Recombinant Mouse Myosin-binding protein H-like (Mybphl)

Shipped with Ice Packs
In Stock

Description

Introduction to Recombinant Mouse Myosin-binding Protein H-like (Mybphl)

Recombinant Mouse Myosin-binding protein H-like (Mybphl) is a protein that plays a crucial role in cardiac function, particularly in the regulation of conduction within the atria and ventricular conduction systems . This protein is primarily expressed in atrial tissue and exists in two isoforms, with isoform 2 being almost exclusively restricted to the atria . The recombinant form of Mybphl is used in research to study its functions and implications in cardiac diseases.

Expression and Localization of Mybphl

Mybphl is predominantly expressed in the atria, with some expression in discrete subsets of the ventricle, particularly in areas associated with the ventricular conduction system . Immunofluorescence studies have identified Mybphl-positive ventricular cardiomyocytes near the atrioventricular node and in a subset of Purkinje fibers, suggesting its role in both atrial and ventricular conduction .

Role in Cardiac Function and Disease

Mybphl is associated with myofilament structures in atrial tissue and plays a role in regulating cardiac conduction . Loss or mutations in the Mybphl gene have been linked to dilated cardiomyopathy, atrial and ventricular arrhythmias, and atrial enlargement . The protein's absence leads to increased heterogeneity of calcium release and disorganization of ryanodine receptors, contributing to arrhythmias .

Mybphl as a Biomarker

Mybphl has been identified as a promising biomarker for predicting atrial myocardial damage. After atrial injury, such as that caused by cryo- or radiofrequency ablation, Mybphl is rapidly released into the bloodstream, where its levels remain elevated for up to 24 hours . This release is correlated with established biomarkers like CK-MB, indicating its potential as a specific marker for atrial damage .

Table 1: Expression and Function of Mybphl

FeatureDescription
Primary ExpressionPredominantly in atrial tissue
IsoformsTwo isoforms with a 23 amino acid deletion in isoform 2
Role in Cardiac FunctionRegulates conduction in atria and ventricular conduction systems
Association with DiseaseLinked to dilated cardiomyopathy and arrhythmias
Biomarker PotentialSpecific marker for atrial myocardial damage

Table 2: Effects of Mybphl Loss on Cardiac Function

EffectDescription
Calcium ReleaseIncreased heterogeneity and faster rates of release
Ryanodine Receptor OrganizationDisorganization and larger receptor clusters
Atrial FunctionShortened atrial refractory period and increased susceptibility to arrhythmias
Ventricular FunctionContribution to ventricular arrhythmias and dysfunction

Product Specs

Form
Lyophilized powder

Note: We will prioritize shipping the format currently in stock. If you require a specific format, please specify this in your order notes.

Lead Time
Delivery times vary depending on the purchase method and location. Please contact your local distributor for precise delivery estimates.

Note: All proteins are shipped with standard blue ice packs. Dry ice shipping requires prior arrangement and incurs additional charges.

Notes
Avoid repeated freeze-thaw cycles. Store working aliquots at 4°C for up to one week.
Reconstitution
Centrifuge the vial briefly before opening to collect the contents. Reconstitute the protein in sterile deionized water to a concentration of 0.1-1.0 mg/mL. We recommend adding 5-50% glycerol (final concentration) and aliquoting for long-term storage at -20°C/-80°C. Our standard glycerol concentration is 50%, but this can be adjusted to meet your requirements.
Shelf Life
Shelf life depends on several factors, including storage conditions, buffer composition, temperature, and the protein's inherent stability. Generally, liquid formulations have a 6-month shelf life at -20°C/-80°C, while lyophilized formulations have a 12-month shelf life at -20°C/-80°C.
Storage Condition
Store at -20°C/-80°C upon receipt. Aliquoting is essential for multiple uses. Avoid repeated freeze-thaw cycles.
Tag Info
Tag type is determined during the manufacturing process.

The tag type is determined during production. If you require a specific tag, please inform us, and we will prioritize its development.

Synonyms
MybphlMyosin-binding protein H-like
Buffer Before Lyophilization
Tris/PBS-based buffer, 6% Trehalose.
Datasheet
Please contact us to get it.
Expression Region
1-355
Protein Length
full length protein
Purity
>85% (SDS-PAGE)
Species
Mus musculus (Mouse)
Target Names
Mybphl
Target Protein Sequence
METATTLEIA SCSQRQVEAA ADPADAKGPR TSHQQEAGSP SLQLLPSIEE HPKIWLPRAL KQTYIRKAGE TVNLLIPIQG KPKPQTTWTH NGCALDSSRV SVRNGEHDSI LFIREAQRTD SGCYQLCVQL GGLQATATIN ILVIEKPGPP QSIKLVDVWG ANATLEWTPP QDTGNTALLG YTVQKADKKS GLWFTVLERY HRTSCVVSNL IVGNSYAFRV FAENQCGLSD TAPVTADLAH IQKAATVYKA KGFAQRDLSE APKFTQPLAD CTTVTGYDTQ LFCCVRASPR PKIIWLKNKM DLQGNPKYRA LSQLGICSLE IRKPSPFDGG IYTCKAINAL GEASVDCRVD VKAPH
Uniprot No.

