Separation of Bombyxin from a neuropeptide of Bombyx mori showing Summer-morph-producing Hormone (SMPH) activity in the Asian Comma Butterfly,Polygonia c-aureum L

A neuropeptide from brain-suboesophageal ganglion (Br-SG) complexes of the silkmoth, Bombyx mori, shows summer-morph-producing hormone (SMPH) activity in the Asian comma butterfly, P. c-aureum. The SMPH-active peptide was extracted and demonstrated to be almost the same molecular size as bombyxin (4-5kD), a nueropeptide which shows prothoracicotropic hormone (PTTH) activity when assayed in vitro with prothoracic glands (PGs) of 4th-instar B. mori larvae in vitro. A Sephadex G-50 fraction of 3-8kD molecules prepared from Br-SG complexes of B. mori adults was applied to CM-, SP-, DEAE- or QAE- Toyoperal columns at pH 5.6 (or pH 6.9). The SMPH-activity could be separated from the PTTH-activity (or bombyxin) by subjecting a SMPH- and PTTH-active preparation of B. mori to anion-exchange chromatography at pH 6.9. By reversed-phase HPLC following an anion-exchange chromatography, SMPH-activity was recovered in two fractions of 40-45% acetonitril. Results demonstrate that the B. mori peptide showing the SMPH-activity in P. c-aureum is a different molecule than bombyxin.     

Analysis of the NH2-Terminal 83rd Amino Acid of Escherichia coli GyrA in Quinolone-Resistance

Artificial mutations of Gyrase A protein (GyrA) in Escherichia coli by site-directed mutagenesis were generated to analyze quinolone-resistant mechanisms. By genetic analysis of gyrA genes in a gyrA temperature sensitive (Ts) background, exchange of Ser at the NH₂-terminal 83rd position of GyrA to Trp, Leu, Phe, Tyr, Ala, Val, and Ile caused bacterial resistance to the quinolones, while exchange to Gly, Asn, Lys, Arg and Asp did not confer resistance. These results indicate that it is the most important for the 83rd amino acid residue to be hydrophobic in expressing the phenotype of resistance to the quinolones. These findings also suggest that the hydroxyl group of Ser would not play a major role in the quinolone-gyrase interaction and Ser83 would not interact directly with other amino acid residues.     

Mucopolysaccharidosis IVA: structural gene alterations identified by Southern blot analysis and identification of racial differences

Ninety-six alleles (36 alleles of Japanese and 60 of Caucasian origin) from forty-eight patients with mucopolysaccharidosis IVA were investigated for structural gene alterations using Southern blot analysis. All patients had a previously demonstrated deficiency of N-acetylgalactosamine-6-sulfate-sulfatase and exhibited a wide spectrum of clinical severity. Initially, using the fulllength cDNA as a probe, five of 36 chromosomes from the Japanese patients revealed similar rearrangements with respect to DNA digested with BamHI, SacI, and XhoI. Subsequent analysis using seven genomic fragments, covering the entire gene, enhanced the detection of aberrant fragments produced by the above restriction enzymes. Conversely, the 60 chromosomes of Caucasian origin revealed no evidence of large structural rearrangements when analyzed by these methods. There was a statistically significant difference between the two populations (P < 0.01). A severely affected Japanese patient showed structural rearrangements on both chromosomes by means of BamHI blots. An 8.0-kb fragment and a highly polymorphic 7.0-kb to 11.0-kb fragment present in normal individuals disappeared and two aberrant fragments of 11.5 kb and 12.0 kb were observed. Three other Japanese patients also showed these two aberrant fragments, in addition to the normal fragment pattern, and were thus heterozygous for this rearrangement. Interpretation of Southern blots was difficult because of the complexity of polymorphic bands resulting from variable number of tandem repeat elements. However, by utilizing these aberrant fragments or polymorphic bands, carrier detection was effective, even in families with poorly characterized mutations. Hybridization with probe MG-A (5end genomic probe in intron 1) showed a 8.4-kb fragment in BamHI blots of one Japanese and one Caucasian patient; XhoI, SacI, and EcoRI blots were normal. Since this BamHI alteration was also observed in one normal control, it appears to be a rare nonpathological polymorphism.     

