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D S Brown

Publications and source records attributed to D S Brown.

At least 55 records · Page 3Linked to original sources
PubMed2001

Measurement of the high energy two-body deuteron photodisintegration differential cross section.

The first measurements of the d(gamma,p)n differential cross section at forward angles and photon energies above 4 GeV were performed at the Thomas Jefferson National Accelerator Facility (JLab). The results indicate evidence of an angular dependent scaling threshold. Results at straight theta(cm) = 37 degrees are consistent with the constituent counting rules for E(gamma) greater, similar 4 GeV, while those at 70 degrees are consistent with the constituent counting rules for E(gamma) greater, similar 1.5 GeV.

Journal Article↗
PubMed2001

Measurement of the midrapidity transverse energy distribution from square root of [(s)NN] = 130 GeV Au + Au collisions at RHIC.

The first measurement of energy produced transverse to the beam direction at the Relativistic Heavy-Ion Collider at Brookhaven National Laboratory is presented. The midrapidity transverse energy density per participating nucleon rises steadily with the number of participants, closely paralleling the rise in charged-particle density, such that / remains relatively constant as a function of centrality. The energy density calculated via Bjorken's prescription for the 2% most central Au+Au collisions at square root[s(NN)] = 130 GeV is at least epsilon(Bj) = 4.6 GeV/fm(3), which is a factor of 1.6 larger than found at sqrt[s(NN)] = 17.2 GeV ( Pb+Pb at CERN).

Journal Article↗
PubMed2001

Observation of exotic meson production in the reaction pi- p --> eta'pi- p at 18 GeV/c.

An amplitude analysis of an exclusive sample of 5765 events from the reaction pi- p-->eta'pi- p at 18 GeV/c is described. The eta'pi- production is dominated by natural parity exchange and by three partial waves: those with J(PC) = 1(-+), 2(++), and 4(++). A mass-dependent analysis of the partial-wave amplitudes indicates the production of the a2(1320) meson as well as the a4(2040) meson, observed for the first time decaying to eta'pi-. The dominant, exotic (non- qq) 1(-+) partial wave is shown to be resonant with a mass of 1.597+/-0.010(+0.045)(-0.010) GeV/c2 and a width of 0.340+/-0.040+/-0.050 GeV/c2. This exotic state, the pi1(1600), is produced with a t dependence which is different from that of the a2(1320) meson, indicating differences between the production mechanisms for the two states.

Journal Article↗
PubMed2001

Centrality dependence of charged particle multiplicity in Au-Au collisions at square root of (s)NN = 130 GeV.

We present results for the charged-particle multiplicity distribution at midrapidity in Au-Au collisions at square root of [s(NN)] = 130 GeV measured with the PHENIX detector at RHIC. For the 5% most central collisions we find dN(ch)/d eta(vertical line eta = 0) = 622+/-1(stat)+/-41(syst). The results, analyzed as a function of centrality, show a steady rise of the particle density per participating nucleon with centrality.

Journal Article↗
PubMed2001

Response in hepatic removal of amino acids by the sheep to short-term infusions of varied amounts of an amino acid mixture into the mesenteric vein.

