1. Trang chủ
  2. » Luận Văn - Báo Cáo

Báo cáo khoa học: Purification and characterization of novel salt-active acharan sulfate lyase from Bacteroides stercoris HJ-15 ppt

6 403 0
Tài liệu đã được kiểm tra trùng lặp

Đang tải... (xem toàn văn)

THÔNG TIN TÀI LIỆU

Thông tin cơ bản

Định dạng
Số trang 6
Dung lượng 252,63 KB

Các công cụ chuyển đổi và chỉnh sửa cho tài liệu này

Nội dung

The purified Bacteroidal salt-active acharan sulfate lyase acted to the greatest extent on acharan sulfate,to a lesser extent on heparan sulfate and heparin.. The biochemical properties o

Trang 1

Purification and characterization of novel salt-active acharan sulfate

Sung-Woon Hong1, Ho-Young Shin1, Yeong Shik Kim2and Dong-Hyun Kim1

1

College of Pharmacy, Kyung Hee University, Seoul, Korea;2Natural Products Research Institute, Seoul National University, Seoul, Korea

Salt-active acharan sulfate lyase (no EC number) has been

purified from Bacteroides stercoris HJ-15,which was

iso-lated from human intestinal bacteria with GAG degrading

enzymes The enzyme was purified to apparent homogeneity

by a combination of QAE-cellulose,diethylaminoethyl

(DEAE)-cellulose,CM-Sephadex C-50,HA ultrogel and

phosphocellulose column chromatography with the final

specific activity of 81.33 lmolÆmin)1Æmg)1 The purified

salt-active acharan sulfate lyase was activated to 5.3-fold by salts

(KCl and NaCl) The molecular weight of salt-active

acha-ran sulfate lyase was 94 kDa by SDS/PAGE and gel

filtra-tion The salt-active acharan sulfate lyase showed optimal

activity at pH 7.2 and 40C Salt-active acharan sulfate

lyase activity was potently inhibited by Cu2+,Ni2+ and

Zn2+ This enzyme was inhibited by some agents,butanediol and p-chloromercuric sulfonic acid,which modify arginine and cysteine residues The purified Bacteroidal salt-active acharan sulfate lyase acted to the greatest extent on acharan sulfate,to a lesser extent on heparan sulfate and heparin The biochemical properties of the purified salt-active acharan sulfate lyase are different from those of the previously puri-fied heparin lyases However,these findings suggest that the purified salt-active acharan sulfate lyase may belong to heparin lyase II

Keywords: Bacteroides stercoris HJ-15; salt-active acharan sulfate lyase; acharan sulfate lyase; acharan sulfate; heparin

Heparin,heparan sulfate and acharan sulfate

glycosamino-glycans (GAGs) are comprised of alternating 1–4-linked

glucosamine and uronic acid residues Heparan sulfate is

composed primarily of monosulfated disaccharides of

N-acetyl-D-glucosamine andD-glucuronic acid while

hep-arin is composed mainly of trisulfated disaccharides of

N-sulfonyl-D-glucosamine andL-iduronic acid [1,2]

Acha-ran sulfate,isolated from the giant African snail Achatina

fulica,has a structure closely related to heparin and heparan

sulfate,with a uniform repeating disaccharide structure

of fi4)-a-D-GlcNAc(1fi4)-a-L-IdoA2S (1fi[3] Acharan

sulfate exclusively contains N-acetyl-D-glucosamine instead

of N-sulfonyl-D-glucosamine in GAGs

Related to the degradation of these GAGs,some heparin

lyases that can eliminatively cleave polysaccharides (heparin

or heparan sulfate GAGs) have been reported [4–6] These

enzymes are classified as: (a) heparin lyase I (heparinase I,

EC 4.2.2.7),acting primarily at the fi 4)-a-D-GlcNS(6S or

OH)(1fi4)-a-L-IdoA2S(1fi linkages present in heparin; (b)

heparin lyase II (heparinase II or heparitinase II),acting at

thefi 4)-a-D-GlcNS(6S or OH)(1fi 4)-a-L-IdoA(2S or OH)

or -b-D-GlcA(1fi linkages present in both heparin and heparan sulfate; and (c) heparin lyase III (heparinase III or heparitinase,EC 4.2.2.8),acting on the fi 4)-a-D-GlcNS(or Ac) (1fi 4)-b-D-GlcA (or IdoA) (1fi linkages found exclu-sively in heparan sulfate The heparin lyases have become increasingly important in understanding the biological roles and structure of the glycoaminoglycans (and proteoglycan), which are involved in the well known anticoagulant activity [7] and the regulation of various cellular processes such as the potentiation of angiogenesis [8] and the modulation of cellular proliferation [9] Several heparin lyases of bacterial origin have been purified and characterized from various species including Flavobacterium heparinum [4,10], Bacillus

sp BH 100 [11], Prevotella heparinolyticus [12],and Bacter-oides stercorisHJ-15 [13,14]

