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PubMed1995

Differential regulation of counterregulatory hormone secretion and symptoms during hypoglycemia in IDDM. Effect of glycemic control.

OBJECTIVE: To determine 1) if there was a differential effect of glycemic control on individual counterregulatory hormone responses to hypoglycemia in patients with insulin-dependent diabetes mellitus (IDDM), 2) whether these modifications affect hypoglycemic symptom perception, and 3) if there was a level of glycemic control below which counterregulatory and symptomatic responses to hypoglycemia become consistently altered. RESEARCH DESIGN AND METHODS: We performed hypoglycemic clamp studies on 38 patients with IDDM and 38 healthy control subjects. Glucose was lowered from 5.0 to 2.2 mmol/l over 3 h in decrements of 0.6 mmol/l each 30 min. Epinephrine, cortisol, growth hormone (GH), glucagon, and symptom score were measured at each glucose plateau. RESULTS: In IDDM patients, HbA1 levels were positively correlated with incremental epinephrine (r = 0.58, P < 0.001) and cortisol (r = 0.52, P < 0.01) responses, but inversely correlated with GH responses (r = -0.31, P < 0.05). The increase in symptom score correlated with the epinephrine response in the IDDM patients (r = 0.57, P < 0.001), but not in the healthy control subjects (r = -0.02, NS). In IDDM patients with HbA1 < or = 7.8% (n = 7), the epinephrine, cortisol, and symptomatic responses to hypoglycemia were blunted, but GH secretion was preserved. CONCLUSIONS: These data suggest that 1) there is differential regulation of counterregulatory hormone secretion that is dependent on the level of glycemic control, 2) epinephrine is an important determinant of symptom perception in IDDM patients, but not in healthy control subjects, and 3) multiple defects in counterregulatory hormone secretion and symptom perception are consistently observed in patients with HbA1 levels < or = 7.8%.

Adult↗
PubMed2003

Enhanced secretion of heterologous cyclodextrin glycosyltransferase by a mutant of Bacillus licheniformis defective in the D-alanylation of teichoic acids.

AIMS: To examine whether inactivation of the dlt operon and increased charge density of the wall enhances secretion of heterologous proteins in industrial strains of Bacillus licheniformis. METHODS AND RESULTS: The dltA gene of B. licheniformis was cloned, sequenced and mutated by inserting a chloramphenicol acetyl transferase (cat) gene cassette. The mutation facilitated growth in the late exponential growth phase, increased endogenous autolysis and decreased resistance to a cationic peptide, polylysine. It was observed that dltA mutation increased the production of cyclodextrin glycosyltransferase (CGTase) by 1.5- to sevenfold depending on the growth phase, but decreased the production of penicillinase by twofold. CONCLUSIONS AND SIGNIFICANCE: The results suggest that the d-alanylation of teichoic acids is an element that can be used to improve the production of some secretory proteins in industrial applications based on this important industrial microorganism.

Alanine↗
PubMed1976

A chromosomal gene required for killer plasmid expression, mating, and spore maturation in Saccharomyces cerevisiae.

"Killer" strains of Saccharomyces cerevisiae are those that harbor a double-stranded RNA plasmid and secrete a toxin that kills only strains not carrying this plasmid (sensitives). Two chromosomal genes (kex1 and kex2) are required for the secretion of toxin by plasmid-carrying strains. The kex2 gene, which maps at a site distinct from the mating-type locus, is also required for normal mating by alpha strains and meiotic sporulation in all strains. Strains that are alpha mating-type and kex2 fail to secrete the pheromone alpha-factor or to respond to the alpha-factor II pheromone which causes a morphological change, but they do respond to alpha-factor I which causes G1 arrest in alpha cells. Strains that are alpha mating-type and kex2 show no defect in mating; pheromone secretion, or response to alpha-factor. Diploids that are homozygous for the kex2 mutation, unlike wildtype or heterozygous diploids, fail to undergo sporulation, with the defect occurring in the final spore maturation stage. These same defects in the sexual cycle are present in all kex2 mutants independent of the presence of the "killer" plasmid.

Animals↗
PubMed2001

Gastric secretion in cystic fibrosis in relation to the migrating motor complex.

