Adenosine triphosphatase ATPase An

enzyme which catalyzes the conversion of ATP to ADP with the release of Pi. Some viruses (e.g. vaccinia) possess an ATPase activity.

Adenoviridae A family of double-stranded DNA viruses with icosahedral symmetry. The virion is 70-90nm in diameter, formed of 240 non-vertex capsomeres (hexons) 7-9nm in diameter, and 12 vertex capsomeres (pentons) that consist of a base and an outward projection up to 77.5 nm long of fiber with a knob at its end. The virion is non-enveloped, resistant to lipid solvents and trypsin. Buoyant density (CsCl): 1.33-1.35g/ml. Inside the capsid is the core, consisting of protein and a linear molecule of double-stranded DNAmol. wt. 20-30 x 106 with no single-stranded breaks. The DNA sequence of human adenovirus 2 has 35937 base pairs, with an inverted terminal repetition of 103 base pairs. There are inverted terminal repetitions of 50-200 base pairs in all viruses sequenced. GC content of the DNA varies between 34% and 60%. Viral maturation takes place in the nucleus. Virus is liberated by cell disruption. Adenoviruses may be divided on the basis of their host species and further on the basis of hemagglutination, anti-genic structure and oncogenicity. They express immunoregulatory genes that act against the host defense mechanisms. Usually found in the respiratory tract where they are often associated with disease. There are two genera: Mastadenovirus (viruses of mammals) and Aviadenovirus (viruses of birds); a third is under consideration (Atadenovirus), which would include bovine adenovirus 4 to 8, ovine adenovirus isolate 287 and egg drop syndrome virus (duck aden-ovirus type 1).

Benko M and Harrach B (1998) Arch Virol 143/4, 829

Horwitz M (2001) Virology 279, 1 Nemerow GR (2000) Virology 274, 1 Russell WC (2000) J Gen Virol 81, 2573

adenovirus General name for species in the family Adenoviridae. Most adenoviruses grow in only one species, and they are named accordingly, e.g. human aden-ovirus 2, where 2 refers to the serotype. Adenovirus serotypes are generally defined by neutralization assays with a cut-off ratio (homologous: heterologous titer) greater than 16. The use of human adenoviruses as potential vectors for gene therapy, including selective toxicity to tumor cells, is under active development. See also Adenoviridae.

adenovirus death protein (ADP) A protein which is expressed in increased amounts late in infection, and facilitates the release of progeny virions from adenovirus-infected cells by triggering host cell lysis.

Hausmann J et al (2000) Virology 244, 343

adenovirus-SV40 hybrids First reported between human adenovirus 7 and SV40. An adenovirus 7 isolate was found to be contaminated with SV40 after isolation and passage in primary rhesus monkey kidney cells. Infectious SV40 virus was eliminated by passage in the presence of SV40 antiserum but on injection into newborn hamsters the tumor cells produced contained adenovirus 7 and SV40 T antigens. The virus could be neutralized by adenovirus antiserum, and SV40 genome sequences appeared to be in an adenovirus particle. The adenovirus-SV40 hybrid stock virus was named E46+. The viral DNAs in the hybrid virus are covalently linked. A number of hybrids between SV40 and other adenoviruses have since been described. They may be divided into those that produce free infective SV40 virus and thus contain the complete SV40 genome, and those that do not. Used as experimental tools, e.g. to study SV40 T antigen.

Tjian R (1978) Cell 13, 165

adjuvant Substance added to antigens to enhance immune response. Salts of aluminum (e.g. hydroxide or phosphate) acceptable for use in humans. Saponin or Freund's adjuvant used only in experimental animals.

AdoHcy Abbreviation for S-adenosylho-mocysteine.

AdoMet Abbreviation for S-adenosylme-thionine.

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