Kininogen, High Molecular Weight from Human Plasma

Cat. No.: np001047

GRADE & PURITY BioReagent, Native, ≥95%(SDS-PAGE), Protein concentration: See COA

Accession #

P01042

Visão geral

 High Molecular Weight Kininogen (HMWK) is a multifunctional plasma protein primarily synthesized by hepatocytes. As the precursor to bradykinin, HMWK plays a central role in the kallikrein-kinin system, where it is cleaved by plasma kallikrein to release bradykinin, a peptide that mediates vasodilation, increased vascular permeability, and pain signaling. Beyond its role as a bradykinin precursor, HMWK functions as a critical cofactor in the intrinsic pathway of blood coagulation, facilitating the activation of factors XI, XII, and prekallikrein. Additionally, HMWK acts as a major extracellular cysteine proteinase inhibitor, helping to regulate protease activity and protect tissues from excessive proteolysis.

Common research uses

Dysregulation of HMWK has been implicated in various pathological conditions, including hereditary angioedema, where bradykinin overproduction leads to recurrent swelling episodes. Furthermore, altered kininogen activity is associated with cancer progression, muscular dystrophy, and joint diseases, making HMWK a potential therapeutic target and biomarker in these disorders.

Common uses include cardiovascular research, enzymatic and inhibition assays, therapeutics research, IVD Assay standards, calibrators and controls.

Specifications

Product Name

Kininogen, High Molecular Weight from Human Plasma

Sinónimos

HMW kininogen | Kininogen, HMW | Kininogen-1 | kininogen 1 | KNG1 | BK | HK | BDK | KNG | HAE6 | HMWK | Kininogen, High Molecular Weight | High Molecular Weight Kininogen | High‑molecular‑weight kininogen | HMW kininogen | Kininogen, HMW | Kininogen-1 | k

Grau

BioReagent, Native

Especificações e pureza

BioReagent, Native, ≥95%(SDS-PAGE), Protein concentration: See COA

Mecanismos bioquímicos e fisiológicos

Kininogens are inhibitors of thiol proteases. HMW-kininogen plays an important role in blood coagulation by helping to position optimally prekallikrein and factor XI next to factor XII; HMW-kininogen inhibits the thrombin- and plasmin-induced aggregation

Número de acesso

P01042

Peso molecular previsto

120 kDa

Tipo de molécula

Peptide

Product Line

biological_products

Armazenamento e envio

Forma

Frozen in 10 mM Na acetate, pH 5.5, with 250 mM NaCl

Concentração

Protein concentration: See COA

Condições de armazenamento de armazenamento

Store at -80°C,Avoid repeated freezing and thawing

Enviado em

Dry ice packs + Cold packs

Estabilidade e armazenamento

Store at -80℃ long term (>1 year). Upon receipt, it is recommended to aliquot. Avoid freeze/thaw cycle.

Application Protocols

Tested applications, validated protocols, and recommended working concentrations for this specific item are Not specified for this item; refer to CoA/Spec Sheet.

General caution: Because this is a native plasma-derived protein and sensitive to proteolysis, protocol details (buffers, temperatures, additives, and timing) strongly influence outcomes. Users should optimize conditions for their assay end-points (e.g., bradykinin generation, binding kinetics) and consult peer-reviewed literature for assay-specific parameters.

Note: The above is not a substitute for item-specific instructions. Please refer to the lot-specific documentation when available.

Biological Roles

High-molecular-weight kininogen (HK) is a central cofactor in the kallikrein–kinin and contact activation systems.

• Contact system assembly (literature/general):

  • HK binds to negatively charged surfaces and, in the presence of Zn2+, scaffolds prekallikrein (PK) and factor XI (FXI), facilitating their proximity and activation. Activated plasma kallikrein cleaves HK to release bradykinin (BK), yielding two-chain HKa.

• Bradykinin biogenesis (literature/general):

  • Domain D4 of HK contains the nonapeptide BK (Arg–Pro–Pro–Gly–Phe–Ser–Pro–Phe–Arg). BK is rapidly generated during contact activation and is subsequently degraded by kininases; studies often quantify its appearance to monitor pathway activity.

• Cystatin-like domains and protease regulation (literature/general):

  • HK’s D2–D3 domains share homology with cystatins and can modulate cysteine proteases, influencing pericellular proteolysis and matrix interactions.

• Cell and matrix interactions (literature/general):

  • The histidine-rich D5 domain mediates binding to cell surfaces and extracellular matrices; Zn2+ enhances these interactions. HK/HKa can interface with endothelial and leukocyte receptors in vitro, making it useful for mechanistic binding studies.

