Urine-requiring mutants of Salmonella fyphimurium have been examined for the ability to synthesize 5’-phosphoribosyl-IV-formylglycinamide in a coupled reaction involving the first three enzymes of the biosynthetic pathway for purine nucleotides. Extracts prepared from mutants belonging to the distinct genetic classes, pur F and pur D, were inactive in this assay but were active when mixed toget...

Introduction: Restoring and maintaining normoglycemia by intensified insulin therapy in critically ill patients is a matter of ongoing debate since the risk of hypoglycemia may outweigh positive effects on morbidity and mortality. In this context, adsorption of insulin to different catheter materials may contribute to instability of glucose control. We studied the adsorption of insulin to diffe...

Abstract. We determine the asymptotical satisfiability probability of a random at-most-k-Horn formula, via a probabilistic analysis of a simple version, called PUR, of positive unit resolution. We show that for k = k(n) → ∞ the problem can be “reduced” to the case k(n) = n, that was solved in [17]. On the other hand, in the case k = constant the behavior of PUR is modeled by a simple queuing ch...

A purine repressor (PurR) mediates adenine nucleotide-dependent regulation of transcription initiation of the Bacillus subtilis pur operon. This repressor has been purified for the first time, and binding to control site DNA was characterized. PurR binds in vitro to four operons. Apparent Kd values for binding were 7 nM for the pur operon, 8 nM for purA, 13 nM for purR, and 44 nM for the pyr op...

GABRIEL ISTRATE Abstract. We determine the asymptotical satisfiability probability of a random at-most-k-Horn formula, via a probabilistic analysis of a simple version, called PUR, of positive unit resolution. We show that for k = k(n) ! 1 the problem can be “reduced” to the case k(n) = n, that was solved in [12]. On the other hand, in the case k = constant the behavior of PUR is modeled by a s...