160
`
`lm111111wlogy Toda.Y. uo/. J, No. 6, /fJ,~2
`
`The three-dimensional structure of antibodies
`
`Markus Marquart and Johann Deisenhof er
`Max-Planck l n sritul fi.ir Biochemie, Abtc ilung S tr ukru rforschung IL D-8033 Marrinsried, f.R.G.
`
`Antibody molecules are glycoproteins which occur in
`vertebrate species. T hey recognize and bind an enor(cid:173)
`mous variety of foreign substances (antigens) a nd sub(cid:173)
`sequently trigger further defense mechanisms at the
`molecular or cellular
`level. Specific
`recognition
`requires surface structures complementa ry
`to the
`antigen and hence a h uge v;:iriety of antibody
`molecules. In contrast the effector functions need
`identica l interaction sites in all antibody molecules.
`The determination of the primary structure of
`imrnunoglobulins 1-3 and the X-ray crystallographic
`studies of several antibody molecu les and frag(cid:173)
`ments•.s.7.rn.iz-rs led to an advanced understanding of
`the way in which ant ibodies meet these opposing
`requirements.
`
`I is a schematic drawing of a n anLibody
`Fig.
`molecu le of class IgG I. IL is composed of two identical
`heavy chains and two identical light cha ins with rnol.
`wts of 50,000 and 25,000, respectively. Both types of
`polypeptide chain are folded into domains: the four
`domains of the heavy chain are VH, C H I, CH2, and
`C H 3; the light cha in consists of the two domains VL
`and C~. All doma ins except CH2 are arranged in
`pairs which a rc held together· by non-cova lent forces.
`Inter-chain disulfide bridges provide further stabil ity.
`Among antibody molecules of a given class and
`species, the V-domains differ considerably in amino
`acid sequence, whereas the C-domains have identical
`sequences. The V-domains are composed of about 110
`amino acid residues at. the N-tcr minal end of heavy
`a n<l light chains. The VH-VL pair together forms the
`antigen b inding site; differem a nt ibody specificities
`are the result of different amino acid sequences of the
`V-domains. T he sequence variability in V-domains is
`most pronounced in a few hypervariablc regions. On
`t he other ha nd the framework resid ues are well con(cid:173)
`served . The constant domains C I 12 and Cl-13 a re
`involved in effector fu nctions such as compl.ement
`activation and b inding to receptors on certain cell
`types. There is significant homology between the
`amino acid sequences of all C-domains, and of 1hc
`framework residues of V -domains.
`Proteolytic cleavage at the hinge reg ion yields stable
`a nd functional fragments: t he antigen-bi nding rrag(cid:173)
`rnent P'ab, and the Fe fragment (Fe was the first anti(cid:173)
`body fragment obtained in crystalline form)6 •
`
`A
`
`B
`
`F
`
`E
`
`IGG
`
`Fig. I Schematic represcnlalion of an IgG l immunuglobu lio
`molecul e.
`The a rms ol' the Y-s haped molecule arc limned by 1he Fab pans,
`the s1em is made up by the Fe pan. The ligh1 c hains are linked to
`1he heavy c hains by a disulphide bridge close to the C-tcrmi nus.
`The two heavy chains arc connected via two disu lphide linkages i11
`the hinge regio n.
`
`• £1$evl.;f' KM>m('"(l1nil P11'» 1\1~2
`OJC.7-4Q J<J/82/ 0QOo..oo(l0/$2 l!J
`
`H
`
`G
`
`c
`
`D
`
`x
`
`ARltANGEMENT OF snt.ANDS I N BWHKlGLOSUU H DOMA I NS
`X N-lfRMJ NUS UP. • C-HRMI NUS IJP
`
`Fig. 2 Schc rna1ic drawing of the strand topology in a V(cid:173)
`domain viewed parallel to the strands.
`(x ) and (• ) indi«<lle N- and C-terminal e nd s of the slrnnd~ poin1-
`ing LOw<!rdS I he Observer.
