Abstract: This paper presents a low-cost, eco-friendly and reproducible microbe mediated biosynthesis of TiO2 nanoparticles. TiO2 nanoparticles synthesized using the bacterium, Bacillus subtilis, from titanium as a precursor, were confirmed by TEM analysis. The morphological characteristics state spherical shape, with the size of individual or aggregate nanoparticles, around 30-40 nm. Microbial resistance represents a challenge for the scientific community to develop new bioactive compounds. Here, the antibacterial effect of TiO2 nanoparticles on Escherichia coli was investigated, which was confirmed by CFU (Colony-forming unit). Further, growth curve study of E. coli Hb101 in the presence and absence of TiO2 nanoparticles was done. Optical density decrease was observed with the increase in the concentration of TiO2. It could be attributed to the inactivation of cellular enzymes and DNA by binding to electron-donating groups such as carboxylates, amides, indoles, hydroxyls, thiols, etc. which cause little pores in bacterial cell walls, leading to increased permeability and cell death. This justifies that TiO2 nanoparticles have efficient antibacterial effect and have potential to be used as an antibacterial agent for different purposes.
Abstract: Background: Uncontrolled inflammation may cause serious inflammatory diseases if left untreated. Non-steroidal anti-inflammatory drug (NSAIDs) is commonly used to inhibit pro-inflammatory enzymes, thus, reduce inflammation. However, long term administration of NSAIDs leads to various complications. Medicinal plants are getting more attention as it is believed to be more compatible with human body. One of them is a flavonoid-containing medicinal plants, Strobilanthes crispus which has been traditionally claimed to possess anti-inflammatory and antioxidant activities. Nevertheless, its anti-inflammatory activities are yet to be scientifically documented. Objectives: This study aimed to examine the anti-inflammatory activity of S. crispus by investigating its effects on intracellular oxidative stress and prostaglandin E2 (PGE2) levels. Materials and Methods: In this study, the Maximum Non-toxic Dose (MNTD) of methanol extract of both leaves and stems of S. crispus was first determined using 3-(4,5-dimethylthiazolyl-2)-2,5-diphenytetrazolium Bromide (MTT) assay. The effects of S. crispus extracts at MNTD and half MNTD (½MNTD) on intracellular ROS as well as PGE2 levels in 1.0 µg/mL LPS-stimulated RAW 264.7 macrophages were then be measured using DCFH-DA and a competitive enzyme immunoassay kit, respectively. Results: The MNTD of leaf extract was determined as 700µg/mL while for stem was as low as 1.4µg/mL. When LPS-stimulated RAW 264.7 macrophages were subjected to the MNTD of S. crispus leaf extract, both intracellular ROS and PGE2 levels were significantly reduced. In contrast, stem extract at both MNTD and ½MNTD did not significantly reduce the PGE2 level, but significantly increased the intracellular ROS level. Conclusion: The methanol leaf extract of S. crispus may possess anti-inflammatory properties as it is able to significantly reduce the intracellular ROS and PGE2 levels of LPS-stimulated cells. Nevertheless, further studies such as investigating the interleukin, nitric oxide and cytokine tumor necrosis factor-α (TNFα) levels has to be conducted to further confirm the anti-inflammatory properties of S. crispus.
Abstract: Rice bran is normally used as a raw material for rice
bran oil production or sold as feed with a low price. Conventionally,
the protein in defatted rice bran was extracted using alkaline
extraction and acid precipitation, which involves in chemical usage
and lowering some nutritious component. This study was conducted
in order to extract of rice bran protein concentrate (RBPC) from
defatted rice bran using enzymes and employing polysaccharides in a
precipitating step. The properties of RBPC obtained will be compared
to those of a control sample extracted using a conventional method.