• Hemostatic cross-talk (literature/general):

  • Through scaffolding FXI and PK, HK influences intrinsic pathway activation in vitro. Researchers use purified HK to dissect contact pathway contributions in coagulation models.

These roles are provided as biochemical context for research use; no medical or clinical claims are implied. Item-specific activity or binding properties are Not specified for this item; refer to CoA/Spec Sheet.

Buffer Applications

HK’s structural integrity and complex assembly behavior depend on pH, ionic strength, and divalent cations. The following are literature-based guidelines for preparing buffers; they are not item-specific specifications.

• Working buffers:

  • HEPES-buffered saline (20–50 mM HEPES, 150 mM NaCl, pH 7.4): strong pH control near 37°C; minimal metal binding; suitable for kinetic assays.
  • PBS (1×, pH 7.2–7.6): widely used for binding and handling; supplement ZnCl2 (e.g., 10–50 µM) when studying assembly with PK/FXI.
  • Tris-buffered saline (20–50 mM Tris, 150 mM NaCl, pH 7.5–8.0): common for biochemical work; verify compatibility with metal-dependent steps as Tris can weakly coordinate metals.

• Additives (if compatible with assay goals):

  • 0.01–0.1% carrier protein (HSA/BSA) to reduce adsorption.
  • 5–20% glycerol for frozen aliquots; avoid for LC–MS BK quantitation unless validated.
  • Protease inhibitors to prevent unintended cleavage; omit in BK-generation assays.

• Metal ion control:

  • Include defined Zn2+ to promote PK/FXI binding; use metal-clean plastics and Chelex-treated buffers if low-background metal control is required.

• Example buffer recipes (literature/general):

  • “Contact assembly buffer”: 20 mM HEPES, 140 mM NaCl, 2 mM CaCl2, 50 µM ZnCl2, pH 7.4.
  • “Handling buffer”: PBS + 0.1% HSA, pH 7.4, for short-term storage on ice.

Item-specific buffer requirements or formulation, if any, are Not specified for this item; refer to CoA/Spec Sheet.

Green Alternatives

For protein reagents, sustainability focuses on source, buffer composition, and workflow efficiency rather than organic solvent replacement.

• Source considerations:

  • Plasma-derived (this item): reflects native human post-translational modifications. Ethical sourcing and donor screening are essential but involve human-derived material.
  • Greener alternative (context): recombinant human HMW kininogen fragments or domains produced in mammalian cells can reduce reliance on human plasma and enable defined composition; however, recombinant full-length HK is not widely available and may differ in glycosylation/activity (tradeoff).

• Buffer and additive choices:

  • Prefer Good’s buffers (HEPES, MOPS) over phosphate if downstream metal-ion–sensitive assays require precise control; avoid azide where possible due to toxicity and waste handling concerns.
  • Use glycerol (biobased grades available) for cryoprotection instead of high concentrations of organic cosolvents.

• Process efficiency:

  • Plan aliquoting to eliminate repeated freeze–thaw cycles, reducing waste.
  • Employ miniaturized assay formats (microplates, microfluidics) to lower material use and waste generation.

Comparison (general):

• Plasma-derived HK: native modifications; potential lot variability; human-source biosafety considerations.
• Recombinant domains: defined composition; potentially greener sourcing; may not fully recapitulate native full-length function.

These are general sustainability notes; item-specific certifications or environmental attributes are Not specified for this item; refer to CoA/Spec Sheet.

Pharmaceutical Uses

This plasma-derived protein is supplied strictly for research use only.

• Formulation/bioprocess research roles (literature/general, not therapeutic use):

  • Reference material in in vitro coagulation/contact-activation models supporting development of medical device hemocompatibility assays (e.g., evaluating surface-induced activation pathways under controlled conditions).
  • Analytical standards and positive controls in kallikrein–kinin pathway assays (e.g., bradykinin generation tests) for method development and validation.
  • Ligand in binding studies to characterize interactions with prekallikrein or factor XI, informing mechanistic understanding relevant to upstream process development decisions.

• Excipient/compendial status: Not applicable. There is no item-specific pharmacopeial monograph or excipient status provided. Not specified for this item; refer to CoA/Spec Sheet.

• Manufacturing considerations (research context):

  • Because it is native and potentially microheterogeneous, HK is best suited as a biochemical reagent rather than a process raw material where lot-to-lot constancy is critical.

