Protein load

It is also possible to control the release of proteins by varying the protein load within the formulation. The effect of changing the protein load of a formulation was examined by incorporating bovine serum albumin 

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Because the separation is nearly independent of the total amount of protein loaded onto the column, no limitation with respect to the protein concentration exists for concentrations at least up to 60 mg. The high mechanical stability enables the injection of even highly viscous samples with high concentrations of protein. 

In the development of a SE-HPLC method the variables that may be manipulated and optimized are the column (matrix type, particle and pore size, and physical dimension), buffer system (type and ionic strength), pH, and solubility additives (e.g., organic solvents, detergents). Once a column and mobile phase system have been selected the system parameters of protein load (amount of material and volume) and flow rate should also be optimized. A beneficial approach to the development of a SE-HPLC method is to optimize the multiple variables by the use of statistical experimental design. Also, information about the physical and chemical properties such as pH or ionic strength, solubility, and especially conditions that promote aggregation can be applied to the development of a SE-HPLC assay. Typical problems encountered during the development of a SE-HPLC assay are protein insolubility and column stationary phase... 

With only 100 pg total protein loaded (for method development), peaks I and II were very well resolved. When the full sample (6 mg) was injected for preparative purposes, peak II shifted to an earlier retention time. A shift to earlier retention on increased loading is a common problem in purification. If the major component can be made to elute before the minor component, the retention shift will not harm the separation as greatly as if the major component elutes after the major component. 

In patients with bleeding varices, digestion of swallowed blood represents a high protein load this causes nausea and can precipitate symptoms of HE. 

Theoretical and model analysis based on a nanofluidic approach is needed for this situation. One may ask, is it possible to release proteins loaded in nanotubules We have found that the addition of the polycation PEI in the release solvent resulted in much quicker protein release, as demonstrated in Figure 14.9. In this case, most of the insulin was released in 1 hour instead of 100 hours. 10-40% of glucose oxidase, catalyse, and hemoglobin were released within 4 hours through complexation with PEI. It is unclear, whether the proteins were replaced by the polycation or released in a complex with PEI. 

Murthy N, Xu M, Schuck S et al (2003) A macromolecular delivery vehicle for protein-based vaccines Acid-degradable protein-loaded microgels. Proc Natl Acad Sci USA 29 4995-5000... 

Fig. 17 Protein loaded Dex-g-PLLA nanogel. Reprinted from [164] with permission...

Jiang and Zhu (2000) and Qiu and Zhu (2001) have reported the fabrication of multilayered devices composed of stacks of compression-molded disks of alternating compositions. One type of disk is either P(SA-EG) or P[SA-co-TMAgly)-Z>-EG] and the other is a pH-sensitive, protein-loaded blend of, for example, poly(methacrylic acid) and polyethoxazoline. The release of model proteins, myoglobin, bovine serum albumin, and FITC-dextran, and compounds such as brilliant blue have been studied and pulsatile release profiles have been demonstrated (Jiang and Zhu, 2000 Qiu and Zhu, 2001). 

Recently, we reported a CPE-amplified silica NP-based immunoassay for IgG detection [96]. Silica NPs (100 nm) were used as the substrate in view of their small size and high surface-to-volume ratio for maximum protein loading, which could... 

Amidi M, Romeijn SG, Borchard G, Junginger HE, Hennink WE, Jiskoot W (2006) Preparation and characterization of protein-loaded N-trimethyl chi-tosan nanoparticles as nasal delivery system. J Control Release 111(1-2) 107-116. 

If the purpose of gel electrophoresis is to identify low-abundance proteins (e.g., low-copy-number proteins in a cell extract or contaminants in a purification scheme), then a high protein load (0.1 to 1 mg/ml) and a high-sensitivity stain such as silver or fluorescence should be used. When the intention is to obtain enough protein for use as an antigen or for sequence analysis, then a high protein load should be applied to the gel and the proteins visualized with a staining procedure that does not fix the proteins in the gel, e.g., colloidal CBB G-250 (Subsection 8.2.8.1). Furthermore, for purposes of quantitative comparisons, stains with broad linear ranges of detection response should be used. 

Detection system lacks sensitivity necessary to detect the amount of protein loaded... 

Different proteins have dissimilar expression in differing cell types. To get a good signal for analysis, the total amount of protein loaded into each well should be optimized for different cell types. 

IV then based on response 250 g/48 h max Peds. 0.5—1 g/kg/dose inf at 0.05-0.1 g/min Caution [C, ] Sev e anemia cardiac, renal, or h atic insuff d/t protein load h5 pCTVolemia Contra CHF Disp Soln SE Chills, fevCT, CHF, tach, -1- BP, hypervolemia Interactions At5 pical Rxns W/ ACEI w/hold 24 h prior to plasma administration EMS May cause pulm edema, monitor resp status/lung sounds OD May cause circulatory ov load (T venous pressure) or pulm edema slow flow to KVO and evaluate... 

An issue sometimes raised in relation to bone maintenance in the elderly concerns the endogenous acid generated by the metabolism of dietary protein, which when regularly excreted in the urine can cause calciuresis via various mechanisms (Dawson-Hughes, 2003a,b). Opinions have varied in terms of the extent to which protein-induced increases in Ca excretion may impact bone mass via bone dissolution and/or resorption (Barzel and Massey, 1998 Heaney, 1998, 2002). Protein intake in conjunction with Ca supplementation has now been positively associated with bone accrual, and only more recently has the notion of Ca economy been considered as a compensatory mechanism in response to an acute increase in the dietary protein load (Bonjour, 2005 Kerstetter et ah, 2005). 

The major problem of protein precipitation is experienced particularly in the application of high protein loadings (>1 mg). To avoid this, two solutions are suggested. 

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