共查询到20条相似文献,搜索用时 31 毫秒
1.
The N-methyl-D-aspartate (NMDA) receptor subunit NR1 gene can produce eight isoforms in rat brain. A novel methodology for purifying
NMDA receptor NR1 subunit from rat brain is reported here using chicken polyclonal antibodies (IgYs) against synthetic peptides
corresponding to N1, C1 and C2′ cassettes. The isolated protein was recognized by produced IgYs and commercial anti-NR1 IgGs,
shown by MALDI-TOF MS a MW = 131,192 Da (glycosylated form); the enzymatically deglycosylated protein revealed a MW = 102,754 Da.
The NMDA receptor NR1 subunit was characterized as being a heavily N-glycosylated protein. The isoelectric point was determined
(6.3) as being different from that predicted for any of the isoforms (7.9–9.02). Attempts to separate the isoforms from the
purified NR1 were unsuccessful, indicating the presence of just one isoform (NR1111). Immunohistochemistry on hippocampus regions CA1, CA3 and Dentate gyrus with anti-N1, anti-N2 and anti-C2′ IgYs showed different
staining intensity, depending upon the antibody assayed. 相似文献
2.
Relative DNase, RNase (efficiency of hydrolysis of ribo- and deoxyribooligonucleotides (ON)), and phosphatase (removal of
the ON 5′ terminal phosphate) catalytic activities of antibodies (AB) obtained after rabbit immunization by DNA, DNase I,
and DNase II were compared. It is shown that electrophoretically homogeneous preparations of polyclonal AB from non-immunized
rabbits did not exhibit such activities. Immunization of rabbits by DNA, DNase I, and DNase II results in generation of IgG
abzymes that exhibit high activity in the ON hydrolysis reaction and even higher activity in cleavage of 5′ terminal phosphate
of ON. In this case K
m values for supercoiled plasmid DNA and ON found in reactions of their AB-dependent nuclease hydrolysis and phosphatase cleavage
of 5′ terminal phosphate differ by 2–4 orders of magnitude. This shows that nuclease and phosphatase activities belong to
different abzyme fractions within polyclonal AB. Thus, in this work data indicative of the possibility of a formation of antibodies
exhibiting phosphatase activity after immunization of animals with DNA, DNase I, and DNase II, were obtained for the first
time. Possible reasons for production of AB with phosphatase activity after immunization of rabbits with these immunogens
are discussed. 相似文献
3.
Y. Inoue T. Ohta H. Tada S. Iwasa S. Udaka H. Yamagata 《Applied microbiology and biotechnology》1997,48(4):487-492
Expression/secretion vectors for the production of Fab′ and single-chain (sc) Fab′ by Bacillus brevis have been constructed. For the production of Fab′, the cDNAs encoding the L chain and Fd′ fragment (Fd with the hinge region)
of a mouse-human chimeric Fab′ against human urokinase-type plasminogen activator were fused directly with the translation-start
and signal-peptide-encoding regions of the mwp gene, the gene for one of the major cell-wall proteins of Bacillus brevis. The two fused genes were placed tandemly downstream from the promoter of the cell-wall protein gene operon (cwp) of B. brevis. For the production of scFab′, the two cDNAs were linked with a synthetic oligonucleotide encoding a flexible peptide linker
of 17 or 24 amino acids, and fused with the translation start and signal-peptide-encoding regions of the mwp gene. Fab′ was efficiently produced by B. brevis, being accumulated at a level of 100 mg/l in the culture medium in a simple shake-flask culture, which is the highest level
obtained so far for a gram-positive bacterium. On the other hand, the scFab′ remained at a level of a few milligrams per liter
in the culture medium. The Fab′ produced by B. brevis showed comparable antigen-binding activity to that of the parental antibody. The L chain and Fd′ fragment, constituting the
Fab′, had the correct N-terminal amino acid sequences. These results indicate that B. brevis is a very promising host for the production of native Ig fragments.
Received: 25 April 1997 / Received revision: 3 June 1997 / Accepted: 29 June 1997 相似文献
4.
