Search results for "plasma protein"

Absence of binding of human salivary glycoprotein to human gingival fibroblast-like cells in vitro.

1996

The aim of this study was to determine whether human high molecular weight salivary glycoprotein binds in vitro to human gingival fibroblast-like cells. Primary monolayer cultures of 2 human gingival fibroblast-like cell lines were incubated with a high molecular weight fraction of salivary glycoprotein which expressed blood group A activity and glycoprotein-cell binding probed using an FITC-conjugated mouse monoclonal antibody to human blood group A antigen. Surface fluorescence of protein-treated cells was found to be no greater than that of untreated or serum-treated control cultures. As significant binding of salivary glycoprotein to gingival fibroblast-like cells does not occur in vitr…

Absorption of kininogen from human plasma by Streptococcus pyogenes is followed by the release of bradykinin.

1997

H-kininogen (high-molecular-mass kininogen, HK) is the precursor of the vasoactive peptide hormone bradykinin (BK). Previous work has demonstrated that HK binds to Streptococcus pyogenesthrough M-proteins, fibrous surface proteins and important virulence factors of these bacteria. Here we find that M-protein-expressing bacteria absorb HK from human plasma. The HK bound to the bacteria was found to be cleaved, and analysis of the degradation pattern suggested that the cleavage of HK at the bacterial surface is associated with the release of BK. Moreover, addition of activated plasma prekallikrein to bacteria preincubated with human plasma, resulted in BK release. This mechanism, by which a p…

Photoinduced and Self‐Activated Nuclease Activity of Copper(II) Complexes with N ‐(Quinolin‐8‐yl)quin­olin‐8‐sulfonamide – DNA and Bovine Serum Album…

2016

Two CuII complexes with a new quinoline sulfonamide derivative and phenanthroline (phen), [Cu(QSQ)(phen)]ClO4·0.5H2O (1) and [Cu(QSQ)(phen)(H2O)]ClO4 (2) [HQSQ = N-(quinolin-8-yl)quinolin-8-sulfonamide], have been synthesized and physicochemically characterized. Single-crystal X-ray diffraction studies have revealed a highly distorted trigonal-bipyramidal structure for 1 (τ = 0.68) and an almost perfect trigonal-bipyramidal geometry for 2 (τ = 0.92). DNA binding studies, which were performed by thermal denaturation, viscometry, fluorescence spectroscopy, and cyclic voltammetry, indicated a partial intercalation of 1 with Kapp = 2.45 × 106 M–1. The nuclease activity of 1 was investigated upo…

Citrate Sensing by the C 4 -Dicarboxylate/Citrate Sensor Kinase DcuS of Escherichia coli : Binding Site and Conversion of DcuS to a C 4 -Dicarboxylat…

2007

ABSTRACT The histidine protein kinase DcuS of Escherichia coli senses C 4 -dicarboxylates and citrate by a periplasmic domain. The closely related sensor kinase CitA binds citrate, but no C 4 -dicarboxylates, by a homologous periplasmic domain. CitA is known to bind the three carboxylate and the hydroxyl groups of citrate by sites C1, C2, C3, and H. DcuS requires the same sites for C 4 -dicarboxylate sensing, but only C2 and C3 are highly conserved. It is shown here that sensing of citrate by DcuS required the same sites. Binding of citrate to DcuS, therefore, was similar to binding of C 4 -dicarboxylates but different from that of citrate binding in CitA. DcuS could be converted to a C 4 -…

Developments in the Synthesis of Glycopeptides Containing Glycosyl l-Asparagine, l-Serine, and l-Threonine

1994

Interaction of glutamic-acid-rich proteins with the cGMP signalling pathway in rod photoreceptors.

1999

The assembly of signalling molecules into macromolecular complexes (transducisomes) provides specificity, sensitivity and speed in intracellular signalling pathways. Rod photoreceptors in the eye contain an unusual set of glutamic-acid-rich proteins (GARPs) of unknown function. GARPs exist as two soluble forms, GARP1 and GARP2, and as a large cytoplasmic domain (GARP' part) of the beta-subunit of the cyclic GMP-gated channel. Here we identify GARPs as multivalent proteins that interact with the key players of cGMP signalling, phosphodiesterase and guanylate cyclase, and with a retina-specific ATP-binding cassette transporter (ABCR), through four, short, repetitive sequences. In electron mic…

A discourse on human hair fibers and reflections on the conservation of drug molecules

1996

A gross discourse on human hair fibers and their formation is presented stressing the various interdisciplinary aspects, such as the morphological, biological, structural and biochemical data considered to be important in the field of hair analysis. An attempt is made to explain the incorporation of drug molecules during hair fiber formation by using the classical concepts of drug absorption based on lipoid theory and the pH-partition hypothesis as well as a modern biological approach on the permeability of cell membranes. In addition to the physiochemical considerations of the transport properties of a particular drug molecule such as a) the lipophilicity, which determines permeability thr…

Benzodiazepines: specific competitors for the binding of L-tryptophan to human serum albumin.

1975

By means of the gel filtration technique, the effect of nine benzo-diazepine derivates on the binding of l-tryptophan to human serum albumin was investigated. Using equimolar tryptophan and benzodiazepine concentrations, all benzodiazepines with binding constants higher than 104 (M−1), displace l-tryptophan from its binding site to a high degree. The mechanism of the displacement was characterized as a competition for a common binding site. Some of the benzodiazepines displace l-tryptophan to a greater extent than salicylic acid. The benzodiazepines and tryptophan are the only substances known with a high degree of stereospecific binding to human serum albumin. This study shows that there i…

Bestimmung der Tagesschwankungen des Plasma-Testosterons normaler M�nner durch kompetitive Proteinbindung

1970

Bei der Bestimmung von Tagesschwankungen von Plasma-Testosteron normaler Manner mit der kompetitivenProteinbindung wurden tiefste Werte um 20.00 Uhr und hochste Werte entweder um 4.00 Uhr oder um 12.00 Uhr gefunden.

Additive effect of factors related to assisted conception on the reduction of maternal serum pregnancy-associated plasma protein A concentrations and…

2013

Objective To analyze whether assisted conceptions need adjustments in first-trimester Down syndrome screening and why modifications in screening markers occur. Design Eleven-year cohort retrospective analysis. Setting Maternal-fetal medicine unit. Patient(s) Two thousand eleven naturally conceived normal singleton pregnancies and 2,042 normal singleton pregnancies achieved with assisted conception: 350 by IUI and 1,692 with IVF (n = 328) or intracytoplasmic sperm injection (ICSI; n=1,364), using nondonor (n = 1,086) or donated ova (n = 606), with fresh (n = 1,432) or frozen (n = 260) embryos. Intervention(s) Comparison of ultrasound and biochemical markers of first-trimester Down syndrome s…