Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:1.9.3.1 (cytochrome oxidase)
 8,822 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The activities of various enzymes in some subcellular organelle fractions were examined after fixation in glutaraldehyde of various concentrations. A high speed centrifuge was used to shorten the fixation time. At the lowest concentration (0.01%) glutaraldehyde stabilized instable configurational states of mitochondria as revealed by electron microscopy. In addition, at this concentration, at least 70% of the original monoamine oxidase, ATPase and cytochrome oxidase activities were preserved. The activity of acid phosphatase, on the other hand, was enhanced in a lysosomal fraction when fixed with the aldehyde at higher concentrations, e.g. 0.1% and 1.0%. It is possible that the aldehyde at higher concentrations has the same effects on the lysosomal membrane as freeze-thawing. Glucose-6-phosphatase activity was well-preserved in a microsomal fraction fixed with 0.01% glutaraldehyde but was decreased drastically when the concentration of the aldehyde was greater than 0.05%.
 ...
PMID:Stabilization of configurational states and enzyme activities in subcellular fractions after fixation with extremely low concentrations of glutaraldehyde. 17 35

We have undertaken the analytical fractionation of epithelial cells from toad urinary bladder, a tissue extensively used to study epithelial transport of ions and water. In an attempt to establish markers for the main subcellular organelles, a number of enzymes were assayed in cell homogenates. The nearly ubiquitous plasma membrane marker 5'-nucleotidase, and the transferases that donate N-acetylglucosaminyl, galactosyl, and sialyl residues to glycoproteins and glycolipids in the Golgi complex were not detectable. Glucose-6-phosphatase activity was low in relation to that of nonspecific phosphatases and, therefore, not suitable for identifying the endoplasmic reticulum. Like the cytosolic enzyme lactate, dehydrogenase, catalase was essentially found in the high-speed supernatant, with a noteworthy part of aminopeptidase (substrate, leucyl-beta-naphthylamide) and NAD glycohydrolase. Other enzymes, including cytochrome c oxidase, acid phosphatase, acid N-acetyl-beta-glucosaminidase, alkaline phosphatase, alkaline phosphodiesterase I, nucleoside diphosphatase (substrate ADP), oligomycin-resistant Mg++-ATPase, and mannosyltransferase (acceptor, dolichylphosphate) were fairly active and largely sedimentable. After differential centrifugation, cytochrome oxidase, acid phosphatase, and acid N-acetyl-beta-glucosaminidase were typically associated with the large granule fraction, whereas the other sedimentable enzymes exhibited a broad distribution profile overlapping the nuclear, large granule, and microsome fractions. Their behavior in density equilibrium centrifugation is examined in a companion paper.
 ...
PMID:Subcellular fractionation of epithelial cells from toad urinary bladder. 1. Assay of marker enzymes and differential centrifugation. 250 71

Ultrastructural cytochemical techniques were used for the localization of phosphatases and oxidases in spermatid and spermatozoon of the phytophagous bugs Acrosternum aseadum and Nezara viridula (Hemiptera: Pentatomidae). Acid phosphatase was found mainly in the trans most portion of the Golgi complex, and in the acrosome of spermatozoon. Glucose-6-phosphatase was located in the endoplasmic reticulum, trans portion of the Golgi complex and in the acrosome of spermatids. The axoneme showed activity of acid phosphatase, glucose-6-phosphatase and thiamine pyrophosphatase. This observation supports the idea that various phosphates may play some role in spermatid differentiation. Indeed, the presence of cytochrome oxidase activity was only shown in the mitochondrial cristae of early spermatids, suggesting also the participation of this enzyme during spermatid differentiation of this insect.
 ...
PMID:Ultrastructural localization of enzymatic activity during spermiogenesis in two phytophagous bugs (Hemiptera: Pentatomidae). 1862 62