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A 60-year-old female was hospitalized because of anemia, edema, and diarrhea. She was diagnosed as having short bowel syndrome. The patient developed acrodermatitis enteropathica and taste impairment. Laboratory data showed that the serum zinc level was 21 μ g/dl and erythrocyte CAI specific activity was 0 units/mg isozyme (normal range 0.37 ± 0.08 units/mg isozyme) and CAII specific activity was 2.99 units/mg isozyme (normal range 3.02 ± 0.05 units/mg isozyme). The patient was diagnosed as being in a zinc deficient status. Zinc supplementation resulted in the disappearance of these complications. The serum zinc level reached 50 μ g/dl and erythrocyte CAI specific activity was recovered to 0.26 units/mg isozyme and CAII specific activity was 1.60 units/mg isozyme. CAI is found in gastrointestinal epithelial cells, in vascular epithelium, corneal, lens, ciliary body epithelium, and in sweat glands. CAII is found in virtually all tissues and is especially abundant in secretory and absorbing epithelia. The tissue distribution of CAI corresponds to clinical and physiologic indicators of zinc deficiency. Thus, the erythrocyte CAI specific activity may reflect the actual tissue zinc deficiency status.

The preparation and assessment of carbonic anhydrase and paraoxonase enzyme inhibition properties of 3-(2-(5-amino-4-(4-bromophenyl)-3-methyl-1H-pyrazol-1-yl)ethoxy)phthalonitrile (2) and its nitrogen-containing non-peripheral phthalocyanine derivatives (3 and 4) are reported for the first time. The new phthalonitrile and its phthalocyanine derivatives have been elucidated by FT-IR spectroscopy, ¹H-NMR, ${}^{13}$C-NMR, mass and UV-vis spectroscopy. The results demonstrated that all synthesized compounds moderately inhibited carbonic anhydrase and paraoxonase enzymes. Among the compounds, the most active ones were found to be compound 4 for PON (Ki : 0.14 $\mu$M), compound 3 for hCA I (Ki : 22.52 $\mu$M) and compound 1 for hCA II (Ki : 13.62 $\mu$M).

We report a novel method to simultaneously extract superoxide dismutase (SOD), catalase (CAT) and carbonic anhydrase (CA) from the same sample of red blood cells (RBCs). This avoids the need to use expensive commercial enzymes, thus allowing this to be cost effective for large-scale production of a nanobiotechnological polyHb-SOD-CAT-CA with enhancements to all three RBC functions. The best concentration of phosphate buffer for ethanol-chloroform treatment results in good recovery of CAT, SOD and CA after extraction. Different concentrations of the enzymes can be used to enhance the activity of polyHb-SOD-CAT-CA to 2, 4 or 6 times that of RBCs.

Polyhemoglobin-superoxide dismutase-catalase-carbonic anhydrase (poly-[Hb-SOD-CAT-CA]) contains all three major functions of red blood cells (RBCs) at an enhanced level. It transports oxygen, removes oxygen radicals and transports carbon dioxide. Our previous studies in a 90-minute 30 mm Hg MAP-sustained hemorrhagic shock rat model showed that it was more effective than blood in the lowering of elevated intracellular PCO₂, recovery of ST-elevation and histology of the heart and intestine. This paper analyzes the storage and temperature stability. The allowable storage time for RBCs is about 1 day at room temperature and 42 days at 4°C. Also, RBCs cannot be pasteurized to remove infective agents like HIV and Ebola. PolyHb can be heat sterilized and can be stored for a year even at room temperature. However, poly-[Hb-SOD-CAT-CA] contains both Hb and enzymes, and enzymes are particularly sensitive to storage and heat. We thus carried out studies to analyze its storage stability at different temperatures and heat pasteurization stability. The results of the storage stability show that lyophillization extends the storage time to a year at 4°C and 40 days at room temperature (compared to 42 days and 1 day, respectively, for RBCs). After the freeze-dry process, the enzyme activities of poly-[SFHb-SOD-CAT-CA] was 100 ± 2% for CA, 100 ± 2% for SOD, and 93 ± 3.5% for CAT. After heat pasteurization at 70°C for 2 hours, lyophilized poly-[Hb-SOD-CAT-CA] retained good enzyme activities of CA (97 ± 4%), SOD (100 ± 2.5%) and CAT (63.8 ± 4%). More CAT can be added during the crosslinking process to maintain the same enzyme ratio after heat pasteurization. Heat pasteurization is possible only for the lyophilized form of poly-[Hb-SOD-CAT-CA] and not for the solution. It can be easily reconstituted by dissolving it in suitable solutions that continue to have good storage stability (though less than that for the lyophilized form). According to the P50 value, poly-[SFHb-SOD-CAT-CA] retains its oxygen-carrying ability before and after long-term storage.

