Nucleic Acids Research, 2002, Vol. 30, No. 22 e126
© 2002 Oxford University Press
A novel procedure for simple and efficient genotyping of single nucleotide polymorphisms by using the Zn2+cyclen complex
Emiko Kinoshita-Kikuta,
Eiji Kinoshita1 and
Tohru Koike*
Department of Functional Molecular Science, Division of Medicinal Chemistry, Graduate School of Biomedical Sciences and
1 Department of Cardiovascular Physiology and Medicine, Division of Molecular Medical Science, Graduate School of Biomedical Sciences, Hiroshima University, Kasumi 1-2-3, Minami-ku, Hiroshima 734-8551, Japan
*To whom correspondence should be addressed. Tel: +81 82 257 5323; Fax: +81 82 257 5336; Email: tkoike{at}hiroshima-u.ac.jp
Received August 27, 2002; Revised and Accepted September 19, 2002
 |
ABSTRACT
|
|---|
The analysis of single nucleotide polymorphisms (SNPs) is increasingly
utilized in the study of various genetic determinants. Here,
we introduce a simple, rapid, low-cost and accurate procedure
for the detection of SNPs by polyacrylamide gel electrophoresis
(PAGE) with a novel additive, the Zn
2+ cyclen complex
(cyclen = 1,4,7,10-tetraazacyclododecane). The method is based
on the difference in mobility of mutant DNA (in the same length)
in PAGE, which is due to Zn
2+cyclen binding to thymine
bases accompanying a total charge decrease and a local conformation
change of target DNA. Various nucleotide substitutions (e.g.
AT to GC) in DNA fragments (up to 150 bp) can be visualized
with ethidium bromide staining. Furthermore, heteroduplex and
homoduplex DNAs are clearly separated as different bands in
the gel. We demonstrate the analysis of single- and multiple-nucleotide
substitutions in a voltage-dependent sodium channel gene by
using this novel procedure (Zn
2+cyclenPAGE).
 |
INTRODUCTION
|
|---|
Single nucleotide polymorphisms (SNPs) in the human genome are
important markers for establishing genetic linkage and genetic
diseases (
1
4). In order to make large-scale genotyping
feasible, various SNP detection methods have been developed
(
5
6). However, simpler, faster, and more economical procedures
are required for the analysis of genetic diseases. The most
commonly used procedure for determining single-base mutations
is as follows: (i) amplification of a target DNA sequence by
PCR; (ii) scanning a mutation of the PCR products by using a
single-strand conformation polymorphism (
7), enzymatic or chemical
cleavage of mismatched base pairs (
8
13), conformation-sensitive
gel electrophoresis (
14) and denaturing gradient gel electrophoresis
(
15); (iii) confirmation of the sequence of mutant DNA by various
DNA sequence analyses. However, the procedures so far developed
require complicated processes, special apparatus, expensive
reagents and/or a skillful analyst.
In 1993, Shionoya et al. (16) reported that Zn2+cyclen (cyclen = 1,4,7,10-tetraazacyclododecane) selectively and reversibly binds to an imide-containing nucleobase, deoxythymidine (dT), in aqueous solution with a dissociation constant Kd = [free dT][free Zn2+cyclen] / [dTZn2+ cyclen] = 0.8 mM at pH 7.4 (Fig. 1). In the resulting 1:1 complex, the nucleobase is an imide-deprotonated species (dT) that binds with the Zn2+ ion, where the total charge of the dT molecule increases from 0 to +1. Recently, we reported that Zn2+cyclen derivatives selectively bind dT-rich regions and change the local conformation in double-stranded DNA (e.g. a bulbous structure, as shown in Fig. 2), as proven by nuclease footprinting experiments and gel mobility shift assays (1719). The dissociation of AT hydrogen bonds is promoted by Zn2+cyclen, as observed by lowering the melting temperature (Tm) with an increase in the concentration of Zn2+cyclen (17,20,21). We have extended such T-recognizing property of Zn2+cyclen in the polyacrylamide gel electrophoretic separation of various DNA fragments. We selected 18 mutants of a skeletal muscle voltage-dependent sodium channel
-subunit (Nav1.4) gene as DNA samples (see DNA fragments 119 in Table 1). These mutants were constructed in a study on the relationship between the structure and function of the channel (2225). Several of the mutations are related to the loss of binding activity of a sodium channel activator, Grayanotoxin (a diterpenoid extracted from the family of Ericaceae). We here describe a simple, rapid, low-cost and accurate polyacrylamide gel electrophoresis (PAGE) method for analyzing PCR products by using Zn2+cyclen as a novel additive (Zn2+cyclenPAGE). As the first practical example, we demonstrate the analysis of SNPs in the sodium channel mutants.