The results showed that extraction of protein from rice bran using
enzymes exhibited the higher protein recovery compared to that
extraction with alkaline. The extraction conditions using alcalase 2%
(v/w) at 50 C, pH 9.5 gave the highest protein (2.44%) and yield
(32.09%) in extracted solution compared to other enzymes. Rice bran
protein concentrate powder prepared by a precipitation step using
alginate (protein in solution: alginate 1:0.016) exhibited the highest
protein (27.55%) and yield (6.84%). Precipitation using alginate was
better than that of acid. RBPC extracted with alkaline (ALK) or
enzyme alcalase (ALC), then precipitated with alginate (AL)
(samples RBP-ALK-AL and RBP-ALC-AL) yielded the precipitation
rate of 75% and 91.30%, respectively. Therefore, protein
precipitation using alginate was then selected. Amino acid profile of
control sample, and sample precipitated with alginate, as compared to
casein and soy protein isolated, showed that control sample showed
the highest content among all sample. Functional property study of
RBP showed that the highest nitrogen solubility occurred in pH 8-10.
There was no statically significant between emulsion capacity and
emulsion stability of control and sample precipitated by alginate.
However, control sample showed a higher of foaming capacity and
foaming stability compared to those of sample precipitated with
alginate. The finding was successful in terms of minimizing
chemicals used in extraction and precipitation steps in preparation of
rice bran protein concentrate. This research involves in a production
of value-added product in which the double amount of protein (28%)
compared to original amount (14%) contained in rice bran could be
beneficial in terms of adding to food products e.g. healthy drink with
high protein and fiber. In addition, the basic knowledge of functional
property of rice bran protein concentrate was obtained, which can be
used to appropriately select the application of this value-added
product from rice bran.
Abstract: Diagnostic enzymes like aspartate aminotransferase
(AST), alanine aminotransferase (ALT) and alkaline phosphatase
(ALP) were determined as indices of heavy metal pollution in Tilapia
guinensis. Three different sets of fishes treated with lead (Pb), iron
(Fe) and copper (Cu) were used for the study while a fourth group
with no heavy metal served as a control. Fishes in each of the groups
were exposed to 2.65mg/l of Pb, 0.85mg/l of Fe and 0.35 mg/l of Cu
in aerated aquaria for 96 hours. Tissue fractionation of the liver
tissues was carried out and the three diagnostic enzymes (AST, ALT,
and ALP) were estimated. Serum levels of the same diagnostic
enzymes were also measured. The mean values of the serum enzyme
activity for ALP in each experimental group were 19.5±1.62,
29.67±2.17 and 1.15±0.27 IU/L for Pb, Fe and Cu groups compared
with 9.99±1.34 IU/L enzyme activity in the control. This result
showed that Pb and Fe caused increased release of the enzyme into
the blood circulation indicating increased tissue damage while Cu
caused a reduction in the serum level as compared with the level in
the control group. The mean values of enzyme activity obtained in
the liver were 102.14±6.12, 140.17±2.06 and 168.23±3.52 IU/L for
Pb, Fe and Cu groups, respectively compared to 91.20±9.42 IU/L
enzyme activity for the control group. The serum and liver AST and
ALT activities obtained in Pb, Fe, Cu and control groups are
reported. It was generally noted that the presence of the heavy metal
caused liver tissues damage and consequent increased level of the
diagnostic enzymes in the serum.
Abstract: Whey is the lactose rich by-product of the dairy
industry, having good amount of nutrient reservoir. Most abundant
nutrients are lactose, soluble proteins, lipids and mineral salts.