Under conditions of chronic supply the liver removes most amino acids (AA) in excess of net anabolic needs. Little information is available, however, on how acute alterations in AA supply (as might occur with once-daily feeding regimens) are controlled by the liver. Are these also extracted completely in a 'first-pass' manner or are there limitations to hepatic uptake? Furthermore, is the rate of removal 'saturable' (by Michaelis-Menten kinetics) over the range of supply experienced under normal feeding conditions? These questions have been addressed in a study that involved acute (4.5 h) increases in AA supply. Four sheep were prepared with trans-hepatic vascular catheters and were offered a basal diet (equivalent to 1.6xenergy maintenance) throughout. On four occasions, at 7 d intervals, they were infused with various amounts of an AA mixture into the mesenteric vein over a 4.5 h period. The mixture contained fourteen AA in the proportions present in rumen microbial protein. The amounts infused were calculated to provide an additional one, two, three and four times that absorbed from the basal diet. Continuous blood collections were removed over 2 h intervals before (basal diet only) and at 0.5-2.5 and 2.5-4.5 h of AA infusion. Transfers of AA, from the digestive tract and to the liver, were calculated for both plasma and total blood. The recovery of the infused AA across the portal-drained viscera (PDV) was quantitative (100%) only for histidine and proline, the remaining AA were recovered at 56-83 %. These losses correlated with the arterial concentrations and were probably due to removal of AA from the systemic circulation by the tissues of the digestive tract. Despite the wide range of net PDV appearances (i.e. absorbed plus infused), the percentage of most AA removed by the liver remained constant, but the percentage varied with AA (from 34 for proline to 78 for tryptophan for blood transfers). Thus, even when supply was increased 5-fold over baseline there was no indication that the transport into the liver declined, indeed the absolute removals continued to increase. In contrast, the branched-chain AA (isoleucine, leucine and valine) did not exhibit constant percentage extractions. Their percentage extractions were always the lowest (16, 10 and 25 respectively) and tended to decline at the highest infusion rates, indicative of saturation in hepatic transport and/or metabolism. The arterial concentrations of all infused AA increased with rate of infusion, again indicative that the liver did not extract all the net AA available across the PDV. Absolute amounts removed were similar between plasma and blood, indicating that most of the hepatic transfers occurred from plasma. The fractional rates of transfer from total inflow to the liver (i.e. with re-circulated AA included) were 3- to 4-fold lower than rates based on the amounts absorbed plus infused. The highest percentage extraction for total blood inflows was for serine (27), but most were between 6 and 16, except for the branched-chain AA, which were all <1. Use of percentage extractions based on total inflows are probably more appropriate for development of mathematical models of liver metabolism, and the current data suggest that constant values may be applied. The needs of the liver for specific mechanisms involving phenylalanine and histidine (plasma protein synthesis), glycine (detoxification of xenobiotics) and alanine (gluconeogenesis) probably also require to be included in such models.

Amino Acids↗
PubMed2001

A response to California's mandated nursing ratios.

PURPOSE: To explore the need for evidence-based health policy, as illustrated by the mandatory staffing bill passed by the California state legislature in 1999. DESIGN: Prospective data were collected from a voluntary sample of California acute care hospital representatives to describe selected patient safety and clinical outcomes and nurse staffing variables at the patient-care unit level. METHODS: Data for descriptive analysis were collected on hospital nurse staffing, patient falls, and pressure ulcers from 257 medical, surgical, medical-surgical combined, step-down, 24-hour observation units, and critical care patient care units in 38 California acute care hospitals from June 1998 to June 1999. FINDINGS: Nursing staffing ratios varied among the 257 units. RNs provided 91% of the nursing care in critical care units. Patients in medical-surgical units received 59% of their care from RNs, 11% from licensed vocational nurses, and 30% from other caregivers. Preliminary data showed no relationships between reported staffing ratios in these hospitals and the incidence of patient falls or hospital-acquired pressure ulcers. CONCLUSIONS: California Nursing Outcomes Coalition (CalNOC) data showed wide variations in staffing ratios, patient falls, and hospital-acquired pressure ulcers among nursing units and hospitals. These early findings indicate the need for additional research before determining minimal RN staffing requirements. Analysis of multiple sources of data may be necessary to determine safe staffing ratios and to provide evidence-based data for public policy.

Accidental Falls↗
PubMed2000

Maternal protein deficiency causes hypermethylation of DNA in the livers of rat fetuses.

Maternal protein deficiency during pregnancy is associated with changes in glucose tolerance and hypertension in the offspring of rats. In this study the growth of rat fetuses was examined when the dams were fed diets containing 18% casein, 9% casein or 8% casein supplemented with threonine. The extra threonine was added to reverse the decrease in circulating threonine concentrations that occurs when pregnant rats are fed protein-deficient diets. The fetuses of the group fed the low protein diet supplemented with threonine were significantly smaller than those of the control group and not significantly different from those fed low protein. Homogenates prepared from the livers of dams fed the diet containing 9% casein oxidized threonine at approximately twice the rate of homogenates prepared from dams fed the diet containing 18% casein. We conclude that circulating levels of threonine fall as a consequence of an increase in the activity of the pathway that metabolizes homocysteine produced by the transulfuration of methionine. Serum homocysteine was unaffected in the dams fed low protein diets compared with controls, but was significantly greater in dams fed the low protein diet supplemented with threonine. Elevated levels of homocysteine are associated with changes in the methylation of DNA. The endogenous methylation of DNA was greater than that of controls in the livers of fetuses from dams fed the 9% protein diets and increased further when the diet was supplemented with threonine. Our results suggest that changes in methionine metabolism increase homocysteine production, which leads to changes in DNA methylation in the fetus. An increase in maternal homocysteine may compromise fetal development, leading to the onset of glucose intolerance and hypertension in adult life.