View larger version (25K):
[in this window]
[in a new window]
|
Figure 2. A proposed mechanism of Zn2+cyclen binding to double-helical DNA. (A) Native DNA and (B) Zn2+cyclen-bound DNA.
|
|
 |
MATERIALS AND METHODS
|
|---|
Single-stranded oligonucleotides
All oligonucleotides (
20
28) and PCR primers were obtained
commercially (Espec Oligo Service, Japan). The PCR primers for
300 bp (pUC 19 nucleotides 17312030) were 5'-ATT AAG
CAT TGG TAA CTG TC-3' and 5'-AGT TAC CTT CGG AAA AAG AG-3',
and those for 336 bp (pUC 19 nucleotides 481816) were
5'-GCG GTA TTT CAC ACC GCA TA-3' and 5'-AAT GTA TTT AGA AAA
ATA AA-3' (
26).
Target double-stranded DNA molecules
The mutations onto the cDNA coding the rat skeletal muscle voltage-dependent sodium channel
-subunit (Nav1.4) (27) were introduced by site-directed mutagenesis using a PCR strategy as described before (2225,28). The wild-type and mutated DNA fragments were cloned into a pGEM-T Easy Vector (Promega, USA), and the inserted regions were then confirmed with restriction mapping and sequencing entirely using an ABI PRISMTM 310 Genetic Analyzer (Applied Biosystems, USA). The sequences of target regions for wild-type (1) and mutated DNA (219) are listed in Table 1.
The target regions were amplified by PCR using the forward/reverse primers 5'-CAA TTG TGG GAG CCC TGA TCC-3'/5'-CGT ACG CCA TGG CCA CCA CG-3', which produced 621 bp fragments from nucleotides 7131333 of the Nav1.4 gene. Each 50 µl of PCR solution contained 50 ng of pGEM-T Easy Vector DNA in which a wild-type or a mutated fragment was inserted, forward and reverse primers (0.6 µM), dNTPs (each at 65 µM) and 2.5 U Thermoprime plus (Advanced Biotechnologies, UK). After initial denaturation at 95°C for 3 min, amplification was carried out for 30 cycles of 1 min denaturation at 95°C, 1 min annealing at 60°C and 1 min extension at 72°C. PCR products were purified by precipitation in ethanol. PCR products from Nav1.4 mutants were digested with restriction endonucleases to generate short fragments, which have appropriate length for the electrophoretic analysis.
Zn2+cyclenPAGE
Electrophoresis was performed at 200 V for 150 min at room temperature, in a 1-mm-thick, 9-cm-wide and 9-cm-long gel prepared with an appropriate concentration of polyacrylamide (30:1 ratio of acrylamide to N,N'-methylenebisacrylamide), 5 mM Zn2+cyclen, 90 mM Tris and 90 mM borate, on a standard PAGE apparatus (ATTO, Japan; model AE-6500). DNA samples were dissolved in 3 µl of a loading buffer containing 60% (v/v) glycerol, 18 mM Tris/18 mM borate, 0.05% (w/v) bromophenol blue and 0.05% (w/v) xylene cyanol. The anode buffer was 90 mM Tris/90 mM borate, and the cathode buffer was 90 mM Tris/90 mM borate/5 mM Zn2+cyclen. At the end of the run, the gels were stained in an aqueous solution of ethidium bromide (10 µg/ml). Zn2+cyclen was prepared as dinitrate salt (colorless prisms) by a similar method to that reported for Zn2+cyclen diperchlorate salt (16). Anal. Calc. for C8H20N6O6Zn (Zn2+cyclen·2NO3): C, 26.57; H, 5.57; N, 23.24. Found: C, 26.61; H, 5.60; N, 23.28. 1H NMR (500 MHz, in D2O):
2.80 (8H, m), 2.94 (8H, m). 13C NMR (125 MHz, in D2O):
46.6. IR: 3177, 2918, 1483, 1444, 1384 (NO3), 1279, 1092, 1010, 993, 806 cm1. The dissociation constant for the HPO42-bound Zn2+cyclen complex was determined with 1 mM Zn2+cyclen and 1 mM Na2HPO4 by potentiometric pH titration (29) to be 0.10 ± 0.02 mM (= [HPO32][Zn2+cyclen] / [HPO32Zn2+cyclen]) at 35°C with I = 0.10 (NaNO3) in aqueous solution.
 |
RESULTS AND DISCUSSION
|
|---|
Effect of Zn2+cyclen on the electrophoretic migration of single-stranded DNA
In order to evaluate the binding effect of Zn
2+cyclen
to single-stranded DNA fragments, we conducted PAGE in the presence
of 5 mM Zn
2+cyclen (Zn
2+cyclenPAGE) with
20mer (
20
24) and 50mer (
25
28) oligonucleotides,
as shown in Table
2. Those DNA fragments are different in T-content,
which should influence the binding number of Zn
2+cyclen
[5 mM Zn
2+cyclen is enough for its thymine-binding (
16)].
In the absence of Zn
2+cyclen, same-length oligonucleotides
were observed to have slightly different mobilities (see Fig.
3A for 20mer and Fig.
4A for 50mer fragments). The small differences
are possibly due to variation in the single-stranded conformation.
On the other hand, in the presence of 5 mM Zn
2+cyclen,
the electrophoretic migration was retarded as the number of
thymine bases increased (see Fig.
3B for 20mer and Fig.
4B for
50mer fragments). The migration distances of 20mer fragments
20
24 are inversely proportional to the T-contents [i.e.
22 (2T) >
24 (3T) >
21 (4T) >
20 (5T) >
23 (7T)].
Among the 50mer samples, the most T-rich fragment,
26 (20T),
showed the largest retardation compared to the other oligonucleotides,
25,
27 and
28 (10T). The retardation of T-rich oligonucleotides
by Zn
2+cyclen could be explained by the decrease in the
negative charge of oligonucleotides (i.e. phosphodiester polyanions)
and the increase in the molecular size (see a proposed structure
of Zn
2+cyclen binding DNA in Fig.
2).