C₃ plants lose a significant part of previously fixed CO₂ in the process of photorespiration. Reduction in photorespiration is expected to increase the productivity of crop plants and reduce the requirements for irrigation and fertilization. For more than ten years, research at our institute has focused on the genetic engineering of dicotyledonous crop plants toward improved CO₂ fixation. In this paper, we summarize results form our work vis-à-vis reports from other laboratories and define future challenges. Furthermore, we introduce an alternative approach based on the installation of a bypass of photorespiration in the chloroplast.

Plans to make a C₄ rice plant date back to a document in 1987 and the first patent application for C₄ rice submitted in 1991. In addition, an attempt to make a C₄ rice plant was made in collaboration with Japan Tobacco Inc. during the 1990s. This collaboration recognized the importance of two compartments in C₄ photosynthesis, normally provided by mesophyll and bundle sheath cells. However, a single-cell system was devised in which the endogenous compartments of the cytosol and the chloroplast of C₃ plants were used to mimic the two C₄ compartments. Phosphoenolpyruvate carboxykinase (PEPCK) was used as the C₄ acid decarboxylating enzyme and was synthesized with a transit peptide to ensure location in the chloroplasts. The PEPCK gene from Urochloa panicoides was transferred to rice and was expressed successfully: carbon flow was altered toward a C₄ pathway but without appreciable increases in photosynthesis or growth. The properties and location of enzymes postulated to be required to convert a C₃ plant to a C₄ plant (carbonic anhydrase, phosphorenolpyruvate carboxylase, PEPCK, and pyruvate, orthophosphate dikinase) are reviewed. Further modifications to maximize the efficiency of a C₄ pathway in C₃ plants are discussed.

The 10,000 or more species of diatoms are microscopic photosynthetic organisms of the class Bacillariophyceae in the phylum Heterokontophyta. They are dominant primary producers in marine and inland water habitats, and may account for up to 20% of global primary productivity. The core carboxylation enzyme in their photosynthesis is Form ID Rubisco (ribulose bisphosphate carboxylase–oxygenase), which, if it replaced rice Form IB Rubisco on a molecule-for-molecule basis, would give slightly lower rates of photosynthesis at extant CO₂ concentrations. These kinetic characteristics, along with the low conductance for CO₂ of aqueous boundary layers, rationalize the occurrence of CCMs (inorganic carbon-concentrating mechanisms) in all diatoms investigated. It was assumed that these mechanisms, which increase the CO₂ concentration around Rubisco, were all based on active transport of CO₂, HCO₃^- or H⁺ across membranes. It now appears, from recent extensions of earlier work, that there is a C₄-like photosynthetic carbon metabolism in certain diatoms. However, more work is needed to determine the extent to which diatoms have photosynthesis analogous to that of single-cell C₄ higher plants. The relevance of this work to producing C₄ rice probably comes more from concepts than from the direct introduction of diatom genes in rice. One such concept is the possibility that C₄-like photosynthesis in diatoms involves no carbonic anhydrases (CAs), and so needs less Zn. However, this requires HCO₃^- entry, so decreased Zn costs of growth may be less readily achieved in rice unless phosphorenolpyruvate carboxykinase (using CO₂) replaces phosphoenolpyruvate carboxylase (using HCO₃^-) as the C₄ carboxylase.