`
`1 of 7
`
`Celltrion, Inc., Exhibit 1082
`
`

`

`!111mu11olugy Today, wl. 3, Nu. Ii, 1982
`
`161
`
`Besides IgC I, several other classes (IgM, l g!\, lgD,
`IgE) and subclasses of immunoglobulins have been
`identified; the differences between these are located in
`the constant region of the heavy chain. The two types
`of light chain (kappa, lambda) can combine with
`heavy chains of any class.
`
`Domain folding
`The general folding pattern in a ll immunoglobulin
`domains is very similar. It is shown schematically in
`Fig. 2 for a V-domain. The folding is characterized
`by two pleated sheets connected by an internal di(cid:173)
`sulphide bridge linking strands 13 and C. The Lwo
`sheets cover a large number of hydrophobic amino
`acid side chains.
`Despite that gross similarity there exist substanlial
`differences when one compares V- and C- domains:
`C-domains lack strand X, strand D is very short (2-3
`amino acids) and connected to strand E. In addition
`the length of the loop regions in C-domains is different
`from V-domains, thus changing the overall shape con(cid:173)
`siderably.
`VH and V L, on the other hand, show only minor
`differences when compared with each other (except in
`the hypervariable regions) as do CL, C H I and CH3.
`CH 2 represents yet a
`third
`type of domain,
`differentiated from the other C -domains mainly by the
`branched carbohydrate chain linked to it. It will be
`discussed in more detail below.
`
`Do main-do ma in inter actio n
`Two kinds of domain interactions occur in immuno(cid:173)
`globulins: lateral (or trans) interactions and longi(cid:173)
`tudinal (or cis) interactions.
`In lateral interactions immunoglobu lin domains
`other than CH2 strongly associate to form modules
`VL-VH, CL-CHI, CH3-CH3. In V modules VH
`may be replaced by VL lo form light chain V dimers
`as seen in the Bence-Jones protein fragments Rei or
`Au7- 9 • In Bence-Jones proteins, which are light chain
`dimers, one of the light chains simulates the Fab pans
`of the heavy chain, as described for Mcg1 ~.
`V modules associate in a differenL way than C
`modules do. In V modules MGCD faces (see Fig. 2) of
`the domains get into contact, in C modules the /\ BFE.
`faces are involved.
`/\ considerable loss of accessible surl'ace area 11 i~
`connected with contact formation of the immuno(cid:173)
`globulin domains. It amounts to 1760 A2, 1923 f..2 and
`21801\2 for VL-VH, CL-CH I modules of IgC KoJIW
`and
`the C I l3-CH3 module of an human Fe
`fragmem '·'·11 respectively. In VL- VH association both
`framework residues and amino acids from hyper(cid:173)
`variable segments <:u-e involved. I\ comparison of V(cid:173)
`domain amino acid sequences of different animal
`species shows that the contacting framework residues
`are highly conserved. /\lso the consume dom;iin
`residues participating in lateral conlact arc either
`invariant or replaced by homologous residues in
`
`different immunoglobulin chains. This low deg ree of
`sequence variability for the residues importan1 for
`lateral comacc formation provides an explanation for
`the fact that differenl L-chains c.;an associate with
`different f I-chains to give intact irnmunoglobulins.
`In addition to the extensive Van dcr Waals cornacts,
`there exist a few trans hydrogen bonds, in which
`ma inly pol<1r side c;h;iin groups are involved. There <1re
`1.wo s;ilt linkages in Kol CL-CH I contact: Glu 125
`light chain - Lys 214 heavy chain, G lu 126 light chain
`- .Lys 148 heavy chain, which have their analgon in
`CH3 - CT-13 pairing: Glu 356- Lys 439, Glu 357 - Lys
`370.
`CJ 12 is an exception, as it forms a single unit
`without lateral domain interactions (see Fig. 3)*.