View larger version (16K):
[in this window]
[in a new window]
|
Figure 3. Electrophoresis of 20mer oligonucleotides 2024 with 20% (w/v) polyacrylamide gel in the absence (A) and presence (B) of 5 mM Zn2+cyclen.
|
|

View larger version (18K):
[in this window]
[in a new window]
|
Figure 4. Electrophoresis of 50mer oligonucleotides 2528 with 12% (w/v) polyacrylamide gel in the absence (A) and presence (B) of 5 mM Zn2+cyclen.
|
|
Effect of Zn2+cyclen on electrophoretic migration of double-stranded DNA
Zn
2+cyclenPAGE experiments with various concentrations
of Zn
2+cyclen and two double-stranded DNA molecules,
300 bp DNA (AT content of 61.7%) and 336 bp DNA (AT content
of 48.5%) in the plasmid pUC19 (
26), were conducted. In the
absence of Zn
2+cyclen, both DNA fragments moved in proportion
to the molecular weight (see the DNA bands in Fig.
5, left),
where the 300 bp DNA showed faster migration. The difference
of the migration distances of those DNA fragments decreased
with the increase in the concentration of Zn
2+cyclen,
and the migration distances of those DNAs were then reversed
above 2 mM Zn
2+cyclen (Fig.
5). We used 5 mM Zn
2+cyclen
for a general Zn
2+cyclenPAGE experiment, as shown
below. These facts imply that Zn
2+cyclen prefers the
AT-rich double-stranded DNA and that the electrophoretic migration
is retarded as the thymine content increases. This result clearly
explains our previous finding that Zn
2+cyclen changes
the local conformation in double-stranded DNA (Fig.
2B) (
17
19).