Bacteroides stercoris HJ-15 has been recently isolated from human intestine and it contains several kinds of GAG degrading enzymes including heparin,heparan sulfate, acharan sulfate and chondroitin sulfate [13–16] We purified two kinds of novel heparin lyases,heparin lyase II-1 (acharan sulfate lyase 1),and heparin lyase II-2 (acharan sulfate lyase 2) and III,from this B stercoris HJ-15 [15,16] The Bacteroidal heparin lyase III cleaved heparin as well as heparan sulfate,but did not cleave acharan sulfate The Bacteroidal acharan sulfate lyase,which potently cleaved acharan sulfate as well as heparin,are highly specific to acharan sulfate compared to the previously reported heparin lyases [16] The purified acharan sulfate lyases 1 and 2 (no EC number) were not activated by salts such as KCl However,when Bacteroidal acharan sulfate lyase-active fraction isolated from B stercoris HJ-15 was incubated with salts (KCl),the enzyme fraction was

Correspondence to D.-H Kim,College of Pharmacy,Kyung Hee

University,1 Hoegi-dong,Dongdaemun-ku,Seoul 130–701,

South Korea Fax: + 82 2 957 5030,Tel.: + 82 2 961 0374,

E-mail: dhkim@khu.ac.kr

Abbreviations: CM,carboxymethyl; DEAE,diethylaminoethyl;

DUA,4-deoxy-a- L -threo-hex-4-enopyranosyl uronic acid;

GAG,glycosaminoglycan; GlcA,glucuronic acid; GlcN,glucosamine;

HA,hydroxyapatite; IdoA,iduronic acid; IEF,isoelectric focusing;

QAE,quaternary amino ethyl; PCMS,p-chloromercurisulfonic acid.

(Received 3 April 2003,revised 15 May 2003,

accepted 30 May 2003)

Trang 2

activated by salts Therefore,we tried to purify salt-active

acharan sulfate lyase from B sterocoris HJ-15 that acts

predominantly on acharan sulfate

Materials and methods

Materials

Heparin (porcine intestinal mucosa),heparan sulfate

(por-cine intestinal mucosa),chondroitin sulfate A (bovine

trachea),chondroitin sufate B (porcine intestinal mucosa),

chondroitin sufate C (shark cartilage),thioglycolic acid

(sodium salt),QAE cellulose Fastflow,and HA Ultrogel

(microcrystalline hydroxyapatite,4% beaded in agarose)

were supplied by Sigma Chemical Co Sodium dodecyl

sulfate,CM-Sephadex C-50,phosphocellulose,Sephacryl

S-300 HR resins and molecular weight markers for gel

filtration and protein electrophoresis were obtained from

Pharmacia Biotech Co (Uppsala,Sweden)

Diethylamino-ethyl (DEAE)-cellulose resin was purchased from Wako

Pure Chemical Industries (Tokyo,Japan) Protein assay kit

and Coomassie Brilliant Blue R-250 were from Bio-Rad

(Hercules,CA,USA) Tryptic soy broth was provided by

Difco Co Acharan sulfate was prepared as described by

Kim et al [3] All other chemicals were of the highest grade

available

Bacterial strains and purification of salt-active acharan

sulfate lyase

B stercorisHJ-15 was isolated and cultivated as described

previously [14,16] It was cultured anaerobically under an

atmosphere of 90% (v/v) nitrogen and 10% (v/v) carbon

dioxide at 37C in 100 L of tryptic soy broth (pH 7.2)