Disposing of whey by most of milk plants which do not have proper
pre-treatment system is the major issue. As a result of which, there
can be significant loss of potential food and energy source. Thus,
whey has been explored as the substrate for the synthesis of different
value added products such as enzymes. β-galactosidase is one of the
important enzymes and has become the major focus of research due
to its ability to catalyze both hydrolytic as well as
transgalactosylation reaction simultaneously. The enzyme is widely
used in dairy industry as it catalyzes the transformation of lactose to
glucose and galactose, making it suitable for the lactose intolerant
people. The enzyme is intracellular in both bacteria and yeast,
whereas for molds, it has an extracellular location. The present work
was carried to utilize the whey for the production of β-galactosidase
enzyme using both yeast and fungal cultures. The yeast isolate
Kluyveromyces marxianus WIG2 and various fungal strains have
been used in the present study. Different disruption techniques have
also been investigated for the extraction of the enzyme produced
intracellularly from yeast cells. Among the different methods tested
for the disruption of yeast cells, SDS-chloroform showed the
maximum β-galactosidase activity. In case of the tested fungal
cultures, Aureobasidium pullulans NCIM 1050 was observed to be
the maximum extracellular enzyme producer.
Abstract: Lignocellolusic material is a substance that is resistant to be degraded by microorganisms or hydrolysis enzymes. To be used as materials for biofuel production, it needs pretreatment process to improve efficiency of hydrolysis. In this work, chemical pretreatments on rice straw using three diluted organic acids, including acetic acid, citric acid, oxalic acid, were optimized. Using Response Surface Methodology (RSM), the effect of three pretreatment parameters, acid concentration, treatment time, and reaction temperature, on pretreatment efficiency were statistically evaluated. The results indicated that dilute oxalic acid pretreatment led to the highest enhancement of enzymatic saccharification by commercial cellulase and yielded sugar up to 10.67 mg/ml when using 5.04% oxalic acid at 137.11 oC for 30.01 min. Compared to other acid pretreatment by acetic acid, citric acid, and hydrochloric acid, the maximum sugar yields are 7.07, 6.30, and 8.53 mg/ml, respectively. Here, it was demonstrated that organic acids can be used for pretreatment of lignocellulosic materials to enhance of hydrolysis process, which could be integrated to other applications for various biorefinery processes.
Abstract: Rice straw is lignocellulosic biomass which can be utilized as substrate for the biogas production. However, due to the property and composition of rice straw, it is difficult to be degraded by hydrolysis enzymes. One of the pretreatment methods that modify such properties of lignocellulosic biomass is the application of lignocellulose-degrading microbial consortia. The aim of this study is to investigate the effect of microbial consortia to enhance biogas production. To select the high efficient consortium, cellulase enzymes were extracted and their activities were analyzed. The results suggested that microbial consortium culture obtained from cattle manure is the best candidate compared to decomposed wood and horse manure. A microbial consortium isolated from cattle manure was then mixed with anaerobic sludge and used as inoculum for biogas production. The optimal conditions for biogas production were investigated using response surface methodology (RSM). The tested parameters were the ratio of amount of microbial consortium isolated and amount of anaerobic sludge (MI:AS), substrate to inoculum ratio (S:I) and temperature. Here, the value of the regression coefficient R2 = 0.7661 could be explained by the model which is high to advocate the significance of the model. The highest cumulative biogas yield was 104.6 ml/g-rice straw at optimum ratio of MI:AS, ratio of S:I, and temperature of 2.5:1, 15:1 and 44°C respectively.
Abstract: Beta-glucosidase, chitinase, leucine-aminopeptidase, acid phosphomonoesterase and acetate-esterase enzyme activities in
the soils under the impact of metallurgical industrial activity in Lori
marz (district) were investigated. The results of the study showed that
the activities of the investigated enzymes in the soils decreased with increasing distance from the Shamlugh copper mine, the Chochkan
tailings storage facility and the ore transportation road. Statistical
analysis revealed that the activities of the enzymes were positively
correlated (significant) to each other according to the observation
sites which indicated that enzyme activities were affected by the
same anthropogenic factor. The investigations showed that the soils
were polluted with heavy metals (Cu, Pb, As, Co, Ni, Zn) due to
copper mining activity in this territory. The results of Pearson
correlation analysis revealed a significant negative correlation
between heavy metal pollution degree (Nemerow integrated pollution
index) and soil enzyme activity. All of this indicated that copper
mining activity in this territory causing the heavy metal pollution of
the soils resulted in the inhabitation of the activities of the enzymes
which are considered as biological catalysts to decompose organic
materials and facilitate the cycling of nutrients.