View larger version (24K):
[in this window]
[in a new window]
|
Figure 5. Relationship between [Zn2+cyclen] and migration distance of 300 (AT-content of 61.7%) and 336 bp (AT-content of 48.5%) DNA fragments in 4% (w/v) polyacrylamide gel. Electrophoresis results in the absence and presence of 5 mM Zn2+cyclen gel are shown on the left and right, respectively.
|
|
Analysis of single- and multiple-base substitutions by Zn2+cyclenPAGE
To examine the sensitivity of Zn
2+cyclenPAGE for
the detection of DNA mutations, 19 PCR products of a wild-type
DNA,
1, and various base-substituted mutant DNAs,
2
19,
of the voltage-dependent sodium channel

-subunit (Na
v1.4) gene
(Table
1) were prepared. The series of mutants consist of substitutions
of a single base (
6,
8,
11,
12 and
16
19), two bases (
3,
5,
7,
9,
10 and
13
15), three bases (
4) and seven bases
(
2). The PCR-amplified 621 bp products were digested with restriction
endonuclease
AluI, which produces a fragment of a mutated region
(99 bp) and seven other fragments (177, 158, 63, 61, 35, 15
and 13 bp). In the absence of Zn
2+cyclen, all 99 bp fragments
for
1
19 showed almost the same migration distance (Fig.
6A). In contrast, by using Zn
2+ cyclenPAGE, the
99 bp fragment bands varied widely (Fig.
6B). The other fragments
stayed at individual positions in both electrophoresis experiments.
With the increase in the number of T bases (
2
7,
9,
14,
16 and
17), the migration distance decreased in the Zn
2+cyclen
gel (Fig.
6B). Especially, mutations forming poly-AT alignments
resulted in a significant decrease of the migration distance
(see
2,
4 and
7). On the contrary, the migration distances of
8,
10,
11,
13 and
15 (A, T

G, C) increased (Fig.
6B). The mobility
shift was, however, not proportional to the T-content, as shown
for
5 and
6 (+1 AT pair) or
10 and
13 (2 AT pairs). Each
mutant DNA has a characteristic conformation at the mutated
region in the double-stranded DNA, which would reflect the binding
affinity to Zn
2+cyclen. In fact, the mutants with unchanged
T-content,
18 (G to C) and
19 (C to G), showed a small decrease
in the migration distances compared to the wild-type
1. Further
determination of various mutant DNAs by using the Zn
2+cyclenPAGE
would give a rational explanation for the relationship between
the DNA sequence and local conformation.

View larger version (44K):
[in this window]
[in a new window]
|
Figure 6. Electrophoresis of the AluI digested PCR products from wild-type 1 and its mutants 219 of the voltage-dependent sodium channel -subunit (Nav1.4) gene in 12% (w/v) polyacrylamide gel in the absence (A) and presence (B) of 5 mM Zn2+cyclen. Fragment sizes are shown on the right.
|
|
In order to determine the appropriate length of a DNA fragment
for Zn
2+cyclenPAGE, the PCR-amplified 621 bp products
were also digested with restricted endonucleases
MspI and
XmnI
to prepare longer fragments of 151 and 120 bp, respectively.
Although differences in mobility for the samples were observed
in both cases, they were smaller than those with
AluI. Thus,
a DNA fragment length of up to 150 bp should be suitable for
this analysis.
Application of Zn2+cyclenPAGE to heterozygosity analysis
Finally, we applied Zn2+cyclenPAGE to a more accurate SNP detection procedure by a combination of the well known heterozygosity screening technique. PCR using a 1:1 mixture of a wild-type and a mutant gene as a template gave the complementary DNA (two homoduplexes) and a single or more mismatched DNA (two heteroduplexes). The PCR products were digested with AluI and then subjected to Zn2+cyclenPAGE. Figure 7A shows the case of single-nucleotide substitutions 6, 8, 11, 12 and 1619. One or two upper bands corresponding to the two heteroduplexes are clearly observed. Even the substitutions A to T (i.e. 12) and G to C (i.e. 18 and 19) showed clear band(s) at different position(s) from those for homoduplexes. In the case of multiple-base substitutions 25, 7, 9, 10 and 1315, heteroduplexes are more clearly detectable as upper shifted bands (Fig. 7BD). The migration distances of all heteroduplexes are shorter than those of corresponding homoduplexes. These results indicate that a DNA mismatch promotes Zn2+cyclen binding to the thymine base around the mismatch site, resulting in a relatively large conformation change (e.g. a large bubble in the double-helical DNA), which enables visualization of all mutations as different DNA bands.

