Trading Update & Placing

For immediate
release                                                                  31
March 2005

                     PROTEOME SCIENCES TMT REAGENTS DEAL,                      

                                TRADING UPDATE                                 

                                      AND                                      

                                    PLACING                                    

Proteome Sciences plc ('Proteome Sciences' or the 'Company') is pleased to
announce that it has signed Heads of Agreement for an exclusive global license
in the field of proteomics with a major global healthcare player for its Tandem
Mass Tags, part of the Sensitizer family of chemical reagents and expects to
complete the definitive licence agreement shortly, at which time full details
of the licensee will be disclosed.

Proteome Sciences has developed TMT chemical mass tags at its Frankfurt
facility.  Tandem Mass Tags increase the output of proteomics experiments by
reducing sample complexity in a way that allows accurate and sensitive
quantification and identification of protein biomarkers in complex biological
materials such as tissue and body fluids for applications in mass spectrometry,
bioinformatics, statistics and pattern recognition.

The Board believes that the market potential for isobaric mass tag reagents in
proteomics is likely to grow extremely rapidly and is projected to generate
sales into many hundreds of million dollars over the TMT patent life on which
Proteome Sciences will receive royalties.

It is proposed that Proteome Sciences may initially receive US $2.3m to include
milestone patent payments and a signing fee together with a double-digit
royalty on sales.  Proteome Sciences will retain all rights to the other
chemical reagents in the Sensitizer family, including PST, qPST and Sensitizer
and the use of TMT for diagnostic and therapeutic applications.

Trading Update

We are pleased to confirm that, as previously stated in the Interim Report,
that we are continuing to make good progress with the other legs of our
business - the biomarker portfolio and ProteoSHOP, and would like to provide an
update:

In the case of our stroke biomarkers, we have moved the existing license
arrangements for Point of Care applications to a non-exclusive basis.  This
will considerably simplify and increase the commercial freedom to operate in
the field of high throughput stroke (HTS) applications and should expedite the
process to effect a number of HTS non-exclusive licenses at more favourable
terms with the major players with whom negotiations are well advanced.

The first ProteoSHOP deal has been concluded with Regen Therapeutics plc,
details of which are contained in a separate press release. A healthy pipeline
of prospective strategic alliances is building up for the remainder of the year
and beyond.

Intronn

The main objective for Intronn's SMART technology, following the successful
development of the high capacity screen, was to apply SMART in RNA therapeutics
for the liver.  The goal was to try and demonstrate in-vivo proof of principle
for one of its three primary programmes in haemophilia, dyslipidemia
(hypercholesterolemia) or AAT deficiency.

We are delighted to report that Intronn has demonstrated in-vivo proof of
principle for the dyslipidemia programme in the early part of 2005, with good
progress being made in the other applications.

2004 Financial Update
                                                                                      

As anticipated, the unaudited headline loss for the period to 31 December 2004
is expected to be broadly similar to the £4.26m in the previous year and cash
at the 31 December 2004 was £2.43m (2003: £6.16m). 

The commercial transactions currently envisaged should generate significant
signature payments, milestones and royalties.  With a similar pattern of cash
burn expected by the Board for 2005 to previous years, this will make a
considerable impact on the cashflow and future financial requirements of the
Company.

Details of the Placing

To provide the Company with the flexibility to undertake its business plan for
the foreseeable future, Proteome Sciences announces that it has raised
approximately £4.7 million (net of expenses) by way of a cash placing (the
'Placing') of 8,087,658 new ordinary shares (the 'Placing Shares'), with an
institutional investor, representing 6.6 per cent. of the Company's existing
ordinary share capital at a price of 59.5 pence per share. 

In addition, the Company is raising approximately a further £255,000 through
the exercise of warrants by Christopher Pearce, Chief Executive.  Christopher
Pearce intends to hold the shares resulting from this transaction.

The Placing Shares will rank pari passu with the Company's existing issued
ordinary shares.  Application will be made for the Placing Shares to be
admitted to the Alternative Investment Market ('AIM') of the London Stock
Exchange plc.  Dealings in the Placing Shares are expected to commence on 6
April 2005.

Commenting, Christopher Pearce, CEO of Proteome Sciences, said:

        'We are delighted to have signed Heads of Agreement with a major global
player in healthcare as the licensing partner to our TMT reagents which has the
structure and resources to maximise the TMT products and revenue streams. 
Having completed the process of commercialising TMT, we will continue to
develop and expand the range of Sensitizer reagents and concentrate on using
PST and qPST in strategic alliances with our ProteoSHOP toolbox.

