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1.
Anandan D Marmer WN Dudley RL 《Journal of industrial microbiology & biotechnology》2007,34(5):339-347
Aspergillus tamarii expresses an extracellular alkaline protease that we show to be effective in removing hair from cattle hide. Large quantities
of the enzyme will be required for the optimization of the enzymatic dehairing process so the growth conditions for maximum
protease expression by A. tamarii were optimized for both solid-state culture on wheat bran and for broth culture. Optimal protease expression occurred, for
both cultural media, at initial pH 9; the culture was incubated at 30 °C for 96 h using a 5% inoculum. The crude enzyme was
isolated, purified and characterized using MALDI TOF TOF. The alkaline protease was homologous to the alkaline protease expressed
by Aspergillus viridinutans.
Mention of trade names or commercial products in this publication is solely for the purpose of providing specific information
and does not imply recommendation or endorsement by the U.S. Department of Agriculture. 相似文献
2.
Studies to determine the physiological and nutritional characteristics of protease synthesis by Bacteroides splanchnicus NCTC 10825 showed that the proteases were constitutive and cell-associated during exponential growth in batch culture. As growth slowed and the bacteria entered the stationary phase, proteases that had accumulated intracellularly were released into the culture media. In continuous cultures, [dilution rate (D)=0.03 h–1 to D=0.29 h–1], protease activity was completely cell-bound and maximal during nitrogen-limited growth at high dilution rates. The proteases hydrolysed a relatively restricted range of protein substrates including casein, azocasein and gelatine (comparative maximum rates of hydrolysis were 1.0, 4.1 and 2.7 units mg–1 protein respectively). B. splanchnicus proteases exhibited arylamidase activities against leucine p-nitroanilide, valylalanine p-nitroanilide and glycylproline p-nitroanilide. Inhibition experiments indicated that the bacterium produced a mixture of serine, thiol and, possibly, metalloproteases. Protease activities were affected by reducing agents and divalent metal ions. Mercaptoethanol at 1 mm was slightly stimulatory; however, dithiortheitol and dithioerythritol (each 10 mm) respectively inhibited protease activities by 91% and 100%. Calcium ions (5 mm) stimulated protease activity by 30%, whereas Mn2+ and Mg2+ had little or no effect. Protease and arylamidase activities had neutral to alkaline pH optima. Together, these results show that with respect to the types of protease formed and the physiology of the process, B. splanchnicus proteolysis is similar in many respects to that occurring in species belonging to the B. fragilis group.
Correspondence to: G. T. Macfarlane 相似文献
3.
Disney Ribeiro Dias Danielle Marques Vilela Marialice Pinto Coelho Silvestre Rosane Freitas Schwan 《World journal of microbiology & biotechnology》2008,24(10):2027-2034
Two strains of Bacillus, one from a culture collection (B. subtilis ATCC 6633) and a wild type (Bacillus sp. UFLA 817CF) isolated during coffee fermentation in the south of Minas Gerais, Brazil, were evaluated in relation to secretion
of alkaline proteases. The strains were grown on nutrient broth, nutrient broth with sodium caseinate and nutrient broth with
three different concentrations of cheese whey powder for 72 h. Samples were collected at 24-h intervals to evaluate the proteolytic
activity, protein content and cell population. Maximum protease activity was observed after 24-h growth for both the microorganisms,
a period that coincided with the end of the exponential phase. The specific activity values were, respectively, 839.8 U/mg
for B. subtilis ATCC 6633 and 975.9 U/mg for Bacillus sp. UFLA 817CF. The 60% saturation presented the best results for specific protease activity in all the growth culture media
tested with B.
sp. UFLA 817CF. Bacillus sp. UFLA 817CF showed highest enzymatic activity at pH 9.0 and 40°C in the three culture media tested. The protease obtained
from culture of the wild Bacillus strain presented stability at pH 7.0 and considerable heat stability at 40°C and 50°C, and could be an alternative for the
industry to utilize cheese whey to produce proteolytic enzymes. 相似文献
4.