No clinical or therapeutic claims are made. Any use in regulated applications would require independent qualification of the lot; such qualification data are Not specified for this item; refer to CoA/Spec Sheet.

Physical Properties

• Item-specific physicochemical specifications (BP, MP, density, exact molar mass, extinction coefficient, pI): Not specified for this item; refer to CoA/Spec Sheet.

• General/literature properties for HMW kininogen (for context only; not item specifications):

  • Molecular mass: typically reported ~120 kDa for the intact single-chain protein; two-chain HKa remains ~120 kDa total after BK release (literature)
  • Isoelectric point: reported near neutral to slightly acidic depending on glycoform (approx. pI ~6–7, literature, glycosylation-dependent)
  • Solubility: readily soluble in physiological buffers (e.g., PBS, Tris, HEPES at pH 7.2–7.8); solubility enhanced by low ionic strength and presence of carrier proteins (literature)
  • Stability: sensitive to proteolysis (especially by kallikrein and trypsin-like proteases); stabilized on ice and by inclusion of protease inhibitors when proteolysis is not desired (literature)
  • Metal ion interactions: binds Zn2+ (low-to-micromolar affinity), which promotes complex formation with prekallikrein and factor XI on surfaces (literature)

• Practical notes (general):

  • Avoid vigorous vortexing and foam; proteins may denature at interfaces.
  • Filter sterilization should use low-protein-binding membranes (e.g., PVDF, PES) to minimize loss.
  • If concentration is required, use centrifugal ultrafiltration devices with an appropriate MWCO (e.g., 30–50 kDa), pre-rinsed to reduce nonspecific binding.

All numerical values above are literature context and not item specifications.

Quality and Grades

• Item-specific grade: BioReagent, Native (plasma-derived). This indicates the material is isolated from human plasma without recombinant tags and is intended for research and biochemical applications, not for diagnostic or therapeutic use.

• Implications of “Native, plasma-derived” for HMW kininogen:

  • Authentic post-translational modifications: Retains native human glycosylation and proteolytic processing propensities, important for functional studies of contact activation and bradykinin release.
  • Microheterogeneity: Glycoforms and partial processing can vary between lots; functional activity and apparent molecular mass may show minor lot-to-lot differences. Always consult the lot-specific CoA for purity (e.g., SDS-PAGE profile), activity, and buffer composition.
  • Pathogen safety: Plasma-derived materials are typically sourced and processed under donor screening and pathogen-reduction steps, but they remain for research use only. Follow institutional biosafety practices.

• What to check on the CoA/Spec Sheet (not specified here):

  • Purity assessment method (e.g., SDS-PAGE densitometry), residual protease activity, endotoxin level, buffer formulation, and protein concentration determination method (A280 vs. BCA).
  • Any stabilizers or preservatives present (e.g., sugars, salts). Not specified for this item; refer to CoA/Spec Sheet.

• Suitability: BioReagent grade is appropriate for enzymology, binding assays, pathway reconstitution, and method development. For highly sensitive cell-based or omics workflows, verify endotoxin and excipient profile on the lot CoA.

Reaction and Applications

As a functional cofactor of the contact activation system, high-molecular-weight kininogen (HK) is widely used in reconstituted biochemical pathways and surface-activation models.

• Typical research applications (literature/general):

  • Kallikrein–kinin system reconstitution: Combine HK with prekallikrein and negatively charged surfaces (e.g., kaolin, dextran sulfate) to study FXII-independent contact activation and bradykinin release kinetics.
  • Bradykinin generation assays: Monitor BK release upon addition of plasma kallikrein; detect BK by LC–MS, ELISA, or bioassay.
  • Coagulation/contact pathway studies: Assess assembly with factor XI and prekallikrein on polyanionic surfaces; evaluate the role of Zn2+ in promoting complex formation.
  • Protease inhibition/interaction mapping: Use HK/HKa to probe binding to endothelial cell receptors and to study cystatin-like domain interactions with cysteine proteases.
  • Method controls and standards: Serve as a positive control substrate/cofactor in enzymatic assays or as a capture ligand in binding experiments.

• Practical tips:

  • Handle on ice and minimize shear and foam. Include protease inhibitors only when the goal is to prevent unscheduled cleavage; omit them in BK-generation assays.
  • Titrate Zn2+ (e.g., 10–100 µM, literature) for optimal assembly with prekallikrein/FXI; use metal-clean buffers to ensure reproducibility.
  • Use low-protein-binding plastics and pre-blocked surfaces to reduce adsorption losses at low nanomolar concentrations.

