Studies of the purified protein

45 mT (B) 8T magnetic fields. The solid lines are spectral simulations obtained with the parameters listed in [5]. 

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To prove that one theory, the other, or even a combination of both is correct, further studies of the purified secreted and cellular proteins from the bacteria will be part of the next series of experiments planned. 

In order to be exploitable for extraction and purification of proteins/enzymes, RMs should exhibit two characteristic features. First, they should be capable of solubilizing proteins selectively. This protein uptake is referred to as forward extraction. Second, they should be able to release these proteins into aqueous phase so that a quantitative recovery of the purified protein can be obtained, which is referred to as back extraction. A schematic representation of protein solubilization in RMs from aqueous phase is shown in Fig. 2. In a number of recent publications, extraction and purification of proteins (both forward and back extraction) has been demonstrated using various reverse micellar systems [44,46-48]. In Table 2, exclusively various enzymes/proteins that are extracted using RMs as well as the stability and conformational studies of various enzymes in RMs are summarized. The studies revealed that the extraction process is generally controlled by various factors such as concentration and type of surfactant, pH and ionic strength of the aqueous phase, concentration and type of CO-surfactants, salts, charge of the protein, temperature, water content, size and shape of reverse micelles, etc. By manipulating these parameters selective sepa-... 

A crucial point when discussing economics of phase systems is the loading of the system. The more biological material that can be loaded, lesser is the cost of phase system per unit processed. Furthermore, extensive studies have been carried out concerning recirculation of the phase components. The latter efforts have mainly been focused on PEG/salt systems, and also on the polymer/polymer phase systems employing affinity ligands. Kula and coworkers reported the reuse of the salt phase when carrying out extractive purification (37). They showed that the phases could be recycled 4 times without any marked loss in performance of the phase separation and in specific activity of the purified protein. 

The spectroscopic and photochemical properties of the synthetic carotenoid, locked-15,15 -cA-spheroidene, were studied by absorption, fluorescence, CD, fast transient absorption and EPR spectroscopies in solution and after incorporation into the RC of Rb. sphaeroides R-26.1. High performance liquid chromatography (HPLC) purification of the synthetic molecule reveal the presence of several Ai-cis geometric isomers in addition to the mono-c/x isomer of locked-15,15 -c/x-spheroidene. In solution, the absorption spectrum of the purified mono-cA sample was red-shifted and showed a large c/x-peak at 351 nm compared to unlocked all-spheroidene. Spectroscopic studies of the purified locked-15,15 -mono-c/x molecule in solution revealed a more stable manifold of excited states compared to the unlocked spheroidene. Molecular modeling and semi-empirical calculations revealed that geometric isomerization and structural factors affect the room temperature spectra. RCs of Rb. sphaeroides R-26.1 in which the locked-15,15 -c/x-spheroidene was incorporated showed no difference in either the spectroscopic properties or photochemistry compared to RCs in which unlocked spheroidene was incorporated or to Rb. sphaeroides wild type strain 2.4.1 RCs which naturally contain spheroidene. The data indicate that the natural selection of a c/x-isomer of spheroidene for incorporation into native RCs of Rb. sphaeroides wild type strain 2.4.1 was probably more determined by the structure or assembly of the RC protein than by any special quality of the c/x-isomer of the carotenoid that would affect its ability to accept triplet energy from the primary donor or to carry out photoprotection. 

In vitro studies of the purified yeast enzymes and, for Revlp, its mammalian counterpart have established some of the basic properties of these proteins. They have also been used to investigate the role of these enzymes, often in combination with other DNA polymerases, in replication past various lesions, leading to proposals concerning the in vivo function of the enzymes. It is likely, however, that such reactions lack important factors present within cells, emphasizing the need for validation of the models with in vivo studies, as discussed in Section III. 

One can anticipate further advances along the same lines as have been exploited in the study of bacterial ribosomes characterisation and amino acid sequencing of the purified proteins, precise determination of their stoichiometry, and investigations into the topography of the ribosomes using methods for the chemical... 

In a remarkable cooperative program between Emil Smith s and James Bonner s laboratories [65, 66], the complete amino acid sequence of the 102 residues of calf thymus histone 4 was established from the chymo-tryptic and tryptic peptides of the purified protein. This study reveals two important characteristics of the histone sequence the presence of an unusual amino acid—acetyllysine—in position 16 and the clustering... 

Pikus JD, Studts JM, Achim G, Kattffinann KE, Mtinck E, Steffan RJ, McGIay K, Fox BG. 1996. Recomhinant toluene-4-monooxygenase catatytic and Mossbauer studies of the purified diiron and Rieske components of a four-protein complex. Biochemistry 35 9106-9119. 

As set forth in Section IV, study of the plasma proteins has thrown much light upon such phenomena of clinical interest as edema formation, the elaboration of antibodies, the differentiation of true and biological false-positive reactions for syphilis, the factors affecting the erythrocyte sedimentation rate, the formol gel reaction, and many others. The therapeutic potentialities of highly purified normal human plasma albumin and 7-gIobulins, and of protein hydrolysates, are being actively investigated and have found important applications. 

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