Evidence that both Ca2+-ATPase and (Ca2+ + Mg2+)-ATPase activities in the plasma membrane-rich fraction from bovine parotid gland reside on the same enzyme molecule

• 1.1. Evidence was obtained that activities of both low-affinity Ca²⁺-ATPase and high-affinity (Ca²⁺ + Mg²⁺)-ATPase in the plasma membrane-rich fraction from bovine parotid gland reside on the same enzyme.
• 2.2. Two solubilized ATPases were purified by four steps of HPLC; and both activities eluted at the same fractions from each column, and the specific activity ratio of the two enzymes at each step was constant.
• 3.3. By non-denaturing PAGE, the final preparation gave a single band for both protein staining and activity staining for the two ATPases; and the Ca²⁺-ATPase activity comigrated with that of (Ca²⁺ + Mg²⁺)-ATPase.
• 4.4. In SDS-PAGE, each activity staining for the ATPases also gave a single band, and both activities comigrated.
• 5.5. These findings suggest that Ca²⁺-ATPase and (Ca²⁺ + Mg²⁺)-ATPase are a single enzyme.

     

Glucosyl and galactosyl transferase activities of diabetic (db/db) and obese (ob/ob) mice kidneys

• 1.1. Glucosyl and galactosyl activities were determined in kidney cortex tissue prepared from two strains of mice, genetically diabetic and obese mice.
• 2.2. These activities were measured as a function of ageing between 6 weeks and 13 months.
• 3.3. For both strains glucosyl transferase activity was shown to increase with respect to ageing whereas galactosyl transferase activity decreased at the same time.
• 4.4. These changes of enzymatic activities would suggest that a smaller increase of hydroxylysine-linked glycans than expected was observed under these pathological conditions.

     

Carbonic anhydrase activity in blood of early sheep fetuses

• 1.1. The level of carbonic anhydrase activity in the red cells was measured in sheep fetuses at different times after conception: 39, 56, 77, 90 and 140 days, the last being close to full term. Measurements were also made on blood from four of the mothers.
• 2.2. There was a low level of the enzyme present in the 39 day fetuses (0.037 enzyme units (E.U.)/100 μg Hb) and its increase up to 90 days of gestation (0.19 E.U./100 μg Hb) had a form approximating exponential.
• 3.3. The earliest levels were only 11% of the full term levels and only 4% of the adult levels previously reported.
• 4.4. Even the earliest samples were of blood that was fetal rather than embryonic but these results are the earliest carbonic anhydrase activities reported in this mammal.

     

Alteration of the protein composition of bothrops jararaca venom and venom gland by isoproterenol treatment

• 1.1. The protein composition of Bothrops jararaca venom and venom gland was analyzed through SDS-PAGE, after isoproterenol (IPR) treatment.
• 2.2. Some proteins (47, 48, 57 and 72 kDa) were detected in the gland homogenate from the control but not from the IPR-treated samples.
• 3.3. Three proteins (26.5, 44.5 and 53 kDa) were detected in the venom gland from IPR-treated snakes but not from the venom gland from the control.
• 4.4. In the venom samples proteins of 41 and 74 kDa were detected only in the IPR treated samples, while proteins of 17 and 28 kDa were detected only in the control.
• 5.5. The biological activity of the venom did not change with IPR treatment.

     

Studies on sodium-potassium-activated adenosinetriphosphatase—XV the rectal gland of the elasmobranchs

• 1.1. The enzyme NaK activated adenosinetriphosphatase (NaK ATPase) was found in high activity in the rectal gland of nine elasmobranch species.
• 2.2. Species with a radial arrangement of tubules in the gland had higher activities per kg body weight than species with lobular division of the glandular parenchyma.
• 3.3. The properties of the NaK ATPase system suggest that it has a primary, rate-limiting role in the NaCl secretion by this gland.

