Free Proteins

Several of the products discussed herein are under intense development. One product, based on recombinant hemoglobin, is in early human trials as of this writing. Other hemoglobin-based solutions are also under review at the EDA. Replacement of red blood cells using massive amounts of protein, free in solution, is an unprecedented therapeutic adventure. 

Protein S. Protein S is a single-chain molecule of approximately 78,000 daltons that contains 10 y-carboxy glutamic acid residues in the NH -terminal portion of the molecule. Protein S is a regulatory vitamin K-dependent protein. In plasma 40% of this protein circulates free and 60% circulates bound to C4b binding protein. Free Protein S functions as a nonenzymatic cofactor that promotes the binding of Protein C to membrane surfaces (22—25). 

The environmental (i.e., solvent and/or protein) free energy curves for electron transfer reactions can be generated from histograms of the polarization energies, as in the works of Warshel and coworkers [79,80]. 

Protein-Free 50S Ribosomal Subunits Catalyze Peptide Bond Formation In Vitro... 

Cormier and Dure (1963) found another type of luciferin and called it protein-free luciferin. Protein-free luciferin was found in the vapor condensate of freeze-drying whole animals, and also in the 3 5-56 % ammonium sulfate fraction of the crude extract noted above. The protein-free luciferin behaved like an aromatic or heterocyclic compound and it was strongly adsorbed onto Sephadex and other chromatography media, requiring a considerable amount of solvent to elute it. The luminescence reaction of protein-free luciferin in the presence of luciferase required a 500-times higher concentration of H2O2 compared with the standard luciferin preparation. Both types of the luciferin preparation had a strong odor of iodoform. 

Xylose-rich pectic polysaccharide was extracted from defatted and protein-free cell wall preparation (5) using HCl solution (pH 1.6) at 85° C for 4 h. The extract was adjusted to pH 5.0 with ammonia, concentrated on a rotary evaporator under reduced pressure at 40°C, and precipitated with 5 volumes of 96% ethanol. After washing twice with 80% ethanol and drying in an air circulated oven at 40°C for 2 h, the pellet was ledissolved with distilled water and then precipitated with 4 vols 96% ethanol. Before the pellet was gently ground, the precipitated pellet was washed twice with 70% ethanol and dried at 40 ° in an air circulated oven for 16 h. The resultant white powder was labelled "xylose-rich pectic polysaccharide" and stored in a refrigerator. 

Table 1. The composition of neutral sugars and content of anhydrogalacturonic acid (%) in XRPP extracted with pH 1.6 HCl solution at 85° C for 4 h (1 g wheat straw/100 mL extractant) from defatted, protein-free wheat straw.

HyClone is a supplier of cell culture and bioprocessing systems, which also offers customized work to configure particular applications. Services address activities, research, and production. Business is centered on culturing media, and consequently support is offer for the development of a given formulation. HyClone supplies FBS and other sera for cell culture, serum-free and protein-free media, etc. 

Shen, B., Greenfield, P., and Reid, S., Calcium Alginate Immobilized Hybridomas Grown Using a Fluidized-Bed Perfusion System with a Protein-Free Medium, Cytotechnol., 14 109 (1994)... 

Kokubo et al. [16,17] showed that the hydroxyapatite formation on the surfaces of bioactive materials in the living body can be reproduced even in an acellular protein-free simulated body fluid (SB F) with ion concentrations nearly equal to those of human blood plasma. This indicates that the hydroxyapatite layer is formed through chemical reaction of the bioactive glass with the surrounding body fluids. The formed layer consists of carbonated hydroxyapatite with small crystallites and low crystallinity, which is similar to bone hydroxyapatite. Hence the bioactivity of a material can be evaluated even in vitro by examining the hydroxyapatite formation on its surface in SBF. 

Although plant cell culture is not as cost effective as plant cultivation in the open field, it will become an economical process if higher protein yields can be achieved [58]. The cultivation medium of plants is chemically defined, consisting of a carbon source, minerals, vitamins and phytohormones [69]. Furthermore, it is protein-free and relatively inexpensive. In contrast, animal cells often require complex supplements such as fetal calf serum and/or expensive growth factors, although serum-free cultivation is possible in case of Chinese hamster ovary (CHO) cells [70]. 

Freedman and others (2001) determined the effects of purple grape juice and its main flavonoids on the functionality of platelets and the production of NO. They observed that incubation of platelets with diluted grape juice resulted in the inhibition of aggregation, increased production of NO, and decreased production of superoxide. To confirm the relevance of these findings, 20 healthy subjects were supplemented with 7 mL of black grape juice/kg/day for 14 days. The inhibition of platelet aggregation was also observed ex vivo there was an increase in the production of NO from 3.5 1.2 to 6.0 1.5 pmol/108 platelets and a decrease in the release of superoxide, from 29.5 5.0 to 19.2 3.1 arbitrary units. Under these conditions the antioxidant capacity of protein-free plasma increased by 50% (Freedman and others 2001). 

In 2003, Prior and others described methods for the extraction and analysis of hydrophilic and lipophilic antioxidants, using modifications of the ORAC procedure. These methods provide, for the first time, the ability to obtain a measure of total antioxidant capacity in the protein free plasma, using the same peroxyl radical generator for both lipophilic and hydrophilic antioxidants. This assay was also used to measure the total antioxidant capacity of guava fruit extracts (Thaipong and others 2006). 

The lethal effects of cadmium are thought to be caused by free cadmium ions, that is, cadmium not bound to metallothioneins or other proteins. Free cadmium ions may inactivate various metal-dependent enzymes however, cadmium not bound to metallothionein may have the capacity to directly damage renal tubular membranes during uptake (USPHS 1993). 

Figure 2. FFEM images of BR reconstituted and protein-free vesicles.

A) Fractured convex half and (B) concave half of Mab (PhytVSQDG (9 1 mol/ mol) vesicle containing BR (C) convex half and (D) concave half of protein-free vesicle. Bar = 50 nm. Samples were prepared at the initial concentration of 2 mM Mab (Phyt)2, 0.22 mM SQDG and 50pg/ml BR and concentrated by ultracentrifugation in 75 mM K2SO4 buffer solution. 

Over thirty different elements have been determined in medical and biological materials by atomic absorption spectroscopy. The popularity of the technique is due to a number of factors, including sensitivity, selectivity, and ease of sample preparation. With biological fluids, often no preparation at all is required. The techniques employed usually involve simple dilution of the sample with water or with an appropriate reagent to eliminate interference. Alternatively, the element to be determined is separated by solvent extraction. Either an untreated sample, a protein free filtrate, or an ashed sample is extracted. 

Savory et al. 3S) measured calcium and magnesium directly in protein-free filtrates of serum or urine. Baker et al. 36) found that both trichloroacetic acid and hydrochloric acid suppress calcium absorption and that uniform acid content is therefore required for the determination of calcium. Okuda and Sasamoto37) determined calcium by adjusting solution conditions to 20 — 50 % methanol and 650 mg % lanthanum serum is diluted 21-fold and urine is diluted 10—21 fold to bring the calcium concentration into the optimum range of 1 to 0.5 mg %. 

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