Laccases With Improved Dyeing Properties

The present invention relates to a dyeing composition comprising a microbial laccase, the use of said dyeing composition for dyeing keratinous fibres, in particular hair, fur, hide and wool, and a method for dyeing keratinous fibres.

It has been used for many years to dye the hair to cover appearing grey hair. The need to do so arises from the fact that grey hair is the first sign of having past adolescence, which can be hard to accept for many people.

For instance, in certain parts of Asia it is widely used by both men and women to dye the hair with dyes often referred to by humorous people as "black shoe polish".

During the last few decades hair dyeing has become more and more popular in the western world. At first Punk Rockers and other society critical groups dyed their hair in extreme colours as a part of their protest against the established society, but today especially many young people also uses hair dyes (in more soft tints than the Punk Rockers) as a sort of "cosmetic" to change or freshen up their "look".

Hair dyes

In general hair dyeing compositions on the market today can be divided into three main groups:

temporary hair dyes,

semi-permanent hair dyes, and

permanent oxidative hair dyes.

The temporary hair dyes are only intended to change the natural hair colour for a short period of time and usually functions by depositing dyes on the surface of the hair. Such hair dyes are easy to remove with normal shampooing.

When using semi-permanent hair dyes the colour of the dyed hair can survive for five or more shampooings. This is achieved by using dyes having a high affinity for hair keratin and which is able penetrate into the interior of the hair shaft.

Permanent hair dyes are very durable to sunlight, shampooing and other hair treatments and need only to be refreshed once a month as new hair grows out. With these dyeing systems the dyes are created directly in and on the hair. Small aromatic colourless dye precursors (e.g. p-phenylene-diamine and o-aminophenol) penetrate deep into the hair where said dye precursors are oxidised by an oxidising agent into coloured polymeric compounds. These coloured compounds are larger than the dye precursors and can not be washed out of the hair.

By including compounds referred to as modifiers (or couplers) in the hair dyeing composition a number of hair colour tints can be obtained. Cathecol and Resorcinol are examples of such modifiers.

Traditionally H.sub.2 O.sub.2 is used as the oxidizing agent (colour builder), but also as a bleaching agent. Dyeing compositions comprising H.sub.2 O.sub.2 are often referred to as "lightening dyes" due to this lightening effect of H.sub.2 O.sub.2.

The use of H.sub.2 O.sub.2 in dyeing compositions have some disadvantages as H.sub.2 O.sub.2 damages the hair. Further, oxidative dyeing often demands high pH (normally around pH 9-10), which also inflicts damage on the hair and on the skin. Consequently, if using dye compositions comprising H.sub.2 O.sub.2 it is not recommendable to dye the hair often. To overcome the disadvantages of using H.sub.2 O.sub.2 it has been suggested to use oxidation enzymes to replace H.sub.2 O.sub.2.

U.S. Pat. No. 3,251,742 (Revlon) describes a method for dyeing human hair by dye formation in situ (i.e. on the hair). An oxidative enzyme is used to the colour formation reactions at a substantially neutral pH (7-8.5). Laccases, tyrosinases, polyphenolases and catacolases are mentioned as suitable oxidation enzymes. The only exemplified oxidation enzyme is tyrosinase.

EP patent no. 504.005 (Perma S.A.) concerns dyeing compositions for keratinous fibres, in particular hair, which do not require the presence of H.sub.2 O.sub.2 (hydrogen peroxide). The composition comprises an enzyme capable of catalysing the formation of the polymeric dyes and also dye precursors, such as bases and couplers, in a buffer solution wherein the pH of said composition is between 6.5 and 8 and said enzyme has an optimal activity in the pH range between 6.5 and 8.

Rhizoctonia praticola laccase and Rhus vernicifera laccase are the only laccases exemplified in the patent.

Abstract of Papers American Chemical Society vol. 209, no. 1-2, 1995 discloses the cloning of laccases from Scytalidium thermophilum and Myceliophthora thermophila. The abstract does not mention the use of said laccases for dyeing.

The object of the present invention is to provide improved dyeing compositions for keratinous fibres, such as hair, fur hide and wool, comprising an oxidative enzyme as the oxidising agent.

In the context of the present invention an "improved" composition for dyeing keratinous fibres means a composition being capable of dyeing the keratinous fibres in question faster or by the use of a smaller amount of oxidation enzyme to obtain an optimal dyeing effect, determined as .increment.E*, in comparison to corresponding prior art dyeing compositions.