     

Possible involvement of adenylylation in the modification of a 26 kDa protein in rat parotid acinar cells

• 1.1. Adenylylation, a posttranslational modification of proteins, was investigated in saponin-permeabilized acinar cells of the rat parotid gland.
• 2.2. When cells were incubated with [2,8-³H]ATP, several proteins, including a 26 kDa protein in the particulate fraction, were labeled.
• 3.3. Upon incubation of cells with [α-³²P]ATP in the presence of cAMP and 3-isobutyl-lmethylxanthine, ³²P-labeling of the 26 kDa protein was observed.
• 4.4. After treatment with snake venom phosphodiesterase, [³²P]AMP was released from the 26kDa protein. Such release was not observed when cells were labeled with [γ-³²P]ATP.
• 5.5. The ³²P-labeling pattern of proteins with [α-³²P]ATP was clearly different from that with [adenylate-³²P]NAD⁺.
• 6.6. The results suggest that the 26 kDa protein is one of the adenylylation substrates in rat parotid acinar cells.

     

Na+-K+ ATPase and carbonic anhydrase activities in larvae,postlarvae and adults of the shrimp Penaeus japonicus (Decapoda,Penaeidea)

• 1.1. Activities of Na⁺-K⁺ ATPase and carbonic anhydrase were measured through the early post-embryonic development of Penaeusjaponicus. In adults, only the Na⁺-K⁺ ATPase activity was measured.
• 2.2. ATPase activity was variable in the successive development stages. From zero in nauplii, the activity slightly increased in zoeae, and rose sharply in mysis stages 2 and 3.
• 3.3. A further significant increase in activity was noted at the transition from late mysis to early postlarvae, concomitant with a change from the larval osmoconforming pattern of osmoregulation to the postlarval and adult hyper-hyporegulating pattern.
• 4.4. The activity of Na⁺-K⁺ ATPase, measured in isolated cephalothorax, increased from PL3 to PL4 to its maximum value in PL5; at this stage, osmoregulatory capacity was fully efficient.
• 5.5. In young stages of P. japonicus, the variations in Na⁺-K⁺ ATPase activity appear correlated with the development of osmoregulatory ultrastructures, and with osmoregulation and salinity tolerance.
• 6.6. These results are discussed with regard to their ecological and physiological implications.
• 7.7. In adults, the activity of Na⁺-K⁺ ATPase was high in gills and epipodites and no activity was detected in branchiostegites. These results are related to the ultrastructure of these organs.
• 8.8. The activity of carbonic anhydrase did not change significantly in larval and postlarval stages.
• 9.9. From these results, it is proposed that the effector sites of osmoregulation are located in branchiostegites, pleurae and epipodites in postlarvae, and in epipodites and mainly in gills in adults.

     

Ontogeny of type I and type III deiodinase activities in embryonic and posthatch chicks: Relationship with changes in plasma triiodothyronine and growth hormone levels

• 1.1. The ontogeny of type I and type III deiodinase activities was studied in embryonic and posthatch chicks.
• 2.2. Hepatic type I activity showed a 3-fold increase up to the period of pipping and hatching and decreased slowly thereafter.
• 3.3. Hepatic type III activity increased by 3-fold from E14 to E17 and decreased more than 10-fold from E17 to CO. Posthatch levels were very low.
• 4.4. Type I activity in the kidney decreased slowly after hatching while type III activity was very low over the whole period studied.
• 5.5. Developmental changes during the late embryonic period suggest a causal relationship between the increase in plasma GH and T₃ levels and the decrease in hepatic type III activity.

     

Properties and distribution of Mg2+-HCO−3-ATPase in brush border membranes isolated from rat small intestine

• 1.1. The small intestine was cut into seven segments and properties and distribution of brush border Mg²⁺-HCO⁻₃-ATPase activity in each segment were examined.
• 2.2. The optimal Mg²⁺ concentration was 1.0 mM.
• 3.3. The optimal HCO⁻₃ concentration was 100 mM in the first (duodenal), 50 mM in the 3rd and 40 mM in the 5th segment, respectively.
• 4.4. The optimal pH value was about 9.0.
• 5.5. l-phenylalanine (above 1 mM) and SCN⁻ (above 50 mM) significantly inhibited both Mg²⁺- and Mg²⁺-HCO⁻₃-ATPase activity.
• 6.6. The enzyme activity was found to be highest in the duodenal segment and then gradually decreased in consecutive segments as well as β-glycerophosphatase, Na⁺-K⁺-ATPase and supernatant carbonic anhydrase.
• 7.7. The functional significance of this ATPase and the relationship with carbonic anhydrase was discussed.