Animals↗
PubMed2000

Interactions among the branched-chain amino acids and their effects on methionine utilization in growing pigs: effects on plasma amino- and keto-acid concentrations and branched-chain keto-acid dehydrogenase activity.

The present experiment was designed to elucidate the mechanism of the methionine-sparing effect of excess branched-chain amino acids (BCAA) reported in the previous paper (Langer & Fuller, 2000). Twelve growing gilts (30-35 kg) were prepared with arterial catheters. After recovery, they received for 7 d a semipurified diet with a balanced amino acid pattern. On the 7th day blood samples were taken before (16 h postabsorptive) and after the morning meal (4 h postprandial). The animals were then divided into three groups and received for a further 7 d a methionine-limiting diet (80% of requirement) (1) without any amino acid excess; (2) with excess leucine (50% over requirement); or (3) with excesses of all three BCAA (leucine, isoleucine, valine, each 50% over the requirement). On the 7th day blood samples were taken as in the first period, after which the animals were killed and liver and muscle samples taken. Plasma amino acid and branched-chain keto acid (BCKA) concentrations in the blood and branched-chain keto-acid dehydrogenase (BCKDH; EC 1.2.4.4) activity in liver and muscle homogenates were determined. Compared with those on the balanced diet, pigs fed on methionine-limiting diets had significantly lower (P < 0.05) plasma methionine concentrations in the postprandial but not in the postabsorptive state. There was no effect of either leucine or a mixture of all three BCAA fed in excess on plasma methionine concentrations. Excess dietary leucine reduced (P < 0.05) the plasma concentrations of isoleucine and valine in both the postprandial and postabsorptive states. Plasma concentrations of the BCKA reflected the changes in the corresponding amino acids. Basal BCKDH activity in the liver and total BCKDH activity in the biceps femoris muscle were significantly (P < 0.05) increased by excesses of leucine or all BCAA.

Amino Acids↗
PubMed1999

Responses in the absorptive phase in muscle and liver protein synthesis rates of growing rats.

The effect of time after beginning of a meal (30, 60, 90 and 120 min) on liver and gastrocnemius muscle protein synthesis was tested in growing male rats using the large dose technique, based on a 10 min exposure to [15N]phenylalanine. The fractional synthesis rate was estimated from the ratio between the atom percent excess of tissue protein-bound and free labelled phenylalanine. The latter was measured by gas chromatography mass spectrometry using the tertiary-butyldimethylsilyl amino acid derivatives. The protein-bound phenylalanine of gastrocnemius muscle was separated from the other amino acids using preparative amino acid chromatography and then oxidised to N2 in an automated carbon-nitrogen Roboprep (CN) combustion module attached to a continuous flow isotope ratio mass spectrometer (IRMS), with m/z ions 28 and 29 monitored. The protein-bound phenylalanine from liver was separated by a gas chromatograph attached to a sample preparation module and an isotope ratio mass spectrometer (GC C-IRMS), with again m/z ions of 28 and 29 monitored. The following results were obtained: the daily fractional protein synthesis rates (ks) in gastrocnemius muscle and liver were 13.9% and 65.6% respectively, in 12 h fasted 145 g rats. These ks increased within 30 min after ingestion of meal to 14.9% and 91.8% for muscle and liver, respectively, and remained at these values for the next 90 min (14.6% and 87.4% at 60 min, and 14.3% and 88.6% at 120 min after the beginning of feeding). It was concluded that measurement of protein synthesis rates characteristics for the absorptive phase can be undertaken in a period from thirty minutes to two hours after start of a meal, without significant changes in the ks values.

Amino Acids↗
PubMed1998

Transfers of N metabolites across the ovine liver in response to short-term infusions of an amino acid mixture into the mesenteric vein.

