Orexin B (mouse)

Product Name:Orexin B (mouse)

CAS No:202801-92-1

Purity:95%

Molar Mass:2936.43

Chemical Formula:C126H215N45O34S

Storage:Store at -20 degrees Celsius

Sequence:RPGPPGLQGRLQRLLQANGNHAAGILTM

Target:OX2R

Application:

Orexin B (mouse) is a neuropeptide involved in the regulation of sleep-wake cycles, appetite, and energy homeostasis, similar to its function in humans. Derived from the prepro-orexin precursor, Orexin B primarily interacts with the orexin receptor 2 (OX2R), playing a pivotal role in promoting wakefulness and regulating arousal. In mouse models, Orexin B is extensively studied to understand its role in sleep regulation, particularly in the context of disorders like narcolepsy, where orexin signaling is deficient. Additionally, Orexin B is explored for its involvement in appetite control and metabolic processes, making it a key target in research on obesity, metabolism, and sleep disorders.

Current Research:

Orexin B, also referred to as hypocretin-2, is a 28-amino acid neuropeptide synthesized in the lateral hypothalamus. It plays a pivotal role in regulating wakefulness, feeding behavior, and energy homeostasis. In mice, as in other mammals, orexin B is derived from the prepro-orexin precursor and interacts with two G protein-coupled receptors, orexin receptor 1 (OX1R) and orexin receptor 2 (OX2R), with a preference for OX2R.

Structure
Sequence: The amino acid sequence of mouse orexin B is highly conserved across species and matches the human sequence: NH₂-LPLKYPGRRRLMYPDATDRQKWKMLK-CONH₂
Stability: The linear peptide structure lacks disulfide bridges, enhancing flexibility for receptor interactions.
Mechanism of Action
Orexin B primarily binds to OX2R and activates intracellular signaling pathways, including:

Calcium mobilization via phospholipase C (PLC) activity.
Cyclic AMP (cAMP) production through adenylyl cyclase stimulation.
MAPK phosphorylation, influencing transcriptional and post-transcriptional responses.
These pathways regulate neuronal excitability and physiological responses associated with arousal, metabolism, and stress adaptation.

Physiological Functions
Sleep-Wake Regulation:

Orexin B is crucial for promoting wakefulness and stabilizing non-REM and REM sleep cycles.
Deficiency or dysfunction in the orexin system is associated with narcolepsy and cataplexy in animal models and humans.
Energy Homeostasis:

The neuropeptide modulates feeding behavior and energy expenditure, playing a role in the hypothalamic regulation of metabolic processes.
Autonomic Nervous System Regulation:

Orexin B affects cardiovascular control, thermoregulation, and respiratory function through its influence on autonomic pathways.
Stress and Emotional Regulation:

It modulates responses to stress by interacting with the hypothalamic-pituitary-adrenal (HPA) axis and influencing mood-related behaviors.
Reward and Addiction:

Orexin B is involved in the reward system, affecting addiction pathways and motivational states in response to stimuli.
Research Applications
Sleep Disorders:

Used in studies on narcolepsy, insomnia, and circadian rhythm disorders, focusing on orexin B's role in maintaining wakefulness.
A target for developing orexin receptor modulators for therapeutic intervention.
Metabolic Studies:

Explores the role of orexin B in appetite regulation, obesity, and metabolic syndrome.
Stress and Behavioral Research:

Investigates its role in stress-induced changes in behavior and mood disorders such as anxiety and depression.
Addiction Studies:

Orexin B is studied for its role in the regulation of reward-related pathways and its potential as a target in treating addiction.
Neurodegenerative Diseases:

Relevant in models studying the impact of neuronal excitability on disorders like Parkinson’s and Alzheimer’s disease.
Handling and Storage
Form: Supplied as a lyophilized powder.
Storage: Store at -20°C in a desiccated environment to ensure stability.
Reconstitution: Reconstitute in sterile water or a suitable buffer for experimental use.
Conclusion
Mouse orexin B is a critical regulator of wakefulness, metabolism, and stress responses. Its conservation across species and receptor specificity makes it a fundamental tool for research on sleep regulation, metabolic health, and neuropsychiatric disorders. Its study continues to contribute to advancements in therapeutic approaches for these conditions.

Reference:

Mobarakeh, J. I., Takahashi, K., Sakurada, S., Nishino, S., Watanabe, H., Kato, M., & Yanai, K. (2005). Enhanced antinociception by intracerebroventricularly and intrathecally-administered orexin A and B (hypocretin-1 and-2) in mice. Peptides, 26(5), 767-777.