Antibody Name: 4D5
References: Carter, P., Presta, L., Gorman, C.M., Ridgway, J.B.B., Henner, D., Wong, W.L.T., Rowland, A.M., Kotts, C., Carver, M.E. and Shepard, H.M. "Humanization of an anti-p185HER2 antibody for human cancer therapy." Proc. Natl. Acad. Sci. USA (1992) 89: 4285-4289.
Carter, P. et al, "High level E.coli. expression and production of a bivalent humanized antibody fragment" Bio/Tech. (1992) 10: 163-167. UCHT1
Eigenbrot, C., Randal, M., Presta, L., Carter, P. and Kossiakoff, A.A. "X-ray structures of the antigen-binding domains from three variants of humanized anti-p185HER2 antibody 4D5 and comparison with molecular modeling" J. Mol. Biol. (1993) 229: 969-995.
Donor Antibody: mouse
Acceptor Antibody: Human IgG1, k(REI constant regions)
Antigen: Extracellular domain of protein tyrosine kinase (P186HER2) which is homologous to the human epidermal growth factor receptor
Laboratory: Genentech, CA
Design: Used consensii from the most abundant human FRs. A carefully built model of the mouse mAb aided decisions on backmutations. Eight variants were made.
Frameworks: Human VH SGIII | VkSGI consensii (from Kabat Ed. IV 1987)
CDRs: All 6 VH and VL, Kabat Definition except CDR-H2.
Note: CDR-L1 K24R CDR-L2 R54L T56S (mouse->human)
Backmutations: VH R71A D73T L78A A93S plus CDR-H3 V102Y
VL G66R plus CDR-L2 E55Y
Assuming pure Kabat definitions of the CDR-graft:
VH TFS28-30NIK S49A R71A N73T L78A A93S
Binding: Best version (humAb4D5-8) binds 3-fold more than the mouse mAb and is almost as potent in anti-proliferation assays with human mammary adenocarcinoma cell line SK-BR-3. D73T L78A A93S confer antiproliferative activity, but no effect on binding.
Expression: Transient expression in non-myeloma human embryonic 293 kidney cells
Comment: Mutations in CH (E359D M361L) to convert it from rare A allotype to non-A. Glycosylation site in VL (NRS65-67). No effect on affinity or biological activity. Structure of humanised mAb solved.
Clinical Indication: Breast and ovarian cancers

explanation of symbols and abbreviations

José Saldanha © 1997-8. Birkbeck College, London WC1E 7HX.