Kamakshi Gupta P. K. Mishra Pradeep Srivastava 《Biotechnology and Bioprocess Engineering》2007,12(2):140-146
Lovastatin, a secondary metabolite, was produced by fermentation process usingAspergillus terreus in an internal loop airlift reactor. It is a highly aerobic fermentation process. Biomass concentration and cell morphology
were evaluated and observed to contribute significantly to the high viscosity and pseudoplastic non-Newtonian behavior of
the broth. Typical morphological changes over 10 days in the fermentation broth were studied. The viscosity increased from
the start of the fermentation with an increasing cell mass content, reached to a maximum of 60 N/m2·s at 160 h and then declined after the branching of the hyphae with the formation of arthrospores. Rheological parameters
like consistency index and fluidity index were evaluated. The consistency index was observed to increase from 9.8 to 66.85
N/m2, while fluidity index decreased from 0.69 to 0.48 s−1 during 10 days of lovastatin production. A correlation between growth and consistency index of the broth has been evaluated. 相似文献
5.
A thermophilic Bacillus stearothermophilus strain AP-4 excreting a thermostable alkaline protease, was isolated from a local compost. Maximum activity of protease (250 U/ml) was after 36 h growth in broth at pH 9.0 and at 55°C. The protease was optimally active at pH 9.0 and 55°C and was stable in 5 mm CaCl2. The enzyme was completely inactivated by PMSF, EDTA and -mercaptoethanol. It is therefore a metal ion-dependent, alkaline, serine protease.R. Dhandapani and R. Vijayaragavan are with the Centre for Plant Molecular Biology & Biotechnology, Tamil Nadu Agricultural University, Coimbatore 641 003, India 相似文献
6.
Yuri Matheus Silva Amaral Osmar Soares da Silva Rodrigo Lira de Oliveira 《Preparative biochemistry & biotechnology》2020,50(6):619-626
AbstractThe protease from Aspergillus tamarii Kita UCP1279 extraction by aqueous two-phase PEG-Citrate (ATPS) systems, using a factorial design 24, was investigated. Then, the variables studied were polyethylene glycol (PEG) molar mass (MPEG), concentrations of PEG (CPEG) and citrate (CCIT), and pH. The responses analyzed were the partition coefficient (K), activity yield (Y) and purification factor (PF). The thermodynamic parameters of the ATPS partition were estimated as a function of temperature. ATPS was able to pre-purify the protease (PF = 1.6) and obtained 84% activity yield. The thermodynamic parameters ΔG°m (?10.89?kJ mol?1), ΔHm (?5.0?kJ?mol?1) and partition ΔSm (19.74?J mol?1 K?1) showed that the preferential migration of almost all protein contaminants of the crude extract to the salt-rich phase, while the preferred protease was the PEG rich phase. The extracted enzyme presents optimum temperature and pH at range of 40–50?°C and 9.0–11.0, respectively. Moreover, the enzyme was identified as serine protease based on inhibition profile. ATPS showed the satisfactory performance as the first step for Aspergillus tamarii Kita UCP1279 protease pre-purification. 相似文献
7.
The physiological response of erythromycin fermentation scale-up from 50 L to 132 m3 scale was investigated. A relatively high oxygen uptake rate (OUR) in early phase of fermentation was beneficial for erythromycin
biosynthesis. Correspondingly, the maximal consistency coefficient (K) reflecting non-Newtonian fluid characteristics in 50 L and 132 m3 fermenter also appeared in same phase. Fluid dynamics in different scale bioreactor was further investigated by real-time
computational fluid dynamics modeling. The results of simulation showed that the impeller combination in 50 L fermenter could
provide more modest flow field environment compared with that in 132 m3 fermenter. The decrease of oxygen transfer rate (OTR) in 132 m3 fermenter was the main cause for impairing cell physiological metabolism and erythromycin biosynthesis. These results were
helpful for understanding the relationship between hydrodynamic environment and physiological response of cells in bioreactor
during the scale-up of fermentation process. 相似文献
8.
Thangam E. Berla Rajkumar G. Suseela 《World journal of microbiology & biotechnology》2000,16(7):663-666
Alcaligenes faecalis produced extracellular protease when incubated in media containing protein substrates. Enzyme production was found to be
influenced by various culture conditions. Enzyme production was growth-associated, expressed linearity with growth and reached
a maximum at the end of the growth phase. Carbohydrates and inorganic nitrogen sources could not be utilized by the bacterium
for its growth, and organic nitrogen appeared to be a primary determinant in protease production. Enzyme production reached
its maximum level of 171.2 U/ml when the culture was incubated at 30 °C at pH 8.0. Ca2+ and Mg2+ enhanced the enzyme production. The crude enzyme powder was stable at high alkaline pH and stable upto 6 months at the storage
temperature of 0–4 °C.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
9.
