A variant in the restriction endonuclease cleavage pattern of mitochondrial DNA in the domestic fowl, Gallus gallus domesticus

The cleavage patterns of mitochondrial DNAs (mtDNAs) were investigated from 15 lines of domestic fowls, Gallus gallus domesticus, using 11 restriction endonucleases. The cleavage patterns with 10 restriction endonucleases were identical in all the lines. A variant was found in a line of White Leghorn in the pattern with MspI digestions. Cleavage patterns of the red jungle fowl, Gallus gallus gallus, were identical to the common patterns shown by the 14 lines of domestic fowls.     

Development of human pancreas

The developmental sequence of human pancreatic secretory proteins has not previously been studied in detail. We applied immunohistochemistry to study 20 fetal and neonatal pancreas' (8th to 39th gestational weeks) using antisera against the following pancreatic secretory proteins: pancreatic secretory trypsin inhibitor (PSTI), serine proteinases (trypsin, chymotrypsin, and elastase I), and amylase. PSTI was first detected in developing buds of the pancreas during the 8th gestational week, and proteinases were observed in acinar cells during the 14th week of gestation. Immunoreactivity for both PSTI and proteinases was found in most acinar cells soon after their appearance. Immunoreactivity for amylase could not be detected in fetal or neonatal pancreas tissue. PSTI was also found in developing islets during the 14th gestational week, but the number of immunoreactive cells had decreased by term. Cells positive for serine proteinases were occasionally in contact with islets in second-trimester fetuses. In discussing these results, we give particular attention to the nonparallel appearance of secretory products in the fetal pancreas, and the significance of cells immunoreactive for secretory proteins in endocrine islets.     

Fetal hemoglobin variants in 80,000 Japanese neonates: high prevalence of Hb F Yamaguchi (AγT 80 Asp→Asn)

Summary A population-based screening of newborns for the structural variants of fetal hemoglobin was carried out in Osaka Prefecture, Japan, by isoelectric focusing of globin chains using dried blood on filter paper. Of 80,000 newborns, 18 had globin variants and 55 had globin variants. The incidence of globin variants (1/1,455) was much higher than that of globin variants (1/4,444). Structural studies were then carried out on the abnormal globins in 36 samples, and revealed that 25 of them were Hb F Yamaguchi (^AT 80 AspAsn). The prevalence of this variant in Japanese was estimated to be as high as one per 2,100.     

Biosynthesis of Bacillus licheniformis penicillinase in Escherichia coli and in Bacillus subtilis.

Modified prepenicillinase was accumulated in both Escherichia coli and Bacillus subtilis treated with globomycin. Although the inhibitions of processings of prepenicillinase and prolipoprotein by globomycin in E. coli are qualitatively similar, they differ in the degree of inhibition at given concentrations of globomycin. The processing of prepenicillinase proceeds much more rapidly in E. coli than in B. subtilis.     

Determination of molecular weight of membrane proteins by the use of low-angle laser light scattering combined with high-performance gel chromatography in the presence of a non-ionic surfactant

An assessment study was carried out to evaluate the performance of the low-angle laser light scattering technique combined with high-performance gel chromatography in the presence of a nonionic surfactant, octaethyleneglycol n-dodecyl ether, precision differential refractometry and ultraviolet photometry. It was found that the combined technique is highly promising as a method for the determination of the molecular weight of a membrane protein solubilized by the surfactant. For trial, molecular weights of the following membrane proteins of Escherichia coli, both solubilized in oligomeric forms, were measured; porin that forms the transmembrane diffusion pore in the outer membrane, and lambda-receptor protein that facilitates the diffusion of maltose-maltodextrins across the outer membrane. The result obtained indicates that both porin and lambda-receptor protein exist as trimers in the surfactant solution.     