containing heparin (0.15 gÆL)1) instead of glucose,0.01%

(w/v) sodium thioglycolate and 0.1% (w/v) ascorbic acid

The cultured cells were harvested in the late exponential

phase (11–12 h) by centrifugation at 4000 g

4C and the resulting cell pellet was washed twice with

saline containing 50 mMsodium phosphate (pH 7.0) The

cell pellet was suspended in 600 mL of Buffer A (50 mM

sodium phosphate buffer,pH 7.0) Cell suspension (30 mL

at a time) was placed into a 50-mL centrifuge tube and

disrupted by 30-min periods of sonication at 1-s intervals on

an ultrasonic processor (Eyela Co.) at an 80% output with

cooling Cell debris was removed by centrifugation at

25 000 g

2 for 60 min at 4C All operations were carried

out at 4C unless otherwise noted The cell extract

(600 mL) was passed through a QAE cellulose column

(5· 40 cm) which had been pre-equilibrated with Buffer A

The column was washed with the same buffer until no

acharan sulfate lyase activity was detectable in the effluent

The fractions which passed through the column were

applied to a DEAE-cellulose column (5· 30 cm)

equili-brated with Buffer A The column was then eluted with the

same buffer until any ASL activity could not be detected

The noninteracting fluid passed through the column was

collected The total volume of the flow through was

1800 mL The eluate was loaded onto a CM-Sephadex

C-50 column (3· 30 cm) previously equilibrated with Buffer

A The column was washed with 1000 mL (1 L) of the same

buffer and then eluted with a 2-L linear gradient of KCl

from 0 to 0.6Min Buffer A at a flow rate of 105 mLÆh)1 All fractions obtained were assayed for heparin lyase and acharan sulfate lyase activities Four fractions (Fr-s,Fr-a, Fr-b and Fr-c) containing the activity of these enzymes were collected separately and assayed for the activities degrading acharan sulfate and heparan sulfate Fr-s had acharan sulfate lyase activity,which was activated by salts,was dialyzed against Buffer A for the further purification The dialyzed enzyme preparation (210 mL) was applied

to a HA Ultrogel column (2.5· 9 cm) equilibrated with Buffer A Being washed with 500 mL of the same buffer, the column was eluted with a 800-mL linear gradient,from

50 mM sodium phosphate buffer (pH 7.0) to 400 mM sodium phosphate buffer (pH 7.0) at a flow rate of

120 mLÆh)1 The active fractions were pooled and dialyzed twice against 2 L of Buffer A The dialyzed enzyme (78 mL) was loaded onto a phosphocellulose column (3· 25 cm) equilibrated with Buffer A After washing the nonabsorbed proteins with 300 mL of the same buffer,the column was eluted with an 800-mL linear gradient,from

50 mM sodium phosphate buffer (pH 7.0) to 400 mM sodium phosphate buffer (pH 7.0) at a flow rate of

100 mLÆh)1 The active fractions (salt-active acharan sulfate lyase,fraction numbers 17–25) were investigated for homogeneity by SDS/PAGE

Enzyme activity assay The activity of acharan sulfate lyase was measured accord-ing to the previously published procedure [17] The activity was calculated from the change of absorbance per minute using an extinction coefficient of 3800M )1 for products (1 U¼ 1 micromole of DUA containing product formed per minute) [17] The specific activity was calculated by dividing the micromoles of product produced per minute by the milligrams of protein in the cuvette Protein concentra-tion was measured by a Bradford assay using bovine serum albumin as a standard [18]

Characterization of salt-active acharan sulfate lyase SDS/PAGE was performed for the determination of molecular mass according to Laemmli’s procedure [19] The gel was stained with Coomassie Brilliant Blue R-250 solution and further stained with silver The pI value of heparin lyase was determined by IEF electrophoresis using Model 111 Mini IEF Cell (from Bio-Rad) according to the manufacturer’s instructions The molecular weight of the native enzyme was estimated by gel filtration using Seph-acryl S-300 HR column (1.6· 70 cm) calibrated with gel filtration low molecular weight calibration kit (from Sigma Co.) and high molecular calibration kit (from Amersham Pharmacia Biotech) The pH optimum of acharan sulfate lyase was determined using 50 mMsodium phosphate buffer (pH 6.0–8.5) Temperature dependency of the enzyme was investigated by measuring enzyme activity at different temperatures (25–60C) To investigate the effect of divalent metal ions and KCl (or NaCl) on the lyase activity, divalent metal ion (final concentration,100 lM),chemical modifying agents (50 lM) and KCl (0–500 mM) were added into the reaction mixture Kinetic constant of acharan sulfate lyase was determined by measuring the initial rates at