In-situ recovery of butanol during fermentation 总被引:1,自引:0,他引:1
S. R. Roffler Prof. H. W. Blanch C. R. Wilke 《Bioprocess and biosystems engineering》1987,2(4):181-190
End-product inhibition in the acetone-butanol fermentation was reduced by using extractive fermentation to continuously remove acetone and butanol from the fermentation broth. In situ removal of inhibitory products from Clostridium acetobutylicum resulted in increased reactor productivity; volumetric butanol productivity increased from 0.58 kg/(m3h) in batch fermentation to 1.5 kg/(m3h) in fed-batch extractive fermentation using oleyl alcohol as the extraction solvent. The use of fed-batch operation allowed glucose solutions of up to 500 kg/m3 to be fermented, resulting in a 3.5- to 5-fold decrease in waste water volume. Butanol reached a concentration of 30–35 kg/m3 in the oleyl alcohol extractant at the end of fermentation, a concentration that is 2–3 times higher than is possible in regular batch or fed-batch fermentation. Butanol productivities and glucose conversions in fed-batch extractive fermentation compare favorable with continuous fermentation and in situ product removal fermentations.List of Symbols
C
g kg/m3
concentration of glucose in the feed
-
C
w dm3/m3
concentration of water in the feed
-
F(t) cm3/h
flowrate of feed to the fermentor at time t
-
V(t) dm3
broth volume at time t
-
V
i dm3
initial broth volume
-
V
si dm3
volume of the i-th aqueous phase sample
-
effective fraction of water in the feed
Part 1. Bioprocess Engineering 2 (1987) 1–12 相似文献
10.
The current-voltage (I/V) profiles of Ventricaria (formerly Valonia) membranes were measured at a range of external potassium concentrations, [K+]
o
, from 0.1 to 100 mm. The conductance-voltage (G/V) characteristics were computed to facilitate better resolution of the profile change with time after exposure to different
[K+]
o
. The resistance-voltage (R/V) characteristics were computed to attempt resolution of plasmalemma and tonoplast. Four basic electrophysiological stages
emerged: (1) Uniform low resistance between −60 and +60 mV after the cell impalement. (2) High resistance between +50 and
+150 for [K+]
o
from 0.1 to 1.0 mm and hypotonic media. (3) High resistance between −150 and −20 mV for [K+]
o
of 10 mm (close to natural seawater) and hypertonic media. (4) High resistance between −150 and +170 mV at [K+]
o
of 100 mm.
The changes between these states were slow, requiring minutes to hours and sometimes exhibiting spontaneous oscillations of
the membrane p.d. (potential difference). Our analysis of the I/V data supports a previous hypothesis, that Ventricaria tonoplast is the more resistive membrane containing a pump, which transports K+ into the vacuole to regulate turgor. We associate state (1) with the plasmalemma conductance being dominant and the K+ pump at the tonoplast short-circuited probably by a K+ channel, state (2) with the K+ pump ``off' or short-circuited at p.d.s more negative than +50 mV, state (3) with the K+ pump ``on,' and state (4) with the pump dominant, but affected by high K+. A model for the Ventricaria membrane system is proposed.
Received: 5 November 1998/Revised: 11 May 1999 相似文献
11.
Evaluation of options for harvest of a recombinant E. Coli fermentation producing a domain antibody using ultra scale‐down techniques and pilot‐scale verification
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Ioannis Voulgaris Alex Chatel Mike Hoare Gary Finka Mark Uden 《Biotechnology progress》2016,32(2):382-392
Ultra scale‐down (USD) methods operating at the millilitre scale were used to characterise full‐scale processing of E. coli fermentation broths autolysed to different extents for release of a domain antibody. The focus was on the primary clarification stages involving continuous centrifugation followed by depth filtration. The performance of this sequence was predicted by USD studies to decrease significantly with increased extents of cell lysis. The use of polyethyleneimine reagent was studied to treat the lysed cell broth by precipitation of soluble contaminants such as DNA and flocculation of cell debris material. The USD studies were used to predict the impact of this treatment on the performance and here it was found that the fermentation could be run to maximum productivity using an acceptable clarification process (e.g., a centrifugation stage operating at 0.11 L/m2 equivalent gravity settling area per hour followed by a resultant required depth filter area of 0.07 m2/L supernatant). A range of USD predictions was verified at the pilot scale for centrifugation followed by depth filtration. © 2016 The Authors Biotechnology Progress published by Wiley Periodicals, Inc. on behalf of American Institute of Chemical Engineers Biotechnol. Prog., 32:382–392, 2016 相似文献
12.