M. A. Zenkova N. L. Chumakova A. V. Vlassov N. I. Komarova A. G. Venyaminova V. V. Vlassov V. N. Silnikov 《Molecular Biology》2000,34(3):390-394
The mechanism of hydrolysis of RNA substrates—diribonucleoside monophosphate CpA and decaribonucleotide UUCAUGUAAA—by chemical
constructs functionally mimicking ribonuclease A was studied. It is shown that RNA cleavage by chemical RNases 2L2 and 2D3
proceeds similar to the RNase A-induced RNA hydrolysis through 2′,3′-cyclophosphate as an intermediate product. A comparison
of hydrolyses of CpA in water and D2O revealed an isotope effect (K
H/K
D=2.28), which implies acid-base catalysis at the limiting stage of the reaction. Two feasible mechanisms of RNA hydrolysis
by chemical RNases (linear and adjacent) are discussed. 相似文献
5.
E. S. Odintsova M. A. Kharitonova A. G. Baranovskii L. P. Sizyakina V. N. Buneva G. A. Nevinsky 《Molecular Biology》2006,40(5):770-777
DNase activity was analyzed in 110 IgG preparations from the blood of AIDS patients. The relative activity of the preparations varied markedly among patients, being reliably detectable in 96% of the preparations. It was shown with several rigid criteria that DNAase activity is an intrinsic property of antibodies (Abs) from AIDS patients. Not only intact IgG, but also isolated light chains of polyclonal Abs were shown to possess catalytic activity. The abzymes efficiently catalyzed DNA hydrolysis in a wide range of pH (5.0–9.5). The K M and V max values were evaluated for Ab-dependent hydrolysis of DNA. 相似文献
6.
O. I. Smotrov V. M. Borzenkov V. I. Surovtsev 《Russian Journal of Bioorganic Chemistry》2011,37(5):564-568
The influence of pH within the range 6.9–10.0 on the kinetic parameters of Micrococcus lysodeicticus cell lysis catalyzed by hen egg lysozyme has been studied at 25°C and 37°C. The effective pK
b values have been calculated for the group determining lysozyme catalytic activity. The ΔH
ion value indicates that this group is a carboxyl, although its pK (9.15 at 25°C) is far beyond the range characteristic of carboxylic groups. The cause of this abnormal pK
b value is supposed to be the strong negative charge of the bacterial cell wall. As a result, the enzyme, which catalyzes the
hydrolysis of N-acetylglucosamine-N-acetylmuramic acid copolymer, operates in a highly acidic microenvironment. 相似文献
7.
Dominic D. W. S. Wong Victor J. Chan Amanda A. McCormack Sarah B. Batt 《Applied microbiology and biotechnology》2010,86(5):1463-1471
A novel xyloglucan-specific endo-β-1,4-glucanase gene (xeg5A) was isolated, cloned, and expressed in Esherichia coli. The enzyme XEG5A consisted of a C-terminal catalytic domain and N-terminal sequence of ~90 amino acid residues with unknown
function. The catalytic domain assumed an (α/β)8-fold typical of glycoside hydrolase (GH) family 5, with the two catalytic residues Glu240 and Glu362 located on opposite
sides of the surface groove of the molecule. The recombinant enzyme showed high specificity towards tamarind xyloglucan and
decreasing activity towards xyloglucan oligosaccharide (HDP-XGO), carboxymethyl cellulose, and lichenan. Tamarind xyloglucan
was hydrolyzed to three major fragments, XXXG, XXLG/XLXG, and XLLG. The hydrolysis followed the Michaelis–Menten kinetics,
yielding K
m and V
max of 3.61 ± 0.23 mg/ml and 0.30 ± 0.01 mg/ml/min, respectively. However, the hydrolysis of HDP-XGO showed a decrease in the
rate at high concentrations suggesting appearance of excess substrate inhibition. The addition of XXXG resulted in linear
noncompetitive inhibition on the hydrolysis of tamarind xyloglucan giving a K
i of 1.46 ± 0.13 mM. The enzyme was devoid of transglycosylase activities. 相似文献
8.
Masłyk M Kochanowicz E Zieliński R Kubiński K Hellman U Szyszka R 《Molecular and cellular biochemistry》2008,312(1-2):61-69
Since Svf1 is phosphoprotein, we investigated whether it was a substrate for protein kinase CK2. According to the amino acid
sequence Svf1 harbours 20 putative CK2 phosphorylation sites. Here, we have reported cloning, overexpression, purification
and characterization of yeast Svf1 as a substrate for three forms of yeast CK2. Svf1 serves as a substrate for both the recombinant
CK2α (K
m 0.35 μM) and CK2α′ (K
m 0.18 μM) as well as CK2 holoenzyme (K
m 1.1 μM). Different K
m values argue that CK2β(β′) subunit has an inhibitory effect on the activity of both CK2α and CK2α′ towards surviving factor
Svf1. Reconstitution of α′2ββ′ isoform of CK2 holoenzyme shows that β/β′ subunits have regulatory effect depending on the kind of CK2 catalytic subunit.
