Carbonic anhydrase (CA) is a multi-functional enzyme that catalyzes the hydration/dehydration of carbon dioxide. In the red blood cell (rbc), CA is necessary to facilitate the transport of carbon dioxide out of the body. Results from earlier biochemical studies indicate that ancient vertebrates, such as agnathans, possess a low activity rbc CA isozyme, whereas more recently evolved vertebrates,...

Glutamate receptors and calcium have been implicated as triggering factors in the induction of tolerance by ischemic preconditioning (IPC) in the brain. However, little is known about the signal transduction pathway that ensues after the IPC induction pathway. The main goals of the present study were to determine whether NMDA induces preconditioning via a calcium pathway and promotes translocat...

The histamine H2-receptor antagonists have been identified as inhibitors of human liver aldehyde dehydrogenase (EC 1.2.1.3) isozymes, E1, E2, and E3. Inhibition was strongest with the E3 isozyme, whose substrates include gamma-aminobutyraldehyde, the aldehyde metabolites of polyamines, and betaine aldehyde. Burimamide, metiamide, cimetidine guanidine, cimetidine, and tiotidine were competitive ...

A haloenol lactone derivative has been synthesized and found to be an isozyme-selective and active site-directed inactivator of glutathione S-transferase (GST). Preincubation of the haloenol lactone (100 microM) with murine Alpha, Mu, or Pi GST isozyme (1.0 microM) at pH 6.5, 37 degrees C resulted in time-dependent loss of enzyme activity with highly selective inhibition of the Pi isozyme (t1/2...

Rabbit brain contains three phosphofructo-1-kinase (PFK) isozymic subunits designated A, B, and C. The primary structures of the first of these two isozyme types have been determined previously. The isozyme C of rabbit brain was isolated by immunoaffinity chromatography and subjected to proteolytic and chemical digestion. A large number of peptides were sequenced, the total number of amino acid...

Temporal sequences of allele frequencies in natural populations of Daphnia are analyzed to obtain the mean and variance of the selection coefficient for both asexual and sexual phases. In general, the alleles at enzyme loci appear to be quasi-neutral. Although significant variation exists for the estimated selection coefficients, the means are in all cases close to zero. Estimates of the varian...

Leaf trichomes may serve several biological functions including protection against herbivores, drought, and UV radiation; and their adaptive value can be expected to vary among environments. The perennial, self-incompatible herb Arabidopsis lyrata is polymorphic for trichome production, and occurs in a glabrous and a trichome-producing form. Controlled crosses indicate that the polymorphism is ...

BACKGROUND AND AIMS The phylogenetic relationships among 27 vetch species belonging to the subgenus Cracca of the genus Vicia were studied in comparison with three species of Lathyrus section Lathyrus on the basis of isozyme variation. METHODS Isozymes encoded by 15 putative loci of ten enzymes were resolved by polyacrylamide gel electrophoresis and isozyme variation was analysed by using par...

We studied interactions between the mitogen-activated protein kinase (MAPK) signalling pathway and cAMP-protein kinase (PKA) signaling pathway in regulation of mitogenesis of mesangial cells (MC) determined by [3H]thymidine incorporation, with or without added EGF. Forskolin or dibutyryl cAMP strongly (by 60-70%) inhibited [3H]thymidine incorporation into MC. Cilostamide, lixazinone or cilostaz...

The regulatory subunits of both isozymes of cAMP-dependent protein kinase bind 2 mol of cAMP/mol of monomer. cAMP dissociation studies indicate similar cAMP binding behavior for each isozyme. Each has two different intrachain cAMP binding components present in approximately equal amounts and the rate of cAMP dissociation is 5- to 10-fold slower from one site (Site 1) than from the other (Site 2...