BACKGROUND: Patients with cystic fibrosis (CF) have been claimed to have defect intestinal motility and gastric acid secretion. The aim of this work was to study the interdigestive motility and the motility-related secretions in the upper gastrointestinal tract in patients with CF compared to healthy controls. METHODS: Concomitant gastroduodenal manometry combined with intragastric perfusion was performed in 12 healthy volunteers and 10 patients with CF. RESULTS: Eight CF patients showed a normal migrating motor complex. Motility-related gastric secretion of acid and bicarbonate was evaluated in six patients and did not differ from healthy subjects. Gastric net fluid secretion was significantly decreased in the CF patients and bilirubin reflux was significantly increased. The CF patients with pancreatic insufficiency lacked motility-related variations in plasma levels of motilin and pancreatic peptide. CONCLUSIONS: No defect in fasting motility or gastric secretion of acid or bicarbonate could be seen in well-nourished adult CF patients. The main finding was a significantly lower net fluid secretion and higher bilirubin reflux compared to healthy subjects. Indications of a genetic relationship could be seen.

Adult↗
PubMed1990

Insulin resistance in type II diabetes mellitus.

In vivo studies indicate that patients with NIDDM have defects in both insulin secretion and insulin action. The decrease in insulin action is due to both hepatic and extrahepatic insulin resistance. The impairment in glucose uptake is associated with alterations in both oxidative and nonoxidative disposal. Defective glucose transport may limit both of these processes. NIDDM also is associated with increased concentrations and rates of oxidation of plasma free fatty acids. Insulin resistance appears to be familial and in at least some individuals antedates glucose intolerance. In vitro studies indicate that insulin resistance can involve a variety of insulin sensitive tissues including adipocytes, muscle and liver. While most studies note that insulin binding and insulin receptor kinase activity are decreased in insulin sensitive tissues in obese patients with NIDDM, further delineation of the contribution of obesity and diabetes is required. Alterations in glucose transporter number and function likely account at least in part for impaired glucose transport. The cause of the alterations in other insulin responsive pathways and the role of an abnormal metabolic milieu versus intrinsic cellular defects remain to be established.

Adipose Tissue↗
PubMed1984

The role of B cell differentiation factors and specific T cell help in the pathogenesis of primary hypogammaglobulinemia.

We have examined the function of T and B cells from patients with late onset primary acquired hypogammaglobulinemia (PHG). T cells from these patients give effective help to normal B cells for antigen-dependent antibody synthesis. PHG mononuclear cells also synthesize normal quantities of B cell differentiation factors, which enhance IgG, IgM and antigen-dependent antibody synthesis by normal lymphocytes. While patient T cells appear to behave appropriately, the responsiveness of patient B cells is abnormal. Although they respond to differentiation factors with increased synthesis of IgM, overall levels are 10-50-fold lower than normal B cells, and they produce little or no IgG. This pattern of response is not altered if normal T cells are the source of help. The poor response of the B cell appears to represent immaturity rather than an inherent defect, as IgG-secreting clones can be obtained after Epstein-Barr virus transformation of lymphocytes from certain patients, and some of these clones respond to differentiation factors with increased IgG production. The lack of any functional defect in the T population, and the apparent immaturity rather than abnormality of the B cells, may implicate accessory cells in the pathogenesis of the disease.

Agammaglobulinemia↗
PubMed2000

Biosynthesis and secretion of several enzymes in Escherichia coli dnaK and dnaJ mutants.

Escherichia coli null dnaJ and dnaKdnaJ mutants were defective in the biosynthesis and secretion of several enzymes. The synthesis of beta-galactosidase induced in delta dnaJ and delta dnaKdnaJ mutants was abolished at 42 degrees C and significantly decreased at 30 and 37 degrees C. The activity of alkaline phosphatase in the periplasm in both mutant strains at high temperature was lower than in the wild-type strain. The synthesis of b-type cytochromes was defective in two deletion mutants while the synthesis of nitrate reductase-A at 42 degrees C was influenced by dnaK mutation only. The lack of DnaK and DnaJ does not impair the activity of catechol 2,3-dioxygenase irrespective of growth temperature.

Alkaline Phosphatase↗
PubMed1997

Mechanisms of growth failure in non-growth-hormone deficient children of short stature.

