We also indicate that Irr1p may interact with elements of transcriptional coactivator Mediator.
A general dependence of the enzyme catalytic rate on its mass was revealed when a statistical analysis of 17065 records from the EMP database was performed. selleck chemical 17-DMAG The estimated activation energy of the catalytic process decreases asymptotically with the enzyme molecular mass increase. The proposed theoretical model postulates the existence of an intermediate complex of the enzyme and the departing product. It allows for the explanation of the discovered mass-energy relationship, as an effect of the global enzyme-product interactions during complex dissociation. Fitted parameters of the model seem to be in agreement with those widely accepted for the van der Waals energy of molecular interactions.

Their values also agree with the picture of the hydrogen bonding in the catalytic process and suggest that surface walk can be the favorable way of the product departure.
Adenosine 5′-phosphoramidate (NH2-pA) is a rare natural nucleotide and its biochemistry and biological functions are poorly recognized. All organisms have proteins that may be involved in the catabolism of NH2-pA. They are members of the HIT protein family and catalyze hydrolytic splitting of NH2-pA to 5′-AMP and ammonia. At least five HIT proteins have been identified in mammals; however, the enzymatic and molecular properties of only Fhit and Hint1 have been comprehensively studied. Our study focuses on the Hint2 protein purified by a simple procedure to homogeneity from sheep liver mitochondrial fraction (OaHint2).

Hint1 protein was also prepared from sheep liver (OaHint1) and the molecular and kinetic properties of the two proteins compared. Both function as homodimers and behave as nucleoside 5′-phosphoramidate hydrolases. The molecular mass of the OaHint2 monomer is 16 kDa and that of the OaHint1 monomer 14.9 kDa. Among potential substrates studied, NH2-pA appeared to be the best; the K-m and k(cat) values estimated for this compound are 6.6 mu M and 68.3 s(-1) and 1.5 mu M and 11.0 s(-1) per natively functioning dimer of OaHint2 and OaHint1, respectively. Studies of the rates of hydrolysis of different NH2-pA derivatives show that Hint2 is more specific towards compounds with a P-N bond than Hint1. The thermostability of these two proteins is also compared.

In this study immunoelectrophoretic Cilengitide and double immunodiffusion analyses were used to investigate the antigenic character of zinc-binding proteins (ZnBPs), whereas the indirect immunofluorescence technique was used to identify their origin in boar reproductive tract. The mmunoelectrophoretic analysis of ZnBPs of the seminal plasma resulted in the appearance of three antigenic protein complexes, while specific immunoreactivity selleck chemicals llc patterns of the anti-ZnBP serum were detected by double immunodiffusion analysis.