实验基础

Adenoviruses encode a cysteme endopeptidase synthesized late in virus infection which is essential for virlon maturation and infectivity (1,2). The enzyme 1s encapsidated (approx 20 molecules per vinon) and may also have a role during decapsidation (3–5). Although there are approx 100 a ...

Many types of viral infection produce a transient permeabilization of the Infected cell (see refs. 1 and 2; reviewed in refs. 3 and 4). A large improvement in transfection efficiency was obtained when this phenomenon was applied to receptor-mediated gene delivery (5). A number of permeabilizing ...

The enteric adenoviruses of subgroup F (Ad40 and Ad41) pose some special problems of cultivation, as they cannot be readily passaged in many of the cell types used to propagate the more commonly used subgroup C serotypes (Ad2 and Ad5), and there is no standard plaque assay: A full discussion of the observ ...

Bovine adenovirus (BAV) serotypes 4 through 8 have been found clearly distingushable from BAVs 1,2,3, and 9 and from all other mastadenoviruses, and were therefore classified as subgroup 2 BAVs (1) and were considered as candidate members of a new taxon (2). The distinction was originally based on b ...

The E3 transcription unit of the well-studied subgroup C adenoviruses (Ad) (prototypic serotypes 2 and 5 ) is located between map units 76–86 (see Fig. 1). The E3 region is surrounded by the genes for virion protein VIII and fiber, and is transcribed off the r-strand. The E3-region transcription unit is co ...

Adenovirus mutants that lack essential genes must be grown by complementation, the products of the missing genes supplied by a source other than the viral genome. Two methods are available for the growth of defective adenovirus mutants by complementation. For mutations confined to E1, E4, or p ...

Early region 4 (E4; Fig. 1A) occupies the right-hand 3000 bp of the human adenovirus genome. The sequences of E4 and E4 cDNAs indicate that E4 encodes seven polypeptides (1–4), most of which have been detected in infected cells. Analysis of E4 mutants has implicated E4 products in a variety of processes that ...

The selective packaging of adenovirus DNA into a capsid at late times after viral infection raises a number of interesting questions. How is the viral DNA specifically selected from the pool of viral and cellular DNA for encapsidation? Is the packaging process coordinated with viral DNA repli ...

Adenovirus genetic research has entered a new phase with the recent upsurge in interest in using the virus as a vector for gene transfer, gene therapy, and as a vaccine (reviewed in refs. 1–3). Although the idea of using adenovirus as a vector is not new (4), recent advances both in understanding the functions ...

Construction of mouse adenovirus type 1 (MAV-1) mutants is facilitating studies of adenoviral pathogenesis in the natural host. We have isolated the first site-directed viral mutants of MAV-1, and we are comparing effects of wild-type (wt) and these mutant viruses in infections of mice (Smith ...

When using adenovirus as a vector for the delivery of transgenes, the induction of a cytotoxic T lymphocytes (CTL) can limit the longevity of the transgene expression (1,2). To detect the CTL response to adenovirus proteins or inserted transgenes in a mouse model, even with multiple in vivo immuniz ...

Macrophages are well-known for their ability to serve as phagocytes, ingesting and destroying microorganisms such as bacteria, and for their function in antigen presentation. Less appreciated, perhaps, is the fact that macrophages are also capable of recognizing and destroying cer ...

A common feature of cationic peptides is that their site of action is at the membrane due to channel formation, and that they tend to possess strong selectivity towards then target membrane. For example, although moth cecropin and bee melittin are members of the same family of peptides that adopt amp ...

Some travelers believe that the difficulties of a voyage become its most pleasurable memories. Others doubt this maxim or believe that it operates only in retrospect, and take a guidebook and compass along. This chapter is written for the second type of traveler.

The purification of antimicrobial peptides from natural sources often yields only minute amounts of peptides. Although continuing miniaturization of many analytical methods and bioassays has reduced peptide requirements, X-ray crystallography and 3D NMR still obligate 10 mg ...

Antibiotic peptides are host defense effector molecules broadly distributed throughout the animal kingdom. Many different families of peptides can be identified based on mature peptide structure or, in some cases, by similar propeptide structure (1). These peptides have been iden ...

Host defense in mammals involves a cooperative effort by a variety of antimicrobial peptides (1), which are produced by both phagocyte precursors and some epithelia. They are called on to combat invading pathogens at sites of infection and to help protect mucosal surfaces. Although sharing s ...

The remarkable advances and improvements in nuclear magnetic resonance (NMR) technology and methodology in recent years have made significant impact on the investigation of biological macromolecules, including amphipathic helical peptides. Through NMR studies, the three ...

The optical activity characteristic of organic molecules is a result of the absorption of light as electrons are promoted to higher molecular orbitals. In UV-visible spectroscopy, the transition process is described by the Beer-Lambert Law, A = εcd, in which A is the experimentally measured a ...

Hemolymph of invertebrate animals contains many molecules involved in unique and effective innate defense systems against invading microbes. Their defense systems are activated by the recognition of common epitopes on pathogens, such as bacterial lipopolysaccharide (LPS), p ...