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Additivity residuals

The Rp toxins also have an additional residue at the N-terminus which extends the sheet one residue in that direction. This may be an indication that the structural difference arises from the substitution of F17 for L17 in RpII, because there is also leucine at position 17 in the A. xanthogrammica toxins. The structure of the core sheet is remarkably similar among the different toxins, considering that there is essentially no conservation of the residues involved in forming it, aside from the cystines. [Pg.302]

Hb-Constant Spring (18, 19) was the first variant discovered that has 31 additional residues at the COOH-termlnus of the a-chaln Comparable hemoglobins are Hb-Icarla and Hb-Koya-Dora, and Hb-Tak which has 10 additional residues at the COOH-termlnus... [Pg.7]

Second, our studies of the secondary structure of the H" "-ATPase indicate that about 36% of the polypeptide chain is present in a helical configuration [27,42]. If the membrane-embedded sector of the molecule is helical as shown, only 90 or so additional residues in the molecule can be present as helices. Thus, the great majority... [Pg.127]

Generally, for a US tolerance, there will be a requirement for additional residue... [Pg.200]

Gas chromatography is commonly used to analyse mixtures for quantification. A wide variety of special detectors with adequate linear response ranges are available for quantification of various classes of compounds (cf. Table 4.14). Quantification by direct injection may be used to determine additives, residual monomers and solvents in product formulations, coated films, and solid materials [109]. On the other hand, reliable quantification by means of solid-injection PTV-GC, HS-GC and PyGC techniques is not always trivial. [Pg.193]

Figure 12 Catalytic mechanism of thermolysin and stromelysin-1. (A) The mechanism of thermolysin [54], (B) The mechanism of stromleysin-1 [10]. Equivalent residues to Tyr-157 and His-231 are not observed for stromelysin-1. The proposed mechanism for collagenase-1 [S3] is similar to stromelysin-1, but also involves Asn-180 (equivalent to Asn-162 in stromelysin-1). This residue cannot participate in stromelysin-1 due to an additional residue between Ala-165 and Asn-162. (Adapted from Ref. 10.)... Figure 12 Catalytic mechanism of thermolysin and stromelysin-1. (A) The mechanism of thermolysin [54], (B) The mechanism of stromleysin-1 [10]. Equivalent residues to Tyr-157 and His-231 are not observed for stromelysin-1. The proposed mechanism for collagenase-1 [S3] is similar to stromelysin-1, but also involves Asn-180 (equivalent to Asn-162 in stromelysin-1). This residue cannot participate in stromelysin-1 due to an additional residue between Ala-165 and Asn-162. (Adapted from Ref. 10.)...
Enantiometrically pure alcohols are important and valuable intermediates in the synthesis of pharmaceuticals and other fine chemicals. A variety of synthetic methods have been developed to obtain optically pure alcohols. Among these methods, a straightforward approach is the reduction of prochiral ketones to chiral alcohols. In this context, varieties of chiral metal complexes have been developed as catalysts in asymmetric ketone reductions [ 1-3]. However, in many cases, difficulties remain in the process operation, and in obtaining sufficient enantiomeric purity and productivity [2,3]. In addition, residual metal in the products originating from the metal catalyst presents another challenge because of the ever more stringent regulatory restrictions on the level of metals allowed in pharmaceutical products [4]. An alternative to the chemical asymmetric reduction processes is biocatalytic transformation, which offers... [Pg.136]

Whilst Lewis acids like SbCls or A1C13 form stable adducts with diphenyl cyclopropenone, from which the ketone can be regenerated unchanged208, trialkyl boranes effect a remarkable ring expansion to 2-phenyl indenone derivatives 309 containing an additional residue in the 3-position215. ... [Pg.72]

The repeat sequences in solenoid proteins are often so imperfect that it is difficult to identify them without knowledge of the 3D structure or other supplementary information. In highly regular /1-solenoids, such as antifreeze proteins (Leinala et al., 2002 Liou et al., 2000) or YadA adhesin (Nummelin et al., 2004), the repeats are of the same length and sequence similarity between the repeats is discernible (so-called overt repeats). Frequently, however, the repeats in a given /1-solenoid vary in length because additional residues may be inserted at turn sites without disrupting the pattern of /1-strands that stabilizes the structure (Steinbacher et al., 1994 Yoder et al., 1993). In these cases, the structural repeats are not apparent as sequence repeats (covert repeats). [Pg.76]

Since the discovery of the nuclear Overhauser effect (NOE, see previous section) [4, 5] and scalar coupling constants [36, 37] decades ago, NMR-derived structure calculations of biomolecules largely depended on the measurement of these two parameters [38]. Recently it became possible to use cross-correlated relaxation (CCR) to directly measure angles between bond vectors [39] (see also Chapt 7). In addition, residual dipolar couplings of weakly aligned molecules were discovered to measure the orientation of bond vectors relative to the alignment tensor (see Sect 16.5). Measurement of cross-correlated relaxation was described experimentally earlier for homonuclear cases [40, 41] and is widely used in solid-state NMR [42 14]. [Pg.362]

Imides - Polyimides (PI) have been conventionally prepared by the chemical or thermal cyclodehydration of polyamic acids formed from the solution reaction of aromatic tetracarboxylic dianhydrides and aromatic diamines. The early PI were insoluble and relatively intractable. The polyamic acid was the processable intermediate. However, the polyamic acid precursor has two major shortcomings, hydrolytic instability and the evolution of volatiles during the thermal conversion to PI. In addition, residual solvent was left in adhesive tapes and prepregs to obtain tack, drape and flow. During the fabrication of components, the evolution of volatiles caused processing problems and led to porosity in the part. As work progressed on PI, other synthetic routes were investigated (e.g. reaction of esters of aromatic tetracarboxylic acids with diamines... [Pg.9]

The residues that orient the Asn side chain in AsnRS are conserved in AspRS (Serl99, Gln201, and Glul77) but subtle changes in the position of their side chains induce a different orientation of the a-amino group of Asp. In conclusion, a restricted number of residues differ in the catalytic sites of AspRSs and AsnRSs and are directly involved in the selection of the homologous aa, but additional residues participate in correct orientation of the substrate side chains and thus are involved indirectly in their selection. [Pg.399]

Infrared data in the 1575-400 cm region (1218 points/spec-trum) from LTAs from 50 coals (large data set) were used as input data to both PLS and PCR routines. This is the same spe- tral region used in the classical least-squares analysis of the small data set. Calibrations were developed for the eight ASTM ash fusion temperatures and the four major ash elements as oxides (determined by ICP-AES). The program uses PLSl models, in which only one variable at a time is modeled. Cross-validation was used to select the optimum number of factors in the model. In this technique, a subset of the data (in this case five spectra) is omitted from the calibration, but predictions are made for it. The sum-of-squares residuals are computed from those samples left out. A new subset is then omitted, the first set is included in the new calibration, and additional residual errors are tallied. This process is repeated until predictions have been made and the errors summed for all 50 samples (in this case, 10 calibrations are made). This entire set of... [Pg.55]


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See also in sourсe #XX -- [ Pg.116 ]




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