Abstract: Fungal mutant strains have produced cellulase and
xylanase enzymes, and have induced high hydrolysis with enhanced
of rice straw. The mutants were obtained by exposing Penicillium
strain to UV-light treatments. Screening and selection after treatment
with UV-light were carried out using cellulolytic and xylanolytic
clear zones method to select the hypercellulolytic and
hyperxylanolytic mutants. These mutants were evaluated for their
cellulase and xylanase enzyme production as well as their abilities for
biodegradation of rice straw. The mutant 12 UV/1 produced 306.21%
and 209.91% cellulase and xylanase, respectively, as compared with
the original wild type strain. This mutant showed high capacity of
rice straw degradation. The effectiveness of tested mutant strain and
that of wild strain was compared in relation to enhancing the
composting process of rice straw and animal manures mixture. The
results obtained showed that the compost product of inoculated
mixture with mutant strain (12 UV/1) was the best compared to the
wild strain and un-inoculated mixture. Analysis of the composted
materials showed that the characteristics of the produced compost
were close to those of the high quality standard compost. The results
obtained in the present work suggest that the combination between
rice straw and animal manure could be used for enhancing the
composting process of rice straw and particularly when applied with
fungal decomposer accelerating the composting process.
Abstract: Lipases constitute one of the most important groups of
industrial enzymes that catalyze the hydrolysis of triacylglycerol to
glycerol and fatty acids. Muscarinic antagonist relieves smooth
muscle spasm of the gastrointestinal tract and effect on the
cardiovascular system. In this research the effect of a muscarinic
antagonist on the lipase activity of Pseudomonas aeruginosa was
studied. Lineweaver–Burk plot showed that the drug inhibited the
enzyme by competitive inhibition. The IC50 value (0.16 mM) and Ki
(0.03 mM) of the drug revealed the drug bound to enzyme with high
affinity. Determination of enzyme activity in various pH and
temperature showed that the maximum activity of lipase was at pH 8
and 60oC both in presence and absence of the drug.
Abstract: Diminished antioxidant defense or increased
production of reactive oxygen species in the biological system can
result in oxidative stress which may lead to various
neurodegenerative diseases including Alzheimer’s disease (AD).
Microglial activation also contributes to the progression of AD by
producing several proinflammatory cytokines, nitric oxide (NO) and
prostaglandin E2 (PGE2). Oxidative stress and inflammation have
been reported to be possible pathophysiological mechanisms
underlying AD. In addition, the cholinergic hypothesis postulates that
memory impairment in patient with AD is also associated with the
deficit of cholinergic function in the brain. Although a number of
drugs have been approved for the treatment of AD, most of these
synthetic drugs have diverse side effects and yield relatively modest
benefits. Marine algae have great potential in pharmaceutical and
biomedical applications as they are valuable sources of bioactive
properties such as anticoagulation, antimicrobial, antioxidative,
anticancer and anti-inflammatory. Hence, this study aimed to provide
an overview of the properties of Malaysian seaweeds (Padina
australis, Sargassum polycystum and Caulerpa racemosa) in
inhibiting oxidative stress, neuroinflammation and cholinesterase
enzymes. These seaweeds significantly exhibited potent DPPH and
moderate superoxide anion radical scavenging ability (P
Abstract: The study examined the effect of Bonny Light whole
crude oil (WC) and its water soluble fraction (WSF) on the activities
of antioxidant enzymes (catalase (CAT) and superoxide dismutase
(SOD)) and crude mitochondria ATPases in the radicle of
germinating bean (Vigna unguiculata). The percentage germination,
level of lipid peroxidation, antioxidant enzyme and mitochondria
Ca2+ and Mg2+ ATPase activities were measured in the radicle of
bean after 7, 14 and 21 days post germination. Viable bean seeds
were planted in soils contaminated with 10ml, 25ml and 50ml of
whole crude oil (WC) and its water soluble fraction (WSF) to obtain
2, 5 and 10% v/w crude oil contamination. There was dose dependent
reduction of the number of bean seeds that germinated in the
contaminated soils compared with control (p
Abstract: Bacterial strains capable of degradation of malathion
from the domestic sewage were isolated by an enrichment culture
technique. Three bacterial strains were screened and identified as
Acinetobacter baumannii (AFA), Pseudomonas aeruginosa (PS1),
and Pseudomonas mendocina (PS2) based on morphological,
biochemical identification and 16S rRNA sequence analysis.