`Instead it interacts with bound carbohydrate, which is
`attached to Asn 297. The CH2 residues that are
`involved in carbohydrate contact are, with a few
`exceptions, structurally in the same positions as the
`residues that form the CH3-CH 3 contact (face ABFE
`in Fig. 2). This demonstrates that the carbohydrate
`in CH2 provides a substitute f'or
`the C-C con(cid:173)
`tact and presumably helps to stabilize the CH2-
`domain. The branched carbohydrate forms a few
`hydrogen bonds with the CH2-domain, but the dom(cid:173)
`inant interactions are hydrophobic in nature. The
`carbohydrate covers a hydrophobic pat.ch of the
`protein made up of Phe 241, 243, Val 262, 264, Tyr
`296, Thr 260, Arg 301, which would otherwise be
`exposed to the solvent. The loss of accessible surface
`area of one C l-1 2 domain is 522 A2 , which is only about
`ha lf as much covered surface area as seen in
`CII3-CH3 contact ( 1080 A2). This observation could
`explain the apparent 'softness' of those pans of the
`CH2-domain, as seen in the crysta l structureu·1\
`which are most remote from the C H 3-CH2 interface.
`The functional relevance of ca rbohydra te in ami(cid:173)
`bodies is unclear. It might be involved in intracellular
`movements of the glycoproteins and in secretion lf•. 1•. It
`may well be that the origin of t he a ltered funct ional
`properties of carbohydrate-free antibody variants is
`structural destabilization.
`ln contrast to the extensive lateral interac.:tions,
`nonbondcd longitudinal interactions a long the hcav}
`chain or light chain are much weaker or do not exist al
`all. However,
`they arc interes1ing because con(cid:173)
`formational changes in antibodies affect those inter(cid:173)
`actions.
`Fig. 3, which represents the Fe parr ol' .a n lg(; I
`molecule shows the CH2-CH3 interaction. Wit h a
`loss in accessible surface area of 778 J..z this wntacl
`has rough ly one l hi rd of the size of C H3-CH3 cont11ct.
`The residues that participate in CI-12-CI-13 contact
`arc highly conserved in a ll lg classes, suggesting that
`this contact is likely LO be found in IgC a nd lg/\ 11nd as
`CH3-CH4 contact in lgE and IgM.
`•Most t'<:adcrs will need a sicrco viewer (commcrciallr available )
`10 see in three dimensions the s tructures shown in 1hc paired
`diagrams on pages J 62, 163 and t 66.
`
`2 of 7
`
`Celltrion, Inc., Exhibit 1082
`
`

`

`Fig . .3 Stereo drawing of a space
`fi ll ing model of human Fe-frag(cid:173)
`ment.
`Th~ molecule is bui lt from two
`identical polypeptide ch;i ins (chain I,
`chain 2), and identical carbohydrate
`g roups. Both halves arc related by
`approximate diads.
`
`Fig. 4 lgG l molecule Kol.
`The Fab parts and the hinge segrnen1 are
`well ordered in the Kol crystals, the Fe part
`is disordered and not visible.
`
`PLEASE N O TE
`
`We regret that for tech nical reasons it
`has not been possible to reproduce Figs
`3, 4, 6, 7 and 8 with che colou r codi ng
`that allows different parts of the molec(cid:173)
`ules to be distinguished.
`The
`rull-colou r
`diagrams, with
`explanatory legends, can be found in
`the personal monthly edition of /mm1111-
`ology Today dated June 1982.
`
`D segment
`
`fig. 5 Am ino acid comparison of residues 98-119 (Eu num(cid:173)
`bering) of M603, New, Kol and Eu heavy chains. The
`underlined residues were left out in Fig. 6c.
`
`End ofVH
`
`98
`Cys Ala Arg
`Cys Ala Arg
`Cys Ala Arg
`Cys Ala Gly
`
`M603:
`New
`Kol
`Eu
`
`Asn Tyr Tyr
`Asn Leu
`lie
`Asp Gly Gly
`Gly Tyr Gly
`
`Gly
`Ala
`His
`lie
`
`Ser
`Gly
`Gly
`Tyr
`
`Thr
`Cys
`lie
`Phe Cys Ser Ser Ala Ser Cys
`Ser
`
`Phe
`
`3 of 7
`
`Celltrion, Inc., Exhibit 1082
`
`

`

`Fig. 6 Antigen binding region of
`lgGI Kol.
`(a) The extended third hyper(cid:173)
`variable loop of the heavy chain
`folds
`into
`the putative antigen
`binding pocket.