《Journal of Fermentation and Bioengineering》1989,67(3):200-206
In order to improve the reliability of fixed-bed anaerobic reactors, the effects of a media and biomass control method were studied using bench scale equipment and mathematical simulation. Test results showed that the allowable volumetric loading rates (kg COD/m3·d) were directly proportional to the packed ratio of the media. Although a reactor completely filled with media (packed media ratio: 100%) could handle an 80% reduction in COD at a loading rate of 11 kg COD/m3·d, a packed reactor half-filled with media (packed media ratio: 50%) could not handle more than 5.5 kg COD/m3·d to achieve the same degree of reduction in COD. Simulation results were based on actual commercial plant operation and showed a practical correlation between COD removal and effective void volume ratio. To achieve a steady reduction of more than 80% in COD, the range of the void volume ratio was presumed to be 0.6 ∼ 0.85. 相似文献
13.
Properties of the extracellular amylase produced by the psychrotrophic bacterium, Arthrobacter psychrolactophilus, were determined for crude preparations and purified enzyme. The hydrolysis of soluble starch by concentrated crude preparations
was found to be a nonlinear function of time at 30 and 40 °C. Concentrates of supernatant fractions incubated without substrate
exhibited poor stability at 30, 40, or 50 °C, with 87% inactivation after 21 h at 30 °C, 45% inactivation after 40 min at
40 °C and 90% inactivation after 10 min at 50 °C. Proteases known to be present in crude preparations had a temperature optimum
of 50 °C, but accounted for a small fraction of thermal instability. Inactivation at 30, 40, or 50 °C was not slowed by adding
20 mg/ml bovine serum albumin or protease inhibitor cocktail to the preparations or the assays to protect against proteases.
Purified amylase preparations were almost as thermally sensitive in the absence of substrate as crude preparations. The temperature
optimum of the amylase in short incubations with Sigma Infinity Amylase Reagent was about 50 °C, and the amylase required
Ca+2 for activity. The optimal pH for activity was 5.0–9.0 on soluble starch (30 °C), and the amylase exhibited a K
m with 4-nitrophenyl-α-D-maltoheptaoside-4,6-O-ethylidene of 120 μM at 22 °C. The amylase in crude concentrates initially hydrolyzed raw starch at 30 °C at about the same
rate as an equal number of units of barley α-amylase, but lost most of its activity after only a few hours. 相似文献
14.
Summary A locally isolated strain of Aspergillus foetidus MTCC 4898 was studied for xylanase (EC 3.2.1.8) production using lignocellulosic substrates under solid state fermentation. Corncobs were found as the best substrates for high yield of xylanases with poor cellulase production. The influence of various parameters such as temperature, pH, moistening agents, moisture level, nitrogen sources and pretreatment of substrates were evaluated with respect to xylanase yield, specific activity and cellulase production. Influence of nitrogen sources on protease secretion was also examined. Maximum xylanase production (3065 U/g) was obtained on untreated corncobs moistened with modified Mandels and Strenberg medium, pH 5.0 at 1 5 moisture levels at 30 °C in 4 days of cultivation. Submerged fermentation under the same conditions gave higher yield (3300 U/g) in 5 days of cultivation, but productivity was less. Ammonium sulphate fractionation yielded 3.56-fold purified xylanase with 76% recovery. Optimum pH and temperature for xylanase activity were found to be 5.3 and 50 °C respectively. Kinetic parameters like Km and Vmax were found to be 3.58 mg/ml and 570 μmol/mg/min. Activity of the enzyme was found to be enhanced by cystiene hydrochloride, CoCl2, xylose and Tween 80, while significantly inhibited by Hg++, Cu++ and glucose. The enzyme was found to be stable at 40 °C. The half life at 50 °C was 57.53 min. However thermostability was enhanced by glycerol, trehalose and Ca++. The crude enzyme was stable during lyophilization and could be stored at less than 0 °C. 相似文献
15.