The effect of acute (4.5 h) infusions into the mesenteric vein of an amino acid (AA) mixture, which simulated the composition of rumen microbial protein, on net transfers of NH3, urea and total AA across the portal-drained viscera (PDV) and liver in the ovine has been examined. Four wether sheep were surgically prepared with vascular catheters across the PDV and liver (Lobley et al. 1995) and were offered a basal diet of 1000 g grass pellets/d (approximately 1.4 x energy maintenance). Each animal was infused at weekly intervals with one of four dilutions of the AA mixture. These dilutions provided 0.44, 0.88, 1.32 and 1.84 mmol AA-N/min infused, the lowest of which approximately doubled the net absorption of AA-N from the basal diet. Animals were treated with heparin to allow continuous collection of blood by peristaltic pump for 2 h preceding, and between 0.5-2.5 and 2.5-4.5 h after, the start of the AA infusions. Blood flow in the hepatic artery increased (100 v. 208 g/min; P = 0.002) in response to AA infusion, while hepatic portal venous flow decreased (2090 v. 1854 g/min; P = 0.006). The AA infusion also stimulated O2 uptake by the PDV (P < 0.001) and liver (P = 0.016). Absorption across the PDV and hepatic removal of NH3 were unchanged between basal and amino acid infusion conditions. Urea-N removal across the PDV was unaltered, but hepatic production increased (P < 0.001) with level of AA infusion. During infusions, net appearance of AA across the PDV was below the theoretical level. This may have been due to inhibition of AA uptake from the small intestine, and/or increased removal by the digestive tract of AA from the systemic circulation associated with greater arterial concentrations. Hepatic extraction of AA increased with level of infusion, both for total AA and those included in the infusate. Total hepatic urea-N production tended towards a maximum (estimated as 2 mumol N/g liver wet weight per min). The AA removed by the liver and not used for ureagenesis remained similar (170 mumol AA-N/min) between basal and AA infusions. This was presumed available for anabolic purposes (mainly synthesis of export proteins). The proportion of net AA-N appearance (absorption plus infused) across the PDV removed by the liver declined from 0.71 to 0.53 between basal and AA infusions. In contrast to findings from cattle (Wray-Cahen et al. 1997), increased AA infusion did not alter the net removal of glutamine across the liver. This may reflect differences between the studies in NH3: AA-N absorbed. Further differences between the cattle study and the current findings may relate to the different physiological state (pregnancy v. growth), which may alter the partition of AA between anabolic and catabolic fates.

Amino Acids↗
PubMed1998

Putrescine as a source of instant energy in the small intestine of the rat.

BACKGROUND AND AIMS: It has been suggested that putrescine acts as a growth factor in the gut, but its exact function in some aspects of cellular metabolism is still in question. The aim of the present work was to identify some functions of putrescine in small bowel metabolism. ANIMALS: Rats (about 80 g), in groups of five, were given either phytohaemagglutinin- or lactalbumin-containing diets, fed ad libitum or were fasted for 48 hours and re-fed for six or twelve hours before being killed. METHODS: Uptake of intraperitoneally or intragastrically administered [14C]putrescine and its conversion to succinate by the rat small bowel mucosa was measured. Tissue polyamine and succinate contents were measured by high performance liquid chromatography and amino acid analysis respectively. RESULTS: Uptake of putrescine by the small bowel mucosa from the systemic circulation and conversion of about 30% of this to succinate occurs in the epithelium of the healthy small bowel. Compared with rats given food ad libitum, putrescine uptake was doubled in fasted animals and more than 70% of it was converted to succinate. All these changes returned to control values on refeeding. Using phytohaemagglutinin induced gut growth as a model, the uptake of putrescine from the systemic circulation by the serosal side of the small intestinal epithelium was increased immediately after growth was stimulated. During phytohaemagglutinin induced growth of the gut, putrescine was converted to succinate in the same proportion as in the healthy small bowel. CONCLUSIONS: The experiments identified a novel function for putrescine in gut metabolism: it can be used as an instant energy source when required.

Analysis of Variance↗
PubMed1997

Intracellular levels of polyamines in Krebs II lymphosarcoma cells in mice fed phytohaemagglutinin-containing diets are coupled with altered tumour growth.

The number of Krebs II tumour cells recovered from the ascitic fluid of mice fed for 8 days on a lactalbumin (La) control diet was about three times higher than that in animals fed a phytohaemagglutinin-containing (PHA) diet. Feeding a PHA diet for less than 8 days after tumour cell injection also led to a reduction in tumour cell growth. There was an apparent inverse relationship between the total tumour cell count and the intracellular content of putrescine, spermidine and spermine. Hyperplasia of the small intestine occurred in the mice during the development of the ascites. A series of other organs were not affected in the same manner. The results indicate that the polyamine content of Krebs II ascites cells must increase by more than three-fold in order to achieve the intracellular concentration necessary to be able to enter the S-phase. A partial synchronization of the tumour cell population is suggested. Hyperplastic growth of the small intestine would appear to compete with tumour cells for polyamines from a common body pool.

