Isolation of the first trypsin inhibitor from the genusAspergillus

The fungusAspergillus flavipes was grown on a Czapeck sucrose medium; the biomass so obtained was treated with high concentration of sucrose to release intracellular metabolites. Sephadex G-75 chromatography of the latter yielded a pure protein having anti-trypsin activity in vitro.     

A review of the taxonomy and systematics of the pentastomid genus Raillietiella Sambon, 1910 with a description of a new species

Systematic Parasitology - Four previously established Raillietiella spp. are redescribed. Two of these, R. kochi and R. shipleyi from African monitor lizards, cannot be reliably separated, R....     

In vitro development of the hamster and chick secondary palate

A series of experiments were undertaken to compare the in vitro behaviour of the medial edge epithelium (MEE) of hamster, in which palatal shelves normally fuse, and chick, in which they do not fuse. Homotypic pairs of hamster and chick embryo palatal processes, single palatal processes, and heterotypic palatal shelves of both animals were grown in vitro. The results indicated that contact between palatal shelves may not be crucial for MEE differentiation in mammals. The ability to acquire pre-fusion characteristics may be present in mammalian palatal tissue from their early development and may be expressed by cessation of DNA synthesis in the MEE, elevation of cAMP, and MEE cell death. Isolated chick palatal shelf cultured under identical conditions did not express these mammalian pre-fusion characteristics. When MEE of hamster and chick palatal shelves were placed in contact with one another, the intervening epithelia underwent cytolysis. This could be due to either the destruction of chick MEE by lysosomal enzymes liberated from adjacent degenerating hamster MEE cells, or by induction of cell death in chick MEE by hamster mesenchyme. Heterotypic palatal tissue combinations also suggest that release of lysosomal enzymes in the hamster MEE, which leads to its dissolution, may be the terminal event in epithelial differentiation prior to the establishment of mesenchymal continuity. It is suggested that an inverse relationship exists between DNA synthesis and cAMP levels during palatogenesis: when palate closes (as in mammals) the MEE is eliminated by increasing cAMP levels, whereas when palate remains open (as in birds) low level of cAMP preserve the integrity of MEE by supporting DNA synthesis.     

Definition of essential sequences and functional equivalence of elements downstream of the adenovirus E2A and the early simian virus 40 polyadenylation sites.

In addition to the highly conserved AATAAA sequence, there is a requirement for specific sequences downstream of polyadenylic acid [poly(A)] cleavage sites to generate correct mRNA 3' termini. Previous experiments demonstrated that 35 nucleotides downstream of the E2A poly(A) site were sufficient but 20 nucleotides were not. The construction and assay of bidirectional deletion mutants in the adenovirus E2A poly(A) site indicates that there may be redundant multiple sequence elements that affect poly(A) site usage. Sequences between the poly(A) site and 31 nucleotides downstream were not essential for efficient cleavage. Further deletion downstream (3' to +31) abolished efficient cleavage in certain constructions but not all. Between +20 and +38 the sequence T(A/G)TTTTT was duplicated. Function was retained when one copy of the sequence was present, suggesting that this sequence represents an essential element. There may also be additional sequences distal to +43 that can function. To establish common features of poly(A) sites, we also analyzed the early simian virus 40 (SV40) poly(A) site for essential sequences. An SV40 poly(A) site deletion that retained 18 nucleotides downstream of the cleavage site was fully functional while one that retained 5 nucleotides downstream was not, thus defining sequences required for cleavage. Comparison of the SV40 sequences with those from E2A did not reveal significant homologies. Nevertheless, normal cleavage and polyadenylation could be restored at the early SV40 poly(A) site by the addition of downstream sequences from the adenovirus E2A poly(A) site to the SV40 +5 mutant. The same sequences that were required in the E2A site for efficient cleavage also restored activity to the SV40 poly(A) site.     

