Design, synthesis, and evaluation of peptides with estrogen-like activity.
Currently used antiestrogenic drugs against hormone-dependent breast cancer, and estrogenic drugs used in treatment of osteoporosis, are associated with risk factors. Therefore, there is a strong need to develop selective estrogen receptor modulators with better tissue selectivity. In a recent study (Peptides, 2002, Vol. 3, 573-580), we used a monoclonal antibody to estradiol (mAb-E2) to screen a phage-display peptide library. We identified a 15-mer peptide (peptide H5) that recognizes mAb-E2 (IC(50) 1 microM) and estrogen receptor (ER)alpha (IC(50) 500 microM) but not ERbeta, and displays estrogen-like activity in vitro and in vivo. In this study, we designed and prepared peptides based on peptide H5, which possess improved estrogenic activity, by evaluating their binding to mAb-E2 and to ERs. Initially, we determined the minimal binding sequence of peptide H5 capable of binding mAb-E2 and ER. Subsequently, systematic single-residue replacements of the minimal sequence, followed by multiple-residue replacements, yielded hexa- and heptapeptides with increased affinities to mAb-E2 and to ER. The most promising peptides, VSWFFE (EMP-1) and VSWFFED (EMP-2) (EMP: estrogen-mimetic peptide), bind mAb-E2 with high affinity (IC(50) of 6 and 30 nM, respectively), recognize ERs with increased affinity (IC(50) of 100 microM for ERalpha, and 100-250 microM for ERbeta), and possess estrogenic activity in vivo. The short peptides described in this study may be used as potential lead compounds for developing new ER ligands.
Kasher
Roni
R
Department of Biological Chemistry, Weizmann Institute of Science, Rehovot 76100, Israel.
Gayer
Batya
B
Kulik
Tikva
T
Somjen
Dalia
D
Venkatesh
Natarajan
N
Fridkin
Mati
M
Katchalski-Katzir
Ephraim
E
Kohen
Fortune
F
D000409:Alanine / Q000235:genetics / Q000378:metabolism; D000595:Amino Acid Sequence; D000911:Antibodies, Monoclonal / Q000235:genetics / Q000276:immunology; D004261:DNA Replication / Q000187:drug effects; D015195:Drug Design; D004967:Estrogens / Q000494:pharmacology*; D008969:Molecular Sequence Data; D010455:Peptides / Q000138:chemical synthesis / Q000235:genetics / Q000276:immunology / Q000378:metabolism / Q000494:pharmacology*; D015202:Protein Engineering; D011960:Receptors, Estrogen / Q000276:immunology / Q000378:metabolism
D000911:Antibodies, Monoclonal; D004967:Estrogens; D010455:Peptides; D011960:Receptors, Estrogen; D000409:Alanine