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H Nikaido

Publications and source records attributed to H Nikaido.

248 records · Page 14Linked to original sources
PubMed1966

Genetic determination of enzymes synthesizing O-specific sugars of Salmonella lipopolysaccharides.

Nikaido, Hiroshi (Massachusetts General Hospital, Boston, Mass.), Kishiko Nikaido, and P. Helena Mäkelä. Genetic determination of enzymes synthesizing O-specific sugars of Salmonella lipopolysaccharides. J. Bacteriol. 91:1126-1135. 1966.-Levels of enzymes involved in the biosynthesis of various nucleotide sugars were examined in parental strains and recombinants obtained in crosses between Salmonella of groups B, C(2), and C(1) with the O antigen specificities 4, 5, 12; 6, 8; and 6,7, respectively. The results showed that smooth strains of groups B and C(2) possessed the enzymes for the synthesis of guanosine diphosphate mannose, cytidine diphosphate abequose, and thymidine diphosphate rhamnose; these sugars are constituents of their lipopolysaccharides. Group C(1) lipopolysaccharide is devoid of both abequose and rhamnose, and the corresponding enzymes for cytidine diphosphate abequose synthesis, as well as the enzyme(s) catalyzing the last step(s) of thymidine diphosphate rhamnose synthesis, were undetectable in S. montevideo of this group. Two other enzymes also involved in the biosynthesis of thymidine diphosphate rhamnose were present at a low level of activity; their function in this strain is not known. The analysis of enzyme levels in recombinants indicated that genes determining at least eight of the enzymes involved in the biosynthesis of nucleotide-bound mannose, rhamnose, and abequose were located in the O locus known to determine the specificity of the O antigen. In three rough recombinant strains, enzyme levels indicated that crossing-over had presumably occurred within the O locus. The results also suggested a high degree of nonhomology in this region of the chromosome between groups B and C(1).

Antigens↗
PubMedDate not supplied

Structure and functions of the cell envelope of gram-negative bacteria.

The surface of gram-negative bacteria contains structures that prevent the entry of noxious compounds into the cell and that help the cell evade recognition by host elements such as antibodies and complement while allowing the bacteria to obtain nutrients from the environment and to attach to structures of the host cell. This review discusses the role of outer-membrane components such as lipopolysaccharides and porin, as well as appendages such as capsules and fimbriae in such functions.

Animals↗
PubMedDate not supplied

Physical interaction between lipid A and phospholipids: a study with spin-labeled phospholipids.

When mixed bilayers containing spin-labeled phosphatidylethanolamine (or phosphatidylglycerol) and Escherichia coli B lipopolysaccharide were prepared, electron spin resonance signals indicated that the patches that were initially present and contained only phospholipids or only lipopolysaccharides were unusually stable and that little lateral diffusion of phospholipids into lipopolysaccharide domains, or vice versa, took place. These results explain how the outer layer of the outer membrane, which essentially contains only lipopolysaccharides in addition to proteins, can be generated and maintained stably in bacterial cells. Furthermore, the stability of pure lipopolysaccharide domains may have important implications in the mode of action of endotoxins in the body of the host. For example, lipopolysaccharide molecules may tend to form stable domains or patches spontaneously in the animal cell membrane, and special mechanisms (such as the binding to a special receptor) may be needed to disperse the lipopolysaccharide molecules within the host cell membranes.

Lipid A↗
PubMedDate not supplied

Cream fur: a new mouse mutation that may cause unusual lipid metabolism.

In 1986 an albino mouse with cream yellow coat color was discovered in a breeding colony of strain CAL20, which is an IgH-C congenic strain of BALB/c mice, supported by the Institute for Experimental Animals, Faculty of Medicine, Kanazawa University. Genetic analysis revealed that the cream yellow coat color phenotype was controlled by a single recessive mutant gene on chromosome 13. A preliminary study with biochemical and histologic examinations showed that cream yellow hair contained more fatty acid than unaffected normal hair and a large number of lipid droplets accumulated in parenchyma cells of the liver in mutant mice, as early as the age of 32 days old, suggesting that the cream yellow coat color was due to unusual lipid metabolism. The locus was designated cream fur locus and was given the gene symbol crf. In addition, it was found that recombination frequencies in the vicinity of the region of the crf locus were markedly different between male and female meiosis.