Mucopolysaccharidosis IVA: polymorphic haplotypes and informative RFLPs in the Japanese population

Seven different restriction fragment length polymorphisms (RFLPs) at the N-acetylgalactosamine-6-sulfate sulfatase (GALNS) locus were analyzed using Southern blotting and polymerase chain reaction based techniques to search for the frequency of each RFLP produced by StyI, SphI, HaeIII, StuI, HapII, XhoI, and BamHI restriction endonucleases, respectively, in 36 mutant alleles, including two sibling cases and 100 normal alleles. Calculation of heterozygosity indexes showed that these RFLPs were polymorphic, ranging from 0.31 to 0.69 in mucopolysaccharidosis IVA (MPS IVA) patients compared with 0.21 to 0.65 in normal individuals. There was some significant difference in several RFLPs and in the combination with four kinds of RFLPs (SphI, StuI, HapII, XhoI polymorphisms). The normal alleles were composed of 13 different RFLPs haplotypes; the most common among the Japanese population carrying normal alleles was haplotype 8 (bDEF1) (31.3%), the others being dispersed. The same haplotype 8 was the most frequent in the mutant alleles (44.4%), with seven further haplotypes. These findings revealed the striking variety of polymorphic haplotypes in the MPS IVA gene. By using these five kinds of RFLPs, we examined the theoretical informativity of haplotype analysis in heterozygote detection in nine unrelated MPS IVA families and ten unrelated normal families. All the members of the MPS IVA families studied were diagnosed as a patient, carrier, or noncarrier. We propose that prenatal diagnosis or family analysis in cases in which mutations have not been characterized is now feasible.     

Optimal strategy of plant antiherbivore defense: Implications for apparency and resource-availability theories

Plants produce chemicals as methods against animal herbivory. Such chemical defenses are classified into two major categories: (i) quantitative defenses with massive production of indigestible substances; and (ii) qualitative defenses with production of poisonous substances. A mathematical model was developed that identified factors that favored the evolution of quantitative defenses. Selecting an annual plant for simplicity, the allocation of photosynthetic production between growth substances and defense substances was considered. If the plant invests more in defense substances, it can protect itself more efficiently from herbivory but with a reduced growth rate. If it invests more in growth substances, the contrary holds. Using Pontoryagin's maximum principle, the following results were obtained: (i) the plant should conduct quantitative defenses when the growth rate (G), reflecting resource-availability, is low and the growth period (T) is long as well; (ii) if the plant invests in quantitative defenses, the optimal proportion of defense substances (χ^*) should be higher asG is smaller, but it is independent ofT; and (iii) the value of χ^* is not monotone for the effectiveness of defense substance (A), but has a maximum at an intermediate value ofA. Predictions of the model partly supported both Feeny's apparency theory, claiming that apparent plants or their parts for herbivores should quantitatively defend themselves, and Coley's resource-availability theory, claiming that plants with rich resources should invest in growth rather than defense.     

Teratogenic effects of avidin-induced biotin deficiency in mice

Teratogenic effects of maternal biotin deficiency were examined at different levels of severity by adding three levels of avidin (10, 20, or 40 mg/kg) in the basal diet. There was a considerable increase of fetuses with multiple congenital malformations (micrognathia, cleft palate, and micromelia) with increasing amounts of avidin. The dose-response relationship was observable in the incidence of each malformation as well. The body weight of live fetuses was also significantly reduced. However, the dams did not exhibit any typical signs of biotin deficiency, such as loss of hair, dermatitis, or nervous irritability. These results suggest that biotin is important for early embryonic development in the mouse.     

Depside as potent inhibitor of prostaglandin biosynthesis: a new active site model for fatty acid cyclooxygenase

Forty depsides and depsidones, the esters of phenolcarboxylic acids, were examined for their inhibitory effect against prostaglandin biosynthesis with rabbit renal microsomes. 4-0-Methylcryptochlorophaeic acid was the most active inhibitor so far tested and its IC50 value was 0.34 muM. Kinetic investigation has shown that this depside acts competitively with respect to arachidonic acid as most of the non - steroidal antiinflammatory drugs. X-Ray analysis has revealed that 4-0-methylcryptochlorophaeic acid maintains its rigid conformation by forming a strong hydrogen bond between the hydroxyl and methoxyl groups. Comparison of CPK models between 4-0-methylcryptochlorophaeic acid and non-steroidal antiinflammatory drugs revealed that the carboxyl group and the two rings of these drugs are almost superimposable to those of the depside. This finding led us to propose a new active site model based on the three dimentional structure of the depside.     

Screening method for prolidase deficiency

Summary A simple procedure was developed to determine prolidase activity in dried blood specimens. One thousand dried blood specimens from newborns were examined by this new method. Prolidase activities ranged from 140 to 370 nmol per 3 mm disc per hour (233±43, mean ± SD), and less than 2% of the samples overlapped the heterozygote values. This method should be useful in the mass screening for prolidase deficiency.This research was supported by a Research Grant from the Ministry of Education Japan 1979