The distribution of allelic effects under mutation and selection

The Price (1970, 1972) equation is applied to the problem of describing the changes in the moments of allelic effects caused by selection, mutation and recombination at loci governing a quantitative genetic character. For comparable assumptions the resulting equations are the same as those obtained by different means by Barton & Turelli (1987; Turelli & Barton, 1989). The Price equation provides a natural framework within which to examine certain kinds of non-additive allelic effects, recombination and assortative mating. The use of the Price equation is illustrated by finding the equilibrium genetic variance under multiplicative dominance and epistasis and under assortative mating at an additive locus. The limitations of the use of recursion equations for the moments of allelic effects are also discussed.     

Regulation of protein kinase FA (a transmembrane signal of insulin and epidermal growth factor) in the brain

Two forms of type-1 protein phosphatase activating factor (FA) termed FA1 and FA2 have been identified in plasma membranes of pig brain. FA1 is spontaneously active and trypsin-labile whereas FA2 is inactive and trypsin-resistant. Phospholipid reconstitution studies further indicate that the FA activity in the neutral phospholipids-reconstituted complex is spontaneously active and trypsin-labile whereas the FA activity in the acidic phospholipids-reconstituted complex is trypsin-resistant and inactive. The results indicate that inactive FA2 may have its catalytic domain interacted with negatively-charged phospholipids in brain membranes. This provides initial evidence for the regulation of protein kinase FA (a transmembrane signal of insulin and epidermal growth factor) in the central nervous system.     

Cloning and sequencing of a cDNA encoding the Rieske iron-sulfur protein of bovine heart mitochondrial ubiquinol-cytochrome c reductase

Two cDNA clones encoding bovine heart mitochondrial Rieske iron-sulfur protein were obtained by immunological screening of a bovine heart cDNA expression library in lambda gt11 with antiserum directed against Rieske iron-sulfur protein isolated from bovine heart mitochondrial ubiquinol-cytochrome c reductase. The cDNA inserts were 1005 and 1100 base pairs with an open reading frame of 807 base pairs which encoded a 196-amino acid mature Rieske iron-sulfur protein and a 73-amino acid presequence. The amino acid sequence of Rieske iron-sulfur protein deduced from nucleotide sequencing is the same as that obtained from protein sequencing except at residues #73 and #191 which are Ser and Asp instead of Ala and Gly, respectively.     

Establishment and characterization of 12S adenoviral E1A immortalized rat submandibular gland epithelial cells

Rat submandibular gland (RSMG) cells have been immortalized with a retrovirus vector which encodes the adenovirus 12S E1A gene product. The immortalized cells were epithelial-like in nature and displayed a beta-adrenergic coupled rise in intracellular cAMP upon exposure to norepinephrine. Western- and lectin-blotting experiments of cell lysates demonstrated the presence of blood group A-reactive oligosaccharides. Such oligosaccharides are characteristic of RSMG mucin-glycoproteins. These cells appear to be suitable for use in analysis of cell-specific factors which regulate RSMG glycosylation.     

Active site of bovine adrenocortical cytochrome P-450(11) beta studied by resonance Raman and electron paramagnetic resonance spectroscopies: distinction from cytochrome P-450scc

Cytochrome P-45011 beta was purified as the 11-deoxycorticosterone-bound form from bovine adrenocortical mitochondria and its active site was investigated by resonance Raman and EPR spectroscopies. Resonance Raman spectra of the purified sample revealed that the heme iron adopts the pure pentacoordinated ferric high-spin state on the basis of the nu 10 (1629cm-1) and nu 3 (1490 cm-1) mode frequencies, which are higher than those of the hexacoordinated ferric high-spin cytochrome P-450scc-substrate complexes. In the ferrous-CO state, a Fe2(+)-CO stretching mode was identified at 481.5 cm-1 on the basis of an isotopic substitution technique; this frequency is very close to that of cytochrome P-450scc in the cholesterol-complexed state (483 cm-1). The EPR spectra of the purified sample at 4.2 K showed ferric high-spin signals (at g = 7.98, 3.65, and 1.71) that were clearly distinct from the cytochrome P-450scc ferric high-spin signals (g = 8.06, 3.55, and 1.68) and confirmed previous assignments of ferric high-spin signals in adrenocortical mitochondria. The EPR spectra of the nitric oxide (NO) complex of ferrous cytochrome P-45011 beta showed EPR signals with rhombic symmetry (gx = 2.068, gz = 2.001, and gy = 1.961) very similar to those of the ferrous cytochrome P-450scc-NO complex in the presence of 22(S)-hydroxycholesterol and 20(R),22-(R)-dihydroxycholesterol at 77 K.(ABSTRACT TRUNCATED AT 250 WORDS)     

NMR and computational studies of interactions between remote residues in gangliosides

Conformational preferences of the gangliosides GM1, GM1b, and GD1a have been investigated by using a systematic combination of NMR distance constraints and molecular mechanics calculations. These gangliosides share a common four-sugar core but differ in the number or placement of sialic acid residues attached to the core. Placement of the sialic acid residues is shown to influence the preferred core conformation. The origin of these effects is postulated to be intramolecular interactions of the sialic acid residues with other remote residues. In the case of GM1, hydrogen bonds between the internal sialic acid and an N-acetyl group on GalNAc are suggested. In the case of GD1a, a hydrogen-bonding network between the terminal and internal sialic acids is suggested to play a role.     