Animals↗
PubMed1997

Hepatic response to increased exogenous supply of plasma amino acids by infusion into the mesenteric vein of Holstein-Friesian cows in late gestation.

The hepatic responses of late gestation, dry dairy cows to acute (6 h) infusions of an amino acid (AA) mixture (Synthamin; 0.0, 1.1, 2.2, 4.4, 8.8 and 17.6 mumol/min) into the mesenteric vein were determined. Neither blood flow nor O2 consumption across the portal-drained viscera (PDV) and liver was significantly altered by infusion. Similarly, there were no effects on net absorption, or hepatic removal, of acetate, propionate, butyrate or NH3. Glucose PDV appearance was unchanged but hepatic glucose production increased (P = 0.032) by 0.2 mumol/min per mumol/min of AA infused. Additional extraction of alanine, glycine (both infused) and glutamine (not infused) by the liver was sufficient to account for most of the extra C required for glucose synthesis. The N that would be liberated from these glucogenic AA would also account for a large proportion of the increase in urea-N produced in response to the AA infusion. This supports the concept of a correlation between gluconeogenesis and ureagenesis. Furthermore, the amide-N liberated from the extracted glutamine would contribute up to 0.17 of hepatic NH3 flux and assist in balancing N inputs into the carbamoyl phosphate and arginosuccinate entry points of the ornithine cycle. Rates of fractional extraction of the various AA by the liver were best fitted by linear equations, indicating that even at the highest rates of administration (approximately twice maximal physiological absorption) the transport systems were not saturated. Hepatic fractional extractions of infused essential AA were highest for methionine (0.83) and phenylalanine (0.87) with the lowest proportion removed observed for valine (0.25), leucine (0.30), lysine (0.31) and isoleucine (0.49). For the non-essential AA, the highest apparent fractional extractions were for glycine (0.73), arginine (0.79) and tyrosine (0.63) followed by alanine (0.54), proline (0.47) and serine (0.37). Hepatic removal of AA-N exceeded the increase in urea-N formation such that, at the highest rate of infusion, approximately 10 mmol/min of the extracted AA was apparently available for hepatic anabolism, more than is required to account for assumed increases in liver mass and export protein synthesis. Similarly, the amount of AA available for peripheral tissue protein gain, when assessed against phenylalanine supply as the limitation, would be the equivalent of a maximum of 0.5 g protein retained/min (6 mmol AA-N/min). This would provide sufficient AA for replenishment of peripheral (muscle) protein stores plus support of the placenta and fetus.

Amino Acids↗
PubMed1997

Amino acid use by the gastrointestinal tract of sheep given lucerne forage.

Essential amino acid (EAA) utilization by gastrointestinal tract (GIT) tissues has been investigated in sheep given 800 and 1,200 g/day lucerne pellets. Animals prepared with indwelling catheters into the aorta and the portal drained viscera plus cannulas into the small intestine were infused with mixed U-13C-labeled amino acid or (1-13C]leucine tracers into the jugular vein or directly into the small intestine. GIT sequestration of EAA from arterial and luminal AA pools was determined from tracer and tracee arterioportal concentration differences at both levels of intake. Proportional tracer 13C-labeled EAA extraction of the arterial supply, on first pass across the GIT during jugular infusion, ranged from 0.063 for histidine to 0.126 for leucine. Recovery of intestinally infused tracer 13C-EAA at the portal vein ranged from 0.61 for histidine to 0.83 for valine. These data were independent of intake. Calculated rates of tracee sequestration by GIT tissues represented 0.45-0.65 of whole body EAA flux, except for histidine, for which the values were much lower (0.25-0.32). With the exception of phenylalanine, more than 0.8 of the EAA used by the GIT was extracted from circulating blood, thus calling into question the theory that GIT tissues make preferential use of EAA during absorptive metabolism, restricting supply to peripheral tissues such as skeletal muscle (growth) or mammary glands (lactation). Instead the GIT seems to compete very successfully with these tissues for circulating blood EAA.

Amino Acids, Essential↗
PubMed1997

Absorption of amino acids from the intestine and their net flux across the mesenteric- and portal-drained viscera of lambs.