Further, it is also possible to use a less amount of dye precursor. This is advantageous as certain dye precursors are very unhealthy and very carcinogenic.

Compositions capable of dyeing the keratinous fibres, in particular hair, fur, hide and wool, faster are desirable as such compositions are very user convenient.

Further, it is desirable to be able to use a less amount of enzyme in the dyeing composition. This might make the dyeing process more economical. Further, the risk for creating airborne protein aerosols is reduced.

It has now surprisingly been found that it is possible to provide such improved dyeing compositions for keratinous fibres by using microbial laccases for oxidising the dye precursor(s).

Laccases (benzenediol:oxygen oxidoreductases) (E.C. class 1.10.3.2 according to Enzyme Nomenclature (1992) Academic Press, Inc.) are multi-copper containing enzymes that catalyse the oxidation of phenols. Laccase-mediated oxidation results in the production of aryloxy-radical intermediates from suitable phenolic substrates; the ultimate coupling of the intermediates so produced provides a combination of dimeric, oligomeric, and polymeric reaction products. Certain reaction products may be used to form dyes suitable for dyeing keratinous fibres, such as hair and wool (see below).

Firstly, the object of the invention is to provide a dyeing composition comprising

a) above 0 to 1 mg enzyme protein per ml dyeing composition of microbial laccase,

b) one or more dye precursors,

c) optionally one or more modifiers.

Specifically contemplated is laccases of microbial origin, derived from a strain of the genus Myceliophthora.

In the second aspect the invention relates to the use of a dyeing composition of the invention for dyeing keratinous fibres, such as hair, fur, hide and wool.

The invention also related to a method for dying keratinous fibres comprising contacting the dyeing composition of the invention to the keratinous fibres in question under suitable conditions and for a period of time sufficient to permit oxidation of the dye precursor into a coloured compound.

The invention also relates to the use of a laccase for permanent dyeing of keratinous fibres wherein said laccase is a laccase that results in a .increment.E*-value higher than the .increment.E*-value resulting from a laccase derived from Rhus under corresponding dyeing conditions.

This means that when dyeing keratinous fibres with a dyeing composition of the present invention the .increment.E*-value determined are higher than the .increment.E*-value determined from corresponding keratinous fibres dyed under the same conditions using a dyeing composition comprising a laccase derived from Rhus.

The term "corresponding dyeing conditions" means under conditions where e.g. the enzyme concentration or enzyme activity, dyeing incubations time, dyeing incubation temperature, pH conditions, keratin fibre type (such as hair type) are the same, and further that the same dye precursor(s) and modifier(s) are used. In other words it defines conditions parallel to the specific dyeing conditions chosen. The dyeing conditions described below in the Examples may be chosen.

In the context of the present invention a "higher" .increment.E* value defines that the total quantitative colour change is more than one .increment.E* unit.

.increment.E* is calculated from the values of the parameters a*, b* and L* determined e.g. on a Minolta CR200 Chroma Meter using the formula .increment.E*=.sqroot.(.increment.L*.sup.2 +.increment.a*.sup.2 +.increment.b*.sup.2). The meaning of a*, b* and L* is explained below in the "Materials and Methods" section.

FIG. 1 shows the dyeing effect of six different laccases. The six laccases are the Polyporus pinsitus accase (rPp-laccase), Myceliophthora thermophila laccase (Mt-laccase wt.), Myceliophthora thermophila T1 variant laccase (Mt-laccase (var)), Rhus vernicifera laccase (Rvl-FXu-1), Scytalidium thermophilum laccase (rStL-FXu-1) and Rhizoctonia solani laccase (rRsL-3-FXu-1). o-aminophenol is used as the dye precursor and m-phenylene-diamine is used as a modifier.

FIG. 2 shows the wash stability of the Myceliophthora thermophila T1 variant laccase (Mt-laccase (var)) and the Polyporus pinsitus laccase (rPp-laccase) as the oxidising agent.

FIG. 3 shows the fastness (speed) of hair dyeing using the Myceliophthora thermophila T1 variant laccase (Mt-laccase (var)) and the Polyporus pinsitus laccase (rPp-laccase) as the oxidising agent.

FIG. 4 shows the dose-response dyeing effect of Myceliophthora thermophila laccase, using from 0.0001 to 0.5 mg enzyme protein per ml dyeing compoisiton.

