Aid for the Choice of Buffer Concentration

The peptic hydrolysis of bovine β-lactoglobulin (β-Lg) was performed to establish the basis for producing a low-phenylalanine peptide rather than a free amino acid mixture for use in the dietetics of phenylketonuria. A 1% β-Lg solution (pH 1.5) was incubated with 0.01% pepsin at 37°C for 24 hr. The peptides produced were fractionated by high-performance liquid chromatograhy to analyze their constituent amino acids. Most of the major peptides were identified in the light of the primary structure of α-Lg to assign 31 cutting points in their protein molecule. These included cutting points at the carboxyl side of Phe-82, Phe-105 and Phe-136. This result suggests that further hydrolysis of the peptic hydrolysate of β-Lg with an exopeptidase, particularly with a carboxypeptidase, would be effective in liberating phenylalanine to produce a low-phenylalanine peptide mixture.     

Correlation between Supercoiling and Conformational Motions of the Bacterial Flagellar Filament

The bacterial flagellar filament is a very large macromolecular assembly of a single protein, flagellin. Various supercoiled states of the filament exist, which are formed by two structurally different conformations of flagellin in different ratios. We investigated the correlation between supercoiling of the protofilaments and molecular dynamics in the flagellar filament using quasielastic and elastic incoherent neutron scattering on the picosecond and nanosecond timescales. Thermal fluctuations in the straight L- and R-type filaments were measured and compared to the resting state of the wild-type filament. Amplitudes of motion on the picosecond timescale were found to be similar in the different conformational states. Mean-square displacements and protein resilience on the 0.1 ns timescale demonstrate that the L-type state is more flexible and less resilient than the R-type, whereas the wild-type state lies in between. Our results provide strong support that supercoiling of the protofilaments in the flagellar filament is determined by the strength of molecular forces in and between the flagellin subunits.     

Natural development time of Eodiaptomus japonicus (Copepoda: Calanoida) in Lake Biwa

Seasonal and ontogenetic changes in natural development timewere studied for Eodiaptomus japonicus in Lake Biwa in 1986and 1987. Wild individuals in a certain developmental stagewere collected, fed on natural food and examined until theyhad moulted twice. Natural development times fluctuated irrespectiveof temperature from May to October. Food deficiency delayeddevelopment in all feeding stages, and food availability probablydetermined natural development time. Serious food limitationraised mortality in copepodid stage I. In November developmentwas delayed even with enough food. The development of E.japonicuswas almost isochronal except for a short prefeeding naupliarstage I and a long copepodid stage V.     

Existence of a Common Glycoprotein Homologous to S-Glycoproteins in Two Self-incompatible Homozygotes of Brassica campestris

S-Glycoproteins (S-locus-specific glycoproteins) in Brassicaspecies are present only in stigmas and thought to play an importantrole in self-incompatibility system. The stigma extract containsalso several other glycoproteins reacting with the antiserumto S-glycoproteins, among which some glycoproteins from S₈S₈-and S₉S₉-homozygotes have the same pI value. Both of the glycoproteinswhich were tentatively termed NS₈- and NS₈S₉-glycoproteins,respectively, were isolated and analyzed. Those were revealedto be identical. Its amino acid sequence was homologous withthe S-glycoproteins in Brassica species. The NS-glycoproteinswere expressed at the same time and only in stigma as S-glycoproteins. (Received July 19, 1988; Accepted September 7, 1988)     

A volumetric comparison of the vestibular nuclei in primates

The volumes of each of the four vestibular nuclei, superior, lateral, medial and descending, were measured in 80 brains from 2 species of Scandentia, 18 species of prosimians, and 26 species of anthropoids. Size indices were calculated by comparing species-specific points to the nucleus volume-body weight allometry in prosimians, where the average prosimian was set at 1.00. The indices range from 1.78 in Saimiri to 0.48 in Gorilla, and the distributions by families overlap partially or completely. The observed trend in size indices is independent of changes in the neocortex and the ventral pons; average indices are 1.35 in New World monkeys, 1.20 in Old World monkeys, 0.74 in apes, 0.82 in man. Among prosimians, Galago, Galagoides and Tarsius (leaping locomotion) show significantly higher indices than Nycticebus, Loris and Perodicticus (slow movement without leaping). The lateral vestibular nuclear indices in Pongidae and man are extremely low, about half of those of the average prosimians. Correlation coefficients of size indices between the vestibular nuclei and other motor nuclei, such as the cerebellar nuclei, ventral pons and striatum, are analysed. The ratio of the vestibular nuclear volumes to the total brain volumes and the distribution of percentages of each vestibular nuclear volume to the total complex are also obtained.     

A new sharpnose pufferfish,Canthigaster flavoreticulata,collected from the South Pacific

A new sharpnose pufferfish,Canthigaster flavoreticulata, is described on the basis of two specimens collected from the Tonga Submarine Ridge in the South Pacific. This species is distinguished from other congeners by having many wavy yellow lines on the dorsal half of the body.     

Volume comparisons in the cerebellar complex of primates. II. Cerebellar nuclei

Volumes of medial, interposed, and lateral cerebellar nuclei (MCN, ICN, and LCN) were measured in Insectivora, Scandentia, and Primates, including man. The relative size of the nuclei was expressed in size indices. Insectivora had by far the smallest cerebellar nuclei. The simians, in general, had larger cerebellar nuclei than the prosimians, but there was considerable overlap. From Insectivora to man, the MCN was the least progressive and the LCN the most progressive. The indices are expected to reflect the relative size of the three longitudinal zones of the cerebellum (vermis/MCN, pars intermedius/ICN, hemisphere/LCN). They, together with those of the ventral pons and cerebellum (part I), are discussed in relation to the predominant locomotor pattern of a species, and with reference to evolutionary trends in primate phylogeny.     

Restriction fragment length polymorphism detected by human salivary amylase cDNA

Summary The plasmid clone which contains human salivary amylase cDNA was used to detect restriction fragment length polymorphisms (RFLPs). After double digestion with Pst 1 and Bam H1, a polymorphism with two alleles was observed. In Japanese, frequencies of these alleles, tentatively called 5.7kb and 6.5kb fragment alleles, are 0.55 and 0.45, respectively.