[Effect of carperitide (alpha-human atrial natriuretic polypeptide) on the cardiovascular system in experimental animals]

The cardiovascular and diuretic actions of carperitide were studied in experimental animals. Carperitide relaxed various canine arteries and veins that were contracted by high K+ or norepinephrine. Carperitide stimulated particulate guanylate cyclase from rat thoracic aortas. Carperitide had almost no effect on coronary perfusion pressure or heart rate, but caused a slight decrease in contractile force in isolated guinea pig hearts. Carperitide tended to decrease isoproterenol-induced renin release from isolated rat kidney slices and elicited decreases in angiotensin II-induced aldosterone release from bovine zona glomerulosa cells. Intravenous injection of carperitide elicited decreases in arterial blood pressure and total peripheral resistance in the anesthetized and conscious dogs. Carperitide also elicited transient increases in cardiac output and coronary blood flow followed by slight decreases in them. Intravenous infusion of carperitide elicited decreases in pulmonary capillary wedge pressure, pulmonary pressure and right atrial pressure in association with elevating plasma carperitide (ANP like immuno-reactivity) level in dogs with heart failure induced by coronary artery occlusion and saline loading. These results suggest that carperitide decreases both preload and afterload and can improve the untoward hemodynamic alterations in animals with acute experimental heart failure.

Intranasal immunization against herpes simplex virus infection by using a recombinant glycoprotein D fused with immunomodulating proteins, the B subunit of Escherichia coli heat-labile enterotoxin and interleukin-2

To establish a novel strategy of mucosal immunization against herpes simplex virus type 1 (HSV-1) infection, we studied the immune responses elicited by intranasal immunization with several forms of a recombinant glycoprotein D (gD) of HSV-1. A truncated gD (t-gD) co-administered with heat-labile enterotoxin B subunit (LTB) from Escherichia coli induced both a mucosal immune response involving secretion of anti-gD IgA and serum IgG production. The levels of these responses are comparable to those in mice which have recovered from intranasal HSV-1 infections. The fusion protein (t-gD-LTB), consisting of t-gD and LTB, induced the responses more efficiently than did co-administration of t-gD and LTB, although GM1 ganglioside binding activity was significantly reduced in t-gD-LTB. We found that another fusion protein, consisting of t-gD and human interleukin-2 (t-gD-IL-2), also elicited antibody responses comparable to those induced by t-gD-LTB. Immunity acquired by intranasal immunization with t-gD-IL-2 protected mice from intraperitoneal HSV-1 infections, whereas t-gD-LTB or t-gD alone failed to provide protection against infection. Even in a mouse strain that responded highly to subcutaneously administered gD, intranasally administered t-gD did not elicit antibody responses. The lack of response to gD was clearly abrogated by co-administration with IL-2, and administration of t-gD-IL-2 induced an excellent level of antibody responses in this strain. These results suggest that the IL-2 fusion strategy yields a new type of mucosal immunization, the mechanism of which differs from that speculated for the mucosal adjuvant activity of LTB.

Immunopharmacological characterization of a highly branched fungal (1-->3)-beta-D-glucan, OL-2, isolated from Omphalia lapidescens

The immunopharmacological activities of a fungal (1-->3)-beta-D-glucan, OL-2, isolated from "Leiwan" Omphalia lapidescens were examined. Intraperitoneal (i.p.) administration of OL-2 to ICR mice induced a significant number of peritoneal exudate cells (PEC) and white blood cells over the period of a few days. Spleen cell numbers were also increased by i.p. administration of OL-2 at about a week. These changes reverted to the normal level within a month. Responses of spleen cells and bone marrow cells (BM) to colony stimulating factors (CSF) were augmented by OL-2 administration assessed by cell proliferation assay. Sera from OL-2 administered mice contained an increased concentration of colony stimulating activity. Gene expressions of interleukin-1 beta, interleukin-6, and tumor necrosis factor alpha in the spleen were also increased. These results suggested the activation of hematopoietic responses, and would well relate to the incremental increase in PEC, white blood cell and spleen cell numbers. OL-2 also increased the serum concentration of fibronectin and complement component C-3. However, OL-2 did not show adjuvant activity to SRBC and antitumor activity against the solid form of Sarcoma 180 by i.p. administration. Yet, OL-2 did not interfere with the antitumor activity of SSG against the same tumor system. These facts suggested that OL-2 could enhance nonspecific host defense mechanisms by enhancing hematopoietic responses, but would not enhance or inhibit the specific immunity mediated by lymphocytes.(ABSTRACT TRUNCATED AT 250 WORDS)

