An antibiotic complex fromAlternaria brassicicola

Zusammenfassung Bei Untersuchungen vonAlternaria brassicicola, die eine antibiotische Komplexverbindung bildet, wurde eine der aktivsten Verbindungen mit Brassicicolin A bezeichnet, isoliert und gereinigt. Die Substanz konnte jedoch nicht kristallisiert werden. In-vitroUntersuchungen zeigen primär eine Antiwirksamkeit gegen Hefen.

---

---

This is a laboratory of the Northern Utilization Research and Development Division, Agricultural Research Service, U.S. Department of Agriculture.     

Thermozymocidin new antifungal antibiotic from a thermophilic eumycete

Riassunto È stato isolato un nuovo antibiotico, denominato termozimocidina, attivo contro lieviti e funghi filamentosi, prodotto in coltura sommersa da un eumicete termofilo. Vengono presentate le principali propietà chimiche, fisiche e biologiche che ne permettono la sua caratterizzazione.     

Peptide antibiotic biosynthesis: A new approach

Zusammenfassung Eine verallgemeinernde biosynthetische Theorie über die Entstehung vond-Aminosäuren in Peptid-Antibiotika wird dargestellt und zur Bildung von makrozyklischen Strukturen aus kleineren Ring-systemen in Beziehung gesetzt.     

Strategies for cloning unknown cellular flanking DNA sequences from foreign integrants

Many virus and transposon DNAs can integrate into the host genome. In this review, techniques, including inverse polymerase chain reaction (IPCR), novel Alu-PCR and vectorette- or splinkerette-PCR are introduced as possible strategies for cloning flanking DNA regions of the integrants. Targeted gene-walking PCR, restriction-site PCR, capture PCR, and panhandle PCR and boomerang DNA amplification are also described. The principles, advantages and limitations of each approach are discussed. Received 9 July 1998; received after revision 2 October 1998; accepted 7 October 1998     

The major OLA histocompatibility complex of sheep. Recent results in the genetic study of 11 factors previously defined by microlymphocytotoxicity]

The genetic study of 11 lymphocyte factors previously described in sheep was continued. 9 factors are the products of alleles at two closely linked loci OLA-A and B. The last two factors are the products of two genes at two distinct loci OL-X and OL-Z. Recombinations between the two closely linked loci are very rare (0.6%); but they are frequent between these two loci and OL-X (26%). The OL-Z locus seems to be independent of the two linked loci OLA-A and B. The allele frequencies at the four loci are given.     

Ionophoric activity of the antibiotic X.14547 A in the mitochondrial membrane

Summary Release of Ca⁺⁺, Mg⁺⁺ and K⁺ by the carboxylic ionophore X-14547 A was studied in the mitochondrial membrane. A comparison was made with A.23187 (Calcimycin) and X.537 A (Lasalocid A) under the same experimental conditions. It was shown that in this test system X.14547 A is primarily a K⁺ carrier comparable with X.537 A.     

Ionophoric activity of the antibiotic X.14547 A in the mitochondrial membrane

Release of Ca++, Mg++ and K+ by the carboxylic ionophore X-14547 A was studied in the mitochondrial membrane. A comparison was made with A.23187 ( Calcimycin ) and X.537 A (Lasalocid A) under the same experimental conditions. It was shown that in this test system X.14547 A is primarily a K+ carrier comparable with X.537 A.     

Paracelsin, a peptide antibiotic containing alpha-aminoisobutyric acid, isolated from Trichoderma reesei Simmons. Part A

A peptide antibiotic has been isolated from Trichoderma reesei QM 9414. Although crystalline and uniform in TLC, this antibiotic could be resolved by HPLC into 3 sequence analogues. The close relationship to alamethicin was proved by chemical and spectroscopic methods, and the formation of ion-conducting pores in lipid bilayers.     

A constrained least squares method for estimating the effects of an unknown monotonically intervening factor

A constrained least squares method is developed for the estimation of the effects of an unknown intervening causal factor in regression analysis, when the unknown factor shifts the regression hyperplane monotonically upwards (downwards) over time. As an illustration, we estimate the price elasticity of cigarettes in the USA and the systematic shifts of the demand curve for cigarettes during the time period 1964-86 (these shifts presumably reflecting the heightened awareness of the general public of the potential dangers of smoking).     

A mutant of the antibiotic resistance factor R124 with altered copy number

Summary A mutation conferring increased antibiotic resistance onSalmonella typhimurium strain 11G carrying R124 was plasmid determined; strains harbouring the mutant plasmid contained more DNA as ccc plasmid than those harbouring R124. The increased copy number was manifested at all growth rates at all growth rates tested.This work was supported by a grant (to R. J. R.) from the Central Research Fund of the University of London and by a studentship (to J. J. P.) from the Science Research Council.     

A new antifungal antibiotic produced byStreptomyces sp. Ac2435

Zusammenfassung Ein neues antifungales Antibioticum,Streptomyces sp. Ac₂(435) wurde mit breitem Spektrum isoliert. Die aktive Substanz ist ein amorphes, nicht-kristallines weisses Pulver, das in Wasser mässig löslich ist. Die Substanz ist lichtempfindlich und bei 100°C inaktiv. Vergleichsproben mit bekannten Substanzen ergaben eine Tetraenverbindung.     

The structure of a novel antitumor antibiotic,saframycin A

Summary A structure is assigned to saframycin A, a novel antitumor antibiotic fromStreptomyces lavendulae No. 314, on the basis of¹³C NMR-spectral data.     

A mutant of the antibiotic resistance factor R124 with altered copy number.

A mutation conferring increased antibiotic resistance on Salmonella typhimurium strain 11G carrying R124 was plasmid determined; strains harbouring the mutant plasmid contained more DNA as ccc plasmid than those harbouring R124. The increased copy number was manifested at all growth rates tested.     

Effect of enkephalins in the presence of the antibiotic bacitracin in the longitudinal muscle strip preparation from guinea-pig ileum

Summary The antibiotic bacitracin (5×10^–5–4×10^–4 M) increases the inhibition of the contractile response caused by both enkephalin release and direct application of Met-enkephalin 5×10^–7 M in the longitudinal muscle strip preparation from guinea-pig ileum. This effect is attributed to an inhibition of enkephalin degrading peptidases by bacitracin.