About NPR1
Guanylyl cyclases, catalyzing the production of cGMP from GTP, are classified as soluble and membrane forms (Garbers and Lowe, 1994 [PubMed 7982997]). The membrane guanylyl cyclases, often termed guanylyl cyclases A through F, form a family of cell-surface receptors with a similar topographic structure: an extracellular ligand-binding domain, a single membrane-spanning domain, and an intracellular region that contains a protein kinase-like domain and a cyclase catalytic domain. GC-A and GC-B function as receptors for natriuretic peptides; they are also referred to as atrial natriuretic peptide receptor A (NPR1) and type B (NPR2; MIM 108961). Also see NPR3 (MIM 108962), which encodes a protein with only the ligand-binding transmembrane and 37-amino acid cytoplasmic domains. NPR1 is a membrane-bound guanylate cyclase that serves as the receptor for both atrial and brain natriuretic peptides (ANP (MIM 108780) and BNP (MIM 600295), respectively).[supplied by OMIM, May 2009]

About Alexa Fluor 750
Alexa Fluor™ 750 (AF750, Alexa 750) has an excitation peak at 749 nm and an emission peak at 775 nm, and is spetrally similar to Cy®7 (GE Healthcare), APC-Fire™ 750 (BioLegend), CF®®750 (Biotium), DyLight™ 750 (ThermoFisher Scientific), iFluor® 750 (ATT Bioquest) and iFluor® 790 (ATT Bioquest). Alexa 750 is often used as a tandem fluorophore in flow cytometry or used on its own in fluorescence microscopy, in-vivo fluorescence microscopy or super-resolution microscopy applications.