Acinetobacter baumannii AFA was the most efficient malathion
degrading bacterium, so used for further biodegradation study. AFA
was able to grow in mineral salt medium (MSM) supplemented with
malathion (100 mg/l) as a sole carbon source, and within 14 days,
84% of the initial dose was degraded by the isolate measured by high
performance liquid chromatography. Strain AFA could also degrade
other organophosphorus compounds including diazinon, chlorpyrifos
and fenitrothion. The effect of different culture conditions on the
degradation of malathion like inoculum density, other carbon or
nitrogen sources, temperature and shaking were examined.
Degradation of malathion and bacterial cell growth were accelerated
when culture media were supplemented with yeast extract, glucose
and citrate. The optimum conditions for malathion degradation by
strain AFA were; an inoculum density of 1.5x 10^12CFU/ml at 30°C
with shaking. A specific polymerase chain reaction primers were
designed manually using multiple sequence alignment of the
corresponding carboxylesterase enzymes of Acinetobacter species.
Sequencing result of amplified PCR product and phylogenetic
analysis showed low degree of homology with the other
carboxylesterase enzymes of Acinetobacter strains, so we suggested
that this enzyme is a novel esterase enzyme. Isolated bacterial strains
may have potential role for use in bioremediation of malathion
contaminated.
Abstract: Liver disorders are one of the major problems of the
world. Despite its frequent occurrence, high morbidity and high
mortality, its medical management is currently inadequate. This study
was designed to evaluate the hepatoprotective effect of saponin
extract of the root of Garcinia kola on the integrity of the liver of
paracetamol induced wistar albino rats. Twenty five (25) male adult
wistar albino rats were divided into five (5) groups. Group I was the
Control group that received distilled water only, group II was the
negative control that received 2 g/kg of paracetamol on the 13th day,
and group III, IV and V were pre-treated with 100, 200 and
400mg/kg of the saponin extract before inducing the liver damage on
the 13th day with 2 g/kg of paracetamol. Twenty four (24) h after
administration, the rats were sacrificed and blood samples were
collected. The serum Alanine Transaminase (ALT), Aspartate
Transaminase (AST), Alkaline Phosphatase (ALP) activities,
Bilirubin and conjugated bilirubin, glucose and protein
concentrations were evaluated. The liver was fixed immediately in
Formalin and was processed and stained in Haematoxylin and Eosin
(H&E). Administration of saponin extract from the root of Garcinia
kola significantly decreased paracetamol induced elevated enzymes
in the test group. Also histological observations showed that saponin
extract of the root of Garcinia kola exhibited a significant liver
protection against the toxicant as evident by the cells trying to return
to normal. Saponin extract from the root of Garcinia kola indicated a
protection of structural integrity of the hepatocytic cell membrane
and regeneration of the damaged liver.
Abstract: Heavy metals are one of the major groups of
contaminants in the environment and many of them are toxic even at
very low concentration in plants and animals. However, some metals
play important roles in the biological function of many enzymes in
living organisms. Metals such as zinc, iron, and cooper are important
for survival and activity of enzymes in plants, however heavy metals
can inhibit enzyme which is responsible for defense system of plants.
Polyphenol oxidase (PPO) is a copper-containing metalloenzyme
which is responsible for enzymatic browning reaction of plants.
