Reactivity and Function of Carboxyl Groups in Bacterial and Fungal Proteinases (Subtilases): Relation to X−-Ray Models

Carboxyl groups in five proteinases from microorganisms, the bacterial mesentericopeptidase, subtilisin DY and subtilisin Carlsberg as well as the fungal proteinase K and thermitase were modified with glycinamide in the presence of water soluble carbodiimide. Computer graphic studies using crystallographic models of the investigated proteinases showed a reasonably good correlation between the chemical reactivity of the carboxyl groups on one side and the degree of their exposure to the solvent or participation in ionic interactions, on the other. Differences in the binding of a large protein substrate by proteinases from microorganisms belonging to two subgroups are discussed

Structural properties of Rapana thomasiana grosse hemocyanin: isolation, characterization and N-terminal aminoacid sequence of two different dissociation products.

1. The native Rapana thomasiana grosse hemocyanin is dissociated under mild conditions and fractionated into two dissociation products, RHSS1 and RHSS2, with an apparent molecular mass of almost-equal-to 250 and almost-equal-to 450 kDa, respectively. The two species are present in approximately equivalent amounts. SDS-PAGE analysis reveals that the latter component is a dimer of almost-equal-to 250 kDa polypeptide chains. 2. The amino acid compositions, as well as some spectroscopic properties of RHSS1, are very similar to those of RHSS2. After dissociation under mild conditions of the native hemocyanin both species preserve their capability of binding reversibly molecular oxygen. 3. RHSS1 and RHSS2 are sequenced directly from the amino-terminus for 15 and 20 steps, respectively. These parts of the two polypeptide chains are highly homologous but with microheterogeneity associated with some positions. They also exhibit high homology with the N-terminal region of subunits or functional domains of other gastropod Hcs

Report on the 5th International Meeting of the IUGS Lower Cretaceous Ammonite Working Group, the Kilian Group (Ankara, Turkey, 31st August 2013)

The 5th meeting of the IUGS Lower Cretaceous Ammonite Working Group (the Kilian Group) held in Ankara, Turkey, 31st August 2013, discussed the Mediterranean ammonite zonation, and its calibration with different ammonite zonal schemes of the Boreal, Austral and Central Atlantic realms. Concerning the standard zonation, that corresponds to the zonal scheme of the West Mediterranean province, some changes have been made on two stages. For the Valanginian, the Busnardoites campylotoxus Zone was abandoned; the upper part of the lower Valanginian is now characterised by the Neocomites neocomiensiformis and Karakaschiceras inostranzewi zones. For the upper Barremian, the former Imerites giraudi Zone is here subdivided into two zones, a lower I. giraudi Zone and an upper Martellites sarasini Zone. The I. giraudi Zone is now subdivided into the I. giraudi and Heteroceras emerici subzones, previously considered as horizons. The current M. sarasini and Pseudocrioceras waagenoides subzones correspond to the lower and upper parts of the M. sarasini Zone, respectively. The Anglesites puzosianum Horizon is kept. The Berriasian, Hauterivian, Aptian and Albian zonal schemes have been discussed but no change was made. The upper Hauterivian zonal scheme of the Georgian (Caucasus) region (East Mediterranean province) has been compared with the standard zonation. Discussions and some attempts at correlations are presented here between the standard zonation and the zonal schemes of differen