This effect was not observed in the case of α2ββ′ isoform, which may be due to interaction between Svf1 and regulatory CK2β subunit (shown by co-immunoprecipitation experiments).
Interactions between CK2 subunits and Svf1 protein may have influence on ATP as well as ATP-competitive inhibitors (TBBt and
TBBz) binding. CK2 phosphorylates up to six serine residues in highly acidic peptide K199EVIPESDEEESSADEDDNEDEDEESGDSEEESGSEEESDSEEVEITYED248 of the Svf1 protein in vitro. Presented data may help to elucidate the role of protein kinase CK2 and Svf1 in the regulation
of cell survival pathways. 相似文献
9.
The recombinant β-carotene 15,15′-monooxygenase from chicken liver was purified as a single 60 kDa band by His-Trap HP and Resource Q chromatography.
It had a molecular mass of 240 kDa by gel filtration indicating the native form to be tetramer. The enzyme converted β-carotene under maximal conditions (pH 8.0 and 37°C) with a k
cat of 1.65 min−1 and a K
m of 26 μM and its conversion yield of β-carotene to retinal was 120% (mol mol−1). The enzyme displayed catalytic efficiency and conversion yield for β-carotene, β-cryptoxanthin, β-apo-8′-carotenal, β-apo-4′-carotenal, α-carotene and γ-carotene in decreasing order but not for zeaxanthin, lutein, β-apo-12′-carotenal and lycopene, suggesting that the presence of one unsubstituted β-ionone ring in a substrate with a molecular weight greater than C30 seems to be essential for enzyme activity. 相似文献
10.
Kim SB Lee DW Cheigh CI Choe EA Lee SJ Hong YH Choi HJ Pyun YR 《Journal of industrial microbiology & biotechnology》2006,33(6):436-444
We have isolated a bacterium (TP-6) from the Indonesian fermented soybean, Tempeh, which produces a strong fibrinolytic protease and was identified as Bacillus subtilis. The protease (TPase) was purified to homogeneity by ammonium sulfate fractionation and octyl sepharose and SP sepharose chromatography. The N-terminal amino acid sequence of the 27.5 kDa enzyme was determined, and the encoding gene was cloned and sequenced. The result demonstrates that TPase is a serine protease of the subtilisin family consisting of 275 amino acid residues in its mature form. Its apparent K
m and V
max for the synthetic substrate N-succinyl-Ala-Ala-Pro-Phe-pNA were 259 μM and 145 μmol mg−1 min−1, respectively. The fibrinogen degradation pattern generated by TPase as a function of time was similar to that obtained with plasmin. In addition, N-terminal amino acid sequence analysis of the fibrinogen degradation products demonstrated that TPase cleaves Glu (or Asp) near hydrophobic acids as a P1 site in the α- and β-chains of fibrinogen to generate fragments D′, E′, and D′ similar to those generated by plasmin. On plasminogen-rich fibrin plates, TPase did not seem to activate fibrin clot lysis. Moreover, the enzyme converted the active plasminogen activator inhibitor-1 to the latent form.Seong-Bo Kim and Dong-Woo Lee contributed equally to the work. 相似文献
11.
Tarasova MV Kuznetsov VV Netesova NA Gonchar DA Degtyarev SKh 《Biochemistry. Biokhimii?a》2010,75(12):1484-1490
A restriction-modification system from Bacillus psychrodurans AC (recognition sequence 5′-CCGC-3′) comprises two DNA methyltransferases: M1.BspACI and M2.BspACI. The bspACIM1 gene was cloned in the pJW2 vector and expressed in Escherichia coli cells. High-purity M1.BspACI preparation has been obtained by chromatography on different carriers. M1.BspACI has a temperature
optimum of 30°C and demonstrates maximum activity at pH 8.0. M1.BspACI modifies the first cytosine in the recognition sequence
5′-CCGC-3′. The kinetic parameters of M1.BspACI DNA methylation are as follows: K
m for phage λ DNA is 0.053 μM and K
m for S-adenosyl-L-methionine is 5.1 μM. The catalytic constant (k
cat) is 0.095 min−1. 相似文献
12.
