Recombinant Mouse Semaphorin 5B Fc Chimera Protein, CF

Recombinant Mouse Semaphorin 5B Fc Chimera Protein, CF Summary

Product Specifications

Product Datasheets

Carrier Free

CF stands for Carrier Free (CF). We typically add Bovine Serum Albumin (BSA) as a carrier protein to our recombinant proteins. Adding a carrier protein enhances protein stability, increases shelf-life, and allows the recombinant protein to be stored at a more dilute concentration. The carrier free version does not contain BSA.

In general, we advise purchasing the recombinant protein with BSA for use in cell or tissue culture, or as an ELISA standard. In contrast, the carrier free protein is recommended for applications, in which the presence of BSA could interfere.

Background: Semaphorin 5B

Semaphorin 5B (Sema5B, previously called SemaG or SemG) is a ~150 kDa protein of the semaphorin family of axon guidance molecules (1, 2). Sema5B is a Class 5 semaphorin and this makes it a single‑pass transmembrane glycoprotein with an N‑terminal Sema domain and multiple juxtamembrane type 1 thrombospondin (TSP) repeats within its extracellular region (1, 2). Sema5B is expressed developmentally in the neuroepithelium along the anterior‑posterior axis in a complimentary pattern with Sema5A (2, 3). It has been identified in oligodendrocytes and their precursors, neurons, dental mesenchyme and pre‑osteoblasts (1 ‑ 6). Sema5B expression may be up‑regulated in cancer cells such as human renal carcinoma clear cells, where blocking Sema5B expression attenuates viability (7). The mouse Sema5B cDNA encodes a 1093 amino acid (aa) type I transmembrane protein with a 19 aa signal sequence, a 959 aa extracellular domain (ECD), a 21 aa transmembrane sequence and a 94 aa cytoplasmic portion (8). The ECD contains one Sema domain (aa 45 ‑ 495) followed by seven consecutive TSP type 1 domains (aa 551 ‑ 952). There is a potential for at least two alternative splice forms. One shows a 32 aa substitution for aa 1041 ‑ 1093, while a second (GenBank Accession # AAH52397) contains a 29 aa insert after Val702 of the third TSP domain. Over aa 20 ‑ 776 of the SwissProt sequence that includes the Sema domain plus the first four TSP type 1 domains, mouse Sema5B shares 98% aa identity with rat, and 93 ‑ 94% aa identity with human, equine and bovine Sema5B. In the hippocampus, either full‑length or proteolytically processed and secreted Sema5B mediates neuronal synapse elimination (6). In the cortex, Sema5B appears to be inhibitory to cortical axons, but not to dorsal thalamic axons, indicating a role in corticothalamic axon guidance during development (3). Sema5B promotes the influx of extracellular calcium, which is necessary to induce neuronal growth cone collapse (9). Semaphorins typically transduce signals through transmembrane plexins. However, additional molecules such as heparin sulfate or chondroitin sulfate proteoglycans which bind TSP repeats on the class 5 family member Sema5A, can also transduce semaphorin signals (10).

Related Research Areas

• Axon Guidance and Neuron Migration
• Proteoglycans
• Semaphorins, Plexin Receptors, and Related Molecules