All application details above are provided as general literature guidance and not as item-specific performance claims.

Reaction Conditions

The “reactions” relevant to high-molecular-weight kininogen are enzymatic cleavages and assembly events in the contact system. The following are general literature conditions for in vitro assays; they are not item specifications.

• Bradykinin generation assays (literature/general):

  • Buffer: HEPES or PBS, pH 7.4; 100–150 mM NaCl; optional 10–50 µM ZnCl2.
  • Temperature: 25–37°C (37°C commonly used to match physiological kinetics).
  • Enzyme: purified plasma kallikrein or contact-activating surface plus prekallikrein.
  • HK concentration: typically 10–500 nM depending on detection method; validate linear range.
  • Readout: BK quantitation by LC–MS/MS or ELISA; time courses 1–60 min.

• Contact pathway assembly (literature/general):

  • Components: HK, prekallikrein, factor XI; polyanionic surface (e.g., dextran sulfate, kaolin); Zn2+ to enhance complex formation.
  • Buffer: 20 mM HEPES, 140 mM NaCl, pH 7.4; low-binding plastics.
  • Conditions: gentle mixing at room temperature or 37°C; sampling across minutes to hours.

• Protease inhibition mapping (literature/general):

  • Conditions: near-neutral pH; inclusion or omission of Zn2+ to probe binding; use of competing peptides for domain mapping.

• Controls and precautions:

  • Include protease inhibitor cocktails for non-cleavage binding assays; exclude them when measuring BK generation.
  • Preclear buffers of trace proteases and metals; verify background BK in blanks.

Item-specific activity, kinetics, or optimal conditions are Not specified for this item; refer to CoA/Spec Sheet.

Safety and Handling

• GHS/CLP information for this specific item (signal word, hazard classes, pictograms, H-statements): Not specified for this item; refer to the product SDS.

• General handling guidance for human plasma–derived proteins (literature/best practice):

  • Biosafety: Although commercial human plasma derivatives are processed, handle as if potentially infectious. Use BSL-2 precautions where appropriate. Wear lab coat, gloves, and eye protection. Avoid aerosol generation.
  • Allergenicity/protein exposure: Minimize inhalation of lyophilized powders or aerosols; work in a biological safety cabinet when reconstituting if feasible.
  • Proteolysis/denaturation risks: Maintain on ice during handling. Use protease inhibitors only if compatible with your assay (avoid if you plan to study kallikrein/FXI activation).
  • Incompatibilities: Avoid strong oxidants, extremes of pH (<5 or >9), organic solvents, and anionic detergents unless the experimental design requires them.
  • First aid (overview; defer to SDS): Skin/eye contact—rinse with water. Inhalation—move to fresh air. Ingestion—rinse mouth; seek medical attention according to institutional policy.

• Waste disposal: Dispose according to institutional biosafety rules for human-sourced materials; decontaminate with appropriate disinfectants (e.g., freshly prepared 0.5% sodium hypochlorite) before discard if required.

Always consult the item’s SDS and your institution’s EHS guidance for authoritative safety and handling instructions.

Solvent Selection

For this protein reagent, “solvent” refers to the aqueous buffer system used for reconstitution, storage, and assays.

• Applicable buffer systems (general guidance):

  • Physiological: PBS (pH 7.2–7.6), HEPES (20–50 mM, pH 7.2–7.6), or Tris (20–50 mM, pH 7.5–8.0), with 100–150 mM NaCl to maintain solubility.
  • Divalent cations: Low micromolar Zn2+ can promote complex formation with prekallikrein and FXI; include only if consistent with your assay objectives (literature).
  • Stabilizers: 0.1% carrier protein (e.g., HSA/BSA) and 5–20% glycerol can reduce adsorption and freeze–thaw damage for aliquots (literature best practice).

• Avoid:

  • Strong denaturants (SDS, high urea/guanidine) unless purposeful denaturation is required.
  • Organic cosolvents (>10%) that can destabilize tertiary structure.
  • Low-ionic-strength water that can increase surface adsorption losses.

• When to choose buffers:

  • PBS: convenient, isotonic; may chelate trace metals weakly—add defined Zn2+ if needed for contact system assembly studies.
  • HEPES: excellent pH control at 37°C; minimal metal binding; suitable for enzymatic assays.
  • Tris: commonly used but can interact with some enzymes and metal ions; verify compatibility in kallikrein assays.

Item-specific buffer recommendations and any formulation components are Not specified for this item; refer to CoA/Spec Sheet.