`(b) C a backbone and sidcchains
`of Kol antigen binding pocket.
`(c) Artificial deletion of nine
`resid ues in
`the third hyper(cid:173)
`variable segmem of Kol, which
`makes it of equal length with lgG I
`Eu'", reveals a deep curved cleft.
`
`J segment
`
`110
`Try Tyr Phe Asp Val Try Gly
`Asp Val Try Gly
`Asp Tyr Try Gly
`Pro Glu Glu Tyr
`
`Ala Gly Thr Thr
`Gin Gly Ser Leu
`Gin Gly Thr Pro
`Asn Gly Gly
`Leu
`
`119
`Val Thr Val Ser Ser
`Val Thr Val Ser Ser
`Val Thr Val Ser Ser
`Val Thr Val Ser Ser
`
`Gly Pro
`
`4 of 7
`
`Celltrion, Inc., Exhibit 1082
`
`

`

`IM
`
`/rmm111ology Today, ~of. 3, No. fi, IY/i2
`
`The C H2-CH 3 orientation is found LO be somc::whaL
`variable and influe::nced by external forces. In the F<'
`fragment crystals t he 1 wo chemically identical chains
`a re in a different environment. As a conse::quencc
`the CH2-CH3 orientation varies by about 6°. In
`Fe-Protein A complex crystals
`this arrangement
`differs slightly from that of Fe crys1als 1s.
`More drastic changes are observed in VI-I-Cl 11 and
`VL-CL longitudinal contacts, when chemically
`different Fab fragments are compared. These
`differences in longitudinal arrangement are most con(cid:173)
`veniently described by an elbow a ngle, which is
`enclosed by the pseudo diads rela ting VL to VH and
`CH1 to CL respectively. The elbow a ngle may vary
`from more than 170° to 135° when we compare Kol
`Fab with M cPc Fab 12- 1>.i9.zo.
`In two cases the elbow angles of the same molecule
`in two different crystal lallices were compared aud
`fou nd to differ by 8° and 17° respectively 19.21 . Tn Fab
`New, with an elbow angle of approximately 137°,
`there exist a few longitudinal contacts between VL
`and C L and VI I and C l 11 22•21, whereas there are no
`non-bonded longitudinal contacts in intact Kol and
`Fab Kol (see Fig. 4), which are characterized by an
`open elbow angle. We interpret these observations to
`mean that in Fab Kol the V- C arrangement is flexible
`in soluLion. In the crys1al the molecule is stablized by
`packing interactions; these will be discussed from a
`different poinl or view later.
`
`The a n tigen-binding area
`Comparison or amino acid sequences of variable
`parts has demonstrated the hypcrvariability of some
`segments. These were considered to be involved in
`antigen bindingH. Indeed, crystal structure analyses
`of lg fragment-haptcn complexes show that haptens
`bind in a cleft or depression formed by the hyper(cid:173)
`variablc segments.
`The VL d imer of Rei7•9 may serve as an illustrative
`examplt:. The symmetrica lly arranged hyperva riablc
`regions form a deep slit-like pocket around the diad
`relating lhe two VL monomers. The walls of t he sliL
`are li ned by tyrpsincs 49, 91, 96, /\sn 34 and G in 89;
`the bottom of the pocket is formed by T yr 36 and G in
`89. A trinitrophcnyl group binds to the Rei fragment
`and fills the binding pocke1 completely.
`Another example of an IgG fragment haptcn
`complex is Fab Ne", which is known to bind among
`other ligands a hydroxy derivative of vitamin K, 2\ .
`The hypervariable segments of l'\cw form a ~hallow
`groove wit~ approxima1c dimensions of 16 x 7 A O:Jnd a
`depth or 6 I\.
