Enzymes of glucose and methanol metabolism in the actinomycete Amycolatopsis methanolica.

The actinomycete Amycolatopsis methanolica was found to employ the normal bacterial set of glycolytic and pentose phosphate pathway enzymes, except for the presence of a PPi-dependent phosphofructokinase (PPi-PFK) and a 3-phosphoglycerate mutase that is stimulated by 2,3-bisphosphoglycerate. Screening of a number of actinomycetes revealed PPi-PFK activity only in members of the family Pseudonocardiaceae. The A. methanolica PPi-PFK and 3-phosphoglycerate mutase enzymes were purified to homogeneity. PPi-PFK appeared to be insensitive to the typical effectors of ATP-dependent PFK enzymes. Nevertheless, strong N-terminal amino acid sequence homology was found with ATP-PFK enzymes from other bacteria. The A. methanolica pyruvate kinase was purified over 250-fold and characterized as an allosteric enzyme, sensitive to inhibition by P(i) and ATP but stimulated by AMP. By using mutants, evidence was obtained for the presence of transketolase isoenzymes functioning in the pentose phosphate pathway and ribulose monophosphate cycle during growth on glucose and methanol, respectively.     

Histoplasma capsulatum peritonitis associated with continuous ambulatory peritoneal dialysis

This paper reports a case of infection byHistoplasma capsulatum apparently restricted to the peritoneum in a woman submitted to continuous ambulatory peritoneal dialysis. Diagnosis was established by culture of dialysis fluid and peritoneal nodule and by histopathologic examination.     

Phylogenetic diversification of immunoglobulin genes and the antibody repertoire

Immunoglobulins are encoded by a large multigene system that undergoes somatic rearrangement and additional genetic change during the development of immunoglobulin-producing cells. Inducible antibody and antibody-like responses are found in all vertebrates. However, immunoglobulin possessing disulfide-bonded heavy and light chains and domain-type organization has been described only in representatives of the jawed vertebrates. High degrees of nucleotide and predicted amino acid sequence identity are evident when the segmental elements that constitute the immunoglobulin gene loci in phylogenetically divergent vertebrates are compared. However, the organization of gene loci and the manner in which the independent elements recombine (and diversify) vary markedly among different taxa. One striking pattern of gene organization is the "cluster type" that appears to be restricted to the chondrichthyes (cartilaginous fishes) and limits segmental rearrangement to closely linked elements. This type of gene organization is associated with both heavy- and light-chain gene loci. In some cases, the clusters are "joined" or "partially joined" in the germ line, in effect predetermining or partially predetermining, respectively, the encoded specificities (the assumption being that these are expressed) of the individual loci. By relating the sequences of transcribed gene products to their respective germ-line genes, it is evident that, in some cases, joined-type genes are expressed. This raises a question about the existence and/or nature of allelic exclusion in these species. The extensive variation in gene organization found throughout the vertebrate species may relate directly to the role of intersegmental (V<==>D<==>J) distances in the commitment of the individual antibody-producing cell to a particular genetic specificity. Thus, the evolution of this locus, perhaps more so than that of others, may reflect the interrelationships between genetic organization and function.      

Identifying Mozambique's most critical areas for plant conservation: An evaluation of protected areas and Important Plant Areas

Successful protected area networks must represent biodiversity across taxonomic groups. However, too often plant species are overlooked in conservation planning, and the resulting protected areas may, as a result, fail to encompass the most important sites for plant diversity. The Mozambique Tropical Important Plant Areas project sought to promote the conservation of Mozambique's flora through the identification of Important Plant Areas (IPAs). Here, we use the Weighted Endemism including Global Endangerment (WEGE) index to identify the richest areas for rare and endemic plants in Mozambique and subsequently evaluate how well represented these hotspots are within the current protected area and IPA networks. We also examine the congruence between IPA and protected areas to identify opportunities for strengthening the conservation of plants in Mozambique. We found that high WEGE scores, representing areas rich in endemic/near-endemic and threatened species, predict the presence of IPAs in Mozambique, but do not predict the presence of protected areas. We also find that there is limited overlap between IPAs and protected areas in Mozambique. We demonstrate how IPAs could be an important tool for ensuring priority sites for plant diversity are included within protected area network expansions, particularly following the adoption of the “30 by 30” target agreed within the post-2020 Convention on Biological Diversity framework, with great potential for this method to be replicated elsewhere in the global tropics.     

Diversity and evolution of leaflet anatomical characters in the Pterocarpus clade (Fabaceae: Papilionoideae)

Journal of Plant Research - The Pterocarpus clade includes 23 genera previously attributed to different Fabaceae tribes. The recent rearrangements of many genera in the clade do not recognize...     

Structural and biological roles of glycosylations in pulmonary angiotensin I-converting enzyme

We enzymatically deglycosylated pig lung angiotensin I-convertingenzyme (ACE) to study the involvement of its glycanic chainsin its physicochemical and catalytic properties. The effectsof endoglycosidases F₂ and H, and of N-glycanase were assessedby ACE mobility in SDS-PAGE. N-Glycanase only was completelyeffective with or without previous denaturation, leading toa shift in ACE M_r from 172 to 135 kDa; endoglycosidase F₂ producedthe same shift but only without previous denaturation. DeglycosylatedACE had the same kcat as native ACE for the substrate hippuryl-histidyl-leucine,and an identical Stokes radius as measured by size-exclusionhigh performance liquid chromatography. Neuraminidase had noeffect on ACE Stokes radius but slightly decreased its kcatwhich could be related to variations in ionization of the activesite. The isoelectric point of ACE, as, determined by isoelectricfocusing, increased from 4.5–4.8 to 5.0–5.3 aftereither endoglycosidase F₂ or neuraminidase digestion, but stillwith microheterogeneities which thus did not seem to be relatedto ACE glycans. Deglycosylated ACE did not bind onto agaroselectinsin contrast to native ACE which bound strongly to concanavalinA showing interactions involving oligomannosidic or biantennaryand sialylated N-acetyl-lactosaminic isoglycans. Finally, tunicamycin,an inhibitor of N-glycosylation, did not modify ACE secretionby endothelial cells. Thus, ACE glycans have no drastic effectson structural and biological properties of the protein, butthey may have a functional role on intracellular targeting ofboth secreted and membrane-bound ACE isoforms, also for theprotection of the soluble plasma form against hepatic lectinsand the maintenance of its hydrosolubility. converting enzyme (peptidyldipeptidase EC.3.4.15.1) endothelium glycosidases lectins     

Cutaneous zygomycosis caused byAbsidia corymbifera in a leukemic patient

A case of cutaneous zygomycosis caused byAbsidia coryabifera in a leukemic patient submitted to chemotherapy is reported. The lesion was located on the little finger of the right hand and probably resulted from a latent osteomyelitis. It progressed to form extensive necrotic area. No systemic infection was detected and the lesion did not appear to be associated with any trauma.     

Effects of Controlled Atmospheres on Production of Sesquiterpenoid Stress Metabolites by White Potato Tuber: Possible Involvement of Cyanide-resistant Respiration

Levels of katahdinone (solavetivone), lubimin, rishitin, and phytuberin, sesquiterpenoid stress metabolites of white potato (Solanum tuberosum), were monitored in tuber slices which were challenged with an extract of Phytophthora infestans and incubated under controlled atmospheres. A mixture of ethylene in air enhanced stress metabolite production. This enhancement was amplified by higher partial pressures of oxygen. Stress metabolite production was inhibited by salicylhydroxamic acid. These results suggest the involvement of cyanide-resistant respiration in the production of potato stress metabolites, compounds which may serve as phytoalexins.