Physicochemical and Biological Examination of Two Glatiramer Acetate Products.

Herein we compared 40 mg/mL lots of the active ingredient, glatiramer acetate, manufactured by Mylan/Natco to the active ingredient, glatiramer acetate in Copaxone (Teva Pharmaceuticals, Ltd., Netanya Israel) using physicochemical (PCC) methods and biological assays. No differences were seen between the Mylan/Natco and Teva lots with some low resolution release PCC assays (amino acid analysis, molecular weight distribution, interaction with Coomassie Brilliant Blue G-250).

Targeting Attenuated Interferon-α to Myeloma Cells with a CD38 Antibody Induces Potent Tumor Regression with Reduced Off-Target Activity.

Interferon-α (IFNα) has been prescribed to effectively treat multiple myeloma (MM) and other malignancies for decades. Its use has waned in recent years, however, due to significant toxicity and a narrow therapeutic index (TI). We sought to improve IFNα's TI by, first, attaching it to an anti-CD38 antibody, thereby directly targeting it to MM cells, and, second, by introducing an attenuating mutation into the IFNα portion of the fusion protein rendering it relatively inactive on normal, CD38 negative cells.

Comparative immunogenicity assessment: a critical consideration for biosimilar development.

An appropriate assessment strategy with validated anti-drug antibody (ADA) assays is critical for comparative evaluation of immunogenicity between a proposed biosimilar and its reference product. The strategy should aim to identify potential differences in immune responses between these products. While an ADA assay employing the proposed biosimilar product as the detecting reagent has been generally recommended for such evaluation, a product-specific assay using the product of interest may be of use as it offers a capability of detecting antibodies against specific epitopes from the respective product.

Challenges facing the development and use of protein chips to analyze the phosphoproteome.

Recent advances in analytical methods, particularly in the area of protein microarrays, have brought the field of proteomics to the forefront of biological science. Protein arrays have shown to be useful for the multiplexed analysis of several hundreds of proteins in parallel. While much of the effort has focused on developing methods to identify expressed proteins, the identification of post-translational modifications is equally important for comprehensive proteome characterization.

Antibody World Summit 2004-SRI Conference 19-21 July 2004, Philadelphia, PA, USA.

Overall, the sessions were well attended and a lot of questions were asked. Two-thirds of the speakers were from industry and the rest from academia. Of particular note, The academics presented cutting-edge science in the antibody discovery and development area.

Recent applications of protein arrays in target identification and disease monitoring.

The focus in the field of protein arrays has shifted from technology development to applying the technology in biological research. This review will highlight several recently published examples of biologically relevant experiments using both planar and bead-based arrays. Examples of the use of antibody arrays, antigen arrays and protein activity arrays will be discussed.

Chip-based analysis of protein-protein interactions by fluorescence detection and on-chip immunoprecipitation combined with microLC-MS/MS analysis.

A new chip-based method to identify protein-protein interactions was developed using the guanine nucleotide exchange factor GRF2 and two interacting proteins, Ras and calmodulin, as model proteins. A generic immobilization strategy for FLAG-tagged bait proteins on a protein-repellent streptavidin chip surface was implemented by presentation of an oriented anti-FLAG antibody. A flow cell device, integrating different chip surfaces, was developed, and the interaction of immobilized GRF2 with the two analytes was verified by fluorescence assays.

Generation of bioreagents for protein chips.

Protein microarrays have the potential to dramatically increase the throughput of proteomic analysis. Protein expression profiling chips with distinct spots of immobilized protein capture agents will allow the simultaneous measurement of hundreds to thousands of proteins from one sample. In contrast to DNA chips, for which the capture probes are easily designed and synthesized, the development of content for protein biochips is a long and laborious process.

Protein expression profiling arrays: tools for the multiplexed high-throughput analysis of proteins.

The completion of the human genome sequence has led to a rapid increase in genetic information. The invention of DNA microarrays, which allow for the parallel measurement of thousands of genes on the level of mRNA, has enabled scientists to take a more global view of biological systems. Protein microarrays have a big potential to increase the throughput of proteomic research.

Recent developments in protein microarray technology.

The sequencing of the human genome and the advent of DNA chips and sophisticated bioinformatics platforms have enabled molecular biologists to take a more global view of biological systems and to analyze naturally occurring genetic variation. Microarrays of antibodies can measure the concentrations of many proteins quickly and simultaneously. Microarrays of genomically encoded proteins allow scientists to screen entire genomes for proteins that interact with particular factors, catalyze particular reactions, or act as substrates for protein-modifying enzymes or as targets of autoimmune responses.

Optimizing antibody immobilization strategies for the construction of protein microarrays.

Antibody microarrays have the potential to revolutionize protein expression profiling. The intensity of specific signal produced on a feature of such an array is related to the amount of analyte that is captured from the biological mixture by the immobilized antibody (the "capture agent"). This in turn is a function of the surface density and fractional activity of the capture agents.

Establishment of intein-mediated protein ligation under denaturing conditions: C-terminal labeling of a single-chain antibody for biochip screening.

Intein-mediated protein ligation is a recently developed method that enables the C-terminal labeling of proteins. This technique requires a correctly folded intein mutant that is fused to the C-terminus of a target protein to create a thioester, which allows the ligation of a peptide with an N-terminal cysteine (1, 2). Here we describe the establishment of this method for the labeling, under denaturing conditions, of target proteins that are expressed insolubly as intein fusion proteins.

Functional protein microarrays.

Microarrays of immobilized functional proteins have the potential to increase dramatically the throughput of proteomic analysis. Micro-immunoassays, in which biological samples are exposed to arrays of immobilized antibodies, can be used for protein expression profiling. In addition, protein function can be elucidated by performing binding and enzymatic assays on arrays of biologically active proteins.

Improved method for pepsinolysis of mouse IgG(1) molecules to F(ab')(2) fragments.

Pepsinolysis of immunoglobulin (IgG) to yield F(ab')(2) fragments has been utilized for over 40 years, but the most common subclass of mouse immunoglobulin, IgG(1), is resistant to pepsin cleavage. We show here that this resistance is due to N-linked glycosylation. Deglycosylation by peptide: N-glycosidase F (PNGase F) improves pepsinolysis to generate F(ab')(2) fragments for mouse and rat monoclonal IgG(1) and, in some cases, IgG(2b).