Orexin A: Unveiling the Molecular Blueprint of a Key Neuropeptide

Orexin A, also known as hypocretin-1, is a crucial neuropeptide — a protein-like molecule used by neurons to communicate — primarily produced by a small cluster of neurons in the hypothalamus. This peptide plays a vital and multifaceted role in regulating several key physiological processes, including the maintenance of wakefulness, the modulation of arousal, and the control of appetite and energy homeostasis. Dysregulation or loss of orexin-producing neurons is strongly implicated in the pathogenesis of narcolepsy type 1, a debilitating chronic neurological condition characterized by overwhelming daytime sleepiness and sudden loss of muscle tone (cataplexy). Beyond narcolepsy, the orexin system is also being investigated for its involvement in addiction, stress responses, and metabolic disorders. A precise understanding of the fundamental molecular structure and properties of such critical endogenous peptides is an indispensable first step for all subsequent research, from basic science to therapeutic development, addressing a foundational knowledge gap in chemical biology.

The PubChem profile unequivocally identifies Orexin A through its unique Compound ID (CID): 56842143, a standard identifier in chemical databases. It precisely outlines the peptide's complex molecular formula as C152H243N47O44S4, indicating a large and intricate molecule composed of 152 carbon atoms, 243 hydrogen atoms, 47 nitrogen atoms, 44 oxygen atoms, and 4 sulfur atoms. This detailed elemental composition is crucial for understanding its biochemical properties. Furthermore, the exact molecular weight is specified as 3561.1 g/mol, a fundamental parameter for accurate synthesis, purification, and quantitative analysis in any experimental setting. The profile also provides the complete IUPAC name, an extremely long and detailed systematic name that describes the exact sequence and structure of its constituent amino acids and modifications. The most significant finding from this PubChem profile is the comprehensive and standardized chemical characterization of Orexin A, providing its precise molecular formula, exact molecular weight, and full IUPAC name, which together form the indispensable foundational data for all scientific and pharmaceutical research involving this critical neuropeptide. This level of chemical detail ensures that researchers worldwide can accurately identify, synthesize, and work with the identical compound, fostering reproducibility and reliability in studies exploring its biological functions and therapeutic applications.