Trang 3

various substrate concentrations (200,400,600,1000,2000,

3000 lg) under the standard reaction conditions

These lyase activities on other sulfated polysaccharides

were also measured One milligram of each substrate was

added to the reaction mixture Because of their low

solubility,100 lg of acharan sulfate were used in this assay

The internal amino acid sequence of purified salt-active

acharan sulfate lyase was analyzed by an Applied Biosystem

protein sequencer model 492 in Korea Basic Science

Institute

Results

Purification of salt-active acharan sulfate lyase

Bacteroides stercoris HJ-15,which degrades a variety of

GAGs including heparin,heparan sulfate,acharan sulfate

and chondroitin sulfates [13],constitutively produced

hep-arin lyase and acharan sulfate lyase activities However,

when induced with acharan sulfate or heparin,total acharan

sulfate activity increased by about 3.5-fold (data not

shown) Furthermore,total acharan sulfate lyase activity

was activated 5.7-fold by salts,KCl and NaCl However,the previously purified enzymes,acharan sulfate lyases and heparinase III,from B sterocoris were not activated by salts Therefore,to purify salt-active heparin lyase,B stercoris HJ-15 cells were disrupted by ultrasonic,and the super-natant,the crude extract,was subjected to a combination

of QAE-cellulose and DEAE-cellulose column chromato-graphy to remove interacting proteins Acharan sulfate lyase activity passed through these columns without binding

to the matrices The effluent was applied to CM-Sephadex C-50 column chromatography (Fig 1) The salt-active acharan sulfate lyase activity fraction was then further purified to homogeneity by a series of hydroxyapatite Ultrogel chromatography and finally phosphocelluose col-umn chromatography (Fig 2) The specific activity and total activity at each purification step are summarized in Table 1

The specific activity of the purified acharan sulfate lyase activity had 80.33 UÆmg)1protein with a yield of 7.4% The purified acharan sulfate lyase was apparently homogeneous

by SDS/PAGE and its molecular mass was identically estimated to be 94 000 Da (Fig 2)

Characterization of salt-active acharan sulfate lyase The molecular weight of salt-active acharan sulfate lyase under nondenaturing conditions was determined by gel filtration (data not shown) Acharan sulfate lyase was estimated to be about 94 000 Da It suggests that acharan sulfate lyase is composed of one subunit The optimal pH

of acharan sulfate lyase was determined to be 7.2–7.3 for acharan sulfate,heparin and heparan sulfate (Fig 3),and the optimum temperature for the maximal activity was shown at 40C (Fig 4)

Fig 1 Elution profile of CM-Sephadex C-50 ion exchange (A),

hydroxyapatite ultrogel (B)and phosphocellulose (C)column

chromato-graphies s,acharan sulfate lyase activity without KCl; m,acharan

sulfate lyase activity with 50 m M KCl;

8 n,heparin lyase activity; simple

line,absorbance at 280 nm.

Fig 2 SDS/PAGE of the purified salt-active acharan sulfate lyase at various steps of purification Lanes 1 and 8,marker; lane 2,preparation after crude extract; lane 3,preparation after QAE column tography; lane 4,preparation after DEAE-cellulose column chroma-tography; lane 5,preparation after CM-Sephadex C-25 column chromatography; lane 6,preparation after hydroxyapatite ultragel column chromatography; and lane 7,purified salt-active heparin lyase

II after phosphocellulose column chromatography.

Trang 4

The purified acharan sulfate lyase was activated 5.3-fold

by the strength of salts,such as KCl and NaCl (Fig 5) However,divalent cations CaCl2,and MgCl2,did not activate this enzyme compared to KCl and NaCl The salt-active acharan sulfate lyase activity was slightly increased by addition of Mn2+,whereas they were severely inhibited

by Cu2+,Ni2+and Zn2+(Table 2) The purified enzyme was inhibited by PCMS

PCMS potently inhibited salt-active acharan sulfate lyase

but little inhibited by the other agents that modify histidine and cysteine residues (Table 3)

Amino acid composition analysis revealed that the salt-active acharan sulfate lyase contains a large proportion of lysine (data not shown) The pI value of the purified salt-active acharan sulfate lyase was 8.5,but slightly lower than those of the previously purified Flavobacterial heparin lyases range from 8.9 to 10.1 We analyzed the internal sequences of a peptide obtained by digestion of each enzyme with trypsin (Table 4) The internal sequence of the salt-active acharan sulfate lyase showed homology of 50% to Flavobacterial heparin lyases I and II previously reported, but did not showed homology to Flavobacterial heparin lyase III [10,20]

Fig 3 Effect of pH on the activity of salt-active acharan sulfate lyase.

