Cleavage pattern

Vmax and Km values using pga as a substrate at the optimum pH 4.1 were calculated as 500 U/mg and 0.15 mg/ml and 2000 U/mg and 0.15 mg/ml for PGI and PGII, respectively. Mode of action analysis revealed a random cleavage pattern for PGII while for PGI multiple attack on a single chain was observed. For PGII a partial subsite map was obtained. 

In order to estimate the number of subsites, the binding affinities, the location of the active site and the cleavage patterns reduced and non reduced oligogalacturonates of DP 4 to 6 were used as substrates and the resulting products analysed by HPLC and TLC. 

Figure 4 shows the cleavage pattern of RG-lyase toward the various RGO s. Again no bond-cleavage frequencies could be given since the response factors of the various products were not known. The RG-lyase cleaved the chain four units from the reducing end. When the... 

Definition of Ej and E2 eonformations of the a subunit of Na,K-ATPase involves identification of cleavage points in the protein as well as association of cleavage with different rates of inactivation of Na,K-ATPase and K-phosphatase activities [104,105]. In the Ei form of Na,K-ATPase the cleavage patterns of the two serine proteases are clearly distinct. Chymotrypsin cleaves at Leu (C3), Fig. 3A, and both Na,K-ATPase and K-phosphatase are inactivated in a monoexponential pattern [33,106]. Trypsin cleaves the E form rapidly at Lys ° (T2) and more slowly at Arg (T3) to produce the characteristie biphasic pattern of inactivation. Localization of these splits was determined by sequencing N-termini of fragments after isolation on high resolution gel filtration columns [107]. 

The structural features of this group are summarized as follows (1) possession of an acetal or a hemiacetal ether linkage between C-8 and C-10, and (2) either absence of a substituent or presence of a hydroxyl group or ester moiety at C-6. Because a large number of hasubanan alkaloids follow this cleavage pattern, the metaphanine-type cleavage may be one of the primary pattern for all hasubanan alkaloids (76). 

The fragments formed by FeBABE fragmentation are analyzed by comparing them to enzymatic or chemical cleavage patterns observed by treatment on the same prey protein. Since the cleaved prey protein is detected by its end-labeled tag, the only fragments detected are those... 

Comparative sequence analysis based on MALDI-TOF-MS analysis of nucleic acids cleaved at specific bases and reference sequences used to construct in silico cleavage patterns enable cross-correlation of theoretical and experimental mass signal patterns. Observed signal pattern differences are indicators of sequence variations and... 

A [4], and Tsujihara demonstrated the antifungal activity of sulfoximine 4 [5]. In a collaboration with Weinhold [6] we discovered an unusual cleavage pattern of pseudotripeptide 5 when it was treated with peptidase A and attributed this effect to the presence of the central acylated P-carboxysulfoximidoyl unit, which we had studied separately previously [7]. 

The five-membered ring heteroaromatics (furan, thiophene, and pyrrole) show very similar ring cleavage patterns. The first step in each case is cleavage of the carbon-heteroatom bond. 

Since dehydrocyclization and ring cleavage are reversible processes, the same mechanisms may be operative in both transformations. Two basic cleavage patterns—a selective and a nonselective ring opening—are known. In the selective process only secondary-secondary carbon-carbon bonds are broken. Conversely, only the formation of carbon-carbon bonds between methyl groups is allowed in ring formation. In contrast, all bonds are cleaved equally in the nonselective reaction. Bonds adjacent to quaternary carbon atoms are exceptions, since they are not cleaved at all. 

Double-crossover molecules have been used extensively to characterize the properties of Holliday junctions. The strong torsional coupling between their crossover points has been exploited to construct symmetric immobile junctions (S. Zhang et al. 1993), junctions in which one of the crossovers is flanked by homology, but is nevertheless unable to branch migrate. Symmetric immobile junctions have been used to characterize crossover isomerization thermodynamics (S. Zhang and Seeman 1994) and, more recently, the sequence dependence of the branch point stability (W. Sun et al., 1998). Double crossover molecules have also been employed to establish the cleavage patterns of endonuclease VII, an enzyme that resolves branched junctions (Fu et al. 1994 a). 

Neyhart GA, Cheng C-C, Thorp HH (1995) Kinetics and mechanism of the oxidation of sugars and nucleotides by oxoruthenium(IV) model studies for predicting cleavage patterns in polymeric DNA and RNA. J Am Chem Soc 117 1463-1471... 

Rustad, R., Irradiation, chemical treatment and the cleavage-cycle and cleavage pattern alteration, in The Sea Urchin Embryo Biochemistry and Morphogenesis, Czihak, G., Ed., Springer-Verlag, Berlin, 1975, 345. 

---