Recombinant Cytomegalovirus Glycoprotein B (gB / UL55) – Purified No Carrier Protein

Human cytomegalovirus (HCMV) glycoprotein B (gB) is encoded by the UL55 open reading frame and synthesized as a 906-amino acid precursor. Following translation, the nascent polypeptide is directed to the endoplasmic reticulum, where it folds and assembles into disulfide-dependent oligomers, then transits to the Golgi, where it is glycosylated and cleaved by the host protease furin into the amino-terminal gp116 and carboxy-terminal gp55 fragments, which remain associated through intramolecular disulfide bonds (1). Each protomer is extensively modified, with 17–18 predicted N-linked glycosylation sites and two O-linked sites near the N-terminus (2). gB is a class III membrane fusion protein: three protomers assemble into a metastable prefusion trimer that undergoes large conformational rearrangement, inserting its hydrophobic fusion loops into the host membrane and collapsing into a stable postfusion state to drive membrane fusion (3). It is required for viral entry into all known cell types (4).
Towne is a laboratory-adapted strain developed as a live attenuated vaccine candidate and evaluated in renal transplant recipients (5). Sequence variation in the UL55 region encompassing the protease cleavage site defines four gB genotypes (6); Towne carries the gB-1 genotype (7).
gB is the dominant target of the humoral response to HCMV, and five antigenic domains (AD-1 through AD-5) have been mapped. AD-1, in the C-terminal portion of the protein, is immunodominant and recognized by nearly all infected individuals, though only a fraction of AD-1 antibodies neutralize; AD-2 lies in the N-terminal region and contains a conserved site I epitope targeted by potent neutralizing antibodies alongside a strain-variable site II (8). Only about half of seropositive donors mount an AD-2 response (8). A postfusion gB subunit vaccine adjuvanted with MF59 conferred roughly 50% protection against primary acquisition in phase 2 trials (9), sustaining interest in gB serology as a correlate of protection against congenital infection and post-transplant disease (10).

Human cytomegalovirus (human herpesvirus 5)

Primary surface protein that helps the virus enter host cells.

P13201 (strain Towne)

SSSTRGTSATHSHHSSHTTSAAHSRSGSVSQRVTSSQTVSHGVNETIYNTTLKYGDVVGVNTTKYPYRVCSMAQGTDLIRFERNIVCTSMKPINEDLDEGIMVVYKRNIVAHTFKVRVYQKVLTFRRSYAYIHTTYLLGSNTEYVAPPMWEIHHINSHSQCYSSYSRVIAGTVFVAYHRDSYENKTMQLMPDDYSNTHSTRYVTVKDQWHSRGSTWLYRETCNLNCMVTITTARSKYPYHFFATSTGDVVDISPFYNGTNRNASYFGENADKFFIFPNYTIVSDFGRPNSALETHRLVAFLERADSVISWDIQDEKNVTCQLTFWEASERTIRSEAEDSYHFSSAKMTATFLSKKQEVNMSDSALDCVRDEAINKLQQIFNTSYNQTYEKYGNVSVFETTGGLVVFWQGIKQKSLVELERLANRSSLNLTHNTTQTSTDGNNATHLSNMESVHNLVYAQLQFTYDTLRGYINRALAQIAEAWCVDQRRTLEVFKELSKINPSAILSAIYNKPIAARFMGDVLGLASCVTINQTSVKVLRDMNVKESPGRCYSRPVVIFNFANSSYVQYGQLGEDNEILLGNHRTEECQLPSLKIFIAGNSAYEYVDYLFKRMIDLSSISTVDSMIALDIDPLENTDFRVLELYSQKELRSSNVFDLEEIMREFNSYKQRVKYVEDK

G-(NANP)3-UL55(AA25-AA700) <br> Note: AA457-460 were replaced with TTQT to prevent furin cleavage of gB

Lyophilized

~110 kDa

Reconstitute at 0.1-1 mg/ml using filtered deionized water. Gently mix by vortexing and/or inversion until fully dissolved. Centrifuge if necessary.

This lyophilized protein is stable for twelve months when stored at -20°C. After aseptic reconstitution, this protein may be stored for one month at 2°C to 8°C or for three months at -20°C to -70°C in a manual defrost freezer. Avoid Repeated Freeze Thaw Cycles.

Ambient

beta 1 integrin, DC-SIGN/DC-SIGNR

Human cytomegalovirus (human herpesvirus 5)

Research Use Only

P13201 (strain Towne)

ELISA, WB

1. Britt, W. J., & Vugler, L. G. (1989). Processing of the gp55-116 envelope glycoprotein complex (gB) of human cytomegalovirus. Journal of Virology, 63(1), 403-410.
2. Spaete, R. R., Saxena, A., Scott, P. I., et al. (1990). Sequence requirements for proteolytic processing of glycoprotein B of human cytomegalovirus strain Towne. Journal of Virology, 64(6), 2922-2931.
3. Liu, Y., Heim, K. P., Che, Y., et al. (2021). Prefusion structure of human cytomegalovirus glycoprotein B and structural basis for membrane fusion. Science Advances, 7(10), eabf3178.
4. Burke, H. G., & Heldwein, E. E. (2015). Crystal structure of the human cytomegalovirus glycoprotein B. PLoS Pathogens, 11(10), e1005227.
5. Plotkin, S. A., Starr, S. E., Friedman, H. M., et al. (1991). Effect of Towne live virus vaccine on cytomegalovirus disease after renal transplant: a controlled trial. Annals of Internal Medicine, 114(7), 525-531.
6. Chou, S., & Dennison, K. M. (1991). Analysis of interstrain variation in cytomegalovirus glycoprotein B sequences encoding neutralization-related epitopes. Journal of Infectious Diseases, 163(6), 1229-1234.
7. Wang, H. Y., Valencia, S. M., Pfeifer, S. P., et al. (2021). Common polymorphisms in the glycoproteins of human cytomegalovirus and associated strain-specific immunity. Viruses, 13(6), 1106.
8. Pötzsch, S., Spindler, N., Wiegers, A. K., et al. (2011). B cell repertoire analysis identifies new antigenic domains on glycoprotein B of human cytomegalovirus which are target of neutralizing antibodies. PLoS Pathogens, 7(8), e1002172.
9. Pass, R. F., Zhang, C., Evans, A., et al. (2009). Vaccine prevention of maternal cytomegalovirus infection. New England Journal of Medicine, 360(12), 1191-1199.
10. Dollard, S. C., Grosse, S. D., & Ross, D. S. (2007). New estimates of the prevalence of neurological and sensory sequelae and mortality associated with congenital cytomegalovirus infection. Reviews in Medical Virology, 17(5), 355-363.