Parallelophoridae - isolierte Analfelder eozäner Schaben (Insecta: Blattodea)

As actuopalaeontological experiments clearly show, the family ParallelophoridaeHaupt 1956 (Blattodea incertae sedisRohdendorf 1962) from the Geiseltal near Merseburg (Middle-Eocene) are not a new family but isolated analfields of the forewings of other cockroach-families. During the process of fossilisation they get isolated from the wing in a rather early stage of destruction by fungi and other microorganisms, during the time the insect corpses are still swimming on the surface of a lake. The reasons, why only two specimens of such isolated analfields have been described till now, are briefly discussed.     

Isolation and characterization of the rat proenkephalin gene

The rat proenkephalin gene has been isolated by molecular cloning and characterized by DNA-sequence analysis. The gene exhibits a structural organization similar to that of the human gene. The nucleotide sequence encoding the biologically active opioid peptides which are generated from the proenkephalin precursor as well as the 3' untranslated region of the mRNA are found on a large exon at the 3' end of the gene (Exon III). The nucleotide sequence encoding the N terminus of the mature protein and its signal peptide are located on Exon II while Exon I encodes the 5' untranslated region of the mRNA. The nucleotide sequence of these exons and their flanking regions has been determined and compared to the human proenkephalin gene. Analysis of the nucleotide sequence homology between the human and rat proenkephalin gene reveals the presence of highly conserved regions within both the coding and noncoding portions of the genes. Enkephalin-coding sequences as well as 5' flanking sequences appear to be the most highly conserved. The importance and possible function of these sequences are discussed.     

Streptococcal Fc receptors. II. Comparison of the reactivity of a receptor from a group C streptococcus with staphylococcal protein A

The reactivity of a soluble Fc receptor from a group C streptococcus ( FcRc ) was compared antigenically and functionally with the staphylococcal Fc receptor, protein A. Protein A and FcRc were found to inhibit each others' binding to the Fc region of human IgG, indicating that they bind to sites that are in close proximity on the Fc region of human IgG. The two bacterial Fc receptors were antigenically unrelated. Differences were observed in the species and subclass reactivity of the two receptors. The patterns of binding of protein A and FcRc under various conditions suggested that these receptors reacted with distinct regions on the Fc region of immunoglobulins. FcRc bound more efficiently to goat, sheep, and cow IgG, protein A bound more efficiently to dog IgG, and neither receptor bound to rat IgG. Differences were also observed in the reactivity towards human IgG subclasses. The FcRc bound to all samples of the four human IgG subclass standards. Protein A bound to IgG1, IgG2, and IgG4, and to one of two IgG3 myeloma proteins tested. The reactivity of our soluble FcRc corresponds to a type III streptococcal Fc receptor classified by the reactivity of intact bacteria.     

Streptococcal Fc receptors. I. Isolation and partial characterization of the receptor from a group C streptococcus

A receptor for the Fc region of immunoglobulin G was extracted from a group C streptococcus, purified and physicochemically characterized. The Fc receptor was extracted in high yield by lysis of the bacteria after infection with bacteriophage. The soluble receptor was purified to functional homogeneity by sequential chromatography on cellulose phosphate, DEAE, and selective elution from a column of immobilized human IgG. Four hundred micrograms of the functionally pure protein was obtained per gram (wet weight) of bacteria extracted. The affinity-purified receptor was functionally homogeneous in binding to the Fc region of human IgG; however, the product was heterogeneous on both non-denaturing and SDS polyacrylamide gels. Four major protein bands were observed, with the predominant form of the Fc receptor having an m.w. of 64,000 daltons. Antibody prepared against the major Fc receptor protein ( FcRc -II) was capable of reacting with all the fractions and completely inhibiting functional activity. The results of the competitive binding studies suggest that the purified Fc receptor behaves as a single receptor, and that the differences in charge and size were probably due to covalently bound cell wall constituents.     

