Localization of N-Type Ca²⁺ Channels

Creative Bioarray is committed to providing our clients with N-type voltage-dependent calcium channels (N-VDCCs) mapping services using analogs of ω-CgTx and our strategies are applicable to a variety of experimental models. We look forward to working with you and providing you with high-quality scientific services and efficient technical support.

Background

N-VDCCs are located mainly in nerve terminals and dendrites, as well as on neuroendocrine cells. These channels play important roles in neurotransmission during development. Since Ca²⁺ diffusion is highly restricted in the nerve cytoplasm, the precise distribution of VDCCs is a major determinant of local Ca²⁺ signaling and of the neurological events that define neural function. By targeting the appropriate VDCC subtypes to select regions, neurons can construct compartments with specific Ca²⁺ signaling properties. The highly polarized distribution of N-VDCCs is consistent with their critical role in signal transduction.

Various strategies have been developed to map N-VDCCs and other channels. Among them, natural toxin-based approaches have rapidly advanced the study of isolated channels. Due to their specificity and potency, toxins have been widely used to identify, differentiate, manipulate or purify many important ligands of the free channel. Pioneering studies of the nicotinic acetylcholine receptor (nAChR) and its high-affinity interactions with specific radiolabelled or fluorescent analogs of snake venom toxins have provided scientists with strategies for using toxins in mapping ion channels. Toxin analogs are now being used to map neuronal voltage-dependent channels.

Fig. 1 Illustration of the inhibitory effect of conotoxin on N-type (Ca_v2.2) calcium channels. (Adams, 2013)

Our Services

Electrophysiological, biochemical purification and pharmacological analyses have shown that the high-affinity ω-Conotoxin GVIA (ω-CgTx) binds only to N-VDCC, and we have therefore developed a variety of ω-CgTx-based strategies including autoradiography, immunochemical, avidin-biotin and fluorescence to visualize the distribution of N-VDCC in neurons. In addition, due to the selective binding and high affinity of ω-CgTX for N-VDCC in different species (including humans, rats, mice, rabbits, bovines, and frogs), our ω-CgTx-based strategies are suitable for a variety of experimental models. Our services include but are not limited to:

• Mapping of N-VDCCs by multiple ω-CgTx-based labels.
• Spatio-temporal distribution of N-VDCCS in development
• Temporal expression of granule cell N-VDCCS
• Spatial distribution of N-VDCCS along motor nerve terminal
• Localization of N-VDCCS at the presynaptic nerve terminal
• Distribution of N-VDCCS at the synaptic terminal
• Localization of N-VDCCS in C-fibers
• Distribution of N-VDCCS in cerebellar and electrosensory neurons
• Identification of N-VDCCs in neuronal regions that are too small to be accessed by recording electrodes.
• Real-time imaging of N-VDCCs to address the cellular dynamics of N-VDCCs and how they respond to factors such as electrical activity, cell contact, and disease.
• Labeling optimization. We help clients develop and optimize labels to improve the mapping efficiency of N-VDCCs by varying labeling concentrations, culture conditions, and tissue quality.

Creative Bioarray has developed a variety of ω-CgTx-based strategies to help our clients locate N-VDCCs. To meet the broader scientific needs of our clients, our research team is committed to developing more sensitive t-CgTx-based methods to enable the mapping of individual N-VDCCs. If you require our technical support, please contact us for more details.

Reference

1. Adams, D. J.; Berecki, G. Mechanisms of conotoxin inhibition of N-type (Ca_v2.2) calcium channels. Biochimica et Biophysica Acta (BBA)-Biomembranes, 2013, 1828(7): 1619-1628.