Trypsin aqueous solution

The three-dimensional structure of trypsin inhibitor 1 from C. maxima was determined in 1989 by X-ray crystallography in complex with bovine trypsin and by in aqueous solution. The three-dimensional... 

A new, more general, way to combine ab initio quantum mechanical calculations with classical mechanical free-energy perturbation approach (QM/FE approach) to calculate the energetics of enzyme-catalysed reactions and the same reaction in solution has been reported." The calculated free energies were in fairly good agreement with the experimental data for the activation energies of the first test case, amide hydrolysis in trypsin and in aqueous solution. 

Figure 9.12 The uptake of water-soluble proteins (p) from an aqueous solution to an AOT micellar solution as a function of the salt concentration in the water phase. Note the remarkable difference between cytochrome-C (Cyt-c) and a-chymo-trypsin (a-Chym), so that in principle it is possible to separate one from the other.

The accumulation method involving foam drying by creation of a pressure drop in the foam liquid phase is effective for extraction of some proteins from aqueous solutions. The drainage and destruction of foams from aqueous globular protein solutions (BSA, egg albumin, HSA, lysozyme and trypsin) under pressure drop have been studied in [74,76,77]. 

Partial hydrolysis of elastin by reagents other than organic acids also gives rise to a mixture of soluble proteins similar to a- and /3-elastin. Thus Wood (quoted by Hall et al, 1952) first demonstrated that partial hydrolysis with dilute sodium hydroxide yields a protein which forms a reversible coacervate on raising the temperature of its solutions. Later Wood (1958) showed that on prolonged heating in aqueous solution a-elastin is converted into an insoluble gellike form. Reconstituted fibers of heat-treated a-elastin resembled fibrous elastin in their elastic behavior and X-ray-dif-fraction pattern but imlike purified elastin they were dissolved by 1 % acetic acid at 100°C and by crystalline trypsin. 

Denisov V, Halle B (1995) Protein hydration dynamics in aqueous solution. A comparison of bovine pancreatic trypsin inhibitor and ubiquitin by oxygen-17 spin relaxation dispersion. J Mol Biol 245 682-697... 

Trypsin in aqueous solution has been studied by a simulation with the conventional periodic boundary molecular dynamics method and an NVT ensemble.312 340 A total of 4785 water molecules were included to obtain a solvation shell four to five water molecules thick in the periodic box the analysis period was 20 ps after an equilibration period of 20 ps at 285 K. The diffusion coefficient for the water, averaged over all molecules, was 3.8 X 10-5 cm2/s. This value is essentially the same as that for pure water simulated with the same SPC model,341 3.6 X 10-5 cm2/s at 300 K. However, the solvent mobility was found to be strongly dependent on the distance from the protein. This is illustrated in Fig. 47, where the mean diffusion coefficient is plotted versus the distance of water molecules from the closest protein atom in the starting configuration the diffusion coefficient at the protein surface is less than half that of the bulk result. The earlier simulations of BPTI in a van der Waals solvent showed similar, though less dramatic behavior 193 i.e., the solvent molecules in the first and second solvation layers had diffusion coefficients equal to 74% and 90% of the bulk value. A corresponding reduction in solvent mobility is observed for water surrounding small biopolymers.163 Thus it... 

The pancreatic secretion probably contains a number of cryptolytes—certainly two. The one of these to which it owes its peptone-forming power has been obtained in a condition of comparative purity by Ktlhne, and cailed by him trypsin in aqueous solution it digests fibrin almost immediately, but it exerts no action upon starch. 

Prepare a trypsin stock solution by dissolving 20 mg of the enzyme in 1 mM hydrochloric acid aqueous solution to a 1-mg/ml final concentration. 

Here, V is the volume of the sphere and // is the viscosity of the solvent As can be seen in Table 1.4, the Tj values of proteins such as bovine serum albumin and trypsin in aqueous solution He in the ns range and become larger with increasing molar mass. The proteins were labeled with fluorescent markers such as l-dimethylamino-5-sulfonyl-naphthalene groups (see Chart 1.10) [38], Segmental motions and molecular flexibiUty have been studied for various polymers, such as polystyrene and the Y-shaped immunoglobulins IgA and IgG. Relaxation times in the range of 10-100 ns were found. In these studies, the... 

Further applications of n.m.r. techniques in specific enzyme systems are discussed below. E.p.r. has been used to investigate the bonding of copper(ii) in several amino-acid, peptide, and trypsin complexes, and the effects of divalent metal ions on the Raman spectrum of ATP in aqueous solution have also been reported. ... 

In duodenal juice trypsin may be determined as follows to 4 ml of 0.1 Af glycine buffer solution, pH 8.5, add 1 ml of 3% aqueous solution of albumin and 0.5 ml of duodenal juice suitably diluted with the same buffer solution (as a rule, 1 70). Withdraw two 2.0-ml samples to the first add immediately 2.0 ml of 20% sulfosalicylic acid solution, and filter. Incubate the second sample at 37°C for 2 hr, and then add 2.0 ml of 20% sulfosalicylic acid solution, and filter. Of each filtrate, add 0.5 ml to 2.5-ml portions of Brdi6ka Co solution, and polarograph (as a rule at the sensitivity 1/500-1/1000). 

A further support to this view has been afforded from our isolation of another fragment from a tryptic digest of bovine serum albumin (Habeeb and Atassi, 1976a,6). The fragmentation pattern of crystalline native BSA by trypsin was studied (Habeeb and Atassi, 1976a,6) in aqueous solution under various conditions with regard to the yield and size of the... 

Simulations of BPTI (bovine pancreatic trypsin inhibitor) in van der Waals solvents have been reported [74, 75], the density and molecular size were chosen to simulate those of water. More realistic water representations were used in further simulations [18, 76, 77]. Avian pancreatic polypeptide hormone in crystal and in aqueous solution has been reported by Kruger [78]. These studies tend to indicate that the calculations in vacuo represent fairly correctly the motion of the protein core, while exposed sidechains react more strongly to solvent effects. 

---