`McPc 603, a mouse lg/\ (K) Fab fragme11t211 u inds
`phosphorylcholine. The site or hapten binding is ~·
`large wedge s hape~ cavity, with dimensions 15 x 20 A
`and a depth of' 12 A. Only five of the six hypcrvariablc
`regions contribuLe to the forma tion of the cavity: L(cid:173)
`chain hypervariable regions one and three, and all
`three H-chain hypervariable regions. The second
`hypervariablc region of L-chain is screened from 1hc
`
`caviLy by the first hypervariable loop or L-chain and
`the third hypervariable loop of H-ehain. The deeper
`cavity in McPc603, as compared to Fab New, is due to
`longer hypervariable loops. The firs l hypervariablc
`region of L-cha in and the thi rd hypervariable region of
`I I-chain is three residues and the second hypcr(cid:173)
`variable loop of the H-chain is two residues longer in
`Mcl'c603 than in r\ew.
`Phosphorylcholine occupies only a small part of the
`cavity and interacts via Van der Waals forces, electro(cid:173)
`static interaciions, and hydrogen bonds with the
`p ro1ein.
`In contrast LO the above examples lgG Kol shows no
`cleft or depression in 1hc antigen-binding region. In
`lgG Kol the heavy chain has a rather long third hyper(cid:173)
`variable loop, which contains six residues more than
`M603 and eight more residues t h;111 Fab New. The
`amino acid sequences of the third hypervariable
`regions of M60326, NcwH, Kol2' and Eu28 a rc com(cid:173)
`pared in Pig. 5. T he sequence alignmc111 and classifi(cid:173)
`cation in VH, I) and J segment26.i• is somewhat
`arbicrary, especially for the beginning ofthe.J segment
`as a nucleotide sequence has been determined only for
`M6Q326 . The additional residues in Kol with the
`nearly palindromic amino acid sequence -Gly-Phc(cid:173)
`Cys-Ser-Ser-Ala-Scr-Cys-Phc-Gly fold into the puta(cid:173)
`tive antigen binding site and fill it comp letely (sec r ig.
`6a,b). The two cystcins arr disulphide bridged and
`form the start and endpoints of a shon ;1ntiparallel ~­
`sheet, comprising residues -Cy~-Scr-Ser-Ala-Scr-Cys - .
`If in a model building experiment nine residues arc cut
`from the third hypcrvariablc region of the Kol heavy
`chain, thus making it of equal length with lgG I Eu2",
`a deep curved cleft appears (Fig. 6c), which easily
`could accommodate haptcn~. With respect to the anti(cid:173)
`gen binding area lgG Kol 1hus looks as if it carried its
`own haptcn in form of an extended third hype::r(cid:173)
`variablc loop. Another peculiarity of lgG Kol mighi be
`of interes1 in that context. In the Kol crystal lattice the
`hypcrvariablc parts of one molecule !Ouch the hinge
`and spa1ially ac\jacent segments of a symmetrically
`related molecule. This contact consists of three salt
`linkages (Arg 49 light chain-COOH light chain, Asp
`50 light chain-Arg 215 heavy chain, /\sp 53 heavy
`ch;1in-Lys 134 heavy chain). a few hydrogen bonds
`and extensive Van der \Vaals interactions. Thus, che
`lauice contact found in Kol crystals might give an
`instructive model for antibody- an1igen interaction, as
`antigens arc usually macromolecules which cover a
`much larger part of the antibody than haptcns do.
`
`T he h inge segm en t
`The hinge segment which cova lcndy links Pab and
`Fe parts, has a unique primnry and spatial structure.
`Its central region consists of two para llel disulphide(cid:173)
`li nked poly L-p rolinc helices wirh an a mino acid
`sequence -Cys-Pro-Pro-Cys-1l.I '. In the lgG I subclass
`represented by the Kol molecule the poly-proline
`double helix is short ( Fi~. 7). However, in lgG3 the
`hinge sequence is quadruplicated'" and model build-
`
`5 of 7
`
`Celltrion, Inc., Exhibit 1082
`
`

`

`Immunology Today, uol. 3, Nv. 6, 1982
`
`165
`
`ing suggests that the poly-prolinc segment of this
`molecule may be more than 100 A long.