View larger version (28K):
[in this window]
[in a new window]
|
Figure 7. Electrophoresis of heteroduplexes and homoduplexes of the AluI-digested PCR products (99 bp) prepared with wild-type 1 and its mutants 219 of the voltage-dependent sodium channel -subunit (Nav1.4) gene in 12% (w/v) polyacrylamide gel in the presence of 5 mM Zn2+cyclen: (A) single-base-, (B) two-base-, (C) four-base- and (D) seven-base-substituted mutants.
|
|
 |
CONCLUSIONS
|
|---|
We introduced the novel procedure Zn
2+cyclenPAGE
for a simple, rapid, low-cost and accurate analysis of DNA mutation.
The Zn
2+cyclenPAGE is based on the principle that
the binding of Zn
2+cyclen to the thymine base changes
the local DNA conformation, resulting in different electrophoretic
mobility of a mutant DNA. Combination of a PCR technique for
heterozygosity screening and Zn
2+ cyclenPAGE enables
more accurate detection of single nucleotide mutations even
for the less detectable substitutions AT to TA and GC to CG.
Since the Zn
2+cyclenPAGE procedure requires a
general electrophoretic system and only one additive Zn
2+cyclen,
it would be a very useful tool for various SNP analyses in an
ordinary laboratory. Furthermore, the DNA-binding Zn
2+cyclen
can be easily dissociated by adding a pH 7 phosphate buffer
(20 mM) (
Kd value of 0.10 mM for HPO
32Zn
2+cyclen)
or decreasing the gel pH to