So far, the clinical evaluation of short children has focused on the measurement of immunoreactive growth hormone (GH) in the blood to determine if the growth retardation is due to GH deficiency. However, GH-dependent short stature may be caused by defects in either the secretion of bioactive GH or by the inability to respond to GH. Both GH secretion and GH responsiveness should, therefore, be evaluated when investigating the cause of short stature. Recent advances in molecular biology have generated new ways of studying different molecules involved in growth regulation, and new genetic defects have been identified in short children.

Child↗
PubMed1982

Cellular location affects protein stability in Escherichia coli.

We study the biosynthesis of preproinsulin and proinsulin in Escherichia coli by pulse-chase experiments. When E. coli is transformed with plasmids bearing a gene consisting of a fusion of preproinsulin DNA to part or to all of the DNA encoding a bacterial signal sequence, a variety of hybrid preproinsulin molecules can be made. Molecules with largely complete hybrid signal sequences are secreted into the periplasm. Molecules with defective signal sequences, lacking the hydrophobic core, are not secreted and remain in the cytoplasm. Such molecules are degraded with a 2-min half-life, whereas the molecules transported to the periplasm are at least 10 times more stable. A full-length preproinsulin precursor appears transiently before the signal sequence is cleaved off by the bacterial signal peptidase, and we propose a model to account for this.

Bacterial Proteins↗
PubMed2002

Cardiomyocyte intracellular calcium and cardiac dysfunction after burn trauma.

OBJECTIVE: To examine the effects of pharmacologic agents designed to limit burn-mediated calcium overload on cardiomyocyte [Ca2+] and cardiac contractile function. DESIGN: Experimental, comparative study. SETTING: Cellular biology and physiology laboratory. SUBJECTS: Adult Sprague Dawley rats. INTERVENTIONS: Rats were given third-degree burn injury over 40% of the total body surface area, were fluid resuscitated, and then were divided randomly to receive one of five treatments: vehicle (normal saline); amiloride (50 mg/kg) to inhibit H+-Na+ exchange and subsequent Na+-Ca2+ exchange; dantrolene (10 mg/kg, 30 mins, 6 and 22 hrs postburn) to inhibit sarcoplasmic reticulum Ca2+ release; diltiazem (10 mg/kg given over first 6 hrs postburn); or amlodipine (0.07 mg/kg, 24 hrs preburn and 30 mins postburn) to block calcium slow channels. Appropriate controls (sham burns given the appropriate pharmacologic agent) were included in each group. Twenty-four hrs postburn, left ventricular function (Langendorff), cardiomyocyte [Ca2+]i and [Na+]i measured by fura-2-AM or sodium-binding benzofurzan isophthalate loading of cardiomyocytes, and myocyte secretion of tumor necrosis factor-alpha (enzyme-linked immunosorbent assay) were assessed in shams and burns from each experimental group. This time point was selected based on our previous work confirming maximal ventricular contractile defects and maximal cytokine secretion 24 hrs postburn. MEASUREMENTS AND MAIN RESULTS: Burn trauma increased myocyte [Ca2+]i and [Na+]i, promoted tumor necrosis factor-alpha secretion by cardiomyocytes, and impaired left ventricular function. All pharmacologic agents reduced the burn-mediated Ca2+/Na+ accumulation in cardiomyocytes and ablated burn-mediated tumor necrosis factor-alpha secretion by myocytes; in contrast, dantrolene and amiloride provided significantly greater cardioprotection than pharmacologic agents that specifically targeted Ca2+ slow channels (diltiazem and amlodipine). CONCLUSION: Our data suggest that the calcium antagonists used in this study provide cardioprotection by modulating several aspects of the overall inflammatory cascade rather than solely limiting cardiomyocyte accumulation of calcium.

Amiloride↗
PubMed1998

Hypothalamo-pituitary disconnection of the late-gestation ovine fetus results in profound changes in cortisol secretion that are not reflected in commensurate changes in adrenocorticotropin secretion.