        The recent major clinical problems experienced by major pharmaceutical
groups, which we had predicted for some time across a broad range of existing
drugs and drugs in development at the end of 2004, require a different approach
to clinical risk management in response to new regulatory requirements.  We
believe that proteomics technology will be one of the major contributors and
beneficiaries of this scenario and that Proteome Sciences has the right
technology at the right time.  Against this background, and with the
commercialisation of our research programmes now visible, the prospects look
most promising.'

Enquiries:

Proteome Sciences plc                                                          
                                                                               
Christopher Pearce, Chief Executive                                       01932
                                                                         865065
                                                                               
James Malthouse, Finance Director                                              
                                                                               
Dresdner Kleinwort Wasserstein                                                 
                                                                               
Michael Covington                                                           020
                                                                           7623
                                                                           8000
                                                                               
IKON Associates                                                                
                                                                               
Adrian Shaw                                                               01483
                                                                         535102
[e-mail]                                                      
                                                                          07979
                                                                         900733
                                                                               

Notes to Editors:

Proteome Sciences plc applies high sensitivity proteomics to identify and
characterise differential protein expression in diseases for diagnostic,
prognostic and therapeutic applications.  It has to date developed sensitive
blood assays for stroke, vCJD, BSE, solid organ transplant rejection and
Alzheimer's disease. The main focus of its research currently addresses
neurological, neurodegenerative, diabetes/obesity, oncology and cardiovascular
conditions.

In addition to its own proprietary biomarkers, Proteome Sciences has developed
ProteoSHOP (Proteome Sciences High Output Proteomics), a toolbox that offers
high sensitivity and high throughput gel and gel-free proprietary technologies
for the identification of potential biomarkers and drug targets.   These
include specialisation in membrane proteins and protein phosphorylation. 

The Company has also developed a range of specialist reagents to improve the
performance and quantitation of protein separation and characterisation with
mass spectrometry, bioinformatics, statistics and pattern recognition. These
include Sensitizer, PST, qPST and TMT.

The process of commercialisation is being actively pursued across the portfolio
of the Company's programmes and technologies and to date licensing deals have
been signed for the commercialisation of tests for Stroke and TSEs.

Proteome Sciences is headquartered in Cobham, Surrey in the UK and has
laboratories at Kings College Hospital, London and in Frankfurt. It employs 40
full time scientists in addition to its corporate and business development
staff. The Company is listed on the Alternative Investment Market.

This announcement has been issued by Proteome Sciences and is the sole
responsibility of Proteome Sciences. This announcement is for information
purposes only and does not constitute an offer to sell or issue any securities
or a solicitation of an offer to buy or acquire any securities or investment
advice in any jurisdiction including, without limitation, the United Kingdom,
the United States, Canada, Australia or Japan.

This announcement includes 'forward-looking statements'.  All statements
relating to Proteome Sciences other than statements of historical facts
included in this announcement, including, without limitation, those statements
regarding the financial position, results of operations, business and outlook
of Proteome Sciences are forward-looking statements.  Such forward-looking
statements involve known and unknown risks, uncertainties and other important
factors that could cause the actual results, performance or achievements of
Proteome Sciences or the markets and economies in which it operates to be
materially different from future results, performance or achievements expressed
or implied by such forward-looking statements.  Such forward-looking statements
are based on numerous assumptions regarding Proteome Sciences' present and
future business strategies and the environment in which Proteome Sciences will
operate in the future.  These forward-looking statements speak only as at the
date of this announcement.  Proteome Sciences expressly disclaims any
obligation or undertaking to disseminate any updates or revisions to any
forward-looking statements contained herein to reflect any change in Proteome
Sciences' expectations with regard thereto or any change in events, conditions,
circumstances or assumptions on which any such statement is based.

The Placing Shares have not been and will not be registered under the US
Securities Act of 1933 (the 'Securities Act') and may not be offered or sold
within the United States absent registration or an exemption from registration.
No public offering of securities will be made in the United States.

Dresdner Kleinwort Wasserstein Limited ('DrKW') and Dresdner Kleinwort
Wasserstein Securities Limited ('DrKWS'), which are each authorised and
regulated by the Financial Services Authority under the Financial Services and
Markets Act 2000 ('FSMA'), are acting for Proteome Sciences and for no one else
in connection with the Placing and will not be responsible to anyone other than
Proteome Sciences for providing the protections afforded to customers of DrKW
and DrKWS, nor for providing advice in relation to the Placing or any other
matter referred to in this announcement.

Neither this document nor any copy of it may be taken, transmitted or
distributed, directly or indirectly, in or into the United States, Canada,
Australia or Japan or in any jurisdiction in which such transmission or
distribution is unlawful. Any failure to comply with this restriction may
constitute a violation of US, Canadian, Australian or Japanese securities laws
or the securities laws of other states as the case may be.

ENDS