Up-regulation of IL-6-receptors by IL-3 on a plasma cell leukaemia cell line which proliferates dependently on both IL-3 and IL-6

In this report we show that IL-3 up-regulates the expression of IL-6-receptors on a plasma cell leukaemia cell line which proliferates in response to both IL-3 and IL-6. Quantitative binding studies and Scatchard analysis revealed that HSM-2.3 has a single class of high-affinity IL-6 binding sites (200/cell, dissociation constant at the equilibrium 1.43 x 10(-11) M). After stimulation with IL-3, HSM-2.3 has 1200 binding sites. IL-6 receptor mRNA expression was detected in HSM-2.3 only after stimulation with IL-3.

Preparation of a photoaffinity probe for the Man6P/IGF-II receptor

A photoaffinity probe, 2-(4-phosphopentamanniminophenyl)ethyl-(4-azido) salicylamide, was prepared for photolabelling of the mannose 6-phosphate/insulin-like growth factor II receptor. The probe was synthesized from phosphopentamannan and 2-(4-aminophenyl)ethylamine followed by coupling with photosensitive 4-azidosalicylic acid. The 125I-labelled probe was reacted with receptor purified from rat liver under irradiation with ultraviolet light. Fluorography of the reaction product on a polyacrylamide gel effectively detected the receptor coupled to the photoprobe as a molecular mass of 250 kDa. Specific binding of the probe or of radiolabelled insulin-like growth factor II was not inhibited by the growth factor or by mannose 6-phosphate, confirming different binding sites to the receptor between the ligands.

The IL-2 receptor complex: its structure, function, and target genes

Proliferation of T lymphocytes is triggered by the interaction of IL-2 with its specific receptor following T lymphocyte activation. The receptor for IL-2 consists of at least three distinct subunits, the alpha chain (IL-2R alpha), the beta chain (IL-2R beta), and the gamma chain (IL-2R gamma). Although the role of IL-2R gamma in IL-2 signalling remains unclear, IL-2R beta is the subunit critical for receptor-mediated signalling. Because IL-2R beta lacks any apparent catalytic motifs, IL-2R beta may be physically or functionally coupled to other signalling molecules. Structure-function studies of IL-2R beta have revealed that at least two distinct cytoplasmic regions of IL-2R beta are involved in IL-2-induced cellular signalling. The "serine-rich" region of IL-2R beta was identified as a region critical for IL-2-induced mitotic signalling from experiments in which IL-2R beta mutant cDNAs lacking a particular cytoplasmic region or regions were expressed in an IL-3-dependent mouse pro-B cell line (BAF-B03). Meanwhile, another cytoplasmic region of IL-2R beta, the "acidic" region, is responsible for its physical association with an src-family protein tyrosine kinase (PTK), p56lck and is critical for activating the p56lck PTK following IL-2 stimulation. It is now evident that IL-2R beta is linked to at least two intracellular signalling pathways that mediate nuclear proto-oncogene induction. One pathway is linked to tyrosine phosphorylation events, mediated by a src-family protein tyrosine kinase (PTK), and that pathway leads to the induction of the c-fos, c-jun, and other genes of this family. Another pathway leads to c-myc gene induction by an as yet unknown mechanism. We discuss the complex signalling machinery that links the cell surface receptor to the nuclear events.

An evaluation of serodiagnostic tests in patients with candidemia: beta-glucan, mannan, candida antigen by Cand-Tec and D-arabinitol

The serodiagnostic tests, beta-glucan, mannan, candida antigen by Cand-Tec, and D-arabinitol were evaluated in 10 patients with candidemia, 14 patients with suspected fungemia, and 10 healthy persons. By blood culture or lysis centrifugation, C. albicans was isolated from 5 patients, C. parapsilosis from 4, and C. tropicalis from 1 patient; no organisms were isolated from the 14 patients with suspected fungemia or the 10 healthy subjects. Beta-glucan was measured by the difference between two chromogenic limulus tests (Endotoxin test-D and Endospecy), which was more than 60 pg/ml in 7 of 9 (78%) candidemic patients and 1 of 12 (8%) patients with suspected fungemia. Mannan was positive in 6 of 10 (60%) candidemic patients and 1 of 13 (8%) patients with suspected fungemia. Both antigens were very sensitive and highly specific for candidemia. However, the Cand-Tec assay was less specific, because titers of more than 4 were observed in 5 of 14 (34%) patients with suspected fungemia. D-Arabinitol was the least sensitive, because a D-arabinitol/creatinine ratio greater than 2.0 mumol/mg was observed in only 2 of 7 (29%) candidemic patients. The titers of serodiagnostic tests decreased after successful treatment with an anti-fungal agent. Our results show that the combined use of the assays in necessary for accurate serological diagnosis of candidemia.

