Dihydropteridine-reductase activity in breast cancer. Preliminary report

The dihydropteridine-reductase activity was measured in 206 breast cancers. Large variations were found: 6% of tumors showing high values closed to those noted in liver, whereas the main group has activities of same magnitude of that in cultured fibroblasts. Significant correlation appeared between dihydropteridine-reductase activities and hormonal dependence, as measured by cytosolic estrogen receptor sites.     

Amino-acid sequence of an alpha-parvalbumin, pI = 4.88, from frog skeletal muscle

The primary structure of the most basic (pI = 4.88) of the two major parvalbumins from frog skeletal muscle (Rana esculenta) has been determined by partial automatic sequencing of the protein which exhibits a free N terminus, and a study of overlapping peptides obtained by cyanogen bromide cleavage and digestion with trypsin, thermolysin and Armillaria mellea protease. This protein shows the typical structure of an alpha-parvalbumin. Comparison of the primary structure of ion-binding loops of alpha and beta-parvalbumins does not provide a clear-cut explanation of their differences in ion-binding properties.     

Assembly of splicing complexes on exon 11 of the human insulin receptor gene does not correlate with splicing efficiency in-vitro

Background  

Incorporation of exon 11 of the insulin receptor gene is both developmentally and hormonally-regulated. Previously, we have shown the presence of enhancer and silencer elements that modulate the incorporation of the small 36-nucleotide exon. In this study, we investigated the role of inherent splice site strength in the alternative splicing decision and whether recognition of the splice sites is the major determinant of exon incorporation.     

Calmodulin intracelluar concentration and cAMP-dependent protein kinase activity in human sperm samples in relation to sperm motphlogy and motlity

Calmodulin concentration and cAMP-dependent protein kinase activity have been determined in human sperm samples. No significant differences have been noticed in the motility index of two groups of sperm samples differing in their intracellular concentration of calmodulin. It was however found that a low intracellular clamodulin concentration is frequently associated with particular anomalies of the head and tail region. In contrast, a positive correlation has been demonstrated between the motility index and the whole extractable cAMP-dependent protein activity of the different sperm samples. In suspension s, When the cAMP-dependent protein kinase activity was measured on intact sperm suspensions, a positive correlation between the activity and the motility index was also found.