Target Background

Function

Myosin-binding protein H-like (MyBP-H-like) plays a critical role in cardiac function. It appears to regulate conduction within the atria and ventricular conduction systems.

Gene References Into Functions
  1. MyBP-H-like knockout mice exhibit reduced ventricular function and conduction system defects. PMID: 28778945
Database Links
Protein Families
Immunoglobulin superfamily, MyBP family
Subcellular Location
Cytoplasm, myofibril, sarcomere.
Tissue Specificity
Expressed in the atria as well as in discrete puncta throughout the right ventricular wall and septum.

Q&A

What is the structure and expression pattern of Mybphl in cardiac tissue?

Mybphl is a sarcomeric protein that shares sequence and domain homology with myosin-binding protein C (MyBP-C). It consists of 4 globular domains: 2 immunoglobulin-like (Ig-like) and 2 fibronectin-III-like (Fn3-like) domains connected in series by flexible linkers . Unlike MyBP-C, Mybphl has a long (78–134 amino acid), proline-alanine rich, unstructured domain that resembles the very N-terminus of skeletal muscle MyBP-Cs .
Expression patterns show Mybphl is highly expressed in the atria with only scarce, distinct clusters of Mybphl-positive cells within and surrounding the ventricular conduction system . Immunofluorescence microscopy of normal adult mouse ventricles has identified Mybphl-positive ventricular cardiomyocytes that co-localize with the ventricular conduction system marker contactin-2 near the atrioventricular node and in a subset of Purkinje fibers . This localization pattern suggests Mybphl plays a specialized role in specific cardiac regions.

What phenotypes are associated with Mybphl deficiency in mice?

Constitutive knockout of Mybphl in mice causes multiple cardiac abnormalities including:

  • Atrial dilation and arrhythmia

  • Dilated cardiomyopathy (DCM)

  • Atrioventricular block and atrial bigeminy

  • Shorter atrial relative refractory period

  • Atrial tachycardia following burst pacing
    At the cellular level, calcium transient analysis of isolated Mybphl-null atrial cardiomyocytes demonstrates increased heterogeneity of calcium release and faster rates of calcium release compared to wild type controls . Super-resolution microscopy reveals ryanodine receptor disorganization in Mybphl heterozygous and homozygous null atrial cardiomyocytes . These findings help explain the observed arrhythmias and cardiac dysfunction at the organ level.

How does conditional deletion of Mybphl affect cardiac function?

Conditional deletion of Mybphl produces distinct phenotypes depending on the timing and location of deletion:

  • Mice with conditional decrease of Mybphl in adulthood develop a hypertrophic phenotype with atrial contractile changes, increased total heart weight to body weight ratio, and increased heart rate variability

  • Deletion of Mybphl solely within the cardiac conduction system (using Contactin-2-Cre) trends toward mild hypercontractility, lower heart rates, and interventricular septal thickening
    These data demonstrate that Mybphl is essential for proper cardiac function, and even minor alterations in protein levels can cause a diseased cardiac phenotype .

What methodological approaches are recommended for studying Mybphl localization in cardiac tissue?

Several complementary imaging techniques provide comprehensive analysis of Mybphl localization:

TechniqueApplicationKey Parameters
Immunofluorescence microscopyVisualization of Mybphl-positive cells in fixed tissue sections and isolated cardiomyocytesTiled sections for quantification; blinded counting of Mybphl-positive cells
Lightsheet microscopyAnalysis of perinatal hearts showing enrichment of Mybphl-positive cells within and adjacent to the contactin-2-positive ventricular conduction systemUsed effectively with P5 mouse hearts
Super-resolution microscopyExamination of subcellular structures such as ryanodine receptor organizationCritical for analyzing heterozygous and homozygous null atrial cardiomyocytes
For quantification, Mybphl-positive cardiomyocytes should be counted by a blinded operator and normalized as the number of positive cells per section . When working with isolated ventricular cardiomyocytes, cells can be plated in 35 mm diameter dishes, imaged using a 10× objective, tiled together, and total cell density measured using image analysis software .

How can researchers generate and validate conditional knockout models of Mybphl?

Conditional knockout models can be generated using the following approach:

  • Create a conditional floxed Mybphl mouse line

  • Cross this line with specific Cre-recombinase expressing lines:

    • ROSA26-Cre(ERT2) LoxP mice for tamoxifen-inducible deletion in adulthood

    • Contactin-2-Cre mice for cardiac conduction system-specific deletion from birth
      These models offer significant advantages over constitutive knockouts:

  • Allow temporal control over gene deletion to distinguish developmental from adult roles

  • Enable tissue-specific deletion to study Mybphl function in specific cardiac regions

  • Help avoid compensatory mechanisms that might develop in constitutive models
    Validation of knockout efficiency should include protein quantification in target tissues and assessment of residual Mybphl-positive cells using immunofluorescence microscopy .

What electrophysiological parameters should be measured to assess the impact of Mybphl deficiency?