Enzymatic browning is a major problem for the handling of
vegetables and fruits in food industry. It can be increased and
effected with many different futures such as metals in the nature and
ground. In the present work, PPO was isolated and characterized
from green leaves of red poppy plant (Papaverr hoeas). Then, the
effect of some known antibrowning agents which can form
complexes with metals and metals were investigated on the red poppy
PPO activity. The results showed that glutathione was the most
potent inhibitory effect on PPO activity. Cu(II) and Fe(II) metals
increased the enzyme activities however, Sn(II) had the maximum
inhibitory effect and Zn(II) and Pb(II) had no significant effect on the
enzyme activity. In order to reduce the effect of heavy metals, the
effects of metal-antibrowning agent complexes on the PPO activity
were determined. EDTA and metal complexes had no significant
effect on the enzyme. L-ascorbic acid and metal complexes decreased
but L-ascorbic acid-Cu(II)-complex had no effect. Glutathione–metal
complexes had the best inhibitory effect on Red poppy leaf PPO
activity.
Abstract: Pomegranate (Punica granatum L.) is an ancient fruit of great medical interest and rich source of antioxidants. Pesticides as dimethoate play a crucial role in the occurrence many diseases in plants, animal and human. Therefore the ability of Pomegranate (Punica granatum L.) to alleviate hepatotoxicity induced by organophosphate pesticide dimethoate was investigated. Albino male rats were divided randomly into 4 groups and kept at 7 animals per group in an environmentally controlled condition for 6 weeks. The first group was served as a control group (basal diet), the second group fed on basal diet supplemented with 5% freeze dried pomegranate seeds, the third group fed on 20 ppm dimethoate contaminated diet and the last group fed on dimethoate contaminated diet supplemented with 5% freeze dried pomegranate seeds. The results revealed that administration of dimethoate caused high significant increased in liver functions: alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP) activities as well as lipid peroxide (malonaldhyde, MDA); on the other hand high significant decreased on glutathione (GSH), glutathione peroxidase (GPx), albumin and total protein were observed. However addition of 5% freeze dried pomegranate seeds significantly improved all previously mentioned parameters. These results indicate the dimethoate induced hepatotoxicity and highlight the protective effect of pomegranate seeds as a potential protective agent against dimethoate induced hepatotoxicity. This may be attributed to the powerful antioxidants (polyphenols, total phenols, and total flavonoids) which present in high levels in pomegranate as well as improving the immunity by activation of antioxidant enzymes GSH and GPx.
Abstract: Enzyme activity was evaluated in the intestine of
juvenile dourado (Salminus brasiliensis) fed with diets containing 0,
10 or 20% of lyophilized bovine colostrum (LBC) inclusion for either
30 or 60 days. The intestinal enzymes acid and alkaline phosphatase
(ACP and ALP, respectively), non-specific esterase (NSE), lipase
(LIP), dipeptidyl aminopeptidase IV (DAP IV) and leucine
aminopeptidase (LAP) were studied using histochemistry in four
intestinal segments (S1, S2, S3 and posterior intestine). Weak
proteolitic activity was observed in all intestinal segments for DAP
IV and LAP. The activity of NSE and LIP was also weak in all
intestines, except for the moderate activity of NSE in the S2 of 20%
LBC group after 30 days and in the S1 of 0% LBC group after 60
days. The ACP was detected only in the S2 and S3 of the 10% LBC
group after 30 days. Moderate and strong staining was observed in
the first three intestinal segments for ALP and weak activity in the
posterior intestine. The activity of DAP IV, LAP and ALP were also
present in the cytoplasm of the enterocytes. In the present results,
bovine colostrum feeding did not cause alterations in activity of
intestinal enzymes.
Abstract: Fibrin degradation is an important part in prevention
or treatment of intravascular thrombosis and cardiovascular diseases.
Plasmin like fibrinolytic enzymes has given new hope to patient with
cardiovascular diseases by treating fibrin aggregation related diseases
with traditional plasminogen activator which have many side effects.
