Proteins protein quality

Table 8. Protein Quality and Digestibility of Nonphotosynthetic Microorganisms...

F. Otalora, J. M. Garcia-Ruiz, A. Moreno. Protein crystal quality studies using rod-shaped crystals. J Cryst Growth 168 93>, 1996. 

Protein trafficking is the transport of proteins to their correct subcellular compartments or to the extracellular space ( secretory pathway ). Endo- and exocytosis describe vesicle budding and fusion at the plasma membrane and are by most authors not included in the term protein trafficking. Protein quality control comprize all cellular mechanisms, monitoring protein folding and detecting aberrant forms. 

Once the proteins have passed the quality control system of the early secretory pathway, they are transported in vesicles via the individual compartments of the Golgi apparatus to the plasma membrane. Soluble proteins are transported in the vesicle lumen, membrane proteins are integrated in the vesicle membrane. The transport to the cell surface is the default pathway for secretory and membrane proteins. Proteins may also become part of one of the intracellular compartments along the secretory pathway, but only if they contain specific retention signals. 

The UPS also plays a major role in protein quality control. In a process known as endoplasmic associated degradation (ERAD), misfolded proteins, which are formed in the endoplasmatic reticulum, are translocated back to the cytoplasm and degraded by the proteasome. 

Qi, P. X. and Onwulata, C. 1. (2011). Physical properties, molecular structures and protein quality of texturized whey protein isolate (WPl) Effect of extrusion moisture content. /. Dairy Sci. (Accepted for publication). doi 10.3168/jds.2010-3942. 

Birds eat sufficient food to satisfy their energy intake, but this does not mean that they will eat enough protein, unless the protein proportion in the rotation is high. Protein quality is also important, the two most essential amino acids being lysine and methionine. The best quality protein for all poultry is white fishmeal (banned only for ruminants by the Soil Association). The best vegetable protein is soya bean which is low in methionine, but this can be made up by using sunflower meal in the ration. 

Once an electron density map has become available, atoms may be fitted into the map by means of computer graphics to give an initial structural model of the protein. The quality of the electron density map and structural model may be improved through iterative structural refinement but will ultimately be limited by the resolution of the diffraction data. At low resolution, electron density maps have very few detailed features (Fig. 6), and tracing the protein chain can be rather difficult without some knowledge of the protein structure. At better than 3.0 A resolution, amino acid side chains can be recognized with the help of protein sequence information, while at better than 2.5 A resolution solvent molecules can be observed and added to the structural model with some confidence. As the resolution improves to better than 2.0 A resolution, fitting of individual atoms may be possible, and most of the... 

Patent flour has two classes of use. It can be used to make whiter bread or where very high protein content is required. The use of patent flour to make bread seems to be dying out. Its use does, however, remain popular in South Wales. There are various examples of products where patent flour is used for its protein quality, e.g. filo pastry and West Indian patties. Both of these products are brown so the colour of the flour is not important. 

Quality of biotechnology products, analysis of the expression construct in cells used for production of r-DNA derived protein product Quality of biotechnological products stability testing of biotechnological/Biology products Availability of Draft Guideline on Quality of... 

The protein efficiency ratio (PER) of field pea flours is considerably less than that of casein (1.46 vs. 2.50), and somewhat less than that of soy flour (1.81). However, composites of wheat flour and pea or rice and pea (50% of the protein from each source) had PER s of 2 or more (22). Thus, supplementation of cereals with pea flour results in improvement of protein quality. 

Cooked glandless cottonseed protein quality was superior to that of raw and roasted cottonseed. The roasting process adversely affected protein quality. Supplementation of roasted cottonseed with 0, 0.2, 0.4, 0.6 and 0.8% L-lysine indicated a peak PER response at 0.45%. The adverse effect of roasting on the protein quality of cottonseed was overcome by addition of L-lysine which made the protein... 

Cottonseed, peanut, sesame seed, and soybean flours, when used as supplements, add to the quality of the protein. The improvement of protein quality was due to the flours compensating for limiting amino acids. Supplementation using various flours improved total protein, amino acid content and some physical characteristics in akamu, yeast bread and sugar cookies. 

Law 480 blends corn-soy and corn-soy-milk, with respect to protein quality by animal assay, organoleptic quality and storage... 

Three animal procedures (protein efficiency ratio, net protein ratio, and protein digestibility) were used to evaluate protein quality. The AOAC (13) animal assay for protein efficiency ratio... 

Hayes, R.E Spadaro, J.J. Wadsworth, J.I. Freeman, D.W. "A study of nine Corn-Based Food Blends Formulated by Computer for Maximum Protein Quality," Agri. Research Results (South.Ser.) ARR-S-18, U.S. Department of Agriculture, 1984. 

Protein quality studies evaluating various edible portions of the winged bean plant and the results of recent International Field Trials are reviewed. Research efforts have been focused upon the mature seed (protein content 20.7-45.9% in 240 accessions), which is occasionally eaten in parts of Indonesia and Papua, New Guinea. Autoclaved seed meal and wet heat treated seed meal provided a corrected PER value of 1.76 and 1.72 respectively, in comparison to casein control of 2.50. 

Previously published reviews (59-61) have analyzed in detail the emergence of winged bean as a legume of significant potential. This paper summarizes recent reports on protein quality evaluation of the edible portions of this legume. 

Tubers Tubers are quite commonly consumed by villagers in Burma. Other tropical countries also report sporadic use of winged bean tubers (59). However, in comparison to the available data on the nutrient, anti-nutrient composition and the protein quality of the seed flour, published data on the nutritional value of winged bean tuber is somewhat limited. The few reported studies dealing with a larger number of varieties grown in different locations (25,67-71) show that tubers are mainly composed of protein and carbohydrates. 

The experimental exploration and confirmation of protein functions are relatively slow processes and always require dedicated experiments. The analysis of protein-protein associations as such improved remarkably in quality and speed. This is accompanied by the creation of new databases that will reflect the network of interacting proteins (the Protein Function and Metabolic Pathway project, http //bioinformer.ebi. ac.uk 80/newsletter/archives/4/pfmp.html, and the Biomolecular Interaction Network Database project http //bioinfo.mshri.on.ca/ BIND/). These activities contribute to the idea that cellular mechanisms can be better understood when they are seen as a multicomponent networked process. 

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