Effects of internal Sr2+ on the activity of large-conductance Ca2+-activated K+ channels were studied in inside-out membrane patches from goldfish saccular hair cells. Sr2+ was approximately one-fourth as potent as Ca2+ in activating these channels. Although the Hill coefficient for Sr2+ was smaller than that for Ca2+, maximum open-state probability, voltage dependence, steady state gating kine...

Bacterial recognition of host sialic acid-containing receptors plays an important role in microbial colonization of the human oral cavity. The sialic acid-binding adhesin of Streptococcus gordonii DL1 was previously associated with the hsa gene encoding a 203-kDa protein. The predicted protein sequence consists of an N-terminal nonrepetitive region (NR1), including a signal sequence, a relative...

BACKGROUND The human immunodeficiency virus type 1 (HIV-1) and other lentiviruses have the capacity to infect nondividing cells like macrophages. This requires import of the preintegration complex (PIC) through the nuclear pore. Although many cellular and viral determinants have been proposed, the mechanism leading to nuclear import is not yet understood. RESULTS Using yeast two-hybrid and pu...

PURPOSE To identify the factors which significantly contribute to the thickness variabilities in macular retinal layers measured by optical coherence tomography with or without magnification correction of analytical areas in normal subjects. METHODS The thickness of retinal layers {retinal nerve fiber layer (RNFL), ganglion cell layer plus inner plexiform layer (GCLIPL), RNFL plus GCLIPL (gan...

Submaximum and maximum forces of the cardiac muscle contractile apparatus, activated by Ca2+ or Sr2+, were determined as a function of Mg2+ concentration. Apical left ventricular tissue from Sprague-Dawley rats was broken by homogenization into small bundles of fibers with disrupted sarcolemmas (skinned). Tension generation was activated by and graded according to the concentration of Ca2+ or S...

Angiotensin II (AII) evokes a biphasic increase in inositol 1,4,5-trisphosphate (Ins(1,4,5)P3) levels in adrenal glomerulosa cells, with an extracellular Ca(2+)-independent early peak followed by a secondary sustained elevation that is highly dependent on the presence of extracellular Ca2+. The Ca(2+)-dependent sustained phase of agonist-induced Ins(1,4,5)P3 production was closely correlated wi...

We demonstrate, for the first time, catalysis by Escherichia coli ribonuclease P (RNase P) RNA with Zn2+ as the sole divalent metal ion cofactor in the presence of ammonium, but not sodium or potassium salts. Hill analysis suggests a role for two or more Zn2+ ions in catalysis. Whereas Zn2+ destabilizes substrate ground state binding to an extent that precludes reliable Kd determination, Co(NH3...

the complexation reactions between mg2+, ca2+, sr2+ and ba2+ metal cations with 15-crown-5 (15c5) were studied in acetonitrile (an)-methanol (meoh) binary mixtures at different temperatures using conductometric method. 15c54 forms 1:1 complexes with mg2+, ca2+ and sr2+ cations in solutions. the ma2+ cation forms a 2:1 complex (ratio of lighand to cation) in solutions. a linear relation was obse...