A transient species of poly(A)+ RNA detected by a myosin heavy chain cDNA probe in muscle cell culture during terminal differentiation

Primary cell cultures were prepared from breast muscles of 11 day 4 hour-embryonic chicks. Cytoplasmic RNAs were isolated from the cultured cells at various time intervals from day 3 to day 8. A [P32] DNA probe complementary to messenger RNA of myosin heavy chain was used to hybridize with the RNAs after gel electrophoresis. A transient species of polyadenylated RNA with a decreased mobility in electrophoresis was detected during a period of time when contractions of syncytial fibers were first observed.     

Existence of Sites for Anions and Divalent Cations in the Solubilized γ-Aminobutyric Acid/Benzodiazepine Receptor Complex

This study evaluated the ability of gamma-aminobutyric acid (GABA), baclofen, monovalent anions, divalent cations, and various combinations thereof to protect solubilized benzodiazepine (BZ) receptors of types 1 and 2, when contained together on the complex, against heat inactivation. Neither anions, cations, nor GABA alone provided significant protection of solubilized BZ receptors against heat, but inclusion of monovalent anions or divalent cations together with 500 microM GABA did afford protection. Monovalent anions combined with GABA (500 microM) provided 50% to full protection. Divalent cations, such as CaCl2 (2.5 mM) or MgCl2 (2.5 mM) in the presence of GABA (500 microM) yielded 45% and 24% protection, respectively. Other divalent cations tested (Zn2+, Hg2+, Co2+, and Ni2+) were poor protectors, even when combined with GABA. Monovalent anions (200 mM NaCl) and divalent cations (5 mM CaCl2) when tested together provided no protection. Similarly, baclofen (the GABA-B agonist) provided no protection, either alone or together with anions or divalent cations. These results indicate that the independent but interacting recognition sites of GABA, BZ, anions, and divalent cations, previously detected in the membrane-bound state, are retained in the solubilized state.     

Structural Decomposition Analysis of Raw Material Consumption

The aim of this article is to quantify the drivers for the changes in raw material consumption (domestic material consumption expressed in the form of all materials extracted and used in the production phase) in terms of technology, which refers to the concept of sustainable production; the product structure of final demand, which refers to the concept of sustainable consumption; and the volume of final demand, which is related to economic growth. We also aim to determine to what extent the technological development and a shift in product structure of the final demand compensate for the growth in final consumption volume. Therefore, we apply structural decomposition analysis (SDA) to the change in raw material consumption (RMC) of the Czech Republic between 2000 and 2007. To present the study in a broader context, we also show other material flow indicators for the Czech Republic for 2000 and 2007. Our findings of SDA show that final demand structure has a very limited effect on the change in material flows. The rapid change in final demand volume was not compensated for crude oil, metal ores, construction materials, food crops, and timber. For the material category of non‐iron metal ores, even the change in technology contributes to an increase in material flows. The largest relative increases are reported for non‐iron metal ores (38%) and construction materials (30%). The main changes in material flows related to the Czech Republic are driven by exports and enabled by imports, the main source of these increased material flows. This emphasizes the increasing role of international trade.     

Amino acid analysis of bone from a possible case of prehistoric iron deficiency anemia from the American southwest

It is possible that dietary conditions can result in the production of abnormal bone protein. For example, a heavily maize-dependent diet could be deficient in one or more essential amino acids necessary to normal human biochemistry and consequently necessary for normal bone protein synthesis. Amino acid analysis of bone tissues, thus, could provide a useful diagnostic tool in paleopathology. To test this potential we have compared the amino acid analyses of bone samples from a prehistoric Southwest Indian child exhibiting porotic hyperostosis with samples taken from (1) two children's skeletons lacking bone lesions but from the same area and time, (2) a modern child who died from accidental causes, and (3) adult human compact bone. Analytical results of the nonpathological prehistoric specimens were virtually identical to that of the modern infant, indicating remarkable preservation of bone protein. The pathological bone sample differed from the three control specimens by having as much as 25% less of those amino acids containing hydroxyl group and acidic side chains. We interpret the amino acid profile for the diseased child as indicating the presence of a greater proportion of helical protein (or less noncollagenous protein) as well as a lowered degree of hydroxylation of proline and lysine. One explanation for our data is that protein biosynthesis is altered in the child exhibiting porotic hyperostosis, and either some proteins important in the early phases of mineralization are not produced in sufficient quantity, or some necessary enzyme cofactors (e.g., dietary ferrous ions) are missing. We conclude that our data are compatible with, but do not prove, the hypothesis that the porotic hyperostosis exhibited by the Southwest Indian child is the result of iron deficiency anemia.     