4, these two methods being simple
post-treatments for subsequent sequence analysis, such as mass
spectroscopy. It is worthwhile to consider using Zn
2+cyclenPAGE
in the medical field for the screening and genotyping of various
disease-causing mutations.
 |
ACKNOWLEDGEMENTS
|
|---|
The authors gratefully acknowledge helpful discussions with
Professor Masanori Sugiyama (Hiroshima University) and Professor
Mitsuhiko Shionoya (University of Tokyo). We wish to thank the
Research Center for Molecular Medicine, Faculty of Medicine,
Hiroshima University for the use of their facilities. This work
was supported by grants from the Ministry of Education and Culture
of Japan to T.K. (12470506, 12559006 and 13877382) and E.K.
(11770023 and 14770014) and by a research grant from Takeda
Science Foundation (2002) to E.K.-K.
 |
REFERENCES
|
|---|
- Collins,F.S., Brooks,L.D. and Chakravarti,A. (1998) A DNA polymorphism discover resourse for the research on human genetic variation. Genome Res., 8, 12291231.[Free Full Text]
- Roses,A.D. (2000) Pharmacogenetics and the practice of medicine. Nature, 405, 857865.[Medline]
- Kleyn,P.W. and Vesell,E.S. (1998) Genetic variation as a guide to drug development. Science, 281, 18201821.[Free Full Text]
- McCarthy,J.J. and Hilfiker,R. (2000) The use of single-nucleotide polymorphism maps in pharmacogenomics. Nat. Biotechnol., 18, 505508.[Web of Science][Medline]
- Shi,M.M. (2001) Enabling large-scale pharmacogenetic studies by high-throughput mutation detection and genotyping technologies. Clin. Chem., 47, 164172.[Abstract/Free Full Text]
- Kristensen,V.N., Kelefiotis,D., Kristensen,T. and Borresen-Dale,L. (2001) High-throughput methods for detection of genetic variation. Biotechniques, 30, 318332.[Web of Science][Medline]
- Orita,M., Iwahana,H., Kanazawa,H., Hayashi,K. and Sekiya,T. (1989) Detection of polymorphisms of human DNA by gel electrophoresis as single-strand conformation polymorphisms. Proc. Natl Acad. Sci. USA, 86, 27662770.[Abstract/Free Full Text]
- Myers,R.M., Larin,Z. and Maniatis,T. (1985) Detection of single base substitutions by ribonuclease cleavage at mismatches in RNA:DNA duplexes. Science, 13, 12421246.
- Novack,D.F., Casna,N.J., Fischer,S.G. and Ford,J.P. (1986) Detection of single base-pair mismatches in DNA by chemical modification followed by electrophoresis in 15% polyacrylamide gel. Proc. Natl Acad. Sci. USA, 83, 586590.[Abstract/Free Full Text]
- Cotton,R.G., Rodrigues,N.R. and Campbell,R.D. (1988) Reactivity of cytosine and thymine in single-base-pair mismatches with hydroxylamine and osmium tetroxide and its application to the study of mutations. Proc. Natl Acad. Sci. USA, 85, 43974401.[Abstract/Free Full Text]
- Ganguly,A. Rooney,J.E., Hosomi,S., Zeiger,A.R. and Prockop,D.J. (1989) Detection and location of single-base mutations in large DNA fragments by immunomicroscopy. Genomics, 4, 530538.[Web of Science][Medline]
- Ganguly,A. and Prockop,D.J. (1990) Detection of single-base mutations by reaction of DNA heteroduplexes with a water-soluble carbodiimide followed by primer extension: application to products from the polymerase chain reaction. Nucleic Acids Res., 18, 39333939.[Abstract/Free Full Text]
- Youil,R., Kemper,B.W. and Cotton,R.G. (1995) Screening for mutations by enzyme mismatch cleavage with T4 endonuclease VII. Proc. Natl Acad. Sci. USA, 92, 8791.[Abstract/Free Full Text]
- Korkko,J., Annunen,S., Pihlajamaa,T., Prockop,D.J. and Ala-Kokko,L. (1998) Conformation sensitive gel electrophoresis for simple and accurate detection of mutations: comparison with denaturing gradient gel electrophoresis and nucleotide sequencing. Proc. Natl Acad. Sci. USA, 95, 16811685.[Abstract/Free Full Text]
- Sheffield,V.C., Cox,D.R., Lerman,L.S. and Myers,R.M. (1989) Attachment of a 40-base-pair G + C-rich sequence (GC-clamp) to genomic DNA fragments by the polymerase chain reaction results in improved detection of single-base changes. Proc. Natl Acad. Sci. USA, 86, 232236.[Abstract/Free Full Text]