A prepartum increase in fetal glucocorticoid concentrations is essential for the perinatal transition to extrauterine life for many mammalian species. In the case of the sheep, this increase in cortisol is also the trigger for parturition, and depends upon an intact hypothalamo-pituitary unit. Fetal sheep that have undergone hypothalamo-pituitary disconnection (HPD) fail to have a prepartum cortisol surge or initiate labor, despite apparently normal fetal ACTH concentrations in late gestation. We have investigated whether a defect exists in the regulation of pulsatile neurohormone secretion in the pituitaryadrenal axis of the HPD sheep fetus, by comparing immunoreactive (ir) ACTH and cortisol secretory dynamics in intact and HPD fetuses at 126 and 145 days of gestation (normal gestation length, 147 days). The fetal surgery was conducted at 115 days of gestation. Blood samples were collected at 5-min intervals for 2 h on each experimental day, and the resulting irACTH and cortisol concentrations were analyzed by multiple-parameter deconvolution and cross-correlation analysis. Basal irACTH secretion was less (P < 0.01) in HPD fetuses than intact fetuses at 126 days, but it had recovered by 145 days. There were no differences in irACTH half-life or the number or duration of irACTH secretory bursts between the two groups of fetuses or the two gestational ages (GAs). The size of the irACTH secretory bursts was not affected by the operation, but it increased with GA to a similar extent in both groups of fetuses (P < 0.01). In keeping with the observations for irACTH secretion, there was no effect of age or the operation on cortisol half-life or on the number or duration of cortisol secretory bursts. In contrast, there were dramatic age-related increases (P < 0.01) in the basal cortisol secretion rate and the size of the cortisol secretory bursts in the intact, but not the HPD, fetuses. Cross-correlation analysis revealed a significant (P < 0.01) concordance between irACTH and cortisol secretion in only the intact fetuses at 126 days; this was not apparent in the intact fetuses at 145 days, or in the young or old HPD fetuses. These findings confirm a major defect in cortisol secretion in the late-gestation HPD fetus but suggest that this is not caused by defects in irACTH secretion. Together with other observations, these data suggest that ACTH may not be the sole, or primary, regulator of adrenal cortisol secretion in the late-gestation ovine fetus.

Adrenocorticotropic Hormone↗
PubMed2005

EsxA and EsxB are secreted by an ESAT-6-like system that is required for the pathogenesis of Staphylococcus aureus infections.

Mycobacterium tuberculosis secretes ESAT-6, a virulence factor that triggers cell-mediated immune responses and IFN-gamma production during tuberculosis. ESAT-6 is transported across the bacterial envelope by a specialized secretion system with a FSD (FtsK-SpoIIIE domain) membrane protein. Although the presence of ESAT-6-like genes has been identified in the genomes of other microbes, the possibility that they may encode general virulence functions has hitherto not been addressed. Herein we show that the human pathogen Staphylococcus aureus secretes EsxA and EsxB, ESAT-6-like proteins, across the bacterial envelope. Staphylococcal esxA and esxB are clustered with six other genes and some of these are required for synthesis or secretion of EsxA and EsxB. Mutants that failed to secrete EsxA and EsxB displayed defects in the pathogenesis of S. aureus murine abscesses, suggesting that this specialized secretion system may be a general strategy of human bacterial pathogenesis.

Abscess↗
PubMed2002

Absence of metabolic cross-correction in Tay-Sachs cells: implications for gene therapy.

We have investigated the ability of a receptor-mediated gene transfer strategy (cross-correction) to restore ganglioside metabolism in fibroblasts from Tay-Sachs (TS) patients in vitro. TS disease is a GM2 gangliosidosis attributed to the deficiency of the lysosomal enzyme beta-hexosaminidase A (HexA) (beta-N-acetylhexosaminidase, EC ). The hypothesis is that transduced cells overexpressing and secreting large amounts of the enzyme would lead to a measurable activity in defective cells via a secretion-recapture mechanism. We transduced NIH3T3 murine fibroblasts with the LalphaHexTN retroviral vector carrying the cDNA encoding for the human Hex alpha-subunit. The Hex activity in the medium from transduced cells was approximately 10-fold higher (up to 75 milliunits) than observed in non-transduced cells. TS cells were cultured for 72 h in the presence of the cell medium derived from the transduced NIH3T3 cells, and they were analyzed for the presence and catalytic activity of the enzyme. Although TS cells were able to efficiently uptake a large amount of the soluble enzyme, the enzyme failed to reach the lysosomes in a sufficient quantity to hydrolyze the GM2 ganglioside to GM3 ganglioside. Thus, our results showed that delivery of the therapeutic HexA was not sufficient to correct the phenotype of TS cells.