Resonance Raman enhancement of phenyl ring vibrational modes in phenyl iron complex of myoglobin.

Resonance Raman spectra are reported for the organometallic phenyl-FeIII complexes of horse heart myoglobin. We observed the resonance enhancement of the ring vibrational modes of the bound phenyl group. They were identified at 642, 996, 1,009, and 1,048 cm-1, which shift to 619, 961, 972, and 1,030 cm-1, respectively, upon phenyl 13C substitution. The lines at 642 and 996 cm-1 are assigned, respectively, as in-plane phenyl ring deformation mode (derived from benzene vibration No. 6a at 606 cm-1) and out-of-plane CH deformation (derived from benzene vibration No. 5 at 995 cm-1). The frequencies of the ring "breathing" modes at 1,009 and 1,048 cm-1 are higher than the corresponding ones in phenylalanine (at 1,004 and 1,033 cm-1) and benzene (at 992 and 1,010 cm-1), indicating that the ring C--C bonds are strengthened (or shortened) when coordinated to the heme iron. The excitation profiles of these phenyl ring modes and a porphyrin ring vibrational mode at 674 cm-1 exhibit peaks near its Soret absorption maximum at 431 nm. This appears to indicate that these phenyl ring modes may be enhanced via resonance with the Soret pi-pi transition. The FeIII--C bond stretching vibration has not been detected with excitation wavelengths in the 406.7-457.9-nm region.     

Large scale purification and immunolocalization of bovine uroplakins I, II, and III. Molecular markers of urothelial differentiation

The differentiation of mammalian urothelium culminates in the formation of asymmetrical unit membrane (AUM). Using gradient centrifugation and detergent wash, we purified milligram quantities of AUMs which, interestingly, contained three major proteins (15, 27, and 47 kDa) that appeared to be identical to the three immunoaffinity purified, putatively AUM-associated proteins that we described earlier (Yu, J., Manabe, M., Wu, X.-R., Xu, C., Surya, B., and Sun, T.-T. (1990) J. Cell Biol., 111, 1207-1216). Peptide mapping and immunoblotting established that these three proteins were distinct molecules. Using monospecific antibodies to these three proteins, we showed that they were all restricted to the superficial urothelial cells and were AUM-associated. The 27- and 15-kDa proteins were detected exclusively on the luminal side of mature, apical AUMs. In contrast, epitopes of the 47-kDa protein were detected on both sides of apical AUMs suggesting a transmembranous configuration. These results (i) provide the strongest evidence thus far that AUM contains three major proteins (the 27-kDa uroplakin I, 15-kDa uroplakin II, and 47-kDa uroplakin III) which form an extremely insoluble complex, (ii) suggest that uroplakin II, like uroplakin I (Yu, J., Manabe, M., Wu, X.-R., Xu, C., Surya, B., and Sun, T.-T. (1990) J. Cell. Biol. 111, 1207-1216), translocates from one side of the membrane to another during AUM maturation, (iii) indicate that uroplakin III may play a different structural role than uroplakins I and II in AUM formation, and (iv) establish the three uroplakins as markers for an advanced stage of urothelial differentiation.     

球形芽孢杆菌Ts—1毒蛋白的分离纯化

Bacillus sphaericus strain Ts-1 is highly insecticidal to larvae of the mosquito. It's insecticidal component is toxic proteins. The toxin was extracted from spore-crystal complexes by disruption in a Sonicator Cell Disruptor Model W-220F followed by treatment with 0.05 mol/L NaOH. Fraction recovered from chromatography of the spore-crystal complexes on column of Sephadex G-200 were assayed against mosquito larvae and the toxic fractions from gel chromatography were subjected to SDS-PAGE. The toxic proteins in B. sphaericus Ts-1 spore-crystal complex migrated in position corresponding to 42kD and 43kD. Bioassay of the two purified proteins prepared by PAGE indicated that they were all toxic to mosquito larvae. Toxic protein was further purified by DEAE-cellulose chromatography. The toxic protein with a molecular weight of 42kD was obtained.     

High-performance liquid chromatography of sialic acid-containing oligosaccharides and acidic monosaccharides

Many sialic acid-containing oligosaccharides and five acidic monosaccharides have been separated by high-performance anion-exchange chromatography using a Dionex AS6 ion-exchange column eluted with aqueous 50 mM NaOH plus 50-175 mM sodium acetate. Using a pulsed amperometric detector, as little as 50 pmol oligosaccharide can be detected. Many factors, such as the presence of fucosyl groups or sialyl groups, glycosidic linkage positions, and branching structure, can have a tremendous influence on overall acidity of the oligosaccharide, which can lead to excellent separations and make this method an important addition to existing alternatives for the separation of sialic acid-containing oligosaccharides.