Inhibition of mitochondrial respiration by furancarboxylic acid accumulated in uremic serum in its albumin-bound and non-dialyzable form

3-carboxy-4-methyl-5-propyl-2-furanpropionic acid (CMPF) accumulates markedly in uremic serum in its albumin-bound form. To determine if CMPF can be removed by newly developed dialyzers with high-flux membranes which are permeable to low-molecular-weight proteins, such as beta 2-microglobulin (beta 2-MG), serum levels of CMPF were determined before and after hemodialysis using these high-flux membrane dialyzers. In addition, to determine the pathogenic role of CMPF in uremic patients, its cellular toxicity due to its effect on mitochondrial respiration was studied. The reduction rates of CMPF by hemodialysis using the dialyzers ranged from -17% to -24%, demonstrating the nondialyzability of CMPF due to its strong albumin-binding, while those of beta 2-MG ranged from 11% to 43%. CMPF inhibited ADP-stimulated oxidation of NADH-linked substrates in isolated mitochondria dose-dependently regardless of the presence of serum albumin. This inhibition was observed even at a concentration of 0.2 mM, which is comparable to the serum levels of CMPF in the hemodialysis patients. In conclusion CMPF which cannot be removed even by high-flux membrane dialyzers, is a strong inhibitor of mitochondrial respiration, and novel purification methods to remove CMPF from the blood of uremic patients should be developed.

Charged collagen structure mediates the recognition of negatively charged macromolecules by macrophage scavenger receptors

Macrophage scavenger receptors mediate the recognition of a wide range of negatively charged macromolecules including modified low density lipoproteins (LDL). Truncated bovine receptors lacking residues 330-342, which include the conserved lysine cluster of a collagen-like domain, were unable to degrade modified LDL in spite of their expression on the cell surface. Substitution of lysine 337 into alanine abolished the acetyl-LDL degradation and binding at 37 degrees C, but did not abolish the 4 degrees C binding. In contrast, substitution of more than 2 lysines in this region are needed to abolish the oxidized LDL degradation and 37 degrees C binding. Based on computational modeling of this domain, we propose that a "charged collagen" structure containing a lysine cluster forms a positively charged groove which specifically interacts with negatively charged ligands.

Suppressive effect of an oral sorbent on the accumulation of p-cresol in the serum of experimental uremic rats

Serum p-cresol and phenol are markedly accumulated in uremic patients. To determine if an oral sorbent (AST-120) can decrease their serum concentrations in the uremic state, an oral sorbent was administered to experimental nephrectomized uremic rats. In uremic rats fed with oral sorbent, the serum concentration and the urinary excretion of p-cresol were markedly and significantly lower than those in control uremic rats, while those of phenol tended to be low in the uremic rats with oral sorbent as compared with control uremic rats. The concentrations of serum creatinine and blood urea nitrogen were significantly decreased in the uremic rats with oral sorbent. These findings demonstrate that oral sorbent adsorbs especially p-cresol in the intestine and prevents the accumulation of p-cresol in the serum of uremic rats.

Sulfolipids and glycolipid sulfotransferase activities in human renal cell carcinoma cells

A cell line (SMKT-R3) established from human renal cell carcinoma was characterized for the presence of sulfolipids and glycolipid sulfotransferases. Sulfolipids were found to constitute a large part of the acidic glycolipid fraction in SMKT-R3 cells. These findings were confirmed by metabolic labelling with 35S-sulfate. These sulfolipids were expressed at the surface of SMKT-R3 cells as ascertained by cytofluorometry using a monoclonal antibody directed to sulfolipids. Furthermore, markedly high activity levels of glycolipid sulfotransferases were observed in SMKT-R3 cells compared with other cell lines. These results suggest that the increased synthesis of sulfolipids in renal cell carcinoma tissue (Sakakibara et al., 1989. Cancer Res., 49, 335-339) is due to the elevation of the sulfotransferase activities of renal carcinoma cells themselves.