Solubility characteristics of Micrococcus lysodeikticus membrane components in detergents and chaotropic salts analyzed by immunoelectrophoresis

In order to evaluate the effectiveness and selectivity of various reagents in the solubilization of bacterial membranes, membranes of Micrococcus lysodeikticus were treated with detergents and chaotropic agents. The composition of the extracts so obtained was analyzed by rocket and two-dimensional immunoelectrophoretic techniques. Recovery of succinate-, malate-, and reduced nicotinamide adenine dinucleotide- (NADH) dehydrogenases, ATPase, succinylated lipomannan and cytochromes in the extracts was measured. Treatment with a variety of non-denaturing detergents produced extracts that were generally qualitatively uniform although quantitative differences were observed. The degree of extraction of various components was correlated with the hydrophile-lipophile balance. Several chaotropic agents were also evaluated as reagents for membrane solubilization. These agents were less effective in extraction of bulk protein, but produced extracts enriched in some membrane components.     

A new tubulin-binding protein

A new brain protein is described which forms an insoluble complex with tubulin, with concomitant stoichiometric hydrolysis of GTP. The complex contains a maximum of one tubulin-binding protein (MW 52,500) per two tubulin dimers. The tubulin-binding protein (TBP) does not compete with colchicine, but in the presence of microtubule-associated proteins tubulin appeared less accessible to it. Proteins such as TBP might sequester tubulin and thereby function either to inhibit indiscriminate polymerization, or to promote ordered nucleation by maintaining high local concentrations.     

Limited proteolysis patterns of the B chain of insulin.

The oxidized B chain of insulin was used as a simple model for further consideration of limited proteolysis with low substrate:enzyme ratios. With low B chain:trypsin ratios, the ordinarily slower cleavage rate of the -Lys₂₉-Ala₃₀ bond essentially equaled the cleavage saturation rate of the -Arg₂₂-Gly₂₃ bond. This led to the disappearance of octapeptide which ordinarily forms most rapidly. Heptapeptide and alanine, formed mainly by cleavage of the octapeptide, decreased somewhat at high enzyme relative levels. Trypsin added to B chain formed a single chromatographic peak.     

The disposition of citric acid cycle intermediates by isolated rat heart mitochondria

The mechanism of depletion of tricarboxylic acid cycle intermediates by isolated rat heart mitochondria was studied using hydroxymalonate (an inhibitor of malic enzymes) and mercaptopicolinate (an inhibitor of phosphoenolpyruvate carboxykinase) as tools. Hydroxymalonate inhibited the respiration rate of isolated mitochondria in state 3 by 40% when 2 mM malate was the only external substrate, but no inhibition was found with 2 mM malate plus 0.5 mM pyruvate as substrates. In the prescence od bicarbonate, arsenite and ATP, propionate was converted to pyruvate and malate at the rates of 14.0 ± 2.9 and 2.8 ± 1.8 nmol/mg protein in 5 min, respectively. Under these conditions, 0.1 mM mercaptopicolinate did not affect this conversion, but 2 mM hydroxymalonate inhibited pyruvate formation completely and resulted in an accumulation of malate up to 13.2 ± 2.9 nmol/mg protein. No accumulation of phosphoenolpyruvate was found under any condition tested. It is concluded that malic enzymes but not phosphoenolpyruvate carboxykinase, are involved in conversion of propionate to pyruvate in isolated rat heart mitochondria.     

Identification of significant regions of transcription factor DP-1 (TFDP-1) involved in stability/instability of the protein

We previously reported the identification of DP-1 isoforms (α and β), which are structurally C-terminus-deleted ones, and revealed the low-level expression of these isoforms. It is known that wild-type DP-1 is degraded by the ubiquitin-proteasome system, but few details are known about the domains concerned with the protein stability/instability for the proteolysis of these DP-1 isoforms. Here we identified the domains responsible for the stability/instability of DP-1. Especially, the DP-1 “Stabilon” domain was a C-terminal acidic motif and was quite important for DP-1 stability. Moreover, we propose that this DP-1 Stabilon may be useful for the stability of other nuclear proteins when fused to them.