinical manufacturing use would require separate qualification; verify all critical quality attributes from the CoA/Spec Sheet and perform in-house testing as needed.

Physical Properties

Item-specific physico-chemical specifications:

• Appearance: Not specified for this item; refer to CoA/Spec Sheet.
• Molecular weight: Not specified for this item; refer to CoA/Spec Sheet.
• Isoelectric point (pI): Not specified for this item; refer to CoA/Spec Sheet.
• Extinction coefficient (A280): Not specified for this item; refer to CoA/Spec Sheet.
• Solubility: Typically soluble in physiological buffers; item-specific solubility not specified for this item; refer to CoA/Spec Sheet.

General literature values/context (non-item-specific):

• Typical apparent MW for serum transferrin (monomeric, unglycosylated backbone) ≈ 75–80 kDa; glycosylation increases apparent size.
• pI commonly near 5.3–6.5 depending on glycoforms and species.
• Highly hydrophilic; readily soluble at neutral pH in PBS, HEPES, or Tris buffers (0.1–10 mg/mL typical working range).
• Iron-binding stoichiometry: up to 2 eq Fe(III) per protein (holo-form); apoprotein is iron-free (apo-form). Protonation state and carbonate availability affect occupancy.

Notes for practical use (general):

• Chelators (EDTA, citrate) reduce iron occupancy; include/exclude intentionally depending on apo/holo needs.
• Avoid strong agitation/foaming; proteins can denature at air–liquid interfaces.
• For accurate concentration, use A280 with a transferrin-specific ε (determine from CoA or literature) or BCA assay with BSA standard.

Quality and Grades

• Grade/Purity (item-specific): Carrier Free — indicates no added carrier proteins (e.g., BSA, gelatin) or stabilizing proteins in the formulation. This facilitates accurate mass balance, label-to-protein conjugation, receptor-binding assays, and proteomics where exogenous proteins would interfere.

Implications of Carrier Free:

• Advantages: Maximizes specific activity per mass; reduces background in immunoassays and cell uptake assays; enables precise molar calculations.
• Considerations: Without carriers, low-concentration solutions may adsorb to plastics and glass. Mitigation strategies include using low-bind tubes, adding inert sugars (trehalose/sucrose) or small amounts of non-interfering protein/PEG post-aliquoting if compatible with your assay.

Identity/Quality controls (item-specific status):

• Specific identity tests, purity by SDS-PAGE/HPLC, endotoxin level, iron saturation state, glycoform distribution: Not specified for this item; refer to CoA/Spec Sheet.

General expectations for native transferrin preparations (literature/good practice):

• SDS-PAGE should show a predominant band in the ~75–85 kDa region with minor glycoform microheterogeneity.
• Functional QC may include Fe(III) binding/release or TfR1 binding assay.

Documentation:

• For method-specific requirements (cell culture, bioassays), verify endotoxin and bioburden from the CoA. If not provided, perform in-house qualification.

Reaction and Applications

Item-specific intended use: Research use only (no clinical use). Transferrin is widely used as a functional protein reagent in iron metabolism and receptor biology.

Common research applications (general literature guidance):

• Iron-loading/iron-release studies: Prepare apo- and holo-transferrin to quantify iron binding, carbonate dependence, and pH-triggered release (endosomal mimic at pH ~5.5).
• Receptor interaction assays: Analyze binding to rat/human TfR1 by ELISA, bio-layer interferometry (BLI), or SPR; measure KD, on/off rates.
• Cell biology: Supplement serum-free media at defined µg/mL levels to support proliferation via iron delivery; compare holo vs apo effects. Validate endotoxin if using with sensitive cells.
• Conjugation/labeling: Attach fluorophores, biotin, or drugs via lysine (NHS-ester) or carbohydrate (periodate-oxidized glycan) chemistries to target transferrin receptor-mediated uptake.
• Analytical standards: Use as a mass and glycoprotein standard in SDS-PAGE, SEC, or LC-MS method development.

Practical tips:

• Define and document iron saturation: prepare apo-form with mild chelators and reconstitute holo-form using Fe(III)-nitrilotriacetate plus carbonate; verify at A465/A280 or by ICP-MS (literature).
• Maintain protein integrity: keep on ice during manipulations; avoid vigorous vortexing; use low-bind plastics.
• For binding studies, pre-clear buffers of trace metals or chelators according to the experimental aim to avoid shifting saturation state.

Reaction Conditions

Typical conditions for common transferrin manipulations (general literature guidance; not item-specific):

• NHS-ester labeling (lysine-directed): • Buffer: 50 mM HEPES or sodium phosphate, pH 7.5–8.3, chelator-free if iron state must be preserved. • Protein concentration: 0.5–5 mg/mL; dye:protein molar ratio 2–10:1 depending on desired DOL. • Temperature/time: 4–25°C for 30–60 min; quench with Tris or ethanolamine (50 mM).