Experiments were conducted to compare the rates of apparent absorption (disappearance) of individual essential amino acids (EAA) from the small intestine with their net fluxes across the mesenteric- (MDV) and portal- (PDV) drained viscera in sheep given a pelleted alfalfa diet at two levels of intake. Disappearances of individual EAA across the region of the small intestine drained by the mesenteric arcade (jejunum to ileum) were similar to those across the whole of the small intestine (duodenum to ileum). The net MDV flux of each EAA was similar to its rate of disappearance, but, with the exception of threonine on the low intake level, the net PDV flux was lower (P < .05). Increasing the intake of alfalfa from 800 to 1,200 g/d increased the rate of disappearance of individual EAA between the duodenum and ileum by .56 (range .43 to .65) and between the jejunum and ileum by .51 (range .45 to .60). The MDV and PDV blood flows increased by .35 and .39, respectively, and, with the exception of valine, net fluxes of individual EAA increased by .39 (range .20 to .50) across the MDV and by .44 (range .21 to .71) across the PDV. When net fluxes across the MDV and PDV were measured simultaneously, the ratio of PDV: MDV flux for each EAA was less than (P < .05) unity (mean .61, range .55 to .69), even though all MDV blood enters the PDV, contributing approximately .45 of the total portal flow. This observation suggests that, in regions of the tract not drained by the MDV, extraction of arterial blood EAA for tissue and secretory protein synthesis must exceed the release of protein degradation products into the venous drainage. The results are discussed in terms of endogenous protein secretions into the lumen of the tract anterior to the small intestine.

Amino Acids, Essential↗
PubMed1996

Specific inhibition of epidermal growth factor receptor tyrosine kinase by 4-anilinoquinazolines.

Since the mitogenic action of EGF is mediated by ligand-induced autophosphorylation of the EGF receptor (EGFR), and EGFR is commonly overexpressed in solid human tumours, inhibitors of receptor tyrosine kinase activity (RTK) could prove to be effective antitumour agents. Screening of a compound library using an EGF-RTK enzyme prepared from human tumour derived A431 cells identified a series of potent (IC50 < 1 microM) enzyme inhibitors. These inhibitors are quinazolines bearing a variety of substituted anilines at the 4-position. The most potent 4-anilinoquinazolines (IC50 approximately equal to 20 nM) have small non-polar meta substituents on the aniline ring, and are competitive with ATP and non-competitive with substrate. The growth inhibitory activity of these agents was assessed in vitro using KB cells (human oral squamous tumour) grown in the absence or presence of EGF. A selected compound, 4-(3-chloroanilino)quinazoline (CAQ), inhibited EGF-stimulated growth in a concentration dependent manner and complete blockade was observed at concentrations (1-10 microM) which had no effect on basal growth. Selectivity of growth inhibition by CAQ was further exemplified in IGF1-stimulated KB cells where no effect was detected at concentrations which completely blocked EGF-stimulated growth. Similarly, CAQ blocked TGF alpha-stimulated growth in MCF-7 human breast cancer cells without affecting insulin-stimulated growth. These studies define a novel class of EGF-RTK inhibitors which are also potent and selective inhibitors of EGF-stimulated human tumour cell growth in vitro.

Antineoplastic Agents↗
PubMed1996

Potato lectin: a three-domain glycoprotein with novel hydroxyproline-containing sequences and sequence similarities to wheat-germ agglutinin.

Potato (Solanum tuberosum) tuber lectin is a chitin-binding, hydroxyproline-rich glycoprotein, which may be involved in the defence mechanism of the plant. We had previously obtained evidence that it consists of at least two very dissimilar domains. The aim was to use a combination of accurate determinations of molecular weight and protein sequencing to gain more accurate information on the domains. Accurate determinations of the molecular weight of the lectin by a MALDI mass spectrometer have shown that the subunit molecular weight is 65,500 (+/- 1100) and that of a totally deglycosylated sample is 31,250 (+/- 30). This means that the lectin is 52.3 (+/- 1)% carbohydrate with a considerable number of glycoforms being present. Partial sequences and other analyses are consistent with the existence of three distinct domains. These are: (1) an N-terminal region which is rich in proline but poor in hydroxyproline; (2) a glycosylated region with a glycosylated molecular weight of 45,300 (+/- 1100) and a deglycosylated molecular weight of 11,050 (+/- 50) which is extremely rich in glycosylated hydroxyproline residues with a similar sequence to extensins; and (3) a cystine-rich domain which has the sugar binding site shows partial conservation of a repeated motif common to many chitin-binding proteins of the hevin family including wheat-germ agglutinin. The closest similarity seems to be to the sequence of potato basic chitinase.

Amino Acid Sequence↗