[Structural and immunochemical analysis of the products of proteolysis of simian adenovirus hexons].
Hexon capsomers of simian adenovirus sim16 (SA7) and of human adenoviruses h5 (Ad5) and h6 (Ad6) were proteolytically digested and the resulting products studied by SDS-polyacrylamide gel electrophoresis and by radioimmunoprecipitation analysis. The trypsinolysis of native SA7 hexon leads to a stable molecular "core" containing 4-5 fragment species of 10 to 65 kDa and resembling the intact capsomer in quarternary structure (trimer). Similar cores but consisting of smaller fragments (less than 40 kDa) were obtained after chymotryptic digestion of native SA7, Ad5 and Ad6 hexons. The chymotryptic hexon fragments were also held together in pseudotrimeric structures. The similarity of proteolytic hexon fragment patterns between different primate adenoviral hexons suggested a homology to exist in localisation of the exposed tryptic and chymotryptic cleavage sites in their respective hexon polypeptide chains. Papain caused a complete hydrolysis of native SA7 hexon (trimer) yielding small peptides, but at first stage of digestion a stable papain hexon core containing small fragments (less than 10 kDa) was observed. The tryptic SA7 hexon cores in native state retained their antigenicity in reactions with homo- and heterologous antibodies, but after core denaturation the resulting fragments had no antigenic activity of native capsomer. In contrast to the data previously published, chymotryptic cores of SA7, Ad5 and Ad6 hexons not only reacted with respective homologous antibodies but also retained (at least in part) cross-reactive antigenic determinants. The questions of formation and stability of native adenoviral hexon conformation are discussed as well as the possible nature of hexon antigenic determinants.
V G
VG
Grigor'ev
S N
SN
Khil'ko
T I
TI
Tikhonenko
D000256:Adenoviridae / Q000032:analysis*; D000260:Adenoviruses, Human / Q000032:analysis* / Q000276:immunology; D000261:Adenoviruses, Simian / Q000032:analysis* / Q000276:immunology; D000595:Amino Acid Sequence; D000818:Animals; D000956:Antigens, Viral / Q000032:analysis; D001345:Autoradiography; D002213:Capsid / Q000032:analysis* / Q000276:immunology; D036022:Capsid Proteins; D002478:Cells, Cultured; D002522:Chlorocebus aethiops; D004591:Electrophoresis, Polyacrylamide Gel; D000939:Epitopes / Q000032:analysis; D006367:HeLa Cells; D006801:Humans; D006868:Hydrolysis; D010447:Peptide Hydrolases; D011233:Precipitin Tests; D011863:Radioimmunoassay
D000956:Antigens, Viral; D036022:Capsid Proteins; D000939:Epitopes; C018315:hexon capsid protein, Adenovirus; D010447:Peptide Hydrolases
Strukturnyĭ i immunokhimicheskiĭ analiz produktov proteoliza geksonov adenovirusov primatov.