5-Aminolevulinate synthase (ALAS) catalyzes the initial step of mammalian heme biosynthesis, the condensation between glycine and succinyl-CoA to produce CoA, CO2, and 5-aminolevulinate. The crystal structure of Rhodobacter capsulatus ALAS indicates that the adenosyl moiety of succinyl-CoA is positioned in a mainly hydrophobic pocket, where the ribose group forms a putative hydrogen bond with L...

The initial and the terminal three enzymes of the mammalian haem biosynthetic pathway are nuclear encoded, cytoplasmically synthesized and post-translationally translocated into the mitochondrion. The first enzyme, ALAS (5-aminolaevulinate synthase), occurs as an isoenzyme encoded on different chromosomes and is synthesized either as a housekeeping protein (ALAS-1) in all non-erythroid cell typ...

Polychlorinated biphenyls (PCB) are potent inducers of hepatic microsomal CO-binding hemoprotein P-448 (P1-450) and of delta-aminolevulinate synthetase (ALAS) activity. Inorganic cobalt was able to block PCB induction of cytochrome P-448 and to modify the PCB effect on ALAS activity in a time-dependent manner. PCB were also found to decrease the activity of delta-aminolevulinic acid dehydratase...

A previously published working model for the regulation of chlorophyll formation has been tested studying early steps of chlorophyll and porphyrin biosynthesis in developing cotyledons of Helianthus annuus. The activities of delta-aminolevulinate synthetase (ALAS), delta-aminolevulinate dehydratase (ALAD), and the porphobilinogenase complex (PBGase) at any given time have been found to be stron...

The hereditary liver disease, acute intermittent porphyria (ALP), 1 is characterized clinically by a disabling, sometimes lethal, neurological-visceral symptom complex and biochemically by excessive activity of the porphyrin-heme biosynthetic pathway (1-3). The mitochondrial enzyme 6-aminolevulinate synthetase (ALAS), which is rate limiting for this pathway (4), is found at high levels of activ...

Germanium-based materials and device architectures have recently appeared as exciting material systems for future low-power nanoscale transistors and photonic devices. Heterogeneous integration of germanium (Ge)-based materials on silicon (Si) using large bandgap buffer architectures could enable the monolithic integration of electronics and photonics. In this paper, we report on the heterogene...

The results of a full potential linear muffin-tin orbital (FP-LMTO) study on the electronic properties of cubic zinc blende type group III-V semiconductors AlP and AlAs under pressure are presented. The equilibrium lattice constant, bulk modulus, pressure derivative of bulk modulus and the phase transition pressure at which the compounds undergo structural phase transition from ZnS to NaCl and ...