Effect of hemodialysis on plasma levels of vasoactive peptides: endothelin, calcitonin gene-related peptide and human atrial natriuretic peptide

To determine the role of vasoactive peptides such as endothelin (ET), calcitonin gene-related peptide (CGRP) and human atrial natriuretic peptide (hANP) in the regulation of blood pressure in uremic patients, and to determine the effect of various types of dialyzer membranes on hemodialysis (HD)-induced changes in plasma levels of such peptides, plasma ET, CGRP and hANP were measured in HD patients and patients on continuous ambulatory peritoneal dialysis (CAPD). Plasma levels of ET, CGRP, and hANP were significantly higher in HD and CAPD patients than in healthy subjects. There were no significant differences in plasma levels of ET, CGRP, and hANP between hypertensive and normotensive HD patients, and no significant correlation was observed between HD-induced changes in plasma levels and changes in blood pressure. Plasma levels of ET decreased when HD was performed using high-flux membranes, such as polyacrylonitrile (PAN), polymethyl methacrylate (PMMA) and cellulose triacetate (CTA), but did not decrease using a saponified cellulose (SC) membrane. Plasma levels of CGRP decreased in the case of PAN, but increased significantly with PMMA and showed no change with SC and CTA. Plasma levels of hANP decreased in all types of dialyzer membranes due to decreased secretion. These results indicate that the effect of HD on plasma levels of ET and CGRP, but not hANP, depends on the type of dialyzer membrane used.

Cytosolic free magnesium concentration in human platelets

Although the magnesium ion (Mg2+) is considered to play an important role in cell activation, information is limited by the lack of suitable methods for measuring cytosolic free Mg2+ concentration ([Mg2+]i). We measured [Mg2+]i in resting and activated human platelets using a new fluorescent Mg(2+)-indicator, mag-fura-2. [Mg2+]i was 0.54 +/- 0.14 mM in resting platelets from 15 healthy volunteers. [Mg2+]i was elevated to 1.33 +/- 0.44 mM and 0.92 +/- 0.37 mM in platelets stimulated with thrombin and collagen, respectively. Increased Mg2+ was considered to be derived chiefly from intracellular Mg2+ mobilization. These results suggest that platelet activation is associated with the increase in [Mg2+]i. The estimation of [Mg2+]i using this method is useful for the investigation of mechanism for various cell activation.

[Clinically diagnosed corticobasal degeneration (CBD)]

We reported a 67-year-old male, who suffered from apraxia and amnesia for 2 years and for muscle rigidity of right extremities for a year. Neurological examination revealed dysarthria, dysphagia, marked dystonia of right arm, hyperreflexia of all limbs and ataxic gait. He also had dementia and many other higher cortical dysfunction mostly due to left hemisphere damage. No impairment of eye movement was disclosed. Brain MRI as well as CT showed the significant brain atrophy in the left parieto-occipital region. A degenerative atrophy was suspected by 123I-IMP-SPECT and 18F-FDG-PET. By FDG-PET, the decrease of cerebral blood flow and glucose metabolism was detected not only affected unilateral cerebral cortex including primary motor area but ipsilateral basal ganglia and thalamus. Although, it is difficult to distinguish clinically CBD from atypical case of Alzheimer's disease, we speculated that in early stage of dementia, significant unilateral hypoperfusion and hypometabolism of basal ganglia and thalamus is characteristic of CBD.

[An autopsy case with recent memory disturbance, characterized by localized atrophy of parahippocampal gyrus, subiculum and amygdala]