`The poly-proline segment, a relatively rigid struc(cid:173)
`rurc, is Aanked on both sides by Acxible segments: The
`segment on the N-te rminal side is well defined in the
`crystal lattice or Kol due LO crystal packing inter(cid:173)
`actions, but it lacks interna l interactions, that would
`provide stability in solution. The C terminal segment
`is di~ordcrcd and Acxiblc in Kol crystals and in 1 he Fe
`crystal structu rc1 1.1~. The rigid hinge segment allows
`independent movement of the Fab arms and the Fe
`part. There is direct evidence for flexibility in the
`crystal lattice of Kol''-19 and Zie3 ' . This is in contrast
`to the abnormal lgG protein Dob, which lacks a hinge
`rcgion32• The significance of the hinge for Fab-Fc
`flexib ility is obvious.
`
`Complement binding
`The binding of the Clq component of the Cl
`complex to antigcn-ancibody complexes is t he first
`step
`in
`the classical pathway of complement
`ac tivation 13·3 '· The Clq head pieces bind to the CH2
`domains of antibodies3·1•3". Protein /I., a constituent of
`the cell wait of Staphylococcus aureus, binds LO t he Fc(cid:173)
`part of antibody molecules of certain classes and sub(cid:173)
`classes, but does not
`interfere with complement
`binding. The determination of the crystal st ructure of
`the complex between FB (one of the four Fe-binding
`domains of protein AH) and Fe-fragment showed that
`protein A b inds al the Cl 12-CH3 contact•S.Js. Fig. 8
`shows a space-filling model of the FB-Fc complex.
`T he area of CH2 not covered by FB must contain the
`Clq binding site. In view of 1hc size of the Clq he<1d
`pieces (mo!. wt 50,000) it appears unlikely that t hey
`can bind at the inner sides of C H2, i.e. nea r the carbo(cid:173)
`hydrate. T he most plausible binding site is therefore
`near the tip of CH2 on t he outer side of the domain. It
`is worth mentioning that this region is disordered in
`crystals of' the FB-Fc complex which indicates th<tt
`this part of the C H2 domain is flexible. Possibly,
`flexibility is required for antibody C lq interaction.
`
`Summary a nd perspectives
`Investigations of the three-dimensional architecture
`of ;mtibodies h11ve elucidated the folding of the
`polypept ide chains into domains, and the spatial
`arrangement of the domains. The structural basis for
`understanding antibody specificity and antibody
`Aexibility was obtained. Segmental flexibi lity is a n
`important property of amibodics: Flexible segments of
`the polypeptide chains at the switch and hinge regions
`allow the !"ab fragments to change their shape and
`their relative orientation. Conformationill changes of
`this kind are necessary to meet the geometric require(cid:173)
`ments which arise on binding of antibodies to multi(cid:173)
`va lent antigens.
`The undersrnnding of the effector functions of anti(cid:173)
`body molecules is much less complete. One of the
`central problems is the explan:-ition of the strong
`e nh:-incement of C lq binding to antige n-a ntibody
`
`complexes as compared to free antibody molecules.
`Two mechanisms have been considered (for a review
`see Ref. 39): since Clq is multimeric with at least six
`antibody binding sites, binding may be enhanced by
`the form<1tion of a ntigen-antibody aggregates through
`crosslinking. Alternatively, antigen binding might
`induce a conformational change in the Fe-part which
`enhances affi nity for Clq.
`There is strong evidence for the importance or
`aggregation, but a mixed mechanism which involves
`aggregation and a conformational change cannot be
`ruled out.
`The studies described here were almost exclusively
`carried out with myeloma or Hence-Jones proteins
`because these were 1he only homogeneous irnmuno(cid:173)
`globulins which could be obtained in sufficient
`qua nt ity. However, in most cases the specificities of
`such molecules is unknown. Recently, large amounts
`or homogeneous antibodies elicited against strepto(cid:173)
`coccal or pneumococcal polysaccharides became
`available from cen a in rabbit and mouse stra ins"'·"'.
`These sources, and the use of hybrids obtained from
`myeloma and spleen cells have made it possible to
`obtain homogeneous antibodies of defined speci(cid:173)
`fic ity·•?.•~. Structural studies of 'natural' antigen-anti(cid:173)
`body complexes can be expected to lead to a more
`complete understanding of antibody function .
