| abstract |
Short peptide of formula (I): Ra-Ser-Thr-Thr-Thr-Asn-Tyr-Rb where Ra represents an amino terminal residue Ala- or D-Ala and Rb representes a carboxy terminal residue -Thr or -Thr amide or a derivative thereof with an additional Cys- residue at one or both of the amino and carboxy terminals, or a peptide of formula (II): R1-R2-R3-R4-R5 where R1 is an amino terminal residue Thr-, Ser-, Asn-, Leu-, Ile-, Arg- or Glu-, R2 is Thr, Ser or Asp, R3 is Thr, Ser, Asn, Arg, Gln, Lys or Trp, R4 is Tyr and R5 is a carboxy terminal amino group or a derivative thereof with a corresponding D- amino acid as the amino terminal residue and/or a corresponding amide derivative at the carboxy terminal residue and/or additionally a Cys- residue at one or both of the amino and carboxy terminals, or a physiologically acceptable salt thereof. Such peptides bind to T4 receptors are useful in preventing viral infectivity by viruses which bind to the T4 receptors. These peptides are believed to act as competitive blocking agents. |