water soluble amphoteric graft copolymers of polysaccharide were synthesized via grafting of cationic monomer onto the sodium carboxymethylcellulose ()cmc)( and then used as a shale stabilizer in the water-based drilling fluids. accordingly, five types of cmc-graft copolymers with different ratios of acrylamide am)( and diallyldimethylammonium chloride dadmac)( were synthesized. grafting of mon...

Complex U consists of orotate phosphoribosyltransferase (EC 2.4.2.10) and orotidineG’-phosphate decarboxylase (EC 4.1.1.23), the last two enzymes of the de nova pathway for UMP biosynthesis. Earlier studies had shown that orotate and magnesium 5-phosphoribosyl-1-pyrophosphate, substrates for the transferase, and orotidine 5’-monophosphate (OMP), the product of the transferase and also the subst...

Protein catalyzed DNA rearrangements typically require assembly of complex nucleoprotein structures. In transposition and integration reactions, these structures, termed synaptic complexes, are mandatory for catalysis. We characterize the Tn5 pre-cleavage synaptic complex, the simplest transposition complex described to date. We identified this complex by gel retardation assay using short, line...

Targeting CD4+ T cells through their unique antigen-specific, MHC class II-restricted T cell receptor makes MHC class II tetramers an attractive strategy to identify, validate and manipulate these cells at the single cell level. Currently, generating class II tetramers is a specialized undertaking effectively limiting their use and emphasizing the need for improved methods of production. Using ...

T cell activation is initiated by recognition of antigenic peptide presented in complex with MHC molecules on the surface of APCs. The mechanism by which this recognition occurs is still unclear, and many models exist in the literature. CD4 T cells have been shown to respond to soluble oligomers of activating class II MHC-peptide complexes, but not to soluble monomers. In determining the reacti...

During enzymatic replication of plasmids containing the origin of the Escherichia coli chromosome, oriC, formation of an active initiation complex consisting of dnaA, dnaB, dnaC, and HU proteins, requires a supercoiled DNA template. Relaxed covalently closed plasmids are active only if supercoiled by gyrase prior to initiation; nicked and linear DNAs are inactive. Semi-conservative replication ...

Molecular Recognition Features (MoRFs) are short, interaction-prone segments of protein disorder that undergo disorder-to-order transitions upon specific binding, representing a specific class of intrinsically disordered regions that exhibit molecular recognition and binding functions. MoRFs are common in various proteomes and occupy a unique structural and functional niche in which function is...

We previously reported a monoclonal antibody named IF-43 that specifically recognizes thrombin-modified fibrinogen (desAA- and desAABB- fibrin monomer) bound with fibrinogen or other D(1) domain-containing plasmic fragments such as fragments X,Y, and D(1), but not intact fibrinogen or cross-linked fibrin degradation products (XDP). Here, we tentatively named such complexes, soluble fibrin monom...