The object of the present invention is to provide improved dyeing compositions for permanent dyeing of keratinous fibres, such as hair, fur, hide and wool, comprising an oxidation enzyme.

It has now surprisingly been found that it is possible to provide such improved dyeing compositions by using a microbial laccase for oxidising the dye precursor(s).

The Dyeing Composition

In the first aspect the present invention relates to a dyeing composition comprising

a) above 0 to 1 mg enzyme protein per ml dyeing composition of microbial laccase,

b) one or more dye precursor, and

c) optionally one or more dye modifiers.

In a preferred embodiment of the invention the laccase may be present in the dyeing compositions in a concentration within the range from 0.0001 to 1 mg/ml, preferably 0.001 to 0.8 mg/ml, more preferred 0.002 to 0.5, even more preferred 0.003 to 0.2, especially 0.004 to 0.1 mg enzyme protein/ml dyeing composition.

When dyeing with a composition of the invention for permanent dyeing the .increment.E*-value obtained is higher than that obtained when using a dyeing composition comprising a laccase derived from Rhus under corresponding dyeing conditions.

An example of a Rhus laccase is the laccase derived from the Japanese varnish tree Rhus vernicifera (Yoshida, (1883), J. Chem. Soc., 472). The Rhus vernicifera laccase is used in the Example 1 below.

The microbial laccase used according to the invention is of fungal or bacteria origin, in particular of filamentous fungus origin.

In an embodiment of the invention the microbial laccase is derived from a strain of genus Myceliophthora, such as a strain of the species Myceliophthora thermophila e.g. the purified laccase described in WO 95/33836 (PCT/US95/06815) from Novo Nordisk, which is hereby incorporated by reference. SEQ ID NO 1 below shows a DNA sequence encoding a suitable laccase derivable from Myceliophthora thermophila.

E. coli JM101 containing the expression vector pRaMB5 comprising SEQ ID NO 1 has been deposited under the Budapest Treaty with the Agricultural Research Service Patent Culture Collection, Northern Regional Research Center, 1815 University Street, Peoria, Ill., 61604. The vector have been given the Accession Number NRRL B-21261.

Also contemplated according to the invention are laccases derived from other micro-organisms being more than 80% homologous to SEQ ID NO 1 derived from Myceliophthora thermophila.

In addition, Myceliophthora laccases also encompass alternative forms of laccases which may be found in M. thermophila and as well as laccases which may be found in other fungi which are synonyms that fall within the definition of M. thermophila as described by Apinis (Nova Hedwigia 5, 57-78, 1963) and named Sporotrichum thermophile. Subsequent taxonomic revisions have placed this organism in the genus Chysosporium (Von Klopotek, A. Arche., (1974) Microbiol, 98, 365-369) and later Myceliophthora (Van Oorshot, Persoonia, (1977), 9, 401-408). A number of organisms known by other names also appear to belong to this species. These include Sporotrichum cellulophilum (U.S. Pat. No. 4,106,989); Thielavia thermophila (Fergus and Sinden (1968), Can. J. Botany, 47, 1635-1637); Chrysosporium fergussi and Corynascus thermophilus (Von Klopotek, supra).

Also the use of laccase variants are contemplated according to the present invention.

An example of a laccase variant is the Myceliophthora thermophila T1 variant described in PCT/US96/14087 (Novo Nordisk).

T1 variants (or Type I variants) are modified blue copper oxidases, including laccases. T1 variants can for instance be constructed by site-directed mutagenesis and differ from the corresponding wild-type blue copper oxidases by at least one amino acid residue in the Type I (T1) copper site. These modifications generally result in altered pH profiles and/or specific activity relatively to the wild-type enzymes. This can be advantageous when using the enzyme in question in dyeing compositions.

More specific the Myceliophthora thermophila T1 laccase variant may comprise the sequence 509VSGGL511 or may be modified as to increase the negative charge in at least one segment of the T1 copper site.

The above mentioned microbial laccases may advantageously be used in permanent dyeing composition for keratinous fibres. Such compositions have a superior dyeing effect to corresponding compositions comprising e.g. the Rhus vernicifera laccase as shown in Example 1.

The Myceliophthora thermophila T1 variant laccase is more wash stabile and further dyes faster than the Polyporus pinsitus laccase which is proven in Example 2 and Example 3, respectively.

Example 4 shows that less Myceliophthora laccase activity (i.e. LACU/ml) is needed to obtain a suitable dyeing effect in comparison to the Polyporus pinsitus laccase.