A comprehensive electrophysiological assessment should include:

ParameterTechniqueSignificance in Mybphl Research
Surface ECG parametersConscious telemetryDetects atrioventricular block and atrial bigeminy in Mybphl-null mice
Atrial effective refractory periodIntracardiac programmed electrical stimulationShorter in Mybphl homozygous null mice
Sinus node recovery timeIntracardiac pacingSignificantly longer (corrected) in Mybphl-null mice following pacing
Susceptibility to arrhythmiasAtrial burst pacing (50 ms cycle lengths for 1-2 seconds)2/6 Mybphl-null hearts showed persistent atrial tachycardia for several seconds following burst pacing, while no control mice exhibited this response
These functional assessments provide critical insights into how Mybphl deficiency affects cardiac conduction and rhythm stability.

What are the proposed mechanisms by which Mybphl deficiency leads to cardiac conduction abnormalities?

Several mechanisms have been proposed based on current research:

  • Calcium handling abnormalities: Mybphl-null atrial cardiomyocytes show increased heterogeneity and faster rates of calcium release, which likely contributes to arrhythmogenesis

  • Subcellular structural disarray: Super-resolution microscopy reveals ryanodine receptor disorganization in Mybphl-deficient cardiomyocytes, suggesting disrupted excitation-contraction coupling

  • Conduction system development: The proximity of Mybphl-positive cells to the ventricular conduction system suggests Mybphl may influence conduction system development or function, explaining how a predominantly atrial expressed gene contributes to ventricular arrhythmias and dysfunction

  • Altered functional properties of specialized cardiomyocytes: Mybphl localization in discrete regions of the ventricle suggests it may provide nuanced tuning of specific cells critical for normal conduction
    These mechanisms warrant further investigation, particularly to determine whether abnormalities arise from developmental defects or from dysregulation of adult cardiomyocyte function.

How can recombinant Mybphl be used to study disease-associated mutations?

Recombinant Mybphl offers a powerful tool for investigating the molecular mechanisms of disease-associated mutations:

  • Generation of mutant constructs: Site-directed mutagenesis can be used to generate mouse Mybphl constructs mimicking human MYBPHL nonsense mutations reported in genomic databases like gnomAD

  • Validation and preparation: Plasmids should be sequenced by Sanger reaction and prepared using endo-free maxi prep kits for transfection quality

  • Functional analysis: Experiments can assess:

    • Sarcomere binding properties of mutant Mybphl

    • Protein stability and degradation pathways

    • Effects on cardiomyocyte contraction

  • Proteomic analysis: Mass spectrometry approaches using systems like the Vanquish Neo UHPLC with an Orbitrap Eclipse Tribrid mass spectrometer can provide detailed characterization of mutant proteins and their interactions
    This approach provides mechanistic insights into how genetic variants lead to cardiac dysfunction.

What are the challenges in studying Mybphl in specialized cardiac cell populations?

Investigating Mybphl in specialized cardiac cells presents several methodological challenges:

How can calcium handling abnormalities in Mybphl-deficient cardiomyocytes be assessed?

A comprehensive calcium handling assessment should include:

TechniqueMeasured ParametersRelevance to Mybphl Research
Calcium transient analysisHeterogeneity and rates of calcium releaseReveals fundamental defects in Mybphl-null cardiomyocytes
Super-resolution microscopyRyanodine receptor organizationShows disorganization in Mybphl heterozygous and homozygous null cardiomyocytes
Functional electrophysiologyAtrial refractory periodShorter in Mybphl-null mice, correlating with calcium handling defects
Arrhythmia susceptibility testingResponse to atrial burst pacingMybphl-null hearts show susceptibility to atrial tachycardia not seen in controls
These abnormalities appear to create a substrate for the development of atrial arrhythmias, bigeminy, and atrial tachycardia observed in Mybphl-null hearts .

What are the implications of Mybphl research for understanding human cardiac diseases?

Research on Mybphl has significant clinical implications:

  • Genetic basis of cardiomyopathy: Mutations in human MYBPHL are linked to hereditary dilated cardiomyopathy, atrial fibrillation, and atrioventricular arrhythmias

  • Mechanistic insights: Understanding how Mybphl deficiency causes subcellular disarray and calcium handling abnormalities provides insights into pathogenic mechanisms of cardiac arrhythmias and cardiomyopathy

  • Developmental contributions: The potential role of Mybphl in cardiac development suggests some cardiac diseases may have developmental origins

  • Therapeutic targets: Identification of the molecular pathways affected by Mybphl deficiency could reveal new therapeutic targets for treating cardiac conduction disorders and cardiomyopathies
    Future studies using conditional deletion of Mybphl in adult mice will help determine whether loss of Mybphl during development is required for disease or if MyBP-HL dynamically regulates adult cardiomyocytes such that its absence leads to the observed pathophysiology .

Quick Inquiry

Personal Email Detected
Please use an institutional or corporate email address for inquiries. Personal email accounts ( such as Gmail, Yahoo, and Outlook) are not accepted. *
© Copyright 2025 TheBiotek. All Rights Reserved.