Characterization of a new fetal hemoglobin variant, Hb F Izumi A gamma 6Glu replaced by Gly, by molecular secondary ion mass spectrometry

Molecular secondary ion mass spectrometry has characterized the structure of a new fetal hemoglobin variant, Hb F Izumi, without separation of peptides or amino acid analysis. First, the mass spectrum of a tryptic digest of the abnormal gamma globin revealed a decreased by 72 mass units in the molecular mass of peptide T-1,2, indicating the presence of a Glu leads to Gly substitution. Next, the analysis of the digest produced by the addition of staphylococcal protease, which specifically cleaves glutamyl peptide bonds, determined the site of substitution at 6th glutamic acid residue in peptide T-1,2 which contains two glutamic acid residues. Since this mass spectrometric approach provides digitalized data on peptide analysis, we call it 'digit printing'. The high sensitivity of this technique is especially promising for the analysis of molecular abnormality in various genetic disorders.     

Steady-state kinetics and spectral properties of Corynebacterium sarcosine oxidase

The overall reaction kinetics of Corynebacterium sarcosine oxidase were investigated and the reaction was shown to follow a ping-pong, bi-bi mechanism with two substrates, sarcosine and molecular oxygen. Sarcosine analogs, such as acetate, propionate and methoxyacetate, were competitive inhibitors of the reaction. Acetate caused characteristic alterations in optical and circular dichroic spectra, indicating that the microenvironment of the substrate-binding region of the enzyme increased in hydrophobicity on binding with the substrate analog. The dissociation constants of the analogs calculated from the spectral changes were in agreement with the kinetic inhibition constants. Inorganic metallic ions were also inhibitory. Of interest was the finding that the inhibition by Hg2+ was proportional to the square of its concentration, which suggests that at least two sulfhydryl groups are related to the catalytic activity of the enzyme.     

Flavanol glucosides from rhubarb and Rhaphiolepis umbellata

Investigations of rhubarb and the bark of Rhaphiolepis umbellata led to the isolation of new flavan-3-ol glucosides. Their structures were elucidated on the basis of ¹H and ¹³C NMR analysis hydrolytic studies as (+)-catechin 5-O-β-d-glucopyranoside and (?)-catechin 7-O-β-d-glucopyranoside.     

Micelle formation of diacylglycerophosphocholines in organic solvents I. effects of the solvents on krafft points

Krafft points of diacylglycerophosphocholines (PC) were measured in alkanes-cyclohexane solutions by differential scanning calorimetry, and it was found that they were regularly increased following the increase in alkane content in the solutions and the chain length of the alkanes. From these results it was deduced that the mixing of PC with alkanes occurred in the gel state of the PC, but not in micelles at higher temperatures above the Krafft points. where micellar solutions are provided. The penetration of alkanes into gel state PC was found to be dominated by Langmuir type interaction, and the affinity of alkanes increases with increasing in chain lengths. Above the Krafft points, the micelle formation was confirmed by using the fluorescence probe technique.     

Presence of mast cell precursors in the yolk sac of mice

Concentration of mast-cell precursors in hematopoietic tissues of mouse embryos was evaluated by a limiting dilution method. Cells from yolk sacs, livers, and bodies of (WB x C57BL/6)F1 (hereafter called WBB6F1)- +/+ embryos were injected directly into the skin of adult WBB6F1-W/Wv mice which were genetically depleted of tissue mast cells. Concentration of mast-cell precursors was calculated from the proportion of injection sites at which mast cells did not appear. Since the concentration of mast-cell precursors in the yolk sac was about 30 times as great as that of embryonic body at Day 9.5 of the pregnancy, the mast-cell precursors seemed to be generated within the yolk sac. The concentration in the yolk sac reached the maximum level at Day 11, and then dropped markedly at Day 13. In contrast, mast-cell precursors increased from Day 11 to Day 15 in the fetal liver. As a result, the concentration of 11-day yolk sacs was comparable to that of 15-day fetal liver. Although intravenous injection of 15-day fetal liver cells (2 x 10(6)) rescued the general mast-cell depletion of WBB6F1-W/Wv mice, the intravenous injection of the same number of 11-day yolk sac cells did not rescue it. In contrast with fetal livers, yolk sacs scarcely contained hematopoietic stem cells which were measured by spleen colony formation. Therefore, the mast-cell precursors of the yolk sac may not originate from such stem cells.