Example 5 shows that for the Myceliophthora thermophila laccase the dyeing effect optimum is obtained around 0.005 mg enzyme protein per ml dyeing composition.

In the case of using a Myceliophthora laccase in a permanent dyeing composition it may advantageously be present in concentrations from above 0 to 1 mg/ml, preferably 0.0001 to 0.1 mg/ml, more preferably 0.0005 to 0.05 mg/ml, especially 0.001 to 0.01 mg enzyme protein per ml dyeing composition.

It is to be understood that the laccase may be produced either homologously, or heterologously in a host cell such as filamentous fungus, yeast or bacteria.

Examples of filamentous fungi host cells include strains of the species of Trichoderma, preferably a strain of Trichoderma harzianum or Trichoderma reesei, or a species of Fusarium, or a species of Aspergillus, most preferably Aspergillus oryzae or Aspergillus niger, or yeast cells, such as e.g. a strain of Saccharomyces, in particular Saccharomyces cerevisiae, Saccharomyces kluyveri or Saccharomyces uvarum, a strain of Schizosaccharomyces sp., such as Schizosaccharomyces pombe, a strain of Hansenula sp., Pichia sp., Yarrowia sp., such as Yarrowia lipolytica, or Kluyveromyces sp., such as Kluyveromyces lactis, or a bacteria, such as gram-positive bacteria such as strains of Bacillus, such as strains of B. subtilis, B. Licheniformis, B. lentus, B. brevis, B. stearothermophilus, B. alkalophilus, B. amyloliquefaciens, B. coagulans, B. circulans, B. lautus, B. megaterium or B. thuringiensis, or strains of Streptomyces, such as S. lividans or S. murinus, or gram-negative bacteria such as Escherichia coli.

To obtain dyeing of the keratinous fibres the dyeing composition of the invention comprises one or more dye precursors which is(are) converted into coloured compound(s) by an oxidation agent which according to the present invention is a microbial laccase.

Without being limited thereto the dye precursor(s) may be (an) aromatic compound(s) belonging to one of three major chemical families: the diamines, aminophenols (or aminonaphtols) and the phenols. Examples of isatin derivative dye precursors can be found in DE 4,314,317-A1. Further, a number of indole or indoline derivative dye precursors are disclosed in WO 94/00100. Said dye precursors mentioned in these documents are hereby incorporated herein by reference.

Examples of suitable dye precursors include compounds from the group comprising p-phenylene-diamine (PPD), p-toluylene-diamine (PTD), chloro-p-phenylene-diamine, p-aminophenol, o-aminophenol, 3,4-diaminotoluene, 2-methyl-1,4-diaminobenzene, 4-methyl-o-phenylenediamine, 2-methoxy-p-phenylenediamine, 2-chloro-1,4-diamino-benzene, 4-amino diphenylamine, 1-amino-4-.beta.-methoxyethylamino-benzene, 1-amino-4-bis-(.beta.-hydroxyethyl)-amonibenzene, 1-3-diamino-benzene, 2-methyl-1,3-diamino-benzene, 2,4-diaminotoluene, 2,6-diaminopyridine, 1-hydroxy-2-amino-benzene, 1-hydroxy-3-amino-benzene, 1-methyl-2-hydroxy-4-amino-benzene, 1-methyl-2-hydroxy-4-.beta.-hydroxyethylamino-benzene, 1-hydroxy-4-amino-ebnzene, 1-hydroxy-4-methylamino-benzene, 1-methoxy-2,4-diamino-benzene, 1-ethoxy-2,3-diamino-benzene, 1-.beta.-hydroxyethyloxy-2,4-diamino-benzene, phenazines, such as 4,7-phenazinedicarboxylic acid, 2,7-phenazinedicarboxylic acid, 2-phenazinecarboxylic acid, 2,7-diaminophenazine, 2,8-diaminophenazine, 2,7-diamino-3,8-dimethoxyphenazine, 2,7-diamino-3-methoxyphenazine, 2,7-diamino 3-methoxyphenazine, 3-dimethyl 2,8-phenazinediamine, 2,2'-›(8-amino-7-methyl-2-phenazinyl)imino!bis-ethanol, 2,2'-›(8-amino-7-methoxy-2-phenazinyl)imino!bis-ethanol, 2,2'-›(8-amino-7-chloro-2-phenazinyl)imino!bis-ethanol, 2-›(8-amino-7-methyl-2-phenazinyl)amino!-ethanol, 2,2'-›(8-amino-2-phenazinyl)imino!bis-ethanol, 3-amino-7-(dimethylamino)-2,8-dimethyl-5-phenyl-chloride, 9-(diethylamino)- benzo›a!phenazine-1,5-diol, N-›8-(diethylamino)-2-phenazinyl!-methanesulfonamide, N- (8-methoxy-2-phenazinyl)- Methanesulfonamide, N,N,N',N'-tetramethyl-2,7-phenazinediamine, 3,7-dimethyl-2-phenazinamine, p-amino benzoic acids, such as p-amino benzoic acid ethyl, p-amino benzoic acid glycerid, p-amino benzoic acid isobutyl, p-dimethylamino benzoic acid amil, p-dimethylamino benzoic acid octyl, p-diethoxy amino benzoic amil, p-dipropoxy amino benzoic acid ethyl, acetylsalicylic acid, isatin derivatives, such as 2,3-diamino benzoic acid.