The enzyme activity was assayed in 50 m M sodium phosphate buffer at

the indicated pH d,activity for acharan sulfate; j,activity for

hep-aran sulfate; m,activity for heparin.

Fig 4 Effect of temperature on the activity of salt-active acharan

sul-fate lyase The enzyme activity was assayed in 50 m M sodium

phos-phate.

Fig 5 Effect of KCl on the activity of salt-active acharan sulfate lyase d,salt-active acharan sulfate lyase II purified from Fr-s in Fig 1; m, heparin lyase II-1 (acharan sulfate lyase 1) purified from Fr-a in Fig 1 [16]; j,heparin lyase II-2 (acharan sulfate lyase 2) purified from Fr-a

in Fig 1 [16].

Table 1 Purification summary of salt-active acharan sulfate lyase One

unit (U) is the activity forming 1 lmol disaccharides from acharan

sulfate per minute Numbers in parentheses indicate the activities for

heparin used as a substrate.

Stage

Total activity (U)

Total protein (mg)

Specific activity (UÆmg)1) Crude extract 165.4 5250.12 0.03

QAE cellulose column

chromatography

65.2 1407.18 0.05 DEAE-cellulose column

chromatography

90.3 747.04 0.12

CM Sephadex C-50 column

chromatography

37.2 13.67 2.72 Hydroxyapatite ultrogel

column chromatography

34.5 1.82 18.96 Phosphocellulose column

chromatography

12.2 (1.3) 0.15 81.33 (8.67)

Table 2 Effect of divalent metal ions on salt-active acharan sulfate lyase activity.

Metal iona Residual activityb(%)

a Final concentration,1 m M b 0.03 U of homogenously purified enzyme activity was taken as 100%.

5

Trang 5

Substrate specificity of purified salt-active acharan

sulfate lyase

The purified salt-active acharan sulfate lyase degraded

heparin and heparan sulfate as well as acharan sulfate

(Table 5) The salt-active acharan sulfate lyase was the most

active to acharan sulfate When the salt-active acharan

sulfate lyase activity for heparan was taken as 100%,the

enzyme activities for acharan sulfate and heparan sulfate

were 952.3 and 149.5%,respectively However,all types of

chondroitin sulfates were not also substrates for the enzyme

Kinetic constants of purified salt-active acharan

sulfate lyase

Michaelis–Menten constants were determined under the

optimum reaction conditions in experiments designed to

calculate reaction velocities at each substrate concentration (Table 6) Kmand Vmaxof acharan sulfate on salt-active acharan sulfate lyase were estimated at 65.4 lgÆmL)1and 131.2 lmolÆmin)1Æmg)1,respectively As for heparin on salt-active acharan sulfate lyase, Kmand Vmaxvalues of heparin and heparan sulfate were calculated at 18.5 lgÆmL)1, 8.7 lmolÆmin)1Æmg)1 and 40.7 lgÆmL)1,13.1 lmolÆ min)1Æmg)1,respectively

Discussion

In the present report,we have purified salt-active acharan sulfate lyase specifically acting on acharan sulfate from Fr-s fraction of CM-Sephadex C-50 chromatography,which efficiently resolved GAGs degrading lyases of B stercoris HJ-15 As Fr-b and Fr-c fractions showed a higher specificity to heparan sulfate and heparin,they were considered to be similar to heparin lyase III and heparin

Table 3 Effect of divalent metal ions on salt-active acharan sulfate lyase

activity Homogenously purified enzyme activity (0.03 U) was taken as

100%.

Chemical modifying agent IC 50 (m M )

N-Tosyl- L -phenylalanine chloromethyl ketone >1

Phenylmethylsulfonyl fluoride >1

Sodium-p-tosyl- L -lysine chloromethyl ketone >1

p-Chloromercuric sulfonic acid 0.02

Table 4 Internal amino acid sequence of salt-active acharan sulfate lyase from Bacteroides stercoris HJ-15.

