A novel heme-containing protein with anti-HIV-1 activity from skin secretions of Bufo andrewsi

Toxicon. 2005 Nov;46(6):619-24. doi: 10.1016/j.toxicon.2005.06.022. Epub 2005 Sep 12.


A novel protein, named BAS-AH, was purified and characterized from the skin of the toad Bufo andrewsi. BAS-AH is a single chain protein and the apparent molecular weight is about 63 kDa as judged by SDS-PAGE. BAS-AH was determined to bind heme (0.89 mol heme/mol protein) as determined by pyridine haemochrome analysis. Fifty percentage cytotoxic concentration (CC50) of BAS-AH on C8166 cells was 9.5 microM. However, at concentrations that showed little effect on cell viability, BAS-AH displayed dose dependent inhibition on HIV-1 infection and replication. The antiviral selectivity indexes (CC50/EC50) were 14.4 and 11.4, respectively, corresponding to the measurements of syncytium formation and HIV-1 p24 antigen expression. BAS-AH also showed an inhibitory effect on the activity of recombinant HIV-1 reverse transcriptase (IC50 = 1.32 microM). The N-terminal sequence of BAS-AH was determined to be NAKXKADVIGKISILLGQDNLSNIVAAM, which exhibited little identity with other known anti-HIV-1 proteins. BAS-AH is devoid of antibacterial, proteolytic, trypsin inhibitory activity, l-amino acid oxidase activity and catalase activity.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Anti-HIV Agents / isolation & purification
  • Anti-HIV Agents / pharmacology*
  • Bufonidae*
  • Cytotoxicity Tests, Immunologic
  • Dose-Response Relationship, Drug
  • Electrophoresis, Polyacrylamide Gel
  • Enzyme-Linked Immunosorbent Assay
  • Giant Cells / drug effects
  • HIV Core Protein p24 / metabolism
  • HIV Reverse Transcriptase / antagonists & inhibitors
  • HIV-1 / drug effects*
  • HIV-1 / physiology
  • Hemeproteins / genetics
  • Hemeproteins / isolation & purification
  • Hemeproteins / pharmacology*
  • Humans
  • Molecular Sequence Data
  • Sequence Analysis, Protein
  • Skin / chemistry*
  • T-Lymphocytes / drug effects
  • Virus Replication / drug effects


  • Anti-HIV Agents
  • HIV Core Protein p24
  • Hemeproteins
  • HIV Reverse Transcriptase