In an embodiment the laccase is used with the dye precursor directly to oxidise it into a coloured compound. The dye precursor may be used alone or in combination with other dye precursors.

It is believed that when using a diamine or an aminophenol as the dye precursor at least one of the intermediates in the co-polymerisation must be an ortho- or para-diamine or aminophenol. Examples of such are found below and are also described in U.S. Pat. No. 3,251,742 (Revlon), the contents of which are incorporated herein by reference.

Optionally dyeing compositions (especially hair dyeing compositions) of the invention also comprise a modifier (coupler) by which a number of colour tints can be obtained. In general modifiers are used in dyeing composition for hair as the hair colours resulting from hair dyeing compositions without modifier(s) are usually unacceptable for most people.

Modifiers are typically m-diamines, m-aminophenols, or polyphenols. Upon the optional addition of a modifier (coupler) it reacts with the dye precursor(s) in the presence of e.g. a laccase, converting the dye precursor(s) into a coloured compound.

Examples of modifiers (couplers) include m-phenylene-diamine, 2,4-diaminoanisole, 1-hydroxynaphthalene(.alpha.-naphthol), 1,4-dihydroxybenzene(hydroquinone), 1,5-dihydroxynapthalene, 1,2-dihydroxybenzene(pyrocatechol), 1,3-dihydroxybenzene (resorcinol), 1,3-dihydroxy-2-methylbenzene, 1,3-dihydroxy-4-chlorobenzene(4-chlororesorcinol), 1,2,3,trihydroxybenzene, 1,2,4-trihydroxybenzene, 1,2,4-trihydroxy-5-methylbenzene, 1,2,4-trihydroxytoluene.

When using the dyeing compositions of the invention a reduced amount of enzyme (i.e. mg enzyme protein per ml dyeing composition) is needed to obtain the maximal dyeing effect (See FIG. 1 and FIG. 4), determined as the optimal .increment.E*-value, in comparison to prior art dyeing compositions, such as dyeing compositions comprising a laccase derived from Rhus.

The amount of dye precursor(s) and other ingredients used in the composition of the invention are in accordance with usual commercial amounts.

According to the invention the product comprising the dyeing composition may be a one or a two compartment product. In the one compartment product the laccase, the dye precursor(s) and other ingredients are keep together in a stabilised solution or kept under stable conditions (i.e. the dye precursors are not oxidised by the laccase). In a two compartment product the laccase and the dye precursor(s) and other ingredients are keep in two containers keep apart. The contents of said containers are mixed immediately before use.

USE

In the second aspect the invention relates to the use of the dyeing composition of the invention for permanent dyeing of keratinous fibres, in particular hair, fur, hide and wool.

When using a dying composition of the invention the .increment.E*-value obtained is higher than that of a dyeing composition comprising a laccase derived from genus Rhus under corresponding dyeing conditions (see FIG. 1).

In the third aspect the invention relates to a method for permanent dying of keratinous fibres comprising contacting a dyeing composition of the invention with the keratinous fibres in question under suitable conditions and for a period of time sufficient to permit oxidation of the dye precursor into a coloured compound.

The dyeing procedure may be carried out at room temperature, preferably around the optimal temperature of the enzyme, typically with from 10 to 60.degree. C.; at a pH in the range from 3 to 10, preferably 5 to 9, especially 6 to 8; for a period of time between 10 and 60 minutes, preferably 15 to 50 minutes, especially 20 to 40 minutes.