Enzyme

Internal amino acid sequence

Homology (%) Salt-active acharan sulfate lyase …GTIQYG…

Flavobacterial heparin lyase Ia 213 50

…GKITYV…

Flavobacterial heparin lyase II a 157 50

…GAIVYD…

Flavobacterial heparin lyase IIIa 567 33

…LMIQSL…

a Data from [10,20].

Table 5 Substrate specificity of acharan sulfate lyase and the previously reported heparin lyases Activity on heparin (or heparan sulfate in Flavobacterial heparin lyase III) as the substrate was set at 100%.

Substrate

Activity (%)

Salt-active Hep II Hep II-1 (ASL1)b HepII-2b(ASL2) Hep IIIb Hep I Hep II Hep III

Heparan sulfate (porcine) 149.5 128 121.7 610 30 172 100

a Data from [1,4,5,13,21] b Data from [15,16] c Unpublished data.

Table 6.

7 K m and V max values of salt-active acharan sulfate lyase.

Enzyme

K m (lgÆmL)1) V max (UÆmg protein)1) Acharan sulfate Heparin Heparin sulfate Acharan sulfate Heparin Heparin sulfate Salt-active acharan sulfate lyase 65.4 18.5 40.7 131.2 8.7 13.1

Acharan sulfate lyase 1a 28.1 8.8 7.5 65.0 11.6 14.3

Acharan sulfate lyase 2 a 42.2 20.6 16.4 107.6 22.9 31.3

a

Data from [16].

Trang 6

lyase I prepared from F heparinum,respectively [15,16].

Two acharan sulfate lyases previously purified from Fr-a

fraction showed the different substrate specificity compared

to those of Fr-b,Fr-c and the previously reported heparin

lyases [16] These enzymes were highly specific to acharan

sulfate compared to heparin and heparan sulfate The

salt-active acharan sulfate lyase purified from Fr-s fraction

showed a different substrate compared heparin lyase I and

III,but exhibited a similar substrate specificity of two

acharan sulfate lyase previously purified from Fr-a

Acha-ran sulfate was the best substrate for the purified present

enzyme Particularly,the present enzyme was significantly

activated by salts,KCl and NaCl,although two acharan

sulfate lyases were not activated by salts Several attempts at

N-terminal analysis failed to yield sequence information

suggesting the N-terminus to be blocked Therefore,we

analyzed the internal sequences of a peptide obtained by

digestion with trypsin The internal sequence of the peptide

showed poor homology to Flavobacterial heparin lyases I

and II Although the substrate specificities of heparin lyase I

and III are well understood,the structural requirement for

the cleavage of heparin and heparan sulfate by heparin lyase

II is not well characterized This could be due to a structural

complexity of heparin and heparan sulfate and a lack of

homogeneous polysaccharide A recently characterized

GAG,acharan sulfate,from African giant snail Achatina

fulicacan provide the criteria to classify the heparin lyase II

among the specificity of heparin lyases

In conclusion,the substrate specificity as well as the

characterization of salt-active acharan sulfate lyase are

different from those of the previous reported heparin lyases

(heparin lyase I and III prepared from F heparinum),but is

similar to those of Flavobacterial heparin lyase II

There-fore,we suggest that the salt-active acharan sulfate lyase

may belong to heparin lyase II

Acknowledgements

This work was supported by KOSEF grant 1999-2-209-010-5.

References

1 Jackson,R.L.,Busch,S.J & Cardin,A.D (1991)

Glycosamino-glycans: molecular properties,protein interactions,and role in

physiological processes Physiol Rev 71,481–539.

2 Griffin,C.C.,Linhardt,R.J.,Van Gorp,C.L.,Toida,T.,Hileman,

R.E.,Schubert,R.L & Brown,S.E (1995) Isolation and

char-acterization of heparan sulfate from crude porcine intestinal

mucosal peptidoglycan heparin Carbohydr Res 276,183–197.

3 Kim,Y.S.,Jo,Y.Y.,Chang,I.M.,Toida,T.,Park,Y & Linhardt,

R.J (1996) A new glycosaminoglycan from the giant African snail

Achatina fulica J Biol Chem 271,11750–11755.

4 Lohse,D & Linhardt,R (1992) Purification and characterization

of heparin lyases from Flavobacterium heparinum J Biol Chem.

267,24347–24355.

