Consequences of primer binding-sites polymorphisms on genotyping practice

Herein we investigated the effect of primer binding site polymorphisms in achieving correct genotyping when a mismatch occurs in distinct positions of the primer sequence. For that purpose primer sequences were designed in order to carry either allelic form at the 3’ end and at 3 bp, 5 bp and 7 bp apart from the 3’ end of an intronic polymorphism (rs2247836) observed in phenylalanine hydroxylase (PAH) gene. For one of the alleles annealing failure was obtained when the mismatch occurs at all the four primer-site locations. Primer sequences carrying the alternative SNP allele resulted to be less specific as the distance to the primer-3’ end was increased. Altogether, these results revealthat effects in the extension of the annealing failure is allele and mismatch-position dependent.

Study on Anticoagulation Factor I from Agkistrodon Acutus Venom by Rare Earth Ion Probes

It was observed that rare earth ions (Nd 3+, Sm 3+, Eu 3+, Gd 3+, Tb 3+) have significant quenching effects on the fluorescence of anticoagulation factor I (ACF I). The results of the fluorescence titration of ACF I with rare earth ions demonstrate that ACF I has two RE 3+-binding sites, and the rare earth ions and Ca 2+ bind to ACF I competitively in the two similar sites. The association constants K 1 and K 2 of ACF I with each rare earth ions (Nd 3+, Sm 3+, Eu 3+, Gd 3+, Tb 3+) are close to each other, which indicates the structural similarity of the two binding sites in ACF I. Although the ionic radii of Nd 3+, Sm 3+, Eu 3+, Gd 3+ and Tb 3+ are different, both their K 1 and K 2 are similar, respectively. This reveals the conformational flexibility of the two binding sites in ACF I, which offers a possibility for Ca 2+ to take play in the inducing conformational changes of ACF I and the promoting the binding of ACF I with activated coagulation factor X.

Metal-organic cages containing two types of binding sites:trapping hydrocarbon gas in solution

The design and synthesis of artificial molecular containers for the encapsulation of hydrocarbon gases to study their host-guest chemistry are highly important for potential application in gas storage,separation,and understanding of their biological functions.In this work,we report the subcomponent self-assembly of four cubic Zn_(8)L_(12)Br_(4)(HL=N-(4-R)-1-(5-methyl-1Himidazole-4-yl)methanimine)cages with good solubility in chloroform,which are capable of binding hydrocarbon gases including methane,ethane,and ethene in solution at ambient temperature.Two types of gas binding sites(one is in the cavity,and the other is at the window)are discovered in these cages,which are documented by nuclear magnetic resonance(NMR)spectra and density functional theory(DFT)calculations.Their performance of encapsulation of hydrocarbon gases can be tuned by carefully adjusting substituent groups.These metal-organic cages containing two types of binding sites provide new artificial models to mimic the structures and functions of biological systems in binding and transforming hydrocarbon gases.