Hurwitz E Klapper LN Wilchek M Yarden Y Sela M 《Cancer immunology, immunotherapy : CII》2000,49(4-5):226-234
Poly(ethylene glycol) (PEG) modification of substances with antitumor activity was shown to enhance penetration into growing
solid tumors and extend antitumor effects. Accordingly, PEG was introduced as a modifier to two types of monoclonal antibodies
(N12 and L26) specific to the ErbB2 (HER2) oncoprotein. These antibodies suppress the growth of tumors overexpressing ErbB2
(e.g. N87 human tumor) and the effect of PEG on their antitumor activity was evaluated. Methoxy-PEG-maleimide conjugated to
sulfhydryl groups at the hinge region of the antibodies impaired their antibody binding to N87 tumor cells and did not enhance
the antitumor inhibitory activity in tumor-bearing mice. A branched N-hydroxysuccinimide-activated PEG (PEG2), conjugated through amino groups of the protein, was used for binding to the whole
antibody (Ab) or to its monomeric Fab′ fragment. When tested against N87 cells in vitro, the binding activity and antitumor
cytotoxic effects of Ab-PEG2 were mostly preserved. PEG2 modification did not seem to alter the tumor-inhibitory activity
of the antibodies in vivo and the same pattern of tumor development was observed during the first few weeks following administration.
However, the stimulating effects of PEG were observed at later stages of tumor growth since tumor development was either slowed
down or completely arrested. Furthermore, a second tumor implanted into the same mice during this later stage was significantly
or completely inhibited, as compared to results in mice injected with the unmodified antibody. The Fab′-PEG2 monomeric derivative
was also shown to be effective in inhibiting the growth of a second tumor. The extended and prolonged enhancing effect of
PEG on the antitumor activity of antibodies or Fab′ fragments directed against ErbB2 may be of importance in the treatment
of ErbB2-overexpressing neoplasms.
Received: 2 September 1999 / Accepted: 19 February 2000 相似文献
13.
Rücker B Almeida ME Libermann TA Zerbini LF Wink MR Sarkis JJ 《Molecular and cellular biochemistry》2007,306(1-2):247-254
In the present study we investigate the biochemical properties of the members of NPP family in synaptosomes prepared from
rat heart left ventricles. Using p-nitrophenyl-5′-thymidine monophosphate (p-Nph-5′-TMP) as substrate for E-NPPs in rat cardiac synaptosomes, we observed an alkaline pH dependence, divalent cation dependence
and the K
M
value corresponded to 91.42 ± 13.97 μM and the maximal velocity (V
max
) value calculated was 63.79 ± 3.59 nmol p-nitrophenol released/min/mg of protein (mean ± SD, n = 4). Levamisole (1 mM), was ineffective as inhibitor of p-Nph-5′-TMP hydrolysis in pH 8.9 (optimum pH for the enzyme characterized). Suramin (0.25 mM) strongly reduced the hydrolysis
of p-Nph-5′-TMP by about 46%. Sodium azide (10 and 20 mM) and gadolinium chloride (0.3 and 0.5 mM), E-NTPases inhibitors, had
no effects on p-Nph-5′-TMP hydrolysis. RT-PCR analysis of left ventricle demonstrated the expression of NPP2 and NPP3 enzymes, but excluded
the presence of NPP1 member. By quantitative real-time PCR we identified the NPP3 as the enzyme with the highest expression
in rat left ventricle. The demonstration of the presence of the E-NPP family in cardiac system, suggest that these enzymes
could contribute with the fine-tuning control of the nucleotide levels at the nerve terminal endings of left ventricles that
are involved in several cardiac pathologies. 相似文献
14.