When using the method of the invention the .increment.E*-value obtained is higher than that of corresponding methods where a laccase derived from a strain of the genus Rhus are used under the same dyeing conditions, in the presence or absence of at least one modifier, with at least one dye precursor, for a period of time, and under conditions sufficient to permit oxidation of the dye precursor used for oxidising the dye.

The method can be conducted with one or more dye precursors, either alone or in combination with one or more modifiers.

Hair: 6" De Meo Virgin Natural White Hair (De Meo Brothers Inc. USA)

Enzymes:

Myceliophthora thermophila laccase described in WO 95/33836 (PCT/US95/06815) from Novo Nordisk Biotech, Inc.

Myceliophthora thermophila T1 variant laccase described in U.S. patent application 60/003,142 from Novo Nordisk Biotech, Inc.

Polyporus pinsitus laccase described in WO 96/00290 (PCT/US95/07536) from Novo Nordisk Biotech, Inc.

Rhus vernicifera laccase (Yoshida, J. Chem. Soc., 472 (1883) Rhizoctonia solani laccase described in WO 95/07988 from Novo Nordisk Biotech, Inc.

Scytalidium thermophilum laccase described in WO 95/33837 (PCT/US95/06816) from Novo Nordisk Biotech, Inc.

Deposit of Biological Material

The following biological material has been deposited on the May 25, 1994 under the terms of the Budapest Treaty with the Agricultural Research Service Patent Culture Collection, Northern Regional Research Center, 1815 University Street, Peoria, Ill., 61604 and given the following accession number.

Dye precursors: 0.1% w/w p-phenylene-diamine in 0.1 M K-phosphate buffer, pH 7.0. (pPD) 0.1% w/w p-toluylene-diamine in 0.1 M K-phosphate buffer, pH 7.0. 0.1% w/w chloro-p-phenylenediamine in 0.1 M K-phosphate buffer, pH 7.0. 0.1% w/w p-aminophenol in 0.1 M K-phosphate buffer, pH 7.0. 0.1% w/w o-aminophenol in 0.1 M K-phosphate buffer, pH 7.0. 0.1% w/w 3,4-diaminotoluene in 0.1 M K-phosphate, buffer pH 7.0.

Modifiers: 0.1% w/w m-phenylenediamine in 0.1 M K-phosphate buffer, pH 7.0. 0.1% w/w 2,4-diaminoanisole in 0,1 M K-phosphate buffer, pH 7.0. 0.1% w/w alpha-naphthol in 0.1 M K-phosphate buffer, pH 7.0. 0.1% w/w hydroquinone in 0.1 M K-phosphate buffer, pH 7.0. 0.1% w/w pyrocatechol in 0.1 M K-phosphate buffer, pH 7.0. 0.1% w/w resorcinol in 0.1 M K-phosphate buffer, pH 7.0. 0.1% w/w 4-chlororesorcinol in 0.1 M K-phosphate buffer, pH 7.0.

The dye precursor is combined with one of the above indicated modifiers so that the final concentration in the dyeing solution is 0.1% w/w with respect to precursor and 0.1% w/w with respect to modifier.

Other solutions:

Commercial shampoo

Equipment: Minolta CR200 Chroma Meter

Determination of Laccase Activity (LACU)

Laccase activity is determined from the oxidation of syrin-galdazin under aerobic conditions. The violet colour produced is photometered at 530 nm. The analytical conditions are 19 mM syringaldazin, 23.2 mM acetate buffer, pH 5.5, 30.degree. C., 1 min. Reaction time. 1 laccase unit (LACU) is the amount of enzyme that catalyses the conversion of 1.0 micromole syringaldazin per minute at these conditions.

Assessment of the hair colour

The quantitative colour of the hair tresses is determined on a Minolta CR200 Chroma Meter by the use the parameters L* ("0"=black and "100"=white), a* ("-"=green and "+"=red) and b* ("-" blue and "+" yellow).

.increment.L*, .increment.a* and .increment.b* are the delta values of L*, a* and b* respectively compared to L*, a* and b* of untreated hair (e.g. .increment.L*=L*.sub.sample -L*.sub.untreated hair).

.increment.E* is calculated as .increment.E*=.sqroot.(.increment.L*.sup.2 +.increment.a*.sup.2 +.increment.b*.sup.2) and is an expression for the total quantitative colour change.

