Proteins acids

Fig. 3. The pH dependence, where A, B, and C represent regions corresponding to the p-K s of glutamic and aspartic acids, lysine, and argenine, respectively, of (a) protein swelling, and (b) protein acid-binding capacity. Adapted from Ref. 3.

CS-PG, chondroitin sulfate-proteoglycan these are similar to the dermatan sulfate PGs (DS-PGs) of cartilage ffable 48-11). SPARC, secreted protein acidic and rich in cysteine. 

According to V.d.Hoek (1) the aeration requires at least an input of 36 kWh per pig place per year, summarize all this literature. Just the principles are important. Under anaerobic conditions different types of microbes transported the volatile fatty acids and the aromatic compounds to CH4, C02, H20 and NH4OH. There is also some H2S produced from the digestion of several protein acids (cysteine and methionine). All these endproducts together, known as biogas, have a typical odour, mainly caused by H2S and NH3. Because of the breakdown of the malodorous compounds the slurry has lost its typical smell. 

Hay has been analysed by NIR for crude protein, acid detergent fibre, dry matter, lignin and IVDMD, rapeseed for oil and water and spring field beans for N to name but a few applications. Most macroinorganic constituents of peaty soil can be determined, and moulds have been measured in hay, tall fescue and barley (Malley and Nilsson, 1995). A short bibliography is given below. 

Although L-phenylalanine is a protein amino acid, and is known as a protein acid type of alkaloid precursor, its real role in biosynthesis (providing C and N atoms) only relates to carbon atoms. L-phenylalanine is a part of magic 20 (a term deployed by Crick in his discussion of the genetic code) and just for this reason should also be listed as a protein amino acid type of alkaloid precursor, although its duty in alkaloid synthesis is not the same as other protein amino acids. However, in relation to magic 20 it is necessary to observe that only part of these amino acids are well-known alkaloid precursors. They are formed from only two amino acid families Histidine and Aromatic and the Aspartate family . 

SPARC (Secreted Protein Acidic and Rich in Cysteine), 46 484-485 Specific activity method, of isotope half-life determination, 2 326-327 Specific interaction theory, application, 43 19-21... 

Contrary to what its name suggests, opium is not a single chemical compound. Its chemical make-up is more like a salad, consisting of various substances including sugars, proteins, acids, water, and many alkaloids, among others. The people who grow opium for its narcotic value are primarily interested in the alkaloids. 

Besides his fundamental research in the carbohydrate field, the functions of Courtois as the head of a hospital laboratory for many years led him to publish a number of papers dealing with clinical chemistry, among which may be cited determination of ethyl alcohol, proteins, acidic phosphatases, and trehalase in blood determination of the basic groups of proteins by phytic acid study of the phytosoluble glycoproteins in biological fluids and identification and determination of scyllitol in urine. Under the aegis of the International Pharmaceutical Federation, he participated in the standardization of the methods proposed for the assay of such enzymes as cellulases and hemicellulases. 

With respect to the hydrolysis step, it can be accomplished by acid, by enzymatic, or by direct microbial attack. Microbial hydrolysis results primarily in the production of cellular biomass or single-cell protein. Acid hydrolysis, while simple and direct, results in a sugar syrup with considerable contamination from the side reaction products. Enzymatic hydrolysis is usually the cleanest hydrolysis process. Unfortunately, it is the most costly of the three to operate. 

Puolakkainen P, Bradshaw AD, Kyriakides TR, Reed M, Brekken R, Wight T, Bomstein P, Ratner B, Sage EH. Compromised production of extracellular matrix in mice lacking secreted protein, acidic and rich in cysteine (SPARC) leads to a reduced foreign body reaction to implanted biomaterials. American Journal of Pathology 2003,162, 627-635. 

Pentosidine is determined by HPLC with spectrofluorimetric detection (excitation and emission wavelengths of 335 and 385 nm, respectively) (S14), although immunochemical and ELISA assays for determination of various protein oxidative modification products have become increasingly popular (08). Protein-aldehyde adducts can be estimated using adduct-specific antibodies (U2, Wl). Another approach requires stabilization of adducts, producing derivatives resistant to conditions used in protein acid hydrolysis and quantification of hydrolysis products by gas chromatography-mass spectrometry (R7). 

Partial hydrolysis of proteins using acid, alkali or enzymes is commonly employed to improve functionality and usefulness of novel proteins. Acid hydrolysis is the most common method for preparing hydrolysates of soy, zein, casein, yeast and gluten. Hydrolysates are used in formulated foods, soups, sauces, gravies, canned meats, and beverages as flavorants and thickeners (2,3,6). Alkaline treatments have been employed to solubilize and facilitate protein extraction from soy, single cells, and leaves. 

An alternative and possibly more effective way is the determination of the change in the acid-base property of the protein itself. If the binding of a substance to a protein can significantly change this behavior, the detection of this change enables the construction of a new type of biosensor. This chapter focuses on the use of ISFETs for the determination of the protein acid-base behavior. 

A titration study of a peroxidase from Japanese radish has been reported by Morita and Kameda (1958). The titration curves of native protein, acid-denatured protein, and alkali-denatured protein are dramatically different. Unfortunately only continuous titration curves were obtained, so that an interpretation of the data is not possible at this time. 

Figure 15.22. Conformational Changes in Calmodulin on Calcium Binding. In the absence of calcium (top), the EF hands have hydrophobic cores. On binding of a calcium ion (green sphere) to each EF hand, structural changes expose hydrophobic patches on the calmodulin surface. These patches serve as docking regions for target proteins. Acidic residues are shown in red, basic residues in blue, and hydrophobic residues in black. The central helix in calmodulin remains somewhat flexible, even in the calcium-bound state.

Yao Y, Lamkin MS, Oppenheim FG Pellicle precursor proteins acidic proline-rich proteins, statherin and histatins, and their crosslinking reaction by oral transglutaminase. J Dent Res 1999 78 1696-1703. 

Many mathematical models have been used to describe proton binding by humic substances however, in every case, the models were initially developed for other purposes, often for the description of proton binding by proteins, acidic polymers, ion exchange resins, and so on. The assumptions and approximations that were inherent in the original models have often been overlooked or forgotten when those models are applied to humic substances. In this section, several common models are examined to evaluate their applicability to humic substances, with due consideration for the complexity of this mixture of nonidentical organic acids. 

No dedicated acid catalyst which donates a proton to 04 has as yet been found in any pectin or pectate lyase transfer from solvent or from more remote protein acids and bases via a Grotthus mechanism appears to be all that is required. 

The pK of proteinous acids is pK > 4. Thus the fraction of active site retaining a free proton will be 10-4 or less. Consequently, the true presentation of a proton, even in a protogenic site, is not as a free hydrated proton but as a covalently linked hydrogen atom. 

Protein acid residues Protein acid residues... 

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