We reported an autopsy case with recent memory disturbance, characterized by localized atrophy of parahippocampal gyrus, subiculum and amygdala. This patient initially exhibited recent memory disturbance at the age of 73. She was disoriented to time and place and immediately forgot having had a meal. At the age of 75, she was hospitalized because of progressive forgetfulness and congestive heart failure. One year later, she was admitted to our medical center. On admission, she was alert, but showed severe recent memory disturbance and disorientation to time and place. By contrast, she had neither aphasia nor apraxia. No other neurological symptoms were found. Brain CT showed localized atrophy of the medial part of bilateral temporal lobes and brain SPECT (123I-IMP) revealed a decrease of cerebral blood flow in the same regions. We considered her as early stage of Alzheimer type dementia (ATD) clinically. She died of pneumonia and DIC at the age of 78. Her illness lasted about 5 years. General autopsy showed prolapse of mitral valves, bronchopneumonia and DIC. The brain weighed 1,150 gm. Coronal sections of the brain revealed locarized atrophy of bilateral mediobasal part of the temporal lobes including the rostral parahippocampal gyrus, subiculum and amygdala. There were severe neuronal loss with astrogliosis and a few neurofibrillary tangles (NFT) in the rostral para-hippocampus, CA1 of the hippocampal formation, prosubiculum and amygdala. There were neither senile plaques (SP) nor NFT in the cerebral neocortex. This case lacked neocortical SP and NFT and showed bilateral localized atrophy of rostral parahippocampal gyrus, CA1, subiculum and related structure of the ventromedial temporal lobe with severe neuronal loss and astrogliosis.(ABSTRACT TRUNCATED AT 250 WORDS)

Urinary trehalase activity in chronic glomerulonephritis

To determine the diagnostic role of urinary trehalase in chronic glomerular disease, urinary trehalase activity and other urinary markers such as N-acetyl-beta-D-glucosaminidase (NAG), alanine aminopeptidase (AAP), alkaline phosphatase (ALP), gamma-glutamyltranspeptidase (gamma-GTP), lactate dehydrogenase (LDH), lysozyme and beta 2-microglobulin (BMG) were measured in patients with chronic glomerulonephritis, nephrotic syndrome and chronic renal failure. Urinary trehalase activity was significantly increased in chronic glomerular disease, especially nephrotic syndrome, as compared with that in the healthy subjects. The highest incidence of elevated excretion was observed for trehalase with 52% in chronic glomerular disease, followed by NAG. Urinary trehalase activities in the patients were significantly correlated with the urinary levels of protein, NAG and AAP and total score of tubular damage, but not correlated with urinary levels of BMG or lysozyme. In patients with chronic glomerulonephritis and nephrotic syndrome, there was no significant difference in urinary trehalase activities between with and without hematuria. These results indicate that in some patients with chronic glomerular disease, there is tubular involvement as substantiated by elevation of the other urinary enzymes and BMG. Urinary trehalase is elevated more often in these types of disease than other markers of tubular damage.

A rare case of extramedullary plasmacytoma in the mediastinum

A rare case of extramedullary plasmacytoma in the mediastinum is reported. An 80-year-old man was admitted for further examination of a mediastinal tumor. Chest computed tomography (CT) revealed a large mediastinal mass and right interlobar pleural effusion. Needle biopsy under CT guidance established a diagnosis of plasmacytoma. Immunohistochemical staining revealed that the tumor cells were producing monoclonal IgA kappa. Serum immunoelectrophoresis revealed an IgA kappa monoclonal component with a serum concentration of 5,040 mg/ml. The bone marrow aspiration was normal. Bone roentgenogram and bone scintigram showed osteoporosis but no neoplastic lesion.

[Clinical usefulness of the quantitative assessment of exercise thallium-201 myocardial imaging in patients with ischemic heart disease]

To clarify the significance of the quantitative analysis of the area of decreased activity in exercise thallium-201 myocardial imaging, 42 patients with one vessel disease (20 patients with angina pectoris without myocardial infarction, 22 patients with old myocardial infarction: MI) were evaluated by exercise thallium scan and compared with clinical findings and wall motion assessed by left ventriculography (LVG). Patients with MI were divided into two groups by LVG (Mild MI: MI with only hypokinesis on LVG, Severe MI: MI with akinesis or dyskinesis on LVG). The degree of defected area was expressed by the ratio of the counts of defected area to the normal area (Relative Activity: RA). RA of the area of decreased activity in patients with angina was higher than that of patients with MI (77.5 +/- 4.59% vs. 65.7 +/- 7.85%, p < 0.05). RA of the area of decreased activity in patients with mild MI was higher than that of patients with severe MI (69.5 +/- 4.78% vs. 61.3 +/- 8.45%, p < 0.01). The above results suggest that the regional thallium-201 uptake ratio in the scintigram may help to differentiate viable zones from necrotic ones and detect the degree of MI.