HPLC analysis of furazolidone in goats given the therapeutic dose

Furazolidone (FZ) was given to Nubian goats at the recommended therapeutic dose of 10 mg/kg body wt, for 5 days. The animals were slaughtered 24 hr after the last dose, and their livers, gluteal muscles, kidneys and hearts analysed for FZ residues by an HPLC method with a detection limit of 0.05 micrograms g-1. The drug was detected in the muscle and liver at concentrations of 0.256 +/- 0.009, 0.101 +/- 0.016 micrograms g-1 tissue, respectively. No detectable concentrations of the drug were found in the kidney and heart.     

Isolation of Bacillus licheniformis mutants for stable production profiles of alkaline protease

Summary A phenotypic requirement for cysteine was introduced inBacillus licheniformis producing alkaline protease to facilitate its isolation from poor or nonproducerBacillus species. This facilitated purification of the strain in cases of cross-contamination, preparation of good inocula for commercial production and stabilization of alkaline protease harvest values, alleviating economic losses incurred through cross-contamination.     

Activation of hypoxanthine/guanine phosphoribosyltransferase from yeast by divalent zinc and nickel ions

We have observed previously that the reactions catalyzed by hypoxanthine/guanine phosphoribosyltransferase (HGPRTase) are activated by Mg(II), Mn(II), and Co(II), and we have defined the mechanism by which these activations proceed [Biochemistry 22, 3419-3424 (1983)]. A more extensive survey of the kinds of metal ions that will activate the HGPRTase catalysis now has been completed through the use of an HPLC assay procedure. Although Fe(II) and Ca(II) are unable to activate this reaction, a significant activation was achieved with the addition of spectroscopically pure Zn(II) to the assay solution. In addition some IMP synthesis resulted from the addition of Ni(II) to the assay mixture. Both the Zn(II) and Ni(II) kinetic effects on HGPRTase over a limited metal ion concentration range have been analyzed through the use of curve-fitting exercises. These results, in addition to the similar pH profiles for the activations by Mg(II), Mn(II), Co(II), and Zn(II), suggest that all of these metal ions activate the HGPRTase-catalyzed synthesis of IMP by way of the same mechanism [model II as defined by London and Steck, Biochemistry 8, 1767-1779 (1969)], during which two divalent ions bind to the HGPRTase active site per molecule of PRibPP.     

Structural analysis of a maize gene coding for glutathione-S-transferase involved in herbicide detoxification

Summary We have used the cDNA clone encoding maize glutathione-S-transferase (GST I) to isolate a genomic DNA clone containing the complete GST I gene. Nucleotide sequence analysis of the cDNA and genomic clones has yielded a complete amino acid sequence for maize GST I and provided the exon-intron map of its gene. The mRNA homologous sequences in the maize GST I gene consist of a 107 bp 5 untranslated region, a 642 bp coding region and 340 bp of the 3 untranslated region. They are divided into three exons by two introns which interrupt the coding region. The 5 untranslated spacer contains an unusual sequence of pentamer AGAGG repeated seven times. The inbred maize line (Missouri 17) contains a single gene for GST I, whereas the hybrid line (3780A) contains two genes. Nucleotide sequence analysis of the primer extended cDNA products reveals that the 5 untranslated regions of the two genes in the hybrid 3780A are identical except for a 6 bp internal deletion (or insertion). The amino acid sequence of maize GST I shares no apparent sequence homology with the published sequences of animal GST's and represents the first published sequence of a plant GST. re]19850813 ac]19851126     

Cross reactivity and enzyme sensitivity of immunoaffinity purified Sm/RNP antigens

Immunoaffinity purified Sm/RNP antigens from buffalo and goat liver were studied to determine the role of RNA and proteins towards the antigenicity of Sm and RNP antigens. A more direct approach using enzyme-linked immunosorbent assay on nylon beads has been utilized to look into the problem. The effect of enzyme treatment and the role of RNA and protein fractions in influencing antigenicity have been described. RNA seems to be involved in the maintenance of RNP specific polypeptides in suitable conformation so as to keep them in solution. Removal of RNA leads to insolubilization of RNP specific polypeptides. Antibodies to Sm and RNP antigens have been shown to cross react with poly A containing heterogeneous nuclear ribonucleoprotein with no cross reactivity with thymus RNA or DNA.