Animals↗
PubMedDate not supplied

Male urinary protein-1 (MUP-1) in the rat: Mup-1 assigned to linkage group II.

A polymorphism was found in the electrophoretic mobilities of male-specific rat urinary proteins. The proteins (MUP-1) are inherited as a single autosomal trait. The Mup-1 locus possesses two codominant alleles Mup-1a (fast-migrating type) and Mup-1b (slowing migrating type). Mup-1 is closely linked to b (brown coat color), with a recombination frequency of 7.7 +/- 4.3 percent. The similarity to the linkage between Mup-1 and b in mice and rats is discussed.

Animals↗
PubMedDate not supplied

Components of major urinary proteins (MUP's) in the mouse. Sex, strain, and subspecies differences.

The differences in electrophoretic patterns of major urinary proteins (MUP's) due to sex, strain, and subspecies of the mouse (Mus musculus) were examined by the combined methods of agarose gel electrophoresis and immunofixation. The MUP's from the male of common laboratory inbred mice (M. m. domesticus) showed a component that was absent in females of the same strain, in addition to a strain-specific component that was determined by the Mup-1 allele carried by the strain. In MOA mice, an inbred strain from M. m. molossinus (Japanese wild mice), there was no apparent sex difference in the constitution of the components. The MUP's from this strain contained a major component that was virtually absent in those from laboratory mice, but lacked the strain-specific components of laboratory mice. In addition, the present methods revealed that both liver and serum contained MUP's consisting of components similar to those found in the urine from the same sex and strain.

Animals↗
PubMedDate not supplied

A new allele at the Mup-1 locus controlling an electrophoretic variant of major urinary proteins in mice.

The present study showed that the presence or absence of a new component of major urinary proteins (Mups), which is found in MOA mice, an inbred strain of Mus musculus molossinus (Japanese wild mice), is controlled by a single codominant gene locus. The linkage analysis shows that the locus is on chromosome 4, where the Mup-1 locus is assigned; its alleles, Mup-1a, and Mup-1b determine two phenotypic forms of MUPs in laboratory mice (M. m. domesticus). Recombination values between the locus and other loci on chromosome 4, such as brown (b), Pgm-2, and Gpd-1 are compatible with the gene order, Mup-1-b-Pgm-2-Gpd-1, on chromosome 4. Thus, it is concluded that the locus is identical to Mup-1 and it is proposed that Mup-1c be designated as the allele that determines a third phenotypic form of MUPs in MOA mice.

Alleles↗
PubMedDate not supplied

Evidence for separate gene loci (Es-1 and Es-Si) controlling serum esterases in rats.

The presence or absence of the Es-Si esterase (female specific sex-influenced esterase) in rat sera was reexamined by the zymogram technique using agarosegel electrophoresis. It was found that female rat sera of the BN/Kyo strain, which has been typed as the Es-Si esterase negative, display an esterase migrating between the Es-1A esterase and the Es-2C esterase. Using a specific alloantibody to the esterase, it was shown that this esterase is identical to the Es-Si esterase. Thus, BN rats are the first described inbred rats possessing the Es-Si esterase, as well as the Es-1A esterase. Mating experiments between BN rats and SHR rats confirmed a previous demonstration that the presence or absence of the Es-Si esterase is controlled by a single gene locus closely linked to the Es-2 locus where the Es-1 locus also is linked. A further survey with 39 strains by the present methods revealed that besides two sublines of the BN strain, E3/Han, LOU/Max and PVG/Max strains also possess both the ES-1A esterase and the Es-Si esterase. The results indicate that these esterases are controlled by separate gene loci.

Animals↗