多肽合成中困难序列的缩合研究进展(6)

发布时间:2021-06-08

非常详细的综述性文章

116

药学学报Acta

PharmaceuticaSinica

2007,42(2):111—117

yields

fortherapidSPPS.using

Boc—aminoacid

derivatives,of

CGRP(human一Ⅱ.caleitonin

gene—

relatedpeptide)(8—37).They

observed

that

coupling

yields

are

highly

dependent

on

thesolventused.Maximumresinsolvationoccurred

with

NMP.

NMP—DMSO(8:2)andDMSO.Inefficientsolvationof

the

peptide—resin

occurred

with

these

solvents

and

resultedinpoorsyntheseswithaveragecouplingyieldsof78.1。88.9and

91.8%.respectively.Superior

peptide—resin

solvationwas

obtainedusing

DMA

(dimethylacetamide)

and

DMF,

resultingin

significantlyhigheraveragecouplingyieldsof98.0and

2).

Average

couplingyieldsforthe

synthesisof

Solventsystem

Avg.coupling

yield/%

DMF

provided

themosteffective

peptide—resinand

was

theonly

solventfrom

whichCGRP

obtained

as

singlemajorproductinthe

cleavedmaterial.Itshouldpointout

thatunderconditions

the

peptidyl—resin

has

differentresponses

even

inthe

same

solvent.

solventnot

onlywiththechangeofchainlengthbutalso

withthe

alternation

of

stages

ineach

syntheticcircle.such

as

the

deprotecting

and

couplingsolvents,isnecessary

for

the

enhancement

of

coupling

Thus,the

success

of

SPPSisoften

dependent

solvationoftheresinandthegrowingresin—bound

chain.Theuse

ofnewsupports

thatincreaseseparation

and

peptide

chain

solvation

is

CLPSER(cross—linked

polystyrene—

acrylate

resin)。3“showed

excellent

in

broadrangeofsolventsused

in

SPPS.newresinwascomparedwithcommercialsupportsas

MerrifieldandSheppardresinsbysynthesizing

acylcarrier

protein(65—74)fragment

underthe

experimental

conditions.HPLC

(high—

liquid

chromatography)profiles

revealed

highefficiencyofthenewlydevelopedsupport.CM

(polyethylene

glyc01)一based

resin,performing

excellentlyfor

the

preparationofhydrophobic,highly

structured,andpoly—Argpeptides,ascomparedtoPS

(polystyrene)resins.Themechanistic

reason

behind

thesynthetic

efficiencyofthe

new

resinwasfoundto

beitsabilitytoinducerandomcoilconformation

to

the

growing

peptidechains.

Conclusions

The

phenomenon

of“difficultsequences’’hasbeenattributedto

the

self—association

of

the

peptide

chainbyformationofhydrogenbonds

andresultin

an

incompletecouplingreaction.Itissequencedependentup

to

nowno“GoldenRule”existswhich

allows

predictionofaggregationduringthesynthesisof

sequence!The

aggregation

has

tendency

tooccur

sequence

richinhydrophobicresidues;ithasbeen

as

at

the5/6th

residuefromtheC—terrainus

not

occurring

after

the

21st

one.Two

main

can

beused

to

disrupttheaggregation:the

one

consistsin

modifyingtheenvironmentinwhich

synthesisismadeand

to

introduceelementsknown

disrupthydrogenbonds,

which

include

the

thesolventssuch

as

DMF,DMSO,

mixedsolvent;additionofchaotropicsalts:

at

elevated

temperature.Theotherapproach

to

introducebackboneprotecting

groups

or

spacer

which

willprevent

the

formationof

hydrogen

sHch

as,using

more

potent

newsupportswithexcellentswelling,

reasonableschemes

for

fragment

the

microwave—assistedSPPS

33,34一

alsodescribed

as

successfulstrategiesforsynthesis

sequences”.

[1]Tickler

AK,Barrow

CJ.wadeJD.hnprovedpreparation

of

amyloid-betapeptides

as

Nalpha—Fmoc

deprotection

reagent[J]

唱&

队%

2001,7:488一

494.

DalPozzoA,NiM,MuziL,eta1.Aminoacidbromides:theirN—protectionand

use

in

the

synthesisof

pepti(1eswith

extremely

difficult

sequences[J].J

Org

Chem,

2002,67:6372—6375.Ball

HL,King

DS,CohenFE,eta1.Engineering

the

prionproteinusingchemicalsynthesis[J].J

Pept

Res,

2001,58:357—374.

Miranda

LP,AlewoodPF.

Challengesfo。protein

chemicalsynthesisinthe21st

century:bridginggenomics

and

proteomics[J].J

PeptSci,2000,55:217—226.

99.5%,respectively(TableandTablethenew

CGRP(8—37)

in

describedbut

approachesfirst

theto

following:changingsolvationNMP,orcoupling

is

(8—37)wascrudedifierentswelling

unitsbonds.Approaches

Therefore,varyingpeptidedifferentchanging

very

reagents,usingdesigning

condensations,andare

of“difficult

RefeFences

efficient.

upon

peptideinterchainpreferred.

ethyleneglycolswellingThesuch

an

same

performance

the

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