3T3 Cells↗
PubMed1989

Selective precipitation of 14 kDa stone/thread proteins by concentration of pancreaticobiliary secretions: relevance to pancreatic ductal obstruction, pancreatic failure, and CF.

Concentrated proteins in pancreatic juice could precipitate and plug pancreatic ducts, initiating pancreatic disease. In cystic fibrosis (CF), pancreatic fluid secretion is impaired due to defective anion transport and proteins are hyperconcentrated. To determine whether proteins in pancreatic secretions precipitate selectively or nonspecifically, duodenal secretions were obtained from subjects with and without cystic fibrosis, during pancreatic stimulation with cholecystokinin (CCK) and secretin, dialyzed against phosphate-buffered saline (PBS), and concentrated in stages by ultrafiltration. Precipitates obtained by centrifugation at 15,600 g for 10 min at 4 degrees C were analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The only protein band regularly enriched in precipitates from 10 CF and 9 non-CF samples had an Mr of approximately 14,000. Monoclonal antibodies, raised independently in two laboratories against either pancreatic stone protein (PSP) or pancreatic thread protein (PTP), reacted with the Mr 14,000 protein(s). Differential extraction of PTP and PSP by 0.1N HCl and 10% sodium citrate produced Mr 14,000 products that reacted equally with each monoclonal antibody (MAB). Two-dimensional gel electrophoresis demonstrated two Mr 14,000 spots in each extract with pI's of 5.8 and 6.0. Each spot reacted equivalently with the MABs for PSP and PTP. PSP/PTP type proteins are sparingly soluble in pancreatic secretions and could contribute to protein plugging in pancreatic disease.

Blotting, Western↗
PubMed1995

Ion transport across the jejunum in normal and cystic fibrosis mice.

Cystic fibrosis (CF) mice created by targeted disruption of the murine cystic fibrosis transmembrane conductance regulator gene lack adenosine 3',5'-cyclic monophosphate (cAMP)-mediated Cl- secretion and exhibit marked intestinal complications secondary to inadequate fluid secretion. The basal short-circuit current (Isc) in the normal murine jejuna [43.2 +/- 5.9 microA.cm-2, n = 10 (mean +/- SE)] exhibits marked spontaneous n = 10 (mean +/- SE)] exhibits marked spontaneous oscillations (amplitude = 47.9 microA.cm-2, n = 18), which were completely absent in the CF jejunum. Treatment of normal jejuna with the neuronal blocker tetrodotoxin completely eliminated the oscillations and decreased the Isc to levels not significantly different from the low basal Isc (5.4 +/- 2.8 microA.cm-2, n = 16) exhibited by CF tissue. Ion substitution studies revealed basal Isc in normal jejuna to be due primarily to Cl- secretion but these tissues appeared to be capable of HCO3- secretion as well. In contrast, CF jejuna spontaneously secreted neither Cl- nor HCO3-, which may indicate that CF jejuna have a defect in the ability to secrete both of these anions. Apical glucose elicited an electrogenic absorption of Na+ of identical magnitude in normal and CF jejuna. Without apical glucose, CF jejuna exhibited a very small Isc response to forskolin (delta 2.2 +/- 0.67 microA.cm-2, n = 10). However, in the presence of apical glucose, forskolin elicited an eightfold greater Isc response in the CF tissue (delta 17.2 +/- 4.8 microA.cm-2, n = 9).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMedDate not supplied

Changes induced by hypothyroidism in insulin secretion and in the properties of islet plasma membranes.

This work was aimed at elucidating the effect of thyroid function on the physiology and biochemistry of the islet-cell population within the endocrine pancreas. To this end, we performed a comparative study of the physiochemical properties of islet-cell membranes and of the dynamics of glucose-induced insulin secretion in isolated pancreatic islets prepared from euthyroid i.e. control (C), hypothyroid (H), and thyroxin-supplemented hypothyroid (HT) rats. H rats were obtained by injecting normal rats with 131iodine, while HT rats consisted of H rats treated with thyroxin (T4). Insulin secretion was studied in isolated islets perifused with 3.3 and 16.6 mM glucose. Physicochemical properties of the partially purified islet plasma membranes were assessed by measurements of fluorescence polarization with the fluorophore 1,6-diphenyl-1,3,5-hexatriene (DPH) as a lipidic molecular probe. Insulin output during either the first or second phase of insulin secretion in H islets was significantly lower than in C islets. The slope of the curve in the second phase of insulin secretion was also lesser in H than in C islets, suggesting an additional defect in their velocity of hormone release. T4 administration of H rats reversed the decrease in insulin output to the range found in C islets but was incapable of correcting the defect in the hormone-secretion velocity. Several changes were found in the physicochemical properties of the membranes obtained from H islets as compared to C islets.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1989

Nephrolithiasis in renal tubular acidosis.

