Continuous monitoring of a monoclonal antibody by size exclusion chromatography reveals a correlation between system suitability parameters and column aging.

Size exclusion chromatography (SEC) is a foundational analytical method to assess product purity of biological molecules. To ensure accurate and reproducible data that meet regulatory agency standards, it is critical to monitor the chromatographic column with efficient and continuous approaches. In this study, 19 SEC columns (Waters Acquity BEH200) were evaluated using an in-house monoclonal antibody made at Regeneron.

Low pK of Lys promotes glycation at one complementarity-determining region of a bispecific antibody.

Protein glycation is a common, normally innocuous, post-translational modification in therapeutic monoclonal antibodies. However, when glycation occurs on complementarity-determining regions (CDRs) of a therapeutic monoclonal antibody, its biological activities (e.g.

Physical and Functional Characterization of a Viral Genome Maturation Complex.

Genome packaging is strongly conserved in the complex double-stranded DNA viruses, including the herpesviruses and many bacteriophages. In these cases, viral DNA is packaged into a procapsid shell by a terminase enzyme. The packaging substrate is typically a concatemer composed of multiple genomes linked in a head-to-tail fashion, and terminase enzymes perform two essential functions: 1) excision of a unit length genome from the concatemer (genome maturation) and 2) translocation of the duplex into a procapsid (genome packaging).

Trimerization Dictates Solution Opalescence of a Monoclonal Antibody.

Opalescence, sometimes observed in antibody solutions, is thought to be mediated by light scattering of soluble oligomers or insoluble particulates. However, mechanistic features, such as stoichiometry and self-association affinity of oligomeric species related to opalescence, are poorly understood. Here, opalescence behavior of a monoclonal antibody (mAb-1) solution was studied over a wide range of solution conditions including different protein concentrations, pH, and in the presence or absence of salt.

Thermodynamic Interrogation of the Assembly of a Viral Genome Packaging Motor Complex.

Viral terminase enzymes serve as genome packaging motors in many complex double-stranded DNA viruses. The functional motors are multiprotein complexes that translocate viral DNA into a capsid shell, powered by a packaging ATPase, and are among the most powerful molecular motors in nature. Given their essential role in virus development, the structure and function of these biological motors is of considerable interest.

Analytical Ultracentrifugation as a Tool to Study Nonspecific Protein-DNA Interactions.

Analytical ultracentrifugation (AUC) is a powerful tool that can provide thermodynamic information on associating systems. Here, we discuss how to use the two fundamental AUC applications, sedimentation velocity (SV), and sedimentation equilibrium (SE), to study nonspecific protein-nucleic acid interactions, with a special emphasis on how to analyze the experimental data to extract thermodynamic information. We discuss three specific applications of this approach: (i) determination of nonspecific binding stoichiometry of E.

Integration host factor assembly at the cohesive end site of the bacteriophage lambda genome: implications for viral DNA packaging and bacterial gene regulation.

Integration host factor (IHF) is an Escherichia coli protein involved in (i) condensation of the bacterial nucleoid and (ii) regulation of a variety of cellular functions. In its regulatory role, IHF binds to a specific sequence to introduce a strong bend into the DNA; this provides a duplex architecture conducive to the assembly of site-specific nucleoprotein complexes. Alternatively, the protein can bind in a sequence-independent manner that weakly bends and wraps the duplex to promote nucleoid formation.

Characterization of the non-specific DNA binding properties of the Adenoviral IVa2 protein.

Human Adenovirus (Ad) is a non-enveloped, icosahedral virus with a linear, double-stranded DNA genome. The Ad IVa2 protein is involved in multiple viral processes including viral late gene transcription and virus assembly. Previous studies have shown that IVa2 loads additional viral proteins onto conserved DNA elements within the Ad genome to regulate these viral processes.

Cooperative heteroassembly of the adenoviral L4-22K and IVa2 proteins onto the viral packaging sequence DNA.

Human adenovirus (Ad) is an icosahedral, double-stranded DNA virus. Viral DNA packaging refers to the process whereby the viral genome becomes encapsulated by the viral particle. In Ad, activation of the DNA packaging reaction requires at least three viral components: the IVa2 and L4-22K proteins and a section of DNA within the viral genome, called the packaging sequence.

Thermodynamic linkage of large-scale ligand aggregation with receptor binding.

There are many examples in the literature that deal explicitly with the coupling of ligand oligomerization with receptor binding. For example, many transcription factors dimerize and this plays a fundamental role in sequence specific DNA recognition. However, many biological macromolecules undergo reversible, large scale aggregation processes, some of which are indefinite.

Self-association of the adenoviral L4-22K protein.

Human adenovirus (Ad) is an icosahedral, double-stranded DNA virus that causes infections of the respiratory tract, urinary tract, and gastrointestinal tract. Assembly of virus particles requires condensation and encapsidation of the linear viral genome. This process requires sequence specific binding of two viral proteins, called IVa2 and L4-22K, to a conserved sequence located at the left end of the viral genome, called the packaging sequence (PS).

Interaction of the adenoviral IVa2 protein with a truncated viral DNA packaging sequence.

Adenoviral (Ad) infection typically poses little health risk for immunosufficient individuals. However, for immunocompromised individuals, such as AIDS patients and organ transplant recipients, especially pediatric heart transplant recipients, Ad infection is common and can be lethal. Ad DNA packaging is the process whereby the Ad genome becomes encapsulated by the viral capsid.

Acrolein inhibits cytokine gene expression by alkylating cysteine and arginine residues in the NF-kappaB1 DNA binding domain.

Cigarette smoke is a potent inhibitor of pulmonary T cell responses, resulting in decreased immune surveillance and an increased incidence of respiratory tract infections. The alpha,beta-unsaturated aldehydes in cigarette smoke (acrolein and crotonaldehyde) inhibited production of interleukin-2 (IL-2), IL-10, granulocyte-macrophage colony-stimulating factor, interferon-gamma, and tumor necrosis factor-alpha by human T cells but did not inhibit production of IL-8. The saturated aldehydes (acetaldehyde, propionaldehyde, and butyraldehyde) in cigarette smoke were inactive.

Cost of depression of adults in Taiwan.

Objective: To estimate the direct cost of depression in Taiwanese adults for the years 2000-2002.

Methods: The medical claims database of the National Health Bureau was analyzed and the cost of treating adults (>15 years of age) with the diagnosis of depression was calculated.

Results: The total direct medical costs of adult depression in the three years 2000, 2001, and 2002 were approximately US dollars 93 million, US dollars 117 million, and US dollars 140million, respectively.