[Antimutagenic substances in the Armeniacae semen and Persicae semen]

Using the Ames/Salmonella/microsome assay, we examined the antimutagenic effect of the hexane extract of Armeniacae semen (apricot (Prunus armeniaca L.) seed), Persicae semen (peach (P. persica Bat.) seed), and seeds of cherry (P. avium L.), plum (P. salicina Lindle) and almond (P. dulcis Mill). Hexane extracts of Armeniacae semen and Persicae semen inhibited the mutagenicity of benzo[a]pyrene (B[a]P), but those of seeds of cherry, plum and almond did not. The mutagenicities of 3-amino-1,4-dimethyl-5H-pyrido[4,3-b]indole (Trp-P-1) and 2-(2-furyl)-3-(5-nitro-2-furyl)acrylamide (AF-2) were also inhibited by the extracts of Armeniacae semen and Persicae semen. Inhibitory substances in Persicae semen were fractionated by silica gel column chromatography and high performance liquid chromatography, and were identified as oleic acid and linoleic acid. The contents of oleic acid and linoleic acid were 0.7 and 0.4% in the hexane extract of Armeniacae semen, and 1.5 and 0.5% in that of Persicae semen, respectively.

Increased density of fluorescent adrenergic fibers around the middle cerebral arteries of stroke-prone spontaneously hypertensive rats

The distribution of fluorescent adrenergic nerve fibers in the proximal portion (horizontal segment, Hs) and the three distal portions (major branches) of the middle cerebral arteries (MCA) was examined in stroke-prone spontaneously hypertensive rats (SHRSP) aged 10, 30, 60, 90, and 180 days, by the glyoxylic acid method. The results were compared with those in age-matched normotensive Wistar Kyoto (WKY) rats. While the distribution pattern of fluorescent nerve fibers in the proximal portion of WKY rats changed from a straight linear arrangement at 10 and 30 days of age to a network-like arrangement after 60 days, those from SHRSP showed a constant meshwork pattern throughout the entire examination period. In the distal portions of the MCA of both SHRSP and WKY rats at all ages examined, fluorescent nerve fibers formed a coarse network. The distribution densities of adrenergic nerve fibers in the proximal and distal portions of the MCA of SHRSP were significantly higher (P less than 0.01 and 0.05) than those of WKY rats at all ages examined, except in the proximal portion at 90 and 180 days of age. The difference in nerve fiber density between SHRSP and WKY rats reached a peak at 30 days of age in both proximal and distal portions, and then gradually decreased with age. The present study suggests that sympathetic hyperinnervation is an important factor in the development of hypertension, and is involved in its maintenance in SHRSP.

Polysaccharide-coated liposomal amphotericin B for the treatment of murine pulmonary candidiasis

Amylopectin-coated liposomal amphotericin B was investigated in a murine model of pulmonary candidiasis. The LD50 of amylopectin-coated liposomal amphotericin B in normal mice was more than 10.0 mg/kg, and that of conventional amphotericin B was 1.2 mg/kg. Amylopectin-coated liposomes showed twice the concentration in the lungs of conventional liposomes. Candida albicans was inoculated intratracheally into BALB/C mice. Twenty-four hours later, the number of Candida in the lungs of mice treated with amylopectin-coated liposomes was less than in those treated with conventional liposomes, and amylopectin-coated liposomes improved the survival rate of inoculated mice. Coating liposomes with amylopectin aids the targeting of amphotericin B to the lungs.

Components and proteolytic processing sites of arylsulfatase B from human placenta

Previous studies have shown that mature arylsulfatase B purified from human sources is composed of two non-identical chains with apparent molecular masses of 43 kDa and 8 kDa. Arylsulfatase B purified from human placenta in the present study, however, included another 7 kDa component that could be detected only by carbohydrate staining on reducing SDS-PAGE employing the Tris-Tricine system. The 43 kDa and 7 kDa components contained a carbohydrate moiety, but the 8 kDa one did not, as demonstrated by periodic acid-Schiff staining, Con-A lectin blotting, endo-glycosidase treatment and in vitro phosphorylation by UDP-N-acetylglucosamine: lysosomal enzyme N-acetylglucosamine 1-phosphotransferase. The purified arylsulfatase B migrated as a single polypeptide of 58 kDa on non-reducing SDS-PAGE, indicating that the three chains are linked by disulfide bonds. In order to determine the origin of the components, N-terminal sequencing of the isolated polypeptides was performed. As a result, the 43, 7 and 8 kDa components were found to commence with Ala-41, Ala-424 and Asp-466, respectively. These results suggest that after removal of the signal peptide, human arylsulfatase B undergoes proteolytic processing on at least two sites during maturation.