A UDP-glucose: anthocyanin 3′,5′-O-glucosyltransferase (UA3′5′GT) (EC 2.4.1.-) was purified from the petals of Clitoria ternatea L. (Phaseoleae), which accumulate polyacylated anthocyanins named ternatins. In the biosynthesis of ternatins, delphinidin
3-O-(6″-O-malonyl)-β-glucoside (1) is first converted to delphinidin 3-O-(6″-O-malonyl)-β-glucoside-3′-O-β-glucoside (2). Then 2 is converted to ternatin C5 (3), which is delphinidin 3-O-(6″-O-malonyl)-β-glucoside-3′,5′-di-O-β-glucoside. UA3′5′GT is responsible for these two steps by transferring two glucosyl groups in a stepwise manner. Its substrate
specificity revealed the regioselectivity to the anthocyanin′s 3′- or 5′-OH groups. Its kinetic properties showed comparable
k
cat values for 1 and 2, suggesting the subequality of these anthocyanins as substrates. However, the apparent K
m value for 1 (3.89 × 10−5 M), which is lower than that for 2 (1.38 × 10−4 M), renders the k
cat/K
m value for 1 smaller, making 1 catalytically more efficient than 2. Although the apparent K
m value for UDP-glucose (6.18 × 10−3 M) with saturated 2 is larger than that for UDP-glucose (1.49 × 10−3 M) with saturated 1, the k
cat values are almost the same, suggesting the UDP-glucose binding inhibition by 2 as a product. UA3′5′GT turns the product 2 into a substrate possibly by reversing the B-ring of 2 along the C2-C1′ single bond axis so that the 5′-OH group of 2 can point toward the catalytic center.
K. Kogawa, N. Kato, K. Kazuma, and N. Noda contributed equally to this work. 相似文献
15.
HPLC separation of ionic samples tends to be more complicated and difficult to understand than that of non-ionic compounds.
On the other hand, band spacing is much more easily manipulated for ionic than for neutral samples. Ion-suppressing RP-HPLC
method was used with organic modifier and aqueous buffer solution. In this work, five mononucleotides of cytidine-5-monophosphate
(5′-CMP) disodium salt, uridine-5-monophosphate disodium salt (5′-UMP), guanosine-5-monophosphate disodium salt (5′-GMP),
inosine-5-monophosphate disodium salt (5′-IMP), and adenosine-5-monophosphate disodium salt (5′-AMP) were examined. Acetic
acid and sodium phosphate were used as buffers, and methanol as an organic modifier. A new relationship between the retention
factor and the buffer concentration at a fixed modifier content (5% of methanol) could be expressed by fol|lowing:k=(k
−1+k
0 (K
B/K
S)C
B
a)/(1+(K
B/K
S)C
B
a), whereC
B was the concentration of buffer. Using this relationship, the calculated values closely matched the experimental data. The
derived relationship showed that as the buffer concentration increased, the retention factor approached a certain value, and
this was buffer dependent. 相似文献
16.
Monoclonal antibodies were raised against a -naphthyl phosphonate hapten (1) to elicit antibodies capable of catalyzing the hydrolysis of -naphthyl acetate (3). After cell fusion, potential catalytic antibody-producing hybridomas were selected, by use of a competitive inhibition assay on the basis of the binding activity for a short transition-state analogue (inhibitor 5), followed by use of high-performance liquid chromatography analysis for the hybridoma supernatants to screen the antibodies processing catalytic activities. It was shown that supernatants of 12 wells had high binding activity with inhibitor and of them, 7 had catalytic activities. After cloning by limiting dilution, we got two hybridoma clones producing monoclonal antibodies which catalyzed the hydrolysis of -naphthyl acetate. This combination of competitive inhibition assay with high-performance liquid chromatography analysis represents an improved rapid approach for the screening of potential catalytic antibodies and significantly increases the possibility of obtaining efficient catalytic monoclonal antibodies. Further study of the catalytic antibodies revealed significant rate enhancement (K
cat/K
uncat 106) and specificity. 相似文献
17.
Baranova SV Buneva VN Kharitonova MA Sizyakina LP Zakharova OD Nevinsky GA 《Biochemistry. Biokhimii?a》2011,76(12):1300-1311
It was previously shown that small fractions of IgGs and IgMs from the sera of AIDS patients specifically hydrolyze only HIV
integrase (IN) but not many other tested proteins. Here we present evidence showing that these IgGs and IgMs are extreme catalytically
heterogeneous. Affinity chromatography on IN-Sepharose using elution of IgGs (or IgMs) with different concentration of NaCl
and acidic buffer separated catalytic antibodies (ABs) into many AB subfractions demonstrating different values of K
m for IN and k
cat. Nonfractionated IgGs and IgMs possess serine-, thiol-, acidiclike, and metal-dependent proteolytic activity. Metal-dependent
activity of abzymes increases in the presence of ions of different metals. In contrast to canonical proteases having one pH
optimum, initial nonfractionated IgGs and IgMs demonstrate several optima at pH from 3 to 10. The data obtained show that
IN-hydrolyzing polyclonal IgG and IgM of HIV-infected patients are cocktails of anti-IN ABs with different structure of the
active centers possessing various affinity to IN, pH optima, and relative rates of the specific substrate hydrolysis. 相似文献
18.
