A Cytochemical Study of Golgi Associated Thiamine Pyrophosphatase in the Epididymis of the Mouse

Abstract

The properties and distribution of an enzyme in the epididymis of the mouse hydrolyzing thiamine pyrophosphate were investigated using cytochemical and quantitative methods. Cytochemical study indicated thiamine pyrophosphatase to be restricted to the Golgi regions of the epithelial cells lining the epididymal canal. Activity due to this enzyme was easily separated from that due to alkaline phosphatase (which also hydrolyzed thiamine pyrophosphate) on the basis of differences in localization and on the greater sensitivity of the latter enzyme to cysteine. The thiamine pyrophosphatase present in the epididymis of the mouse had optimal activity in the region of pH 9.5. In the acid range, activity was greatly restricted but the distribution pattern did not differ from that observed in the alkaline range nor did it resemble the pattern of activity associated with acid phosphatase activity in this tissue. Quantitative determinations supported the cytochemical investigations in terms of a pH optimum in the alkaline range and the resistance of thiamine pyrophosphatase to cysteine inhibition.

Ca2+-activated Nucleotidase 1, a Novel Target Gene for the Transcriptional Repressor DREAM (Downstream Regulatory Element Antagonist Modulator), Is Involved in Protein Folding and Degradation

“…Nucleoside 5Ј-triphosphates are only hydrolyzed to a minor extent and nucleoside 5Ј-monophosphates are not hydrolyzed. CANT1 prevents the accumulation of diphosphonucleosides that would otherwise cause product inhibition of the glucosyltransferases, and at the same time generates the nucleoside monophosphates needed for the import of new nucleotide sugars (17,(51)(52)(53).…”

Enzyme Histochemistry

“…The sources of error in the detection method are the same as in the GOMORI procedure for the localization of acid phosphatase.Beside the lead salt method given, a calcium-cobalt reaction has been described for the demonstration of TPPase in unfixed sections(ALLEN and SLATER, 1961). For example, by preincubation of min) myosin ATPase can be extracted from muscle fibers with low activity.…”

Golgi Apparatus and Lysosomal Granules Observed in Some Cultured Cells

“…Following Novikoff and Goldfischer (1961) and Allen and Slater (1961), TPPase activity in the Golgi apparatus has been demonstrated by a considerable number of authors.…”