A novel heme-containing protein with anti-HIV-1 activity from skin secretions of Bufo andrewsi.
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.
Zhao
Yu
Y
Department of Animal Toxinology, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, Yunnan 650223, China.
Jin
Yang
Y
Wang
Jian-Hua
JH
Wang
Rui-Rui
RR
Yang
Liu-Meng
LM
Lee
Wen-Hui
WH
Zheng
Yong-Tang
YT
Zhang
Yun
Y
D000595:Amino Acid Sequence; D000818:Animals; D019380:Anti-HIV Agents / Q000302:isolation & purification / Q000494:pharmacology*; D002025:Bufonidae; D003601:Cytotoxicity Tests, Immunologic; D004305:Dose-Response Relationship, Drug; D004591:Electrophoresis, Polyacrylamide Gel; D004797:Enzyme-Linked Immunosorbent Assay; D015726:Giant Cells / Q000187:drug effects; D016655:HIV Core Protein p24 / Q000378:metabolism; D054303:HIV Reverse Transcriptase / Q000037:antagonists & inhibitors; D015497:HIV-1 / Q000187:drug effects* / Q000502:physiology; D006420:Hemeproteins / Q000235:genetics / Q000302:isolation & purification / Q000494:pharmacology*; D006801:Humans; D008969:Molecular Sequence Data; D020539:Sequence Analysis, Protein; D012867:Skin / Q000737:chemistry*; D013601:T-Lymphocytes / Q000187:drug effects; D014779:Virus Replication / Q000187:drug effects
D019380:Anti-HIV Agents; D016655:HIV Core Protein p24; D006420:Hemeproteins; D054303:HIV Reverse Transcriptase