Topic
Alkaline phosphatase
About: Alkaline phosphatase is a research topic. Over the lifetime, 20218 publications have been published within this topic receiving 540547 citations. The topic is also known as: Alkaline_phosphatase & IPR001952.
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TL;DR: The data show that there is a close association between ALP activity and in vitro calcification of rachitic rat cartilage, and suggest that some ATPase activity of rACHitic rat Cartilage may be distinct from ALP activity.
113 citations
TL;DR: Multiple membrane preparations were highly reproducible with respect to the specific activities of the markers studied and an assay suitable for determining 5'-nucleotidase in the small intestine is described.
Abstract: A technique is described for the isolation of a plasma-membrane fraction from the rat intestinal epithelial cell which is distinct from the microvillus membrane of that cell. The isolated fraction contains only about 0.2% of the sucrase activity in the original homogenate and negligible quantities of nuclear and mitochondrial membrane markers. It contains 12% of the total Na+,K+-dependent adenosine triphosphatase and 7% of the alkaline phosphatase, with significant increments in specific activity of these enzymes. Multiple membrane preparations were highly reproducible with respect to the specific activities of the markers studied. The small intestine of one rat yields material containing about 1.3mg of protein. In addition an assay is described suitable for determining 5′-nucleotidase in the small intestine.
113 citations
TL;DR: The data demonstrate the potential utility of genetically engineering PhoK for the bioprecipitation of uranium from alkaline solutions and show a much higher loading capacity in E. coli strain EK4, which very rapidly precipitated >90% of input uranium in less than 2 h and remained cell bound.
Abstract: Cells of Sphingomonas sp. strain BSAR-1 constitutively expressed an alkaline phosphatase, which was also secreted in the extracellular medium. A null mutant lacking this alkaline phosphatase activity was isolated by Tn5 random mutagenesis. The corresponding gene, designated phoK, was cloned and overexpressed in Escherichia coli strain BL21(DE3). The resultant E. coli strain EK4 overexpressed cellular activity 55 times higher and secreted extracellular PhoK activity 13 times higher than did BSAR-1. The recombinant strain very rapidly precipitated >90% of input uranium in less than 2 h from alkaline solutions (pH, 9 ± 0.2) containing 0.5 to 5 mM of uranyl carbonate, compared to BSAR-1, which precipitated uranium in >7 h. In both strains BSAR-1 and EK4, precipitated uranium remained cell bound. The EK4 cells exhibited a much higher loading capacity of 3.8 g U/g dry weight in 7 h in BSAR-1. The data demonstrate the potential utility of genetically engineering PhoK for the bioprecipitation of uranium from alkaline solutions.
113 citations
TL;DR: Data support the selection and characterization of osteogenic precursors from human bone marrow which were isolated by two “clonings” and successive subculturing and exhibit high alkaline phosphatase activity and positive von Kossa staining.
Abstract: This study reports the selection and characterization of osteogenic precursors from human bone marrow which were isolated by two “clonings” and successive subculturing. These cell lines express alkaline phosphatase activity. Gel electrophoresis of [3H]-proline labeled cultures showed that the cloned cells produce only type I collagen. They synthetize osteocalcin and osteonectin. They respond to 1,25 dihydroxy vitamin D3 by increasing osteocalcin synthesis and secretion, and to parathyroid hormone by increasing cyclic AMP synthesis. After the third subculture in the absence of β-glycerophosphate, these cell lines formed lots of clusters which exhibit high alkaline phosphatase activity and positive von Kossa staining. X-ray energy spectrum shows that these cells are surrounded by “budding” structures containing calcium and phosphorus with a ratio Ca:P identical to those of pure hydroxyapatite. This process was associated with45Ca uptake into the cells. All these data support the selection of osteogenic cells which may be of considerable clinical importance.
113 citations
TL;DR: Estrogen responsiveness of bone is a fundamental regulatory mechanism operative in skeletal homeostasis and ER transcripts, measured using semiquantitative RT-PCR analysis, were expressed at low levels in early stage proliferating osteoblasts and increased at confluence upon initial expression of bone cell phenotypic genes.
Abstract: Estrogen responsiveness of bone is a fundamental regulatory mechanism operative in skeletal homeostasis. We examined the expression of estrogen receptor-α (ER) messenger RNA (mRNA) in cultured rat calvarial-derived osteoblasts during progressive development of the osteoblast phenotype. Levels of ER message were compared with the expression of traditional osteoblastic markers that have been mapped throughout the differentiation process of these cells. ER transcripts, measured using semiquantitative RT-PCR analysis, were expressed at low levels in early stage proliferating osteoblasts and increased at confluence upon initial expression of bone cell phenotypic genes. A 23-fold up-regulation of ER mRNA expression coincided with the initiation of alkaline phosphatase activity (day 8). ER mRNA levels progressively increased 70-fold, reaching a maximum level on days 22–25 in fully differentiated osteoblasts when osteocalcin expression peaked, but declined precipitously by day 32 in osteocytic cells. Analysis of ...
113 citations