Decay and synthesis of ribosomal proteins during Dictyostelium discoideum development

Summary Ribosome turnover is a prominent process during cell differentiation in Dictyostelium discoideum. At the end of 24 h of development on filters, the cells contain only 30% of the ribosome content of vegetatively growing cells. We determined the relative rates of synthesis and decay of each of the ribosomal proteins during this period. Approximately 80% of the total vegetative cell ribosomal proteins were degraded during the course of fruiting body construction. Ribosomal RNA and protein degradation apparently occurred coordinately during development. Although all ribosomal proteins decayed during development, some were more stable and a few less stable than the average. In addition, all the ribosomal proteins were synthesized during this period. Most ribosomal proteins were synthesized at the same rate as other cellular proteins, although a number were made at lower or higher rates. It was estimated that about 35% of the ribosomes in developed cells represented those, that were made during cell differentiation. Differential decay and/or synthesis of ribosomal proteins could account for the observed difference in protein content of ribosomes from growing amoebae and late development cells and spores.Paper No. 4 in the series, Studies on Ribosomal Proteins in Dictyostelium discoideum. Paper No. 3 is Ramagopal and Ennis (1982)     

Characterization of the ugp region containing the genes for the phoB dependent sn-glycerol-3-phosphate transport system of Escherichia coli

Summary The ugp structural genes, coding for the pho regulon dependent sn-glycerol-3-phosphate transport system, were cloned in pBR322 and characterized. The expression of the cloned ugp system was phoB dependent. Cells containing the ugp plasmid overproduced the G3P binding protein upon phosphate starvation. Tn5 mutagenesis of the cloned DNA revealed that the ugp genes are organized in two separate operons which comprise at least four genes: ugpB and ugpD constitute one operon, ugpA and ugpC constitute the other. The structural gene for the G3P binding protein (G3PBP) is ugpB.The ugpC gene product was also synthesized in minicells as a polypeptide, with an apparent molecular weight of 40,000. No gene products could be assigned to the ugpA and ugpD genes. Hybridization experiments allowed the physical characterization of 20 kb of DNA adjacent to the ugp genes on the E. coli chromosome including the liv genes.     

Decreased triiodothyronine binding to isolated nuclei from livers of preobese and obese (ob/ob) mice

L-Triiodothyronine (T3) binding to hepatic nuclei from (ob/ob) mice at different ages was examined and compared with that of lean controls. Results showed a significant reduction in T3 binding in liver nuclei of obese mice at all ages studied. The preobese mice at 2 weeks of age had 27.9% fewer receptor sites/mg DNA compared to lean controls, receptor concentration further decreased to 67.7% at 18 weeks of age. Data presented here demonstrates that the impaired triiodothyronine (T3) binding to hepatic nuclei present in older (ob/ob) obese mice is an antecedent to the obesity. This report also helps to explain the poor thermoregulation and low oxygen consumption present during the preobese phase of the postnatal development of these animals.     

Orbitally magnetized organic solids

The preparation is discussed of polymeric organic solids in which large ring-like delocalized electronic orbitals can be made to enclose or trap magnetic flux. The situation is analogous to snapping shut a loop of superconductor while it is in a magnetic field. The operation of the Meissner effect acts to retain the trapped flux and create remant magnetization.     

In vitro lipid oxidation modifies proteins and functional properties of sarcoplasmic reticulum

Changes in protein and fatty acid compositions of flounder sarcoplasmic reticulum during NADH plus ascorbate-dependent lipid peroxidationin vitro were related to the ability of the sarcoplasmic reticulum to sequester Ca⁺². Progressive accumulation of high-molecular-weight protein components occurred concomitantly with loss of Ca⁺²-sequestering activity. Part of this polymerized protein may be the dimer or trimer of Ca⁺², Mg⁺²-ATPase. Loss in Ca⁺², Mg⁺²-ATPase protein could account for over 60% of the polymerized protein. Rate of loss of polyunsaturated fatty acids was C22:6>C20:4>C20:5>C22:5. Loss of polyunsaturated fatty acids and accumulation of thiobarbituric acid-reactive substances occurred concomitantly with protein polymerization.     

Isolation and partial characterization of a type II Fe receptor from a group A streptococcus

A group A streptococcal strain rich in Fc receptors was selected by an immunoblotting technique and used as the source for isolation of a functionally active Fc receptor. A variety of extraction techniques were compared including (1) heat extraction at neutral, acid or alkaline pH, (2) treatment with the enzymes mutanolysin, hyaluronidase, trypsin, papain or phage lysin, or (3) autoclaving or heating in the presence of sodium dodecyl sulfate. The most homogeneous receptor was recovered following heat extraction and contained two molecular weight forms. The major form had a molecular weight of 56 000 daltons and the minor form had a molecular weight of 38 000 daltons. These two proteins could be isolated without loss of activity by binding to and elution from a column of immobilized human IgG. An antibody prepared against a single form of the affinity purified receptor demonstrated reactivity with both molecular weight forms of the heat extracted receptor. The group A receptor was found to be both antigenically and physicochemically distinct from either the type I receptor found on the majority of Staphylococcus aureus strains or the type III Fc receptors found on the majority of group C streptococcal strains.