Isolation of large peptides derived by cyanogen bromide cleavage of thermolysin using fast protein liquid chromatography (FPLC)

The recently introduced fast protein liquid chromatography (FPLC) system of Pharmacia (Uppsala, Sweden) was employed to isolate rather large peptides derived from thermolysin by selective chemical fragmentation at methionine in positions 120 and 205 of the polypeptide chain of 316 amino acid residues. Thermolysin was cleaved under conditions of limited fragmentation in order to produce, besides fragments 1-120, 121-205 and 206-316, the overlapping fragments 1-205 and 121-316. These polypeptides were separated employing prepacked Mono Q or Mono S columns (quaternary ammonium and sulfonic acid support, respectively). The columns were equilibrated with acetate-7 M urea buffer, pH 5.0 or 6.0, and eluted with a gradient of sodium chloride or acetate. Separations were achieved in 10-20 min and were carried out also at a semi-preparative level (1-3 mg per run). All five protein fragments were isolated in homogeneous form, as judged by amino acid analysis and electrophoresis. Considering that protein fragmentation with cyanogen bromide is the most commonly used procedure to achieve selective chemical fragmentation of a polypeptide chain, these results indicate that FPLC with ionic exchangers can be usefully employed to isolate rather large protein fragments especially suitable for automatic sequence analysis with the sequenator.     

Epidemiological study on the assay of antibodies to anti-TORCH agents and to HBV in a group of mother/child pairs in Palermo

The TORCH group: toxoplasma, rubeola, cytomegalovirus (CMV), herpes virus hominis (HSV) and also the B-virus of hepatitis (HBV) determine congenital malformations in the newborns. For this reason, the Authors leaded an epidemiologic study testing with some antibodies (anti-TORCH and anti-HBV) the serum of groups of mother-newborn of the Obstetrical Clinic of Palermo. This study became manageable because now there are available high specific immunoenzymatic methods, for example ELISA, the passive haemoagglutination and the haemoagglutination-inhibition. In our people, high concentration of rubeola, HSV and CMV and very low concentration of toxoplasma and HBV are shown. The frequency of malformation is related with the subclinical infection. The Authors suggest to extend same investigation at an higher number of pregnant women to prevent these congenital malformations.     

The social context for harvestingIriartea deltoidea (Arecaceae)

Iriartea deltoidea grows abundantly from Nicaragua to Bolivia. The stem is harvested for construction, furniture making, and handicrafts. The objective of my study was to understand the potential for sustainable harvesting of this palm. Ethnographic fieldwork about market patterns and decision-making among harvesters revealed the nature of harvesting pressures near settled areas. The study also demonstrates methods for assessing social and economic influences on harvesting.     

Changes in plasma membrane glycoproteins during differentiation of an established myoblast cell line and a non-fusing α-amanitin-resistant mutant

The glycoproteins of purified plasma membranes from mononucleated myoblasts and from myotubes of the L₆ line were characterized according to their apparent molecular weight (MW) and to their ability to bind concanavalin A (conA). We identified 25 proteins in membranes from mononucleated myoblasts and fused myotubes which specifically bound the lectin. Comparison with the pattern of membrane glycoproteins of a non-fusing mutant allowed us to identify developmentally regulated changes in the accumulation of 8 proteins with an apparent MW of 160, 80, 60, 51.5, 43, 40, 38, and 27 Kilodalton (kD), and changes in the glycosylation of six others which migrate at 215, 150, 135, 90, 85, and 32 kD. Two of them (160 and 38 kD) appeared at fusion, whereas the 51.5 kD band could not be identified in plasma membrane from myotubes. As conA inhibits fusion of myoblasts, it is suggested that at least some of these proteins might be involved in this process.