J. Kloosterman IV P. D. van Wassenaar N. K. H. Slater H. Baksteen 《Bioprocess and biosystems engineering》1988,3(4):181-185
Polydimethylsiloxane and polypropylene glycol-based anti-foam agents adversely influence the ultrafiltration rate of a protease solution with polysulfon membranes. Four propietary agents have been compared, of which Rhodosil 426 R (ex Rhone Poulenc, France), an emulsion of polydimethylsiloxane, proved to have the least influence. With this agent, the relative filtration flux of a protease solution decreased by a factor of two for concentrations of anti-foam agent higher than 0.25 cm3/dm3. A simple, quasisteady-state model developed on the basis of data obtained from total recycle experiments with this anti-foam agent, well predicted the temporal variation of protease concentration during batch ultrafiltration experiments with and without Rhodosil 426 R.List of Symbols
A
uf
m2
total membrane area
-
C
af
dm3/m3
concentration of anti-foam agent
-
C
af,0
dm3/m3
initial concentration of anti-foam agent in the feed solution
-
C
e
kg/m3
protease powder concentration
-
C
e,0
kg/m3
initial protease powder concentration in the feed solution
-
J m3/s
ultrafiltration rate
-
J
w
m3/m2s
water flow for a clean membrane under processing conditions
-
R
af
rejection coefficient for anti-foam agent
-
R
e
rejection coefficient for protein
-
RF %
relative filtration rate
-
t s
filtration time
-
V m3
concentrate volume
-
V
0
m3
volume to be concentrated
-
V
t
m3
end volume 相似文献
16.
T. Kobayashi Y. Hakamada S. Adachi J. Hitomi T. Yoshimatsu K. Koike S. Kawai S. Ito 《Applied microbiology and biotechnology》1995,43(3):473-481
Alkaline protease (EC 3.4.21.14) activity, suitable for use in detergents, was detected in the alkaline culture medium of Bacillus sp. KSM-K16, which was originally isolated from soil. The enzyme, designated M protease, was purified to homogeneity from the culture broth by column chromatographies. The N-terminal amino acid sequence was Ala-Gln-Ser-Val-Pro-Trp-Gly-Ile-Ser-Arg-Val-Gln-Ala-Pro-Ala-Ala-His-Asn-Arg-Gly-Leu-Thr-Gly. The molecular mass of the protease was 28 kDa, and its isoelectric point was close to pH 10.6. Maximum activity toward casein was observed at 55°C and at pH 12.3 in 50 mM phosphate/NaOH buffer. The activity was inhibited by phenylmethylsulfonyl flouride and chymostatin. The enzyme was very stable in long-term incubation with liquid detergents at 40°C. The enzyme cleaved the oxidized insulin B chain initially at Leu15-Tyr16 and efficiently at ten more sites. Among various oligopeptidyl p-nitro-anilides (pNA) tested, N-succinyl-Ala-Ala-Pro-Phe-pNA was efficiently hydrolyzed by M protease. M protease was precipitated in (NH4)2SO4-saturated acetate buffer (pH 5.0) as plank-like cyrstals. 相似文献
17.
An alkaline protease from fresh fruiting bodies of the edible mushroom <Emphasis Type="Italic">Pleurotus citrinopileatus</Emphasis> 总被引:1,自引:0,他引:1
A protease was purified from fresh fruiting bodies of the edible mushroom Pleurotus citrinopileatus. The isolation procedure included ion exchange chromatography on DEAE-cellulose, CM-cellulose, and Q-Sepharose and fast protein
liquid chromatography-gel filtration on Superdex 75. The protease was unadsorbed on DEAE-cellulose and Q-Sepharose, but adsorbed
on CM-cellulose. In sodium dodecyl sulfate-polyacrylamide gel electrophoresis, the protease demonstrated a single band with
a molecular mass of 28 kDa. The protease showed an optimal pH at 10 and an optimal temperature at 50°C. The activity of the
protease was not affected by EDTA, indicating that it is not a metalloprotease. The protease exhibited a higher activity in
the presence of K+ and Li+, but its activity was potently inhibited by Al3+, Cu2+, and Hg2+ ions. It manifested a K
m of 3.44 mg/ml and a V
max of 0.139 mg ml−1 min−1. It was devoid of ribonuclease and antifungal activities. 相似文献
18.
