Hydrogen bonding between phosphate and amino acid side chains

143 (1986) 365-368 Elsevier Science Publishers B.V., Amsterdam -Printed

Journal of Molecular Structure,

HYDROGEN

P.

BONDING

CARMONA

and de

Instituto

BETWEEN

M.

L.

PHOSPHATE

365 in The Netherlands

AND

AMINO

ACID

Serrano

121,

SIDE

CHAINS

RODRIGUEZ

optica

(C.S.I.C.).

28006

Madrid

(Spain)

ABSTRACT Hydrogen bonds between polar groups of amino acid side chains (histidine, lysine, glutamic acid) and phosphate ions have been Proton transfer from amino acid studied by infrared spectroscopy. groups to phosphate occur mainly in case that tribasic and dibasic phosphate ions take part in hydrogen bonds. Conformational changes and continuum are strongly related to the degree of proton transfer and hydration. It is pointed out that the aforementioned properties should be of great significance for nucleation and growth of prostatic and renal stones.

INTRODUCTION Hydrogen is

of

bonding

importance the

However, associations the

calcium

phosphate

an

organic

tion

with

the

of

phate

by

of

is

hydrogen

bonds

of

the

the

in

prostatic

major

component

being

mostly

bonded

compounds

as

bonds

the

complex

the

growth

acid

of

chains

mineral-organic composition

calculi, (ref.1)

of

prostatic

associated

In

Conner

calculi,

we

have

systems

of

phosphate

we

have

protein

of

apatitic

proteins.

models,

between

side

calcifications.

this and

hydrogen

infrared

amino

biological

because

often

hydrogen

these

and

of

Concerning

aetiology

the

the

unknown

fraction,

several Using

nature

nature

phosphate

problem

components.

with

studied

the

remain

organic

acids.

between

in

and

polyamino

investigated

side

chains

the

and

phos-

spectroscopy.

EXPERIMENTAL The

inorganic

polyamino Merck

and as

(Glu), red of

with

in

of

the

(NaH2P04,

(Lys)n.HBr

(His),,,

Sigma

respectively.

sodium

salt.

addition

of

polyamino

tion

phosphates

acids

acids

phosphate. mixtures.

0022-2860/86/$03.50

100% the

were

(Lys)n.HBr protonated

prepared

films

one were

in

Na3P04)

(Glu),

were

was

used

and

the

supplied

by

as

such

poly-L-histidine

stoichiometric

Usually The

Na2HP04, and

amount water

phosphate obtained

and

of

on

0 1986 Elsevier Science Publishers B.V.

HCl.

silicon

prepa-

Solutions

subsequent

ion/residue

and

was

was

addipresent

windows

by

366 drying

under

vacuum.

AND

DISCUSSION

RESULTS The

results the

occurs, the te

at

phosphate

990 ion

cm is

This

is

when

Similarly, can

be

when

domly

coiled

2),

3290

cm-l In

an

the

for

the

proton

shift

the

proton

ions.

potential tral

and

cation

bivalent

than

H2P04 the

formation

predominant.

In is

the

does

In not

shifted

to

this

connection,

tals

in

been

are

It

is

more

group

accurs.

ions

polymer. chain

removed

is by

ran-

phos(see

I band

at

we

have

found

depend

on

the

presence

by

nucleation renal

pH

the

the

growth

calculi

must

of

due the

basicity

this

polyamino

equilibrium

aforementioned

and

a proton is

calcium curbed

neuin-

with of

(Glu),

transfer to

the

HP042of

ion

this acid.

bonds.

phosphate by

the

is

phol

H2P04T&HP042-

hydrogen

be

proton

with

a film

which

of

of

example,

and

such

that

presence

increases

this

of

the

of

and

presence

for

in

that

the

to elec

(ref.5)

prepared

ions

However,

owing

external

(ref.6) the

effect

have

thus, an

be

in

(COO-..HPO), characteri

origins

could

pronounced, We

fact,

and

the

wells

demostrated

calcium

physiological

bonds

Possible

this

cations. of

(ref.4),

disturbed of

presence

left

at

phosphate

amide

potential

bonds

phosphate

the

prostatic

has

the

group.

hydrogen it

bonds

calcium

at

summary,

band

cm-l.

a B-structure

band,

hydrogen

of

prominence

of

form

conforma

A

1645 to

is

of

(ref.2).

- H2P04system, -1 cm , which is

2000

these

shape

bonds

field.

carboxilate

previous

phate

the

A

hydrogen

carboxilate these

fact,

to

amide

this

peptide

proton

tends'

acid

below

of

monovalent

in

sharp

the

to

a-form

amide at

of

the

by

respectively.

the

hydrogen

creasing

to

to

sharp

transition

molecule

appears

in In

of

salts,

and

residue

change

fields

calcium

lysine

the

the

protonated

the

since

from

by -1

1 shows - Phospha

protonated

transfer

polarizable

may

not

found

polarizability

field

system,

is

when

Fig.

residue

that

of

poly-L-glutamic

continuum

fact

I band

are

transfer

indicated

histidine

amide

However,

cm

of

this

a conformational

1625

case

clearly

presence

uncharges

easily

electric

the

groups

indicated

and

the

intense

tric

from

the

residue

ion.

the

(ref.3).

as

tic

by with

c-amino

ions

Fig.

in

is

from

from

proton

poly-L-histidine

N... HP0

predominat

Whenever

phosphate

transfer

inferred

proton

deduced

Thus,

phate

structure

indicated

1.

protonated

histidine

together

cm-l,

Table

towards

the

. Proton

is

appears

3290

the -1

in

shifted of

also

poly-L-histidine tion

is

spectrum where

system,

summarized

proton

infrared

v,(PO3)

are

In crys-

amino

367 acid

side

groups

2.5

g

@O

K E

50-

studied

30

in

4.0

this

50

work.

6.0

10

9.0

12

E 8

20

4000

Fig.

1.

Infrared

4000

Fig.

2.

Infrared

3000

spectrum

of

3000

spectrum

2000

1600

the

poly-L-histidine

2000

of

the

1600

poly-L-lysine

1200

800

+

POa3-

1200

+

800

POa3-

I cm-’

system.

I

cm-9

system.

366 TABLE

1

Proton

transfer

in

(L-His

H+)n---P043-

Yes,

to

phosphate

Yes,

to

phosphate

System

(L-His

H+),---HP04*-

(L-His

H+),---H2P04-

hydrogen

bonds.

Proton

transfer

No

(L-Lys

H+)n---P043-

Yes,

to

phosphate

(L-Lys

H+),---HP04*-

Yes,

to

phosphate

(L-Lys

H+)

Very

small,

n---H2P04-

to

phosphate

(L-Glu-COONa),---HPO4*-

No

(L-Glu-COONa)n---H2P04w

No

REFERENCES 1 2

3

4 5 6

D. J. Sutor and S. E. Wooley, J. Urol. 46 (1974) 533-546 BiopolymeE 10 (1971) 711-719 J. Muelinghaus and G. Zundel, Biopolymers 20 -(i-981) 345-357 K. Kakiuchi and H. Akutsu, W. Kristof and G. Zundel, Biopolymers lV(1980) 1753-1769 E. G. Weideman,H. PfeiffG and G. Zundel, J. Am R. Janoschek, Chem. Sot. 94 (1972) 2387-2396 0. Schrobergand G. Zundel, Can. .J. Chem. 2193-2200 -54 (1976)