`Crystallographic work on a specific antibody and of its
`antigen is already in p rogress44 •
`
`Acknowledgements
`We thank Prof. R. Huber for helpful discussions.
`
`Refer ences
`I Edelman, G. M . ( 1970) Sti. :Im. /\ugusL, 8 t-S7
`2 Porter, R. R . ( 1976) Sri. Am. Oc1obcr, 8 1- 87
`3 Hi lschmann, N. (1%9).V11111rwi.r.1msdlflflm56, 19S-205
`4 F.dmundson, /\. B., Ely, K. R. and Ahola, E. £. ( 1978) 01111.
`To/1 . .lfnl. b1111111111Jf. 7, 95- 118
`5 1\m7.el , L. M . and Polj ak. R. J. ( 1?79) Ann. Rn·. l/i1Jr/1m1. 48,
`96 1- 997
`6 Porter. R. R. (1958)..V11l1ur( / ,md1m) 182, 670-67 1
`7 Epp, O .. Colman. P. M ., Fchlh<1mmcr, H ., Bode, W., Schiffer,
`:--~ .. Huber, R. and P<ilm. W. ( 1974) J\11r. ]. /Jinrhm1. 45,
`513- 524
`8 Fehlhammer, t I. , Schiffer, M., Epp, 0., Colman. P. M ..
`l.auman, E. E., Schwager, I'., Stcigcmann, W. and Schramm,
`1 l..J. ( 1975) /Jin/1/i)'·'· Strn/'/ . .lfrd11111i.wu I, 139-146
`9 Epp, 0., Laurnan, I~. E., Sch iffer, M ., Huber, R. and Palm.
`W. ( 1975) 8i1Jdmnistn• 14, 4943-4?52
`10 Edmundson, /\. B., Ely, K. R., /\bola, R. R., Schiffe r, M. and
`Paniagia1npou los. N. (t975 ) llinc"hmn<I')' 14, 3953-J961
`11 Lee, B. mid Ri<:hards, F. M . ( 1970)]. .\In/. Jim/. 55, 379-400
`t2 Colman, I'. M .. Deisenhofcr, .J .. Huber, R . and Pa lm. W .
`(1976)] . . lfo/. /lfo/. 100. 257-282
`13 Marquart, M ., Deiscnhofcr, J., Huber, R. and P~lm. W.
`(I 980)]. ,\/11/. /Jin/. 14 1. 369-392
`14 Dciscnhofcr,.J., Colman, P. M ., F.pp, 0 . and Huber-, R. (1976)
`H11f'lir-.\r.rifr\ ,(. l'h1•.<i11f. 01r111. 357, 1421- 1434
`I 5 Dei~cn hofcr,J. ( 198 1) Hi1H-lll'1ui.<lr.v 20, 236 1-2370
`16 !'l'lclchers, F. ( 1? 73) lli11rhr11111/TJ' 12, 1471-t47(1
`17 Weitzman, S. and Scharf1, ~I. D. ( 1976)]. .lfol. /Jwl. 102 ,
`237- 252
`II! Hickman,!:>., Kukzycki, /\ . .Jr, 1.ynch, R. G . and Kornfeld, S .
`c 1977)]. 11;"'· u,,111. 2s2. 4402-4408
`
`6 of 7
`
`Celltrion, Inc., Exhibit 1082
`
`

`

`Fig . 7 Confor ma tion of the hinge
`regio n as seen in IgC I Kol.
`
`Fig. 8 Space filling model of
`th e FS ( pro te in A ) - F e
`co m plex.
`
`19 Matsushima, M., Marquart, M., J ones, T. A., Colman, P. M .,
`Bartels, K., Huber, R. nnrl Palm, W. (1978) J. Mn/. BitJI. 121,
`44 1-459
`20 Segal, I). M., Padlan, E. /\., Cohen, G. H., RudikoIT. S.,
`Potter, M. a nd Davies, D. R. ( 1974) Pmc. Nall Acarl. Sci. U.S.A.
`71,4298-4302
`21 /\bola, E. E., l::ly, K. R. a nd Edmundson, A. B. ( 1980)
`B1'telmmslry 19, 432-439
`22 Poljak, R. J., Anncl. L. M., Chen, B. (,., Phiackerley. R. P.