     

Mixed function oxidase activity in the harbour seal (Phoca vitulina) from sable is., N.S.

• 1.1. One adult male, eight pups (including two full term foetuses) and nine adult female harbour seals (Phoca vitulina) were analysed for indices of mixed function oxidase (MFO) activity.
• 2.2. MFO activity was present in liver samples, but was at or below detection limits in samples of kidney, lung and pancreas.
• 3.3. Hepatic ethoxyresorufin O-de-ethylase and benzo[a]pyrene hydroxylase activities were similar to those reported in other seals and in other mammals.
• 4.4. Cytochromes P-450 and b₅ concentrations were slightly lower than those observed in other mammals.
• 5.5. MFO activities in newborn pups and foetuses were significantly lower than those in adult females.
• 6.6. No qualitative differences in cytochrome P-450 isozyme distribution between foetal and adult samples could be discerned by electrophoresis.

     

Phosphatase activity in the hepatopancreas of Helix aspersa

• 1.1. Phosphatase acid (PhA) activity in the digestive gland (hepatopancreas) of the common garden snail Helix aspersa has been investigated using cytochemical methods.
• 2.2. All the cells composing this gland show PhA activity, the distribution pattern differing according to the cell type.
• 3.3. The digestive cells show the most widely distributed reaction product (brush border, phagolysosomes, multivesicular bodies and autophagic vacuoles).
• 4.4. In the excretory cells this activity appears in large sacs, while in the calcium cells the reaction product is abundant in the calcium granules.
• 5.5. Cellular digestion processes performed by each of these cell types is discussed together with their role in the detoxification of heavy elements derived from the environment.

     

Acid hydrolase activity in tissues of mice after physical stress

• 1.1. The activities of β-glucuronidase and cathepsin D and the protein concentration were assayed from brain, kidney, liver, cardiac muscle and skeletal muscle (m. rectus femoris) samples from mice (Mus musculus) 1, 3, and 6 days after intermittent exhaustive (duration 100–145min) and submaximal prolonged (duration 9 hr) running on treadmill.
• 2.2. The activity of β-glucuronidase in skeletal muscle strongly increased being the highest 3 days after both exertions. Cathepsin D activity also slightly increased. In cardiac muscle β-glucuronidase activity was unaffected. Cathepsin D activity slightly increased 3 days after intermittent exhaustive exercise.
• 3.3. The specific activities of β-glucuronidase and cathepsin D in the liver increased 1 day after the both exertions. Simultaneously the protein concentration decreased. In the kidney β-glucuronidase activity and protein concentration were unaffected but cathepsin D activity decreased 1 day after intermittent exhaustive exercise.
• 4.4. In the brain protein concentration transiently decreased 3 days after the exertions. β-Glucuronidase activity transiently decreased 1 day after intermittent exercise thereafter increasing 6 days afterwards above the control level. Cathepsin D activity decreased 1 day after intermittent exercise but was unaffected after prolonged submaximal exercise.
• 5.5. Physical stress affected to varying extent the acid hydrolase activities in all organs studied.

     

The UDP-galactose 4-epimerase of the albumen gland of Lymnaea stagnalis and the effects of photoperiod,starvation and trematode infection of its activity

• 1.1. Kinetic aspects of the enzyme UDP-galactose 4-epimerase in crude homogenates of the albumen gland of the snail Lymnae stagnalis were estimated. The mean values of the Km for UDP-galactose and for NAD are 0.343 and 0.097 mM, respectively. The enzyme is inhibited by NADH. It is inactivated by freezing and raised temperature (25°C), but it can be reactivated by NAD.
• 2.2. In the albumen gland the epimerase activity is 10–100 times higher than in other tissues, reflecting the high turnover of glucose to galactose, essential for the synthesis of galactogen in this organ.
• 3.3. In fed snails long day conditions stimulates albumen gland epimerase activity, coinciding with high egg production.
• 4.4. In starved snails a fairly high residual activity of the enzyme is maintained, irrespective of photoperiod or egg production.
• 5.5. Trematode infection leads to a considerable reduction of the epimerase activity.
• 6.6. The results indicate that the epimerase activity in fed snails, when the gland shows a regular release, reflects long-term adaptations (photoperiod). In starved and parasitized snails, when no regular release or product occurs, a basic epimerase activity is maintained. This might be important for a rapid restoration of egg production after the termination of adverse conditions.