Myeong Min Lee Kyoung Hee Nam Eun Kyoung Lee Sun Hi Lee Ky Young Park 《Journal of Plant Biology》1997,40(2):80-88
We have partially purified S-adenosylmethionine decarboxylase (EC 4.1.1.50, SAMDC) from carnation (Dianthus caryophyllus L.) petals and generated polyclonal antibodies against CSDC 16 protein (Leeet al., 1996) overexpressed inE. coli. The protein has been purified approximately 126.8 fold through the steps involving ammonium sulfate fractionation, DEAE-Sepharose
column chromatography and Sephacryl S-300 gel filtration. Its molecular mass was 42 kDa in native form and we could also detect
a band of 32 kDa molecular mass on SDS-PAGE in western blot analysis using the polyclonal antibodies. The Km value of this
enzyme forS-adenosylmethionine was 26.3 μM. The optimum temperature and pH forS-adenosylmethionine decarboxylase activity were 35°C and pH 8.0, respectively. Putrescine and Mg2+ had no effects on the activation of the enzyme activity. Mg2+ did not have any significant effects on the enzyme activity. SAMDC activity was inhibited by putrescine, spermidine and spermine.
Methylglyoxal bis-(guanylhydrazone) (MGBG), carbonyl reagents such as hydroxylamine and phenylhydrazine, and sulfhydryl reagent
such as 5,5′dithio-bis (2-nitrobenzoic acid) (DTNB) were effective inhibitors of the enzyme. However, isonicotinic acid hydrazide
known as an inhibitor of 5′-pyridoxal phosphate (PLP) dependent enzyme activity had no significant effect on the enzyme activity.
These results and our previously reported results (Leeet al., 1997b) suggest thatS-adenosylmethionine decarboxylase is a heterodimer, αβ, and some carbonyl group and sulfhydryl group are involved in the catalytic
activity. 相似文献
19.
根据过渡态理论设计和合成了能诱导产生催化选择性水解布洛芬甲酯的催化抗体的四面体硫酸盐半抗原,并与牛血清白蛋白(BSA)偶联制备成免疫源,通过免疫手段成功筛选出具有加速选择性水解生成S-布洛芬的特异性催化抗体.其Kcat,app/Kuncat,app达1.6x104.进一步地将催化抗体运用到W/O微乳体系(反胶束)中进行布洛芬酯的选择性水解研究,其动力学研究证明其催化过程同样遵循Michaelis.Menten方程.考察了pH值和温度对催化初速度影响,Wo(体系中水和琥珀酸二辛酯磺酸钠(AOT)的摩尔比)对催化初速度影响呈现为钟罩型,最适的Wo.为21. 相似文献
20.
Chezian Somasundaram Robert Arch Siegfried Matzku Margot Zöller 《Cancer immunology, immunotherapy : CII》1996,42(6):343-350
A bispecific F(ab′)2 antibody conjugate (BAC) was constructed against the complement receptor CR3 of macrophages and a variant CD44 (CD44v6) antigen
of rat pancreatic adenocarcinoma cells to redirect macrophage-mediated tumor cytotoxicity. The Fab′ fragments of monoclonal
antibodies (mAb) 1.1ASML and OX42, recognizing the CD44v6 and the CR3 antigens respectively, were chemically coupled at the
hinge region using 5,5′-dithiobis(2-nitrobenzoate). The BAC was characterized in vitro for its specific, dual binding capacity
to CD44v6 and CR3 antigens. Although the monovalence of the BAC resulted in lower avidities to both the antigens as expected,
it was still able to form stable cross-linkages between tumor cells and macrophages in culture leading to the formation of
“clump-like” cell aggregates. The in vitro and in vivo tumor-targeting capacity of the BAC was compared with that of the parental
antitumor mAb 1.1ASML, which mediates tumor killing by antibody-dependent cell cytotoxicity. These results showed that, even
though the bivalent mAb 1.1ASML did not mediate stable cross-linking of target and effector cells, its Fc-receptor-mediated
killing of tumor cells was more effective when compared to the BAC. Thus, this study strongly supports the hypothesis that
firm persistent binding between effector and target cells per se is not as important as the choice of trigger molecule used for macrophage activation to redirect their tumor cytotoxic potential
effectively.
Received: 2 May 1996 / Accepted: 21 May 1996 相似文献