- Shionoya,M., Kimura,E. and Shiro,M. (1993) A new ternary zinc(II) complex with [12]aneN4 (= 1,4,7,10-tetraazacyclododecane) and AZT (= 3'-azido-3'-deoxythymidine). Highly selective recognition of thymine and its related nucleotides by a zinc(II) macrocyclic tetraamine complex with novel complementary associations. J. Am. Chem. Soc., 115, 67306737.
- Kikuta,E., Aoki,S. and Kimura,E. (2002) New potent agents binding to poly(dT) sequence in double-stranded DNA: bis(Zn2+cyclen) and tris(Zn2+cyclen) complexes (cyclen = 1,4,7,10-tetraazacyclododecane). J. Biol. Inorg. Chem., 4, 473482.
- Kikuta,E., Murata,M., Katsube,N., Koike,T. and Kimura,E. (1999) Novel recognition of thymine base in double-stranded DNA by zinc(II)macrocyclic tetraamine complexes appended with aromatic groups. J. Am. Chem. Soc., 121, 54265436.
- Kikuta,E., Koike,T. and Kimura,E. (2000) Controlling gene expression by zinc(II)macrocyclic tetraamine complexes. J. Inorg. Biochem., 79, 253259.[Web of Science][Medline]
- Kimura,E., Ikeda,T., Aoki,S. and Shionoya,M. (1998) Macrocyclic zinc(II) complexes for selective recognition of nucleobases in single- and double-stranded polynucleotides. J. Biol. Inorg. Chem., 3, 259267.
- Kikuta,E., Katsube,N. and Kimura,E. (1999) Natural and synthetic double-stranded DNA binding studies of macrocyclic tetraamine zinc(II) complexes appended with polyaromatic groups. J. Biol. Inorg. Chem., 4, 431440.[Web of Science][Medline]
- Ishii,H., Kinoshita,E., Kimura,T., Yakehiro,M., Yamaoka,K., Imoto,K., Mori,Y. and Seyama,I. (1999) Point-mutations related to the loss of batrachotoxin binding abolish the grayanotoxin effect in Na+ channel isoforms. Jpn J. Physiol., 49, 457461.[Web of Science][Medline]
- Kimura,T., Kinoshita,E., Yamaoka,K., Yuki,T., Yakehiro,M. and Seyama,I. (2000) On site of action of grayanotoxin in domain 4 segment 6 of rat skeletal muscle sodium channel. FEBS Lett., 465, 1822.[Web of Science][Medline]
- Kimura,T., Yamaoka,K., Kinoshita,E., Maejima,H., Yuki,T., Yakehiro,M. and Seyama,I. (2001) Novel site on sodium channel
-subunit responsible for the differential sensitivity of grayanotoxin in skeletal and cardiac muscle. Mol. Pharmacol., 60, 865872.[Abstract/Free Full Text]
- Maejima,H., Kinoshita,E., Yuki,T., Yakehiro,M., Seyama,I. and Yamaoka,K. (2002) Structural determinants for the action of grayanotoxin in D1 S4-S5 and D4 S4-S5 intracellular linkers of sodium channel
-subunits. Biochem. Biophys. Res. Commun., 295, 452457.[Web of Science][Medline]
- Norrander,J., Kempe,T. and Messing,J. (1983) Construction of improved M13 vectors using oligodeoxynucleotide-directed mutagenesis. Gene, 26, 101106.[Web of Science][Medline]
- Trimmer,J.S., Cooperman,S.S., Tomiko,S.A., Zhou,J., Crean,S.M., Boyle,M.B., Kallen,R.G., Sheng,Z., Barchi,R.L., Sigworth,F.J., Goodman,R.H., Agnew,W.S. and Mandel,G. (1989) Primary structure and functional expression of a mammalian skeletal muscle sodium channel. Neuron, 3, 3349.[Web of Science][Medline]
- Kinoshita,E., Maejima,H., Yamaoka,K., Konno,K., Kawai,N., Shimizu,E., Yokote,S., Nakayama,H. and Seyama,I. (2001) Novel wasp toxin discriminates between neuronal and cardiac sodium channels. Mol. Pharmacol., 59, 14571463.[Abstract/Free Full Text]
- Koike,T., Takamura,M. and Kimura,E. (1994) Role of zinc(II) in ß-lactamase II: a model study with a zinc(II)-macrocyclic tetraamine (1,4,7,10-tetraazacyclododecane, cyclen) complex. J. Am. Chem. Soc., 116, 84438449.

CiteULike
Connotea
Del.icio.us What's this?
This article has been cited by other articles:

|
 |

|
 |
 
E. Kinoshita, E. Kinoshita-Kikuta, H. Kojima, Y. Nakano, K. Chayama, and T. Koike
Reliable and Cost-Effective Screening of Inherited Heterozygosity by Zn2+-Cyclen Polyacrylamide Gel Electrophoresis
Clin. Chem.,
November 1, 2005;
51(11):
2195 - 2198.
[Full Text]
[PDF]
|
 |
|