Storage and Reconstitution

• Item-specific storage/shipping (from Product Data):

  • Storage: Store at -80°C. Avoid repeated freezing and thawing.
  • Shipped in: Dry ice packs + Cold packs.
  • Research use note: For research use only.

• Reconstitution (general guidance; not item-specific):

  • Thaw on ice. Reconstitute gently in a neutral buffered saline (e.g., PBS or HEPES, pH ~7.4). Aim for ≥0.1–1 mg/mL to minimize adsorption; include 0.01–0.1% carrier protein (HSA/BSA) if compatible with your assay.
  • If long-term storage is required after reconstitution, aliquot into single-use volumes and freeze at -80°C. Addition of 5–20% glycerol can improve freeze–thaw stability; validate for your application.
  • Avoid vigorous vortexing and bubbles; mix by gentle inversion.

• Handling tips:

  • Keep on ice during setup; warm to assay temperature immediately before use.
  • Use low-protein-binding tubes and tips to reduce loss at low concentrations.
  • If preventing proteolysis is desired, add an appropriate protease inhibitor cocktail; omit inhibitors when studying kallikrein-mediated cleavage.

• Stability/shelf life: Not specified for this item; refer to CoA/Spec Sheet.

Always consult the lot-specific CoA/SDS for definitive buffer composition, concentration, and any stabilizers or preservatives present.

Structure and Identity

High-molecular-weight kininogen (HMWK; also called HK, Fitzgerald factor) is a native human plasma glycoprotein and a central cofactor of the contact activation/kallikrein–kinin system.

• Item-specific identifiers:

  • SKU: np001047
  • Product Name: Kininogen, High Molecular Weight from Human Plasma
  • Grade: BioReagent, Native (plasma-derived)
  • CAS, CID, InChIKey, SMILES: Not specified for this item; refer to CoA/Spec Sheet.

• Macromolecular identity (literature/general):

  • Gene/protein: KNG1 gene product; high-molecular-weight isoform (HK)
  • Approximate molecular mass: ~120 kDa as a single-chain glycoprotein; after kallikrein cleavage, yields bradykinin (BK, 9 aa) and two-chain high-molecular-weight kininogen (HKa) linked by disulfides (literature)
  • Domain architecture: six domains (D1–D6); D2–D3 are cystatin-like, D4 contains the bradykinin sequence, D5 is histidine-rich, D6 binds prekallikrein/factor XI (literature)
  • Post-translational features: multiple N-linked glycans; several disulfide bonds; Zn2+-binding sites predominantly within histidine-rich D5 (literature)

• Structural description in words (literature/general):

  • HMWK is a flexible, multidomain glycoprotein with disulfide-stabilized heavy and light chain regions. In its native state it circulates as a single chain; proteolysis by plasma kallikrein releases BK (D4) and converts it to HKa with exposed binding motifs that assemble prekallikrein and factor XI on negatively charged surfaces.

Note: As a complex, heterogeneous glycoprotein purified from human plasma, microheterogeneity in glycosylation and exact mass is expected; see lot-specific CoA for definitive characterization.

Synthetic Utility

This product is a native human plasma glycoprotein, not a small-molecule building block. It is not typically used for classical organic synthesis or materials synthesis.

• Not typically applicable:

  • No functional-group transformations, protecting-group strategies, or cross-couplings are relevant here.

• Relevant instead (literature/general):

  • Biochemical reconstitution: HK is employed as a cofactor/substrate in enzymatic pathways (kallikrein activation, bradykinin release) to dissect mechanism and kinetics.
  • Surface interaction studies: Used to probe protein adsorption and activation on negatively charged or contact-activating materials, informing surface chemistry design.

For chemical synthesis–focused users, consider this protein’s role as a biological cofactor that can be incorporated into bioassays evaluating surface or inhibitor effects, rather than as a reagent for synthetic transformations.

Item-specific catalytic or synthetic properties are Not specified for this item; refer to CoA/Spec Sheet.

Target Specificity

This section typically applies to antibodies or affinity reagents with defined antigen/epitope specificity. The current product is a native human plasma protein (kininogen, high molecular weight), not an antibody.

• Item-specific targets, epitopes, clone/isotype, or species reactivity: Not applicable to this product type.

For binding partners relevant to HK in research (literature/general): HK interacts with prekallikrein and factor XI (binding mediated by the light chain; Zn2+-dependent), and is cleaved by plasma kallikrein to release bradykinin. These interactions are provided as biochemical context and are not item-specific performance claims.