... resulted in 55% and 51%loss of the initial activities of BHLmL2 and BHAb,respectively. These results strongly suggest that Ser isinvolved in the catalytic activity of BHLmL2 and BHAb and are consistent ... culture were0.012, 0.025, 0.050, 0.125 and 0.250 mm) and after fur-ther incubation for 24 h, the mycelia were separatedfrom the culture broth by filtration and used for BHactivity assays.GC–MS ... respectively. The influence of pH on the activities of the BHenzymes was investigated in the pH range 6–11. The pH optima were determined to be in the basic range(pH 8.0–10.0) for BHLmL2 and BHAb...
... evaluated by the statistical potentialused in the present study. In the case of the RNA muta-tions to the SRP complex, the mutated RNA residuesare located in a double-stranded region of RNA, and donot ... onto the RNA bases nearest the center of the b-sheet structure of the RRM. We then scoredthese sequence-variant structures with the distance-dependent potential function.Figure 2 shows the ... score; the blue line represents the rank of thesesequences using the distance-dependent potential. The points ineach colored line are sorted independently by rank; the x-axis is the sort order. The...
... investigationof the catalytic mechanism and substrate speci city and to understand the differences therein for this classof enzymes. In order to identify the subsites of the ervatamins and to understand ... both the molecules of the asymmetric unit runs along the extended backbone ofresidues 65–64 and is partly exposed to the solvent(Fig. 2B). On the other hand, the P3 moiety of E-64 ineach of the ... using the programs cns [58] and detwin and sfcheck in the CCP4 suite [59] confirmed that the datawere twinned, and allowed us to calculate the twinningfraction (0.394) (Fig. 6A,B) andthe twinning...
... binding of the Sfbgly interactions with the aglycone. Thus, the effectof the alteration of the glycone structure in the stabil-ity of the ESàcomplex (DDGà) for the wild-type and mutant ... another important issue in understand-ing the aglycone speci city is the contribution of the interactions with the aglycone to the catalysis inb-glycosidases. Mutational studies with ZmGlu1 and SbDhr1 ... is that the interactions with aglycone do not affect the binding of the glycone within the Sfbgly active site.This hypothesis was further investigated by deter-mining the influence on the glycone...
... oxidized andthe negativesignals with the reduced form of the enzyme. For the reduced form, the Soret band can be observed at 415 and 442 nm, and for the oxidized form at 403 and 422 nm. The b–band ... be seen at 517 nm andthe a–band at 547 nm and 603 nm. The difference signals that can be observed between 400 and 700 nm include the contributions of the hemes c, a and a3. The difference signals ... to the different environ-ment of the heme centers. The difference signals observed at442 nm and 603 nm can be assigned to the contributions of the hemes a and a3, with the position of the...
... internal membrane side is the rate-limiting s tep and not – as proposed for most of the other electrogenic symporters – the return of the unloadedtransporter to the outside of the membrane [17].In ... alanine, serine and proline but also osmolytes such as sarcosine and betaine, and the D-enantiomers of serine and alanine. The apparent affinities of PAT1 substrates are mainly in the range of 2–15 ... The apparent Kmvalues ofD-Pro,D-Ala and OH-Pro increased only 1.5- and 2.1-fold bydepolarizing the membrane from )120 to )20 mV. On the other hand, the affinity of b-Ala did not change significantlywithin...
... 3B). Thus for the SBD tree there is not anobvious border between the hydrolases and transglycosi-dases, but rather there may be one between the compactcluster of Bacillus and Thermoanaerobacter ... todomain A, the catalytic (b/a)8-barrel[1].Mostofthempossess a domain B that protrudes from the barrel between the third b-strand and third a-helix and varies greatly inlength, sequence and tertiary ... supports the ideathat there has been a separate evolution of this domain [30].This together with the findings of the present study indicatesa separate evolution of the domains C and E compared tothe...
... linkage speci city. Within these N-ter-mini, the A1 ⁄ A2 and O1 ⁄ O2 parts of the reuteransucr-ase catalytic domains mainly determin the glucosidiclinkages synthesized. Thus, not only the A2 ⁄ ... a)8barrel with the three catalytic resi-dues (Fig. 1C), determine the types and ratios of glu-cosidic linkages synthesized (Table 1). The A1⁄O1 and A2⁄O2 regions within the N-termini of the catalytic ... sequencing),both p15-GTFA-dN-RS and p15-GTFO-dN-RS weredigested with XbaI and SalI, SalI and SacI, and SacI and KpnI, and corresponding fragments were exchanged, yielding the six constructs p15-GTFA-O1-dN-RS,...
... speci city is morepronounced andthe synthetic capacity is, respectively,increased. In the latter system PA behaves as a typicaltransferase [14,15]. The nucleophile or S1Â [16] specicity of the ... close to the position found in the complex with PG [19]. The bond lengths and valence anglesof the nitroaniline moiety were taken from the X-ray datafor the system cyclophilin A andthe tripeptide ... largewhen the substrate’s polar group is directed toward it, and small when the polar group points to ArgB263. The interactionenergyofArgB263withtherestofthecomplex,however, remains large and practically...
... mayinfluence the shape and volume of the acyl binding pocket and thereby alter the binding mode and affinity of the enzyme for PAA and derivatives thereof, while maintaining the hydrophobicity of the binding ... site.To test the effect of the mutations on the speci city forphenylacetylated substrates, the steady-state kinetic param-eters for the hydrolysis of the chromogenic substrateNIPAB andthe inhibition ... interactionswith PAA and shields the binding site from the solvent. Athird phenylalanine, bF57, is located at the bottom of the hydrophobic cleft. The shortest distance between the sidechain of bF57 and PAA...