`and Saul, F. (1974) !'me. Nntl Acnd. Sci. U.S.A. 71, 3440-3444
`23 Sau l, F., Arnzcl, l, . M. and Poljak, R. J. ( 1978)]. I/in/. Clum.
`253, 585- 597
`24 Wu, T. T. and Kabat, E. /\. ( 1970)]. /lrp. Mttl 132, 21 1-250
`25 /\mzel, L. M ., Poljak, R. j.. Saul, F .. Varga, J. M . and
`Richards. F. F. ( I 974) Proc. Nall Acad. Sci. U.S.A. 71,
`1427-1430
`26 Eady, P., Hua ng, H., Oavis, M., Calame, K. a nd Hood, L.
`(1980) Cell 19, 98 1-992
`27 Schmidt, W., Jung, H. D., Palm, W. and Hi lschmann, N.
`(1981) p rivate communication
`28 Cunningham, B. /\., Rutishauser, U., Ga ll, W. E., Cottlicb,P.
`D., Waxdal, M. J. and Edelman, G. M. ( 1970) /Jiochenustry '>,
`3161-3170
`29 Sakano, H., Maki, R., Kurosawa, Y., Roeder, W. and
`Toncgawa, S. (1980) N11ture ( l,ondo11) 286, 676-683
`30 Michaelson, T . E., Frangione, B. and Franklin, E. C. (1977)
`] . Ri11l. (.'hm1. 252, 883- 889
`
`3 I Ely, K. R., Colman, P. M., A bola, E. E., Hess, 1\. C., l'cabody,
`D. S., Parr, D. M ., Connell, G. E., Lauschinger, C. /\. and
`Edmundson , A . B. ( I 978) 8i.11chm1iflry 17. 820-823
`32 Si lverton, E: W ., Navia, M.A. and Davies, D.R. (1977) Pwr.
`Nall Arorl. Sci. U.S.A. 74, 5140-5 I 44
`33 Mueller-Eberhard, H. J. ( 1975) 111111. Rev. Bfocllrm. 44, 697- 724
`34 .Porter, R. R. and Reid, K. 13. M. ( 1979) Adv. Pmt. Cltem. 33,
`1- 71
`35 Connell, C. E. a nd Porter, R. R (197 I) llwchm1. ]. 124, 53P
`36 Yasmeen, D., Ellerson, J. R., Dorrington, I<. J. and Paimer,R.
`H. (1976}]. lmmtmt1/. 116, 518- 526
`37 Sjocdahl, J. (1977) far.J. lJiochem. 78, 47 1-490
`38 Oeisenhofcr, J., Jones, T. /\., Huber, R., Sjoedahl, .J. and Sjoe·
`quist,J. (1978) z. !'hysio/. (:hem. 359, 975-985
`39 Metzger, J-1. (1978) Ctmt. Top. Mo/. lmrmmol. 7, 119-148
`40 Jaton, J.-C., Huser, H., Braun, D. C., C i vol, D., P~dll,J. ;u1d
`Schlessingcr,J. C. (1975) Bif)(/tr.mi.1try 14, 53 12- 5315
`41 Braun, D. G. a nd Huser, H. ( 1977) in f>mgress in lmmwwfflgy If/
`(Mandel,'!'. E., Cheers, C. H., Hosking, C. S .. McKenzie,[. F.
`C. and Nossa!, G. J. V., eds) pp. 255-264, l::lsevie r North·
`Holland, Amsterdam, New York, Oxford
`42 Kuchler, G. and M ils1cin, C. (1975) Na11m ( l.1mdrm) 256,
`495-497
`43 Melchers, F., Potter, B. M. and Bethesda, N. W. (eds) (1978)
`C11rr. Top. Microbfol. lmmwlfll. 8 1
`44 Colman, P. M ., Gough, K. H., Lilley, G. G., Ulagrove, R . .J.,
`Webster, R. C. and Laver, W. G. (198 1) J. Mo/. Bini. 152,
`609--014
`
`7 of 7
`
`Celltrion, Inc., Exhibit 1082
`
`