• Maleimide–thiol conjugation (if free Cys available): • Buffer: 50 mM sodium phosphate, 100–150 mM NaCl, pH 6.5–7.2 to minimize maleimide hydrolysis. • Reducing conditions: Brief TCEP/DTT treatment may be required; remove reducing agent prior to coupling.

• Glycan-directed coupling: • Oxidation: 1–5 mM NaIO4, 0–4°C, dark, 15–30 min in acetate buffer pH ~5.5; immediately quench and proceed to hydrazide/alkoxyamine ligation (pH 5–6) with aniline catalyst if desired.

• Apo/holo interconversion: • Apo preparation: Dialyze against 0.1 M citrate or 10–50 mM EDTA at pH ~5–6, then into chelator-free buffer. • Holo loading: Mix apo-transferrin with Fe(III)-NTA (or FeCl3 + NTA) and 10–25 mM NaHCO3 at pH 7.4; incubate at RT 30–60 min; remove excess by desalting.

• Binding assays (SPR/BLI): • Running buffer: HEPES-buffered saline, pH 7.4, 0.005–0.01% surfactant; temperature 25°C.

Always verify retention of activity (TfR1 binding/iron spectra) after any chemical treatment.

Safety and Handling

Safety data for this specific item:

• GHS classification: Not specified for this item; refer to SDS.
• Signal word / H-statements / Pictograms: Not specified for this item; refer to SDS.
• Research use note: For research use only.
• Storage conditions (item-specific): Store at −20°C; avoid repeated freezing and thawing.
• Shipping (item-specific): Shipped in ice chest with ice pads.

General laboratory safety for proteins (guidance; defer to SDS for authoritative information):

• PPE: Laboratory coat, gloves, and eye protection when handling lyophilized powders or solutions.
• Avoid inhalation of lyophilized dust and contact with eyes/skin; handle in a clean environment to prevent contamination.
• Biological origin note: Although purified and intended for research, treat as potentially bioactive; avoid ingestion and injection; dispose of waste per institutional biosafety procedures.
• Incompatibilities: Strong oxidants, extremes of pH, proteases; metal chelators (EDTA) alter iron-binding state. Sodium azide (if added by user) is incompatible with copper plumbing.

First-aid overview (general):

• Skin/eye contact: Rinse with water for several minutes; seek medical attention if irritation persists.
• Inhalation of dust/aerosol: Move to fresh air; seek medical advice if symptoms occur.
• Ingestion: Rinse mouth; do not induce vomiting; seek medical advice.

Always consult the product SDS for definitive hazard and handling information.

Solvent Selection

This is a protein reagent; solvent selection translates to buffer formulation and excipients rather than organic solvent choice.

Buffer considerations (general guidance):

• pH: Neutral range (pH 7.2–7.5) maintains transferrin structural integrity and physiological conformation.
• Buffer systems: PBS, HEPES (10–50 mM), or Tris (20–50 mM). Avoid phosphate if later using carbodiimide chemistry on carboxylates.
• Ionic strength: 100–200 mM NaCl commonly stabilizes proteins and reduces nonspecific adsorption.
• Metal ions/chelators: Presence of carbonate and absence of chelators favor iron loading; EDTA/citrate promote apo-state. Choose intentionally based on application.
• Additives: 5–10% glycerol or 0.1–0.5 M sucrose/trehalose can improve freeze–thaw stability; nonionic detergents (0.01% Tween-20) may reduce surface loss but can affect some assays.

Limited organic solvent compatibility:

• Avoid >10% v/v organic cosolvents (acetonitrile, ethanol, DMSO) to prevent denaturation; if conjugation chemistry requires organic components, add slowly at low percentage under cold conditions and validate activity.

Comparison (use-case oriented):

• HEPES vs PBS: HEPES offers superior pH buffering near 7.4 and minimal metal chelation; PBS is biologically compatible but phosphate can compete in certain coupling reactions and with some metal coordination steps.

Storage and Reconstitution

Item-specific conditions:

• Storage: Store at −20°C. Avoid repeated freezing and thawing.
• Shipping: Ice chest with ice pads.

General reconstitution guidance (optimize to your assay; not item-specific):

• Reconstitution buffer: Chill and use a neutral buffer (e.g., 20–50 mM HEPES or PBS, 100–150 mM NaCl, pH 7.2–7.5). If iron state matters, omit chelators for holo-forms or include during apo preparation.
• Concentration: Target 0.5–5 mg/mL for stock solutions to minimize adsorption. Use low-bind tubes and pre-wet pipette tips.
• Aliquoting: Immediately divide into single-use aliquots; snap-freeze in liquid nitrogen or a dry ice/ethanol bath and store at −20°C or below. Avoid more than one freeze–thaw cycle.
• Stabilizers (optional, assay-dependent): 5–10% glycerol or 0.2–0.5 M sucrose/trehalose can protect during freezing; avoid if interfering with downstream readouts.
• Thawing: Thaw on ice; gently mix by inversion; avoid vigorous vortexing to reduce foaming/denaturation.
• Sterility: For cell-based work, filter through a 0.22 µm low-protein-binding membrane into sterile tubes.