5 Desai,U.R.,Wang,H.M & Linhardt,R.J (1993) Substrate

specificity of the heparin lyases from Flavobacterium heparinum.

Arch Biochem Biophys 306,461–468.

6 Desai,U.R.,Wang,H.M & Linhardt,R.J (1993) Specificity studies on the heparin lyases from Flavobacterium heparinum Biochemistry 32,8140–8145.

7 Bourin,M.-C & Lindahl,U (1993) Glycosaminoglycans and the regulation of blood coagulation Biochem J 289,313–330.

8 Folkman,J & Shing,Y (1992) Control of angiogenesis by heparin and other sulfated polysaccharides Adv Exp Med Biol 313,355–364.

9 Castellot,J.J Jr,Choay,J.,Lormeau,J.C.,Petitou,M.,Sache,E.

& Karnovsky,M.J (1986) Structural determinants of the capacity

of heparin to inhibit the proliferation of vascular smooth muscle cells II Evidence for a pentasaccharide sequence that contains a 3-O-sulfate group J Cell Biol 102,1979–1984.

10 Godavarti,R.,Davis,M.,Venkataraman,G.,Cooney,C., Langer,R & Sasisekharan,R (1996) A comparative analysis of the primary sequences and characteristics of heparinases I,II,and III from Flavobacterium heparinum Biochem Biophy Res Com-mun 225,751–758.

11 Bellamy,R.W & Horikoshi,K (1992) Heparinase Produced by Microorganism Belonging to the Genus Bacillus in US Patent Research Development Corporation of Japan.

12 Watanabe,M.,Tsuda,H.,Yamada,S.,Shibata,Y.,Nakamura,

T & Sugahara,K (1998) Characterization of heparinase from an oral bacterium Prevotella heparinolytica J Biochem (Tokyo) 123, 283–288.

13 Ahn, M.Y., Shin, K.H., Kim, D.H., Jung, E.A., Toida, T., Lin-hardt,R.J & Kim,Y.S (1998) Characterization of a Bacteroides species from human intestine that degrades glycosaminoglycans Can J Microbiol 44,423–429.

14 Kim,B.-T.,Kim,W.-S.,Kim,Y.-S.,Linhardt,R.J & Kim,D.-H (2000) Purification and characterization of a novel heparinase from Bacteroides stercoris HJ-15 J Biochem 128,323–328.

15 Hong,S.-H.,Kim,B.-T.,Shin,H.-Y.,Kim,W.-S.,Lee,K.-S., Kim,Y.-S & Kim,D.-H (2002) Purification and characterization

of novel chondroitin ABC and AC lyases from Bacteroides ster-coris HJ-15,a human intestinal anaerobic bacterium Eur J Biochem 269,2934–2940.

16 Kim,B.T.,Hong,S.H.,Kim,W.S.,Kim,Y.S & Kim,D.-H (2001) Purificatio and characterization of acharan sulfate lyases, two novel heparinases,from Bacteroides stercoris HJ-15 Eur J Biochem 268,2635–2641.

17 Linhardt,R.J (1994) Analysis of glycosaminoglycans with poly-saccharide lyase In Curr Prot Mol Biol (Varki,A.,ed.),pp 17.13.17–17.13.32 Wiley Interscience,New York.

18 Bradford,M.M (1976) A rapid and sensitive method for the quantitation of microgram quantities of protein utilizing the principle of protein dye binding Anal Biochem 72,248–254.

19 Laemmli,U.K (1970) Cleavage of structural proteins during the assembly of the head of bacteriphage T4 Nature 227,680–685.

20 Su,H.,Blain,F.,Musil,R.A.,Zimmermann,J.J.F.,Gu,K & Bennett,D.C (1996) Isolation and expression in Escherichia coli of hepB and hep C,genes coding for the glycosaminoglycan-degrading enzymes heparinase II and heparinase III,respectively, from Flavobacterium heparinum Appl Environ Microbiol 62, 2723–2734.

21 Riley,T.V & Mee,B.J (1984) Heparinase production by Bac-teroides species Microbios Lett 25,141–149.

Ngày đăng: 23/03/2014, 21:20

TỪ KHÓA LIÊN QUAN

TÀI LIỆU CÙNG NGƯỜI DÙNG

TÀI LIỆU LIÊN QUAN

🧩 Sản phẩm bạn có thể quan tâm