Renal tubular acidosis is a term applied to several conditions in which metabolic acidosis is caused by specific defects in renal tubular hydrogen ion secretion. Three types of renal tubular acidosis generally are recognized based on the nature of the tubular defect. Nephrolithiasis occurs only in type I renal tubular acidosis, a condition marked by an abnormality in the generation and maintenance of a hydrogen ion gradient by the distal tubule. A forme fruste of type I renal tubular acidosis has been described in which the characteristic defect in distal hydrogen ion secretion occurs in the absence of metabolic acidosis (incomplete renal tubular acidosis). Type I renal tubular acidosis is a heterogeneous disorder that may be hereditary, idiopathic or secondary to a variety of conditions. Secondary type I renal tubular acidosis in sporadic cases is associated most commonly with autoimmune diseases, such as Sjögren's syndrome and systemic lupus erythematosus, and it occurs more frequently in women than men. Nephrolithiasis, which may occur in any of the subsets of type I renal tubular acidosis, accounts for most of the morbidity in adults and adolescents. Major risk factors for nephrolithiasis include alkaline urine, hypercalciuria and hypocitraturia. In addition, we found hyperuricosuria in 21 per cent of the patients with type I renal tubular acidosis with nephrolithiasis. The most frequently occurring risk factor, hypocitraturia, is due to decreased filtered load and/or to increased tubular reabsorption of filtered citrate. While increased tubular reabsorption may be due to systemic acidosis, hypocitraturia occurs in incomplete renal tubular acidosis. Furthermore, alkali therapy (either bicarbonate or citrate salts) increases citrate excretion in complete and incomplete type I renal tubular acidosis. These data suggest that hypocitraturia in type I renal tubular acidosis may be due to a defect in proximal tubule function. Hypercalciuria appears to have 2 causes. It may be due to metabolic acidosis, usually in children with a hereditary defect in urine acidification. In other cases familial idiopathic hypercalciuria causes nephrocalcinosis and nephrolithiasis resulting in distal tubular damage and type I renal tubular acidosis. In these latter cases hypercalciuria is present in complete and incomplete type I renal tubular acidosis. Potassium citrate appears to reduce calcium excretion in both types of hypercalciuric type I renal tubular acidosis.(ABSTRACT TRUNCATED AT 400 WORDS)

Acidosis, Renal Tubular↗
PubMedDate not supplied

Processing and secretion of lysosomal acid alpha-glucosidase in Tetrahymena wild type and secretion-deficient mutant cells.

The proteolytic processing and secretion of a lysosomal enzyme, acid alpha-glucosidase, was studied by pulse-chase labeling with [35S]methionine in Tetrahymena thermophila CU-399 cells treated with ammonium chloride. This cell secreted a large amount of acid alpha-glucosidase into the cultured medium during starvation. The secretion was found to be repressed by addition of ammonium chloride (NH4Cl). Acid alpha-glucosidase was produced as a precursor form (108 kDa) and then processed to a mature polypeptide (105 kDa) within 60 min. This mature enzyme was secreted into the media within 2-3 h after chase, whereas the precursor form was not secreted by either control cells or NH4Cl-treated cells. NH4Cl did not affect the processing of the precursor acid alpha-glucosidase. Processing profile of this enzyme was apparently indistinguishable from that of the mutant MS-1 defective in lysosomal enzyme secretion. Furthermore, the purified extracellular (CU-399) and intracellular (MS-1) acid alpha-glucosidases were the same in molecular mass (105 kDa) and enzymatic properties. They contained no mannose 6-phosphate residues in N-linked oligosaccharides. These results suggested that unlike mammalian cells, Tetrahymena acid alpha-glucosidase may be transferred to lysosomes by a mannose 6-phosphate receptor-independent mechanism, and also that low pH was not essential for the proteolytic processing of precursor polypeptide.

Ammonium Chloride↗