Documentation:

• Record buffer composition, pH, and iron saturation state (apo/holo) on aliquot labels.
• If concentration is required, determine by A280 using the extinction coefficient from the CoA or literature; confirm with orthogonal protein assays if critical.

Structure and Identity

Native Rat Transferrin is a glycosylated iron‑transport protein purified from rat source (proteinaceous macromolecule; not a small molecule).

• SKU: np001009
• Product name: Native Rat Transferrin Protein
• CAS: 11096-37-0
• Category: Protein (research reagent)
• Grade/Purity: Carrier Free (no added stabilizing proteins per item listing)
• Molecular formula: Not specified for this item; refer to CoA/Spec Sheet.
• Molecular weight: Not specified for this item; refer to CoA/Spec Sheet.
• SMILES / InChI / InChIKey: Not applicable for macromolecular proteins.

Structural features (general literature description):

• Single-chain serum glycoprotein with two homologous lobes (N- and C-lobes), each capable of binding one Fe(III) ion with a synergistic carbonate (CO3 2−) anion.
• Multiple N-linked glycans; extensive surface lysines enable conjugation via NHS-esters (literature).
• Binds transferrin receptor (TfR1) via defined patches primarily on the C-lobe; pH-dependent conformational change mediates iron release in endosomes (literature).

2D/primary structure description (literature):

• Polypeptide chain (≈ 680–700 aa range in mammals) organized into bilobal architecture connected by a short peptide linker; each lobe subdivided into two domains forming a metal-binding cleft with conserved tyrosines, histidine, aspartate, and carbonate coordination.

Synthetic Utility

As a native protein, transferrin is not a small-molecule building block; however, it offers versatile bioconjugation handles and surface chemistry for creating targeted research tools.

Functional groups (protein context; literature):

• Primary amines (Lys Nε, N-terminus): React with NHS-esters and isothiocyanates for labeling (biotin, dyes, PEG).
• Carboxylates (Asp/Glu, C-terminus): Carbodiimide chemistry (EDC/NHS) to couple amines under mildly acidic/neutral pH.
• Thiols (Cys): If accessible/reduced, conjugate via maleimide/iodoacetamide; disulfide engineering can introduce site-specific handles.
• Glycans: Periodate oxidation yields aldehydes for oxime/hydrazone ligations; enables Fc-free, glycan-directed coupling.

Utility examples:

• Fluorescent or biotinylated transferrin to probe TfR1 internalization kinetics by flow cytometry or microscopy.
• Nanoparticle functionalization (e.g., iron oxide, gold) with transferrin to study receptor-mediated uptake pathways in vitro.
• Affinity matrices: Immobilize transferrin on agarose or magnetic beads to capture TfR1 ectodomains or to enrich carbonate/iron-dependent binding partners.

Practical notes:

• Maintain functional iron-binding state throughout chemistry if receptor affinity is required; perform conjugations in chelator-free buffers with controlled carbonate and pH.
• Characterize conjugates by SDS-PAGE, SEC, UV–Vis, and where applicable, intact MS; quantify degree of labeling via absorbance deconvolution or HABA assay (for biotin).

Target Specificity

Not applicable. This product is a native protein (transferrin), not an antibody or affinity reagent with a defined antigen/epitope specificity. For receptor-binding studies involving transferrin receptor (TfR1), consult literature protocols under Reaction & Applications and Application Protocols.

자주 묻는 질문

What are the CAS number, molecular formula and molecular weight?

The CAS Number is 11096-37-0.

What is the purity of this product, and how is it determined?

This product is supplied at ≥95% purity, determined by SDS-PAGE. Lot-specific values are stated on the Certificate of Analysis.

What does Carrier Free mean?

Carrier Free indicates that the material has been processed and tested for specialty industrial processing. Specifications focus on the impurities that affect performance in that application — for example, metal content for electronics, particle size for batteries, refractive index for optics, or moisture content for moisture-sensitive processes.

How should this product be stored?

Store at ?20 °C. Avoid repeated freeze–thaw cycles. Aliquot into single-use volumes before freezing.

How is this product shipped?

This product ships in an insulated container with ice pads. Unpack on arrival and transfer it to the storage condition stated above.

What documentation is provided?

Available product documentation, including Certificates of Analysis (COA), Safety Data Sheets (SDS), and specification sheets, is shown in the product document area. Document availability and access follow the current site policy.