     

The effect of initiated involution on enzyme activity and substrate uptake by the mammary gland of the lactating rabbit

• 1.1. Arteriovenous difference studies across the lactating rabbit mammary gland for glucose, acetate, triacylglycerol and non-esterified fatty acids during initiated involution are reported.
• 2.2. A significant reduction in substrate utilisation is paralleled by a decrease in the activities of fatty acid synthetase, acetyl CoA synthetase, citrate synthase and glutamate dehydrogenase in biopsy samples taken from the gland.
• 3.3. Results from the analysis of lipid fractions within the gland during this period are discussed in relation to lipid resorption.

     

Evidence for two isoforms of carbonic anhydrase II in the leech (Hirudo medicinalis) central nervous system

• 1.1. We dissected, homogenized and prepared ganglia and connectives from the central nervous system of medicinal leeches for SDS gel electrophoresis. The isolated proteins were transferred to nitrocellulose and incubated with affinity column-purified antibodies.
• 2.2. The immunoblots showed a strong positive reaction of a bovine carbonic anhydrase standard at a molecular weight of 29 kDa, and a distinct double-bond at the same molecular weight in the analyzed material.
• 3.3. We demonstrated with rat antibodies that carbonic anhydrase II is detectable in the leech central nervous system as the main isoenzyme.
• 4.4. The biochemical knowledge of carbonic anhydrase reported here agrees well with the immunocytochemical locations, thus affirming the validity of specific staining.

     

Sheep haemoglobin i or β b13(a10)gly → ser: an example of a cpg mutation in vertebrates. Characterization using fab-mass spectrometry and amino acid sequencing

• 1.1. The amino acid substitution which characterizes the haemoglobin I variant from sheep has been ascertained using a combination of Fast Atom Bombardment mass spectrometry and protein sequencing.
• 2.2. A Ser for Gly substitution at position 13 (10 of the A helix) was found in a polypeptide with the overall sequence of the β^B globin.
• 3.3. On the basis of the nucleotide sequence of the β^B-globin gene, a C to T transition occurring on a CpG doublet is considered to be responsible for the amino acid substitution.
• 4.4. This represents the first observation of a variant sheep Hb due to a mutation which is rather common in the human genome.
• 5.5. Amongst ruminants, serine is normally present at position 13 of goat and sheep ε¹¹ and γ chains and of bovine γ chain which had an independent and more ancient evolutionary origin than the β chains.

     

In-depth Proteome of the Hypopharyngeal Glands of Honeybee Workers Reveals Highly Activated Protein and Energy Metabolism in Priming the Secretion of Royal Jelly

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Highlights

• •In-depth proteome underpins the gland ontogeny and age-specific activity of the HGs.
• •The well-developed acini in the HGs of NBs promote the RJ secretary activities.
• •The enhanced protein and energy metabolism in the HGs boost the stronger RJ secretion of RJBs.

     

Thiosulphate sulphurtransferase (rhodanese) in cephalopoda

• 1.1. The distribution of rhodanese activity in the homogenate and hyaloplasm obtained from gills, digestive gland and kidney of four cephalopods has been studied.
• 2.2. The enzyme activity, which seems to be ubiquitous, is much higher in the octopods (Octopus vulgaris Lam. and Eledone moschata Leach) than in decapods (Loligo vulgaris Lam. and Sepia officinalis L.).
• 3.3. Though no specific study of the subcellular distribution has been made, results seem to indicate that rhodanese activity is, at least partially, hyaloplasmatic.

     

Effect of hibernation on liver and kidney metabolism in 13-lined ground squirrels

• 1.1. Metabolic rates and adenine nucleotide content of liver and kidney from hibernating ground squirrels were measured and compared to rats to study the biochemical adaptation to hibernation.
• 2.2. High rates of renal and hepatic gluconeogenesis were observed in squirrels, particularly from propionate and glycerol compared to rat.
• 3.3. During hibernation and starvation soluble phosphoenolpyruvate carboxykinase activity was increased in both liver and kidney.
• 4.4. Although metabolic rates are decreased during hibernation the results suggest that the enzymic complement is maintained at high activity even during torpor.