Crystals of TELSAM–target protein fusions that exhibit minimal crystal contacts and lack direct inter-TELSAM contacts

While conducting pilot studies into the usefulness of fusion to TELSAM polymers as a potential protein crystallization strategy, we observed novel properties in crystals of two TELSAM–target protein fusions, as follows. (i) A TELSAM–target protein fusion can crystallize more rapidly and with greater propensity than the same target protein alone. (ii) TELSAM–target protein fusions can be crystallized at low protein concentrations. This unprecedented observation suggests a route to crystallize proteins that can only be produced in microgram amounts. (iii) The TELSAM polymers themselves need not directly contact one another in the crystal lattice in order to form well-diffracting crystals. This novel observation is important because it suggests that TELSAM may be able to crystallize target proteins too large to allow direct inter-polymer contacts. (iv) Flexible TELSAM–target protein linkers can allow target proteins to find productive binding modes against the TELSAM polymer. (v) TELSAM polymers can adjust their helical rise to allow fused target proteins to make productive crystal contacts. (vi). Fusion to TELSAM polymers can stabilize weak inter-target protein crystal contacts. We report features of these TELSAM–target protein crystal structures and outline future work needed to validate TELSAM as a crystallization chaperone and determine best practices for its use.     

Interactions of 17beta-estradiol and L-norepinephrine on the rat uterus.

Norepinephrine increased the in vitro uptake of 3H-estradiol by the uterus of spayed rats. This effect was observed at 15 and 30 min but not at 90 min. Norepinephrine also increased the binding of 3H-estradiol by the nuclear (p less than 0.02) and the cytosol fractions (p less than 0.01) when incubated with uterine homogenates, suggesting that norepinephrine does not require the presence of the intact tissue to exert its effects. The in vivo uptake of 3H-estradiol and the determination of the number of binding sites were performed in the uterus of rats treated with estradiol and estradiol plus norepinephrine. Norepinephrine alone increased the uptake of 3H-estradiol and the number of binding sites. The highest increment in both parameters was observed in the uterus of rats treated with estradiol plus norepinephrine. The estradiol Ka of the rat uterus cytosol treated with estradiol alone or plus norepinephrine was higher than that observed in the group without estradiol, suggesting the presence of different proteins that bind estradiol. These results indicate that norepinephrine increases the entrance of estradiol into the rat uterus both in vitro and in vivo.     

Vocal Repertoire of Captive Capybara (Hydrochoerus hydrochaeris): Structure,Context and Function

In this work we describe the structure, behavioral context and functionality of the vocal repertoire of capybaras, a social Caviomorph rodent. Additionally, since territoriality is present in this species, we hypothesize the occurrence of vocal differences among social groups. We analyzed a total of 2069 calls emitted by 28 animals from three different social groups. The capybara’s repertoire is comprised by seven call types (whistle, cry, whine, squeal, bark, click and tooth‐chattering). The vocalizations were functionally categorized as contact, alarm, distress and agonistic calls considering their behavioral contexts. The click calls emitted by the adults of the three captive capybara groups were significantly different, confirming our hypothesis of social groups’ vocal differences. The richness of interactions mediated by vocalization in capybaras suggests that the species’ communication is an important mechanism to regulate social encounters and to alert members of the group about environmental cues.     

Two-step sedimentation process for selection of microcapsules containing cell aggregates

Microencapsulation technologies are being developed to protect transplanted islets from immune rejection, to reduce or even eliminate the need for immunosuppression. However, unencapsulated cells increase the chances of rejection and empty beads increase transplant volumes. Thus, separation processes were investigated to remove these byproducts based on density differences. The densities of islet-sized mouse insulinoma 6 (MIN6) cell aggregates and acellular 5% alginate beads generated via emulsification and internal gelation were ~ 1.065 and 1.042 g/ml, respectively. The separation of empty beads from those containing aggregates was performed by sedimentation under unit gravity in continuous gradients of polysucrose and sodium diatrizoate with density ranges of 1.032–1.045, 1.035–1.044, or 1.039–1.042 g/ml. The 1.039–1.042 g/ml gradient enabled recoveries of ~ 80% of the aggregate-containing beads while the other gradients recovered only ~ 60%. The bottom fraction of the 1.039–1.042 g/ml gradient contained beads with ~ 6% of their volume occupied by cell aggregates. Separation of unencapsulated aggregates from the aggregate-containing beads was then achieved by centrifugation of this purified fraction in a 1.055 g/ml density solution. Thus, these sedimentation-based approaches can effectively remove the byproducts of cell encapsulation.     

Effects of Selective Vegetation Thinning on Seed Removal in Secondary Forest Succession1

Seed removal was assessed for two tree species in three forest types: (1) secondary forest with and (2) without selective vegetation thinning, and (3) mature forest. Selective vegetation thinning meant the removal of all stems ≤3 cm in diameter of secondary‐forest species and was intended as a management technique to accelerate succession toward mature forest. Thinning did not have an effect on seed removal. One of the species showed lower seed removal in mature forest compared to secondary forest.     

Prevention of implantation by [D-Trp6-LH-RH in the rat: comparative study with the effects of large doses of HCG on pregnancy.

Effect of large doses of [D-Trp6]-LH-RH and HCG on implantation of fertilized ova was examined in the rat. Subcutaneous administration of 6ug[D-Trp6]-LH-RH per day from days 1 to 5 of pregnancy by an implanted minipump completely prevented the implantation of fertilized ova associated with a dramatic reduction of plasma progesterone on days 4 and 8, with a slight reduction of estradiol on day 4. There was no balooning of the uterus in the exploratory laparatomy on days 8 and 14. Administration of 1000 U of HCG daily from days 1 to 5 partially prevented implantation and completely terminated gestation. However, plasma progesterone and estradiol levels did not differ from those in the control animals. Ovaries in the [D-Trp6]-LH-RH treated rats appeared to be the same in size as those of the control pregnant rats, whereas the ovaries of the HCG-treated rats were hypertrophied. The results suggest that [D-Trp6]-LH-RH prevents nidation through a mechanism different from that for the adverse effect of excess of HCG on pregnancy.     

Proteome analysis of resting human neutrophils

Neutrophils constitute the first line of host defense against pathogens. In the present study 2-D gel electrophoresis-mass spectrometry technology was employed to analyze the human resting neutrophils proteome. One hundred and two conserved spots were subjected to peptide mass fingerprinting, yielding 22 identifications. Among the identified proteins, nine are related to the inflammatory process, two polypeptides are assigned to metabolic functions and five are classified as structural.