Dyeing effect

The dyeing effect of different laccases were tested and compared under the same conditions using 0.1% w/w o-aminophenol (dye precursor) and 0.1% w/w m-phenylene-diamine (modifier).

The laccases tested were

a Polyporus pinsitus laccase,

a Myceliophthora thermophila laccase

a Myceliophthora thermophila T1 laccase variant,

a Rhus vernicifera laccase

a Rhizoctonia solani laccase

a Scytalidium thermophila laccase

Hair dyeing

1 gram white De Meo hair tresses were used.

4 ml dye precursor solution (including modifier) was mixed with 1 ml laccase on a Whirley mixer, applied to the hair tresses and incubated at 30.degree. C. for 60 minutes.

The hair tresses were then rinsed with running water, washed with shampoo, rinsed with water, combed, and air dried.

a*, b* and L* were determined on the Chroma Meter and .increment.E* was then calculated.

Hair tress samples treated without enzyme were used as a blind.

The result of the test is displayed in FIG. 1.

Wash stability

Tresses of white De Meo hair (1 gram) were used for testing of the wash stability of hair dyed using the Myceliophthora thermophila T-variant laccase and the Polyporus pinsitus laccase.

Oxidative hair dyeing was carried out as described in Example 1, except that p-phenylene-diamine (pPD) were used as the dye precursor and no modifiers were used.

Hair wash

The dyed hair tresses were wetted and washed for 15 seconds with 50 ml of commercial shampoo, and rinsed with water for 1 minute and air dried. The hair tresses were washed up to 18 times.

Then a*, b* and L* were determined on the Chroma Meter and .increment.E* values were then calculated.

Hair tress samples treated without enzymes were used as blinds.

The result of the test is displayed in FIG. 2.

Fastness of hair dyeing

Tresses of white De Meo hair (1 gram) were used for testing fastness (speed) of hair dyeing using the Myceliophthora thermophila T1 variant laccase and the Polyporus pinsitus laccase.

p-phenylene-diamine (pPD) was used as the dye precursor and no modifiers were used.

4 ml dye precursor solution was mixed with 1 ml laccase on a Whirley mixer, applied to the hair tresses and incubated at 30.degree. C. for 10, 20, 30, 40, 50 and 60 minutes, respectively.

The hair tresses were then rinsed with running water, washed with shampoo, rinsed with running water, combed, and air dried.

a*, b* and L* were determined on the Chroma Meter for each incubation time and the .increment.E*-values were then calculated.

Hair tress samples treated without enzymes for 60 minutes were used as blinds.

The result of the test is displayed in FIG. 3.

Dyeing effect of Myceliophthora thermophila T1 variant laccase

The dyeing effect of Myceliophthora thermophila T1 variant laccase were compared with the Polyporus pinsitus laccase using 0.1% w/w p-phenylene-diamine, 0.1% w/w p-touylene-diamine, 0.1% w/w chloro-p-phenylene-diamine, 0.1% w/w p-aminophenol, 0.1% w/w o-aminophenol and 0.1% w/w 3,4 diaminotoluene, respectively, as dye precursors.

The Polyporus pinsitus laccase were applied in a concentration of 10 LACU/ml while the Myceliophthora thermophila T1 variant laccase was applied in a concentration of only 1 LACU/ml.

1 gram white De Meo hair tresses were used.

4 ml dye precursor solution was mixed with 1 ml laccase on a Whirley mixer, applied to the hair tresses and incubated at 30.degree. C. for 60 minutes.

The hair tresses were then rinsed with running water, washed with shampoo, rinsed with running water, combed, and air dried.

The a*, b* and L* were determined on the Chroma Meter and the .increment.E* values were then calculated.

Hair tress samples treated without enzyme were used as blinds.

The result of the test is displayed in Table 1.

As can be seen from Table 1 compositions comprising the Myceliophthora thermophila T1laccase variant dyes the hair as good as the Polyporus pinsitus laccase even though concentration of the Polyporus pinsitus laccase is 10 time higher.

Dose-response dyeing effect of M. thermophila laccase

The dyeing effect of M. thermophila laccase were tested using concentration between 0.0001 to 0.5 mg enzyme protein per ml dyeing composition of laccase. 0.1% w/w p-toluylene-diamine (PTD) was used as the dye precursor.

The same dyeing procedure as described in Example 1 was used.

The result of the tests are displayed in FIG. 4.