Carolina A. B. de Gusmão Raquel D. Rufino Leonie A. Sarubbo 《World journal of microbiology & biotechnology》2010,26(9):1683-1692
Biosurfactant production by Candida glabrata was studied using vegetable fat waste as substrate. A factorial design was initially carried out to investigate the effects
and interactions of waste, yeast extract and glucose on the surface tension after 144 h cultivation. Maximum surface tension
reduction was achieved with vegetable fat waste at 5% and yeast extract at 0.2%. The biosurfactant containing cell-free broth
retained its surface-active properties after incubation at high temperatures, at a wide range of pH values and salt concentrations.
Comparison between three solvent systems for surfactant recovery showed that ethyl acetate extracted both crude extracellular
and intracellular biosurfactant with high product recovery. The isolated extracellular biosurfactant showed a CMC of 1% and
the surface tension at that point was 24 mN m−1. Preliminary chemical composition revealed the presence of carbohydrates, proteins and lipids. The application of the crude
biosurfactant to a soil–water-hydrophobic contaminant system was investigated and the apparent critical micelle concentration
was determined at 7% of the broth, although the best oil removal (92.6%) had been obtained with 10% of the cell-free broth.
The cost of application of the biosurfactant in soils was estimated based on the cost of a commercial biosurfactant. 相似文献
19.
Takao Watanabe Taishi Tanabe Hisaaki Sato Yoko Fuse Kengo Ueda Katsushige Nakano Hiroshi Saito Nobutoshi Maehara 《Microbiology and immunology》1995,39(6):369-377
Optimum culture conditions for the production of exfoliative toxin by Staphylococcus hyicus (shET) were examined. High shET activity was obtained from the culture filtrate of HI and TY broth inoculated with S. hyicus. The pH in these two media ranged from 7 to 8.5 during bacterial culture, while the lowest pH in TS and BHI broth was less than 6. shET activity in the culture filtrate from TY broth inoculated with 107 CFU of S. hyicus per ml was higher than that in TY broth inoculated with 106 and 108 CFU of bacteria per ml. When shET activity in the culture filtrate was measured under various shaking conditions, the culture filtrate shaken at 75 oscillations per min had the highest shET activity of the five shaking conditions. shET activity of the culture filtrate of TY broth to which protease inhibitor had been added was the same as that of TY broth without inhibitor. shET activity in a shaking culture in an Erlenmeyer flask was also the same as that in sac culture and that in shaking culture using a shaking (Sakaguchi) flask. shET activity in TY broth supplemented with 100 mM glucose was significantly lower than that in TY broth without glucose. Based on the above results, the optimum culture conditions for the production of shET were as follows: inoculation of 3 × 109 CFU of S. hyicus strain P-1 into 300 ml of TY broth in a 2,000-ml Erlenmeyer flask, and incubation at 37 C with shaking at 75 oscillations per min. Then shET activity of the culture filtrate under appropriate culture conditions was measured after various incubation periods. shET activity was detected 6 hr after inoculation, reached the maximum (253 exfoliative unit/0.1 ml) at 16 hr and decreased between 20 and 48 hr. Thus, the optimum incubation period was determined to be 16 hr. Then the optimum concentration of ammonium sulfate for isolation of shET from the culture filtrate under appropriate culture conditions was examined. The greatest shET activity was obtained from the fraction salted out with 90% saturated ammonium sulfate. Thus, the optimum concentration of ammonium sulfate for the isolation of shET was determined to be 90% saturation. 相似文献
20.
The level of calcium-activated neutral protease (CANP) activity in the brain and nerve cord of the crayfish Procambarus clarkii was assayed by measuring the degradation of casein yellow by tissue homogenates. When care was taken to maintain the ionic strength of all incubation media at 0.15M and to buffer the Ca2+activity of the media with 5mM EGTA, CANP was found to be very sensitive to Ca2+; maximal activity was achieved at 1 × 10?3M Ca2+, with 50% of this maximum present at the physiologic intracellular Ca2+activity of 1 × 10?7M. We found that the anticonvulsant agent phenytoin was without effect on CANP activity while pentobarbital and a relatively new anticonvulsant agent, valproic acid (an eight-carbon branched fatty acid), significantly inhibited CANP activity in a dose-dependent manner. The inhibitory effect of valproic acid was shared by a straight-chain eight-carbon fatty acid, caprylic acid. These findings demonstrate that inhibition of CANP activity is not limited to agents with a specific molecular structure. They also suggest that CANP plays a role in the normal turnover of proteins that control various cellular functions. 相似文献