Isolation of a full-length cDNA encoding mouse aromatase P450

A full-length cDNA clone for aromatase P450 has been isolated from a pregnant mouse ovarian cDNA library. The insert of this clone (2394 bp) contains a 1509-bp open reading frame encoding 503 amino acid residues together with a 46-bp 5'-untranslated stretch and an 839-bp 3'-untranslated region to which a poly(A) tract is attached. Northern blot analysis of ovarian RNA from pregnant mice reveals a major mRNA band of 2.5 kb with a minor band of 2.1 kb. Comparison of mouse aromatase P450 with that of rat, human, and chicken shows 91, 81, and 69% identity in the nucleotide sequence and 92, 79, and 69% identity in the deduced amino acid sequence, respectively. The membrane-spanning domain of mouse aromatase P450 is estimated to be an extremely hydrophobic segment located within the N-terminal region of the molecule. Furthermore, a highly conserved heme-binding domain is noticed.     

Location of the disulfide bonds in the antitumor protein neocarzinostatin.

Two disulfide bonds in the antitumor antibiotic neocarzinostatin were determined chemically. The peptic and peptic/thermolytic peptides from the native protein were isolated by gel filtration and ion-exchange chromatography followed by reverse-phase HPLC. The cystine peptides obtained were oxidized separately by performic acid treatment and further separated by HPLC into cysteic acid peptides. Sequence analyses of the isolated peptides revealed the location of the disulfide bonds at Cys37-Cys47 and Cys88-Cys93.     

Effects of easily chewable diet and unilateral extraction of upper molars on the masseter muscle in developing mice

The effects of easily chewable diets and unilateral extraction of upper molars on the masseter muscle were studied in developing mice. A liquid diet requiring no mastication suppressed the development of the masseter muscles more than a fine-grained diet, and extraction of unilateral upper molars also caused inhibition of muscle development. Moreover, both unilateral extraction of upper molars and a liquid diet had an additive effect on the suppression of the postnatal development of the masseter muscle, and bilateral suppression of the development of the masseter muscle was induced following unilateral extraction of upper molars. These findings suggest that the sensory input from the sensory endings in the periodontal ligament may also play an important role in the postnatal development of the masseter muscle and that there may be some crossing pathways to convey the sensory input coming from the side of the extracted upper molars to the contralateral motor neurons via the interneuronal circuits.     

Identification of storage-protein messenger RNA of the fleshfly Sarcophaga peregrina.

Storage-protein mRNA was found to be abundant in poly(A)-containing RNA extracted from the fat-body of third-instar larvae of Sarcophaga peregrina (fleshfly). This RNA sedimented at the position of 19S on sucrose-density-gradient centrifugation and the product of its translation in vitro was 75K protein (protein of mol.wt. 75 000), which was precipitated specifically with antibody against storage protein. This product was suggested to contain a signal sequence that is missing in mature storage protein. The poly(A)-containing RNA was also found to contain much of another mRNA coding for 25K protein (protein of mol.wt. 25 000), but the function of this protein is unknown.     

Recombinant human leukocyte interferon produced in bacteria has antiproliferative activity

Recombinant human leukocyte interferon synthesized by Escherichia coli possesses antiproliferative activity in addition to antiviral activity. When the ability to inhibit multiplication of lymphoblastoid Daudi cells was examined, the growth-inhibitory capacity of recombinant leukocyte interferon was equivalent to that exhibited by crude human leukocyte interferon or by the homogeneous gamma 2 species of leukocyte interferon synthesized by human cells.     

Identification of some abnormal metabolites in psoriatic nail using gas chromatography—mass spectrometry

A gas chromatographic—mass spectrometric analysis was used to separate and identify abnormal compounds in the nail of psoriatic patients. The nail was extracted with heated ethanol, and the extract was analyzed with and without trimethylsilylation. Tetradecanoic acid octadecyl ester, hexadecanoic acid octadecyl ester and octadecanoic acid octadecyl ester were first identified in the psoriatic nail, but were not detected in normal nail.     

Effect of cholesterol on human erythrocyte membrane. A spin label study

The effect of cholesterol on the membrane fluidity of human erythrocytes has been studied by electron spin resonance (ESR) spectroscopy, sensing the motion of androstane and fatty acid spin labeles in the cell membrane and in vesicles made from extracted phospholipids. 1. Androstane spin label (ASL) was incorporated from ASL-containing phospholipid vesicles into the erythrocyte membrane, essentially by a partition mechanism in proportion to their phospholipid contents. 2. On increasing the cholesterol or ASl content in the cell membrane, the spin label was gradually immobilized. 3. ASL motion in the cell membrane seemed to be primarily determined by the cholesterol/phospholipid molar ratio, regardless of the membrane protein-lipid interaction, as judged from the temperature effects on the ESR spectra of both membranes. 4. However, glutaraldehyde pretreatment induced considerable changes of the cholesterol-lipid interaction in the cell membrane, i.e., strong immobilization and cluster formation of ASL were observed.