Various researches involving wide range of sources for production of
fibrinolytic proteases, from bacteria, fungi, insects and fermented
foods. But few have looked into endophytic fungi as a potential
source. Sixteen (16) endophytic fungi were isolated from Hibiscus sp.
leaves from six different locations in Shah Alam, Selangor. Only two
endophytic fungi, FH3 and S13 showed positive fibrinolytic protease
activities. FH3 produced 5.78cm and S13 produced 4.48cm on Skim
Milk Agar after 4 days of incubation at 27°C. Fibrinolytic activity
was observed; 3.87cm and 1.82cm diameter clear zone on fibrin plate
of FH3 and S13 respectively. 18srRNA was done for identification of
the isolated fungi with positive fibrinolytic protease. S13 had the
highest similarity (100%) to that of Penicillium citrinum strain TG2
and FH3 had the highest similarity (99%) to that of Fusarium sp.
FW2PhC1, Fusarium sp. 13002, Fusarium sp. 08006, Fusarium
equiseti strain Salicorn 8 and Fungal sp. FCASAn-2. Media
composition variation showed the effects of carbon nitrogen on
protein concentration, where the decrement of 50% of media
composition caused drastic decrease in protease of FH3 from 1.081 to
0.056 and also S13 from 2.946 to 0.198.
Abstract: Protein kinases participate in a myriad of cellular
processes of major biomedical interest. The in vivo substrate
specificity of these enzymes is a process determined by several
factors, and despite several years of research on the topic, is still
far from being totally understood. In the present work, we have
quantified the contributions to the kinase substrate specificity of
i) the phosphorylation sites and their surrounding residues in the
sequence and of ii) the association of kinases to adaptor or scaffold
proteins. We have used position-specific scoring matrices (PSSMs),
to represent the stretches of sequences phosphorylated by 93 families
of kinases. We have found negative correlations between the number
of sequences from which a PSSM is generated and the statistical
significance and the performance of that PSSM. Using a subset
of 22 statistically significant PSSMs, we have identified specificity
determinant residues (SDRs) for 86% of the corresponding kinase
families. Our results suggest that different SDRs can function as
positive or negative elements of substrate recognition by the different
families of kinases. Additionally, we have found that human proteins
with known function as adaptors or scaffolds (kAS) tend to interact
with a significantly large fraction of the substrates of the kinases to
which they associate. Based on this characteristic we have identified
a set of 279 potential adaptors/scaffolds (pAS) for human kinases,
which is enriched in Pfam domains and functional terms tightly
related to the proposed function. Moreover, our results show that
for 74.6% of the kinase–pAS association found, the pAS colocalize
with the substrates of the kinases they are associated to. Finally, we
have found evidence suggesting that the association of kinases to
adaptors and scaffolds, may contribute significantly to diminish the
in vivo substrate crossed-specificity of protein kinases. In general, our
results indicate the relevance of several SDRs for both the positive
and negative selection of phosphorylation sites by kinase families and
also suggest that the association of kinases to pAS proteins may be
an important factor for the localization of the enzymes with their set
of substrates.
Abstract: After cold pressing of pumpkin oil, the defatted oil cake (PUOC) was utilised as raw material for processing of bio-functional hydrolysates. In this study, the in vitro bioactivity of an alcalase (AH) and a pepsin hydrolysate (PH) prepared from the major pumpkin 12S globulin (cucurbitin) are compared. The hydrolysates were produced at optimum reaction conditions (temperature, pH) for the enzymes, during 60min. The bioactivity testing included antioxidant and angiotensin I converting enzyme inhibitory activity assays. The hydrolysates showed high potential as natural antioxidants and possibly antihypertensive agents in functional food or nutraceuticals. Additionally, preliminary studies have shown that both hydrolysates could exhibit modest α-amylase inhibitory activity, which indicates on their hypoglycemic potential.