Viruses stability function

Stability tests on finished dosage forms and products Tests for conformance to pharmacopeial standards Exploratory studies on viruses and cell biology Tests of functionality and/or appropriateness of food additives... 

HIV-1 RT contains RNase H, which is responsible for degradation of viral RNA and removal of RNA primers for minus- and plus-strand DNA synthesis (see reviews [87-89]). The absolute requirement for virus-associated RNase H function [90-93] offers an additional target for antiretroviral drugs. The RNase H domain of HIV-1 RT is located at the C-terminus of the p66 subunit (Figures 2 and 3). In contrast to the polymerase domain of HIV-1 RT, the structure of the RNase H domain is quite similar in all known HIV-1 RT structures and conforms quite well with the structure of the isolated HIV-1 RNase H domain [94-95]. The relative stability of the structure of the RNase H domain suggests that the RNase H active site could be a relatively well-defined target for drug... 

The hepatitis delta virus (HDV) ribozyme is a member of the class of small ribozymes and functions as a self-cleaving RNA sequence critical to the replication of the virus RNA genome (1, 8, 40). HDV ribozymes are proposed to employ several catalytic strategies that include an important example of general acid/base catalysis that involves a specific cytosine residue in the active site. Indeed, a milestone in our understanding of RNA catalysis was the observation that HDV and other small ribozymes could function in the absence of divalent metal ion cofactors, provided that high (molar) concentrations of monovalent ions are present (41, 42). These high monovalent ion concentrations are believed to stabilize the active RNA conformation, which implies that the primary role of divalent metal ions is in structural stabilization (42). 

Adeno-associated virus (AAV) is a non-pathogenic member of the parvovirus family. Its single-stranded DNA viral genome requires co-infection with either adenovirus or HSV for its own replication/propagation. Wild-type AAV encodes two viral gene products, Rep and Cap, which function in rep-lication/integration and structural stability, respectively. Vectors... 

Animal cells cultured in two-dimensional (2D) monolayers in traditional glass or plastic tissue culture flasks have been used successfully for many purposes in research and industrial production. However, such cultures may lose key phenotypic characteristics (e.g. virus susceptibility, morphology, surface markers/receptors) after repeated passage. In vivo the presence of three-dimensional (3D) cellular structures is critical to the correct development, function and stability of cells, tissues and organs. The characteristics that the researcher or technologist wishes to utilize are often a feature of the tissue and not individual cells, e.g. a functional bladder epithelium or crypt structures of the gut. In this section we describe some of the approaches that can be used to simulate certain features of the in vivo environment in an attempt to promote